Not applicable.
Not applicable.
In the operation of a rotary offset printing press, freshly printed substrates, such as sheets or web material, are guided by transfer cylinders or the like from one printing unit to another, and then they are delivered to a sheet stacker or to a sheet folder/cutter unit, respectively. As used herein, the term “transfer cylinder” includes delivery cylinders, transfer rollers, support rollers, support cylinders, delivery wheels, skeleton wheels, segmented wheels, transfer drums, support drums, spider wheels, support wheels, guide wheels, guide rollers, and the like.
The ink marking problems inherent in transferring freshly printed substrates have been longstanding. In order to minimize the contact area between the transfer means and the freshly printed substrate, conventional support wheels have been modified in the form of relatively thin disks having a toothed or serrated circumference, referred to as skeleton wheels. However, those thin disc transfer means have not overcome the problems of smearing and marking the freshly printed substrate due to moving contact between the freshly printed substrate and the projections or serrations. Moreover, the attempts to cover the transfer cylinder with a cover material and/or minimize the surface support area in contact with the freshly printed substrate material often resulted in further problems.
Various efforts have been made to overcome the limitations of thin disk skeleton wheels. One of the most important improvements has been completely contrary to the concept of minimizing the surface area of contact. That improvement is disclosed and claimed in U.S. Pat. No. 3,791,644 to Howard W. DeMoore, incorporated by reference herein in its entirety, wherein the support surface of a transfer cylinder in the form of a wide wheel or cylinder is coated with an improved ink repellent surface formed by a layer of polytetrafluoroethylene (PTFE).
During the use of the PTFE coated transfer cylinders in high-speed commercial printing presses, the surface of the coated cylinders must be washed frequently with a solvent to remove any ink accumulation. Moreover, it has also been determined that the PTFE coated cylinders do not provide a cushioning effect and relative movement, which are beneficial.
The limitations on the use of the PTFE coated transfer cylinders have been overcome with an improved transfer cylinder having an ink repellent, cushioning, and supportive fabric covering or the like for transferring the freshly printed sheet. It is now well recognized and accepted in the printing industry world-wide that marking and smearing of freshly printed sheets caused by engagement of the wet printed surface with the supporting surface of a conventional press transfer cylinder is substantially reduced by using the anti-marking fabric covering system as disclosed and claimed in my U.S. Pat. No. 4,402,267 entitled “Method and Apparatus for Handling Printed Sheet Material,” the disclosure of which is incorporated herein by reference.
That system, which is marketed under license by Printing Research, Inc. of Dallas, Tex., U.S.A. under the registered trademark SUPER BLUE® includes the use of a low friction coating or coated material on the supporting surface of the transfer cylinder, and over which is loosely attached a movable fabric covering. The fabric covering provided a yieldable, cushioning support for the freshly printed side of the substrate such that relative movement between the freshly printed substrate and the transfer cylinder surface would take place between the fabric covering and the support surface of the transfer cylinder so that marking and smearing of the freshly printed surface was substantially reduced. Various improvements have been made to the SUPER BLUE® system, which are described in more detail in U.S. Pat. Nos. 5,907,998 and 6,244,178 each entitled “Anti-Static, Anti-Smearing Pre-Stretched and Pressed Flat, Precision-Cut Striped Flexible Coverings for Transfer Cylinders”; U.S. Pat. Nos. 5,511,480, 5,603,264, 6,073,556, 6,119,597, and 6,192,800 each entitled “Method and Apparatus for Handling Printed Sheet Material”; U.S. Pat. No. 5,979,322 entitled “Environmentally Safe, Ink Repellent, Anti-Marking Flexible Jacket Covering Having Alignment Stripes, Centering Marks and Pre-Fabricated Reinforcement Strips for Attachment onto Transfer Cylinders in a Printing Press”; and U.S. Pat. No. Re. 39,305 entitled “Anti-static, Anti-smearing Pre-stretched and Pressed Flat, Precision-cut Striped Flexible Coverings for Transfer Cylinders,” each of which is hereby incorporated by reference herein in its entirety. The above cited patents are all owned by Printing Research, Inc. of Dallas, Tex., U.S.A.
In an embodiment, in a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is disclosed. The anti-marking device comprises a flexible jacket comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder, the flexible jacket removably attached with free play to the transfer cylinder.
In another embodiment, a method of maintaining a printing press is disclosed. The method comprises removing a flexible jacket from the transfer cylinder, wherein the flexible jacket comprises fluoropolymer and immersing the flexible jacket in a solvent to clean. The method further includes attaching the flexible jacket to the transfer cylinder by a first edge of the flexible jacket, adjusting the free play of the flexible jacket, and attaching the flexible jacket to the transfer cylinder by a second edge of the flexible jacket.
In another embodiment, a method of operating a printing press having a transfer cylinder is disclosed. The method comprises printing a substrate, supporting the substrate during at least a portion of the transfer of the substrate through the printing press with a flexible jacket attached to the transfer cylinder with an effective amount of free play, the flexible jacket comprising fluoropolymer, and exposing the substrate to an artificial radiation source comprising at least one of an ultraviolet lamp and an infrared lamp.
In another embodiment, in a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is disclosed. The anti-marking device comprises a flexible jacket coupled to a base cover. The flexible jacket comprises fluoropolymer and engages the freshly printed substrate as it is transferred over the transfer cylinder. When the anti-marking device is installed over the transfer cylinder, the base cover is facing the transfer cylinder and the flexible jacket is facing outwards towards the freshly printed substrate. The flexible jacket is coupled to the base cover to promote an effective amount of free play of the flexible jacket when the anti-marking device is installed over the transfer cylinder.
In an embodiment, another method of operating a printing press having a transfer cylinder is provided. The method comprises printing a first substrate and supporting the first substrate during at least a portion of the transfer of the first substrate through the printing press with an anti-marking device comprising a flexible jacket comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder and a base cover attached to the flexible jacket at two edges to promote an effective amount of free play of the flexible jacket when the anti-marking device is installed over the transfer cylinder. The method also comprises inserting a non-porous material between the flexible jacket and the base cover from an unattached edge of the anti-marking device and, while the anti-marking device remains installed over the transfer cylinder, cleaning the flexible jacket with one of a cleaning agent and a pressroom solvent. The method also comprises, after cleaning the flexible jacket, printing a second substrate and supporting the second substrate during at least a portion of the transfer of the second substrate through the printing press with the anti-marking device.
In an embodiment, in a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is disclosed. The anti-marking device comprises a flexible jacket comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder, the anti-marking device is removably attached without free play to the transfer cylinder.
In an embodiment, a method of maintaining a printing press having a transfer cylinder is disclosed. The method comprises contacting a flexible jacket comprised of fluoropolymer and attached to the transfer cylinder with an adhesive coupled to a backing and removing the adhesive and backing, whereby at least one of ink or contaminants are removed from the flexible jacket.
In an embodiment, a blanket cleaning device for use in a printing press having a blanket for transferring a print image to a substrate is disclosed. The device comprises a feed cylinder, a continuous tape having an adhesive on one surface initially stored on the feed cylinder, a take-up cylinder configured to take-up consumed continuous tape, and a drive mechanism synchronized to the rotation of a blanket cylinder that rotates the feed cylinder and the take-up cylinder, whereby the continuous tape removes surfactants from the blanket.
In an embodiment, a method of maintaining a printing press is disclosed. The method comprises contacting with an adhesive coupled to a backing one of a flexible jacket comprised of fluoropolymer and attached to the transfer cylinder, a printing plate attached to a cylinder, a blanket attached to a cylinder, or an impression cylinder and removing the adhesive and backing, whereby at least one of ink or contaminants are removed from the one of a flexible jacket comprised of fluoropolymer and attached to the transfer cylinder, a printing plate attached to a cylinder, a blanket attached to a cylinder, or an impression cylinder.
These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
For a more complete understanding of the present disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed systems and methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, but may be modified within the scope of the appended claims along with their full scope of equivalents.
In an embodiment, a transfer cylinder may be at least partially enclosed by a flexible jacket that is installed over the transfer cylinder with an effective amount of free play. In some contexts, the flexible jacket may be referred to as a net. In some embodiments, a cylinder base cover, hereinafter referred to as a base cover, may be installed over the transfer cylinder, for example a low friction base cover, and the flexible jacket may be installed on the transfer cylinder over the base cover. In some embodiments, the flexible jacket and the base cover may be integrated in an assembly, for example with a gripper edge of the flexible jacket and base cover coupled together and a tail edge of the flexible jacket and the base cover coupled together. The integrated flexible jacket and base cover are manufactured to promote an effective amount of free play for the flexible jacket when the assembly is installed on the transfer cylinder. In other embodiments, however, a base cover may be omitted and the flexible jacket may be installed over the transfer cylinder with no intervening base cover.
In an embodiment, a plurality of flexible jackets may be installed over the transfer cylinder with no intervening base cover, the plurality of flexible jackets being installed with an amount of free play that is effective to promote anti-marking operation of the printing press. In an embodiment, two flexible jackets are installed over the transfer cylinder with no intervening base cover, both flexible jackets being installed with an effective amount of free play for promoting anti-marking operation of the printing press. When the printing press is operated, freshly printed substrates are supported by the flexible jackets installed over the transfer cylinders as the substrates are transferred from station to station within the printing press and finally distributed out of the printing press to a stacking apparatus. In an embodiment, not wishing to be bound by theory, it is thought that the free play of the flexible jacket promotes the flexible jacket expanding when the transfer cylinder rotates, providing a yieldable, cushioning support for the freshly printed substrates and allowing the flexible jacket to adhere to the freshly printed substrates. Further, again not wishing to be bound by theory, it is thought that the free play of the flexible jacket promotes the flexible jacket moving with the printed substrate, thereby avoiding marking the freshly printed substrate with spurious inking and/or smearing the ink on the freshly printed substrate.
In another embodiment, however, the transfer cylinder may be at least partially enclosed by a flexible jacket that is installed over the transfer cylinder without free play or snuggly attached to the transfer cylinder. The flexible jacket may be said to be removably attached to the transfer cylinder. In some embodiments, a base cover, may be installed over the transfer cylinder, and the flexible jacket may be installed on the transfer cylinder over the base cover, where the flexible jacket is attached without free play or snuggly.
In some embodiments, an integrated flexible jacket and base cover are manufactured to promote a snug fit of the flexible jacket when the assembly is installed on the transfer cylinder. The flexible jacket may be coupled to the base cover in a variety of ways in this integrated structure. The flexible jacket may be coupled to the base cover along a gripper edge and along a tail edge and may not be coupled to the base cover in a middle portion. For example, the flexible jacket may be free from and not coupled to the base cover at least between four inches inwards from the gripper edge to four inches inwards from the tail edge. The flexible jacket may be coupled to the base cover by stitching. In an embodiment, the flexible jacket may further be coupled to the base cover along the gripper edge by two metal strips that are riveted together in an assembly that clamps the base cover and flexible jacket gripper edges between the two metal strips. In an embodiment, the middle portion of the flexible jacket may be adhered to the base cover. In some contexts, the integrated flexible jacket and base cover may be said to be permanently attached, in that if the flexible jacket is removed from the base cover it either rips the flexible jacket or the base cover or removes the structures that are coupling the flexible jacket and the base cover together, for example removing the stitching and/or the riveting.
In other embodiments, however, a base cover may be omitted and the flexible jacket may be installed snuggly or without free play over the transfer cylinder with no intervening base cover. In an embodiment, a plurality of flexible jackets may be installed over the transfer cylinder with no intervening base cover, the plurality of flexible jackets being installed to attach snuggly and without free play to the transfer cylinder. As used herein, the term flexible jacket may refer to flexible jackets that are either attached snuggly and without free play or attached with free play.
The several embodiments of the present disclosure contemplate a flexible jacket comprised of a fluoropolymer. Fluoropolymers contemplated by the present disclosure comprise polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy (PFA). PTFE is sold under the trademark TEFLON available from DuPont Corporation and is sold under the trademark XYLAN available from Whitford. FEP is a copolymer of hexafluoropropylene and tetrafluoroethylene. Flexible jackets comprised of fluoropolymer may provide a variety of advantages in different printing press environments including extended life, greater imperviousness to ink penetration, ease of washing and/or cleaning, and greater resistance to deterioration from exposure to artificial radiation sources. Flexible jackets comprised of fluoropolymer may be able to withstand temperatures of about 400 degrees Fahrenheit, which may allow the use of the flexible jackets comprised of fluoropolymer in a wider range of printing environments. While in the following the description will commonly refer to PTFE, it is understood that in various embodiments other fluoropolymers may be used in the place of PTFE.
In an embodiment, the flexible jacket may be coated with a layer of PTFE on a single surface facing the transfer cylinder or on an inward facing surface and on an outward facing surface. In another embodiment, the flexible jacket may be at least partially woven of threads comprising PTFE. For example the flexible jacket may be woven of a mixture of metallic threads and threads comprising PTFE. As another example, the flexible jacket may be woven of a mixture of colored threads and threads comprising PTFE. In another embodiment, the flexible jacket may be woven of threads that comprise PTFE, for example PTFE coated threads. In another embodiment, the flexible jacket may be woven of threads that are manufactured partly from PTFE, for example a thread manufactured of a composition comprising PTFE and another suitable material, for example materials that promote improved structural strength such as tensile strength of the threads, that promote desirable stiffness and/or flexure strength of the flexible jacket, and/or that provide improved anti-static properties of the threads. In another embodiment, the flexible jacket may be woven of threads consisting essentially of PTFE. In another embodiment, the flexible jacket may be a sheet of continuous PTFE or a sheet mesh of PTFE, for example a sheet of PTFE that has holes or other apertures removed from an otherwise continuous sheet of PTFE.
In an embodiment, the flexible jacket 100 may be woven of threads that comprise in the range from 50 percent to 100 percent fluoropolymer (such as PTFE, FEP, and PFA), in the range from 60 percent to 100 percent fluoropolymer, in the range from 70 percent to 100 percent fluoropolymer, in the range from 80 percent to 100 percent fluoropolymer, in the range from 90 percent to 100 percent fluoropolymer, in the range from 95 percent to 100 percent fluoropolymerin the range from 96 percent to 100 percent fluoropolymer, in the range from 97 percent to 100 percent fluoropolymer, in the range from 98 percent to 100 percent fluoropolymer, in the range from 99 percent to 100 percent fluoropolymer, or in the range from 99.5 percent to 100 percent fluoropolymer. In an embodiment, the flexible jacket 100 may be woven of threads comprising fluoropolymer (such as PTFE, FEP, and PFA) and from greater than 0 percent up to about 50 percent other material, from greater than 0 percent up to about 40 percent other material, from greater than 0 percent up to about 30 percent other material, from greater than 0 percent up to about 20 percent other material, from greater than 0 percent up to about 10 percent other material, from greater than 0 percent up to about 5 percent other material, from greater than 0 percent up to 4 percent other material, from greater than 0 percent up to 3 percent other material, from greater than 0 percent up to 2 percent other material, from greater than 0 percent up to 1 percent other material, from greater than 0 percent up to 0.5 percent other material. The other materials may be selected to promote structural strength of the threads and/or that promote anti-static properties of the threads, for example carbon and polyester.
In an embodiment, the flexible jacket 100 may be woven of threads that comprise in the range from 50 percent to 100 percent PTFE, comprise in the range from 50 percent to 100 percent PTFE, in the range from 60 percent to 100 percent PTFE, in the range from 70 percent to 100 percent PTFE, in the range from 80 percent to 100 percent PTFE, in the range from 90 percent to 100 percent PTFE, in the range from 95 percent to 100 percent PTFE, in the range from 96 percent to 100 percent PTFE, in the range from 97 percent to 100 percent PTFE, in the range from 98 percent to 100 percent PTFE, in the range from 99 percent to 100 percent PTFE, or in the range from 99.5 percent to 100 percent PTFE. In an embodiment, the flexible jacket 100 may be woven of threads comprising PTFE and from greater than 0 percent up to about 5 percent other material, from greater than 0 percent up to 4 percent other material, from greater than 0 percent up to 3 percent other material, from greater than 0 percent up to 2 percent other material, from greater than 0 percent up to 1 percent other material, from greater than 0 percent up to 0.5 percent other material. The other materials may be selected to promote structural strength of the threads and/or that promote anti-static properties of the threads, for example carbon and polyester.
It is understood that in some embodiments other fluoropolymers may be substituted for PTFE and/or combined with PTFE in each of the flexible jackets described above. In an embodiment, the flexible jacket may be at least partially woven of threads comprising fluoropolymer, such as PTFE, FEP, and PFA. The flexible jacket may be woven of at least 50% threads comprised of flouropolymer, of at least 75% threads comprised of flouropolymer, of at least 82% threads comprised of flouropolymer, or of at least 90% threads comprised of flouropolymer. For example the flexible jacket may be woven of a mixture of metallic threads and threads comprising fluoropolymer, such as PTFE, FEP, and PFA. As another example, the flexible jacket may be woven of a mixture of colored threads and threads comprising fluoropolymer, such as PTFE, FEP, and PFA. In an embodiment, the flexible jacket may be woven of threads that comprise fluoropolymer, for example threads coated with fluoropolymer such as PTFE, FEP, and PFA. In another embodiment, the flexible jacket may be woven of threads that are manufactured partly from fluoropolymer such as PTFE, FEP, and PFA, for example a thread manufactured of a composition comprising fluoropolymer and another suitable material, for example materials that promote improved structural strength such as tensile strength of the threads, that promote desirable stiffness and/or flexure strength of the flexible jacket, and/or that provide improved anti-static properties of the threads. In an embodiment, the flexible jacket may be woven of threads that consist essentially of fluoropolymer, for example threads that consist essentially of PTFE, FEP, and PFA. In another embodiment, the flexible jacket may be a sheet of continuous PTFE or a sheet mesh of PTFE, for example a sheet of PTFE that has holes or other apertures removed from an otherwise continuous sheet of PTFE.
Each of these several embodiments of the flexible jacket may have different price points and benefits that make them suitable in some circumstances and not suitable in other circumstances. In an embodiment, the flexible jacket may be about 8 thousandths (0.008) inch thick (about 0.203 mm thick). In another embodiment, the flexible jacket may be about 12 thousandths (0.012) inch thick (about 0.305 mm thick). In other embodiments, the flexible jacket may have a different thickness. In an embodiment, the thickness of the flexible jacket may be determined substantially by the diameter of the threads employed to weave the material comprising the flexible jacket. The diameter of the threads may be selected to achieve a different combination of price point and durability.
Some of the expected benefits of using flexible jackets at least partially comprised of fluoropolymer, such as PTFE, FEP, and PFA, include superior freedom from ink absorption by the flexible jacket, ability to operate in the presence of artificial radiation sources such as ultraviolet lamps and/or infrared lamps, ability to wash the flexible jacket and return to service on the printing press, and extended life of the flexible jacket. Furthermore, the low coefficient of friction of fluoropolymer, such as PTFE, FEP, and PFA, may permit installation of the flexible jacket over the transfer cylinder without installing a base cover over the transfer cylinder, thereby saving the cost of the base cover. In an embodiment it may be desired that the coefficient of friction between the flexible jacket and the transfer cylinder and/or the base cover be less than the coefficient of friction between the flexible jacket and the printed substrate. In an embodiment, the base cover is coated with a fluoropolymer, for example PTFE, FEP, and PFA.
In an embodiment, the flexible jacket may be cleaned without washing with solvents by engaging an adhesive surface with the outer surface of the flexible jacket, for example at a point observed to be encumbered with ink. In a preferred embodiment, an aggressive or high strength acrylic adhesive surface may be used to clean the flexible jacket without washing. In other embodiments, however, other adhesives may be employed.
Without wishing to be bound by theory, it is thought that this system and method of cleaning the flexible jacket without washing is promoted by the fluoropolymer composition of the flexible jacket. The ink or other contaminants are not absorbed or only weakly absorbed by the flexible jacket comprising fluoropolymer, thereby leaving the ink and/or the contaminants accessible to lifting off with the adhesive surface. Further, because the fluoropolymer composition of the flexible jacket does not absorb the adhesive material, the contact of the adhesive surface with the flexible jacket does not in itself contaminate the flexible jacket with adhesive material.
The effectiveness of cleaning the flexible jacket with the adhesive surface can be visually confirmed to some extent by looking at the adhesive surface before and after contacting with the flexible jacket. For example, if an ink mark is being cleaned, the ink lifted off of the flexible jacket may be seen on the adhesive surface, thereby confirming removal of at least that quantity of ink. A variety of forms for the adhesive surface for cleaning the flexible jacket are contemplated and will be discussed further below. For example, tape may be rolled off a roll, cut or ripped to a desired length, and applied manually to the surface of the flexible jacket. An adhesive may be applied to an outside surface of a roller that may be rolled across the flexible jacket, for example over the ink mark, to clean the flexible jacket. The roller may be mounted on a handle where the axis of rotation of the roller is aligned with axis of the handle. The roller may be mounted on a pin or axle that is not parallel with the axis of the handle, for example the roller may be mounted on an axle that is at a right angle with the axis of the handle or at some other angular offset from the axis of the handle. A print shop may have a plurality of roller and handle assemblies in stock, for example each assembly featuring a different width roller that may be more suited to different cleaning needs. For small ink spots, a narrower roller may be preferred while for larger ink spots, a wider roller may be preferred. The roller may be coupled to a telescoping arm that can be used to reach and clean a flexible jacket on a transfer cylinder located in an awkward position in the printing press. The roller may be coupled to the telescoping arm in such a way as to promote adjusting the angle the roller axis makes with the telescoping arm, whereby the assembly of the roller, handle, and telescoping arm may be adapted by a press operator to different cleaning jobs or different press environments.
In an embodiment, the roller may be at least partially compressible such that as the roller is rolled longitudinally along a cylinder (e.g., in the direction from a gear edge towards an operator edge or in the direction from an operator edge towards a gear edge), the roller may compress and engage a wider longitudinal swath of the cylinder and/or flexible jacket. This may promote ease and speed of cleaning the flexible jacket with the roller. The roller may comprise one or more layers of compressible padding wrapped around the roller. For example, compressible material having an adhesive on one surface may be stuck onto the roller, and one or more layers of compressible material may be built up in this manner to provide the desired amount of compressibility. Double sided adhesive material may be adhered to the outermost layer of compressible material to complete the assembly of the roller. In an embodiment, the roller may compress and restore by at least ⅛ inch. In an embodiment, the roller may compress and restore by at least ¼ inch. In embodiment, the roller may compress and restore by at least ⅜ inch. In an embodiment, the roller may compress and restore by at least ½ inch.
The roller and handle assembly may be sheathed when not in use in a plastic container that is open at one end to receive the roller and enclose it. This promotes laying the roller and handle down without letting the adhesive outer surface of the roller stick to surfaces and/or to collect dust which may interfere with the effectiveness of the roller. The sheathed roller and handle may be set with the open end of the sheath down on a flat surface. In this stored position the roller may be at least partially protected from dust and from the adhesive drying out.
In an embodiment, a first plurality of substrates is printed by a printing press and conveyed through at least a portion of the printing press by a transfer cylinder to which a flexible jacket comprised of fluoropolymer is attached without free play. The press is then stopped. The flexible jacket is then cleaned by contacting the flexible jacket with an adhesive coupled to a backing and by removing the adhesive coupled to the backing. For example, a roller described above is rolled across at least a portion of the flexible jacket. This may be performed, for example, when a press operator notices that printed substrates are marked as if by contamination or by ink build-up on the flexible jacket. By contacting the adhesive coupled to the backing, the ink build-up and/or contaminants on the flexible jacket may be removed and/or reduced. After this cleaning of the flexible jacket, the press may be put back into operation and a second plurality of substrates may be printed and conveyed through at least a portion of the printing press by the transfer cylinder to which the flexible jacket is attached without free play.
In an embodiment, the adhesive, of a tape, or of a roller having an adhesive surface described above may be used to clean a beaded base cover or beaded flexible jacket that is installed over the transfer cylinder without any other flexible jacket being installed over it. The beaded base cover may be formed by adhering glass beads and/or ceramic beads to a base cover, for example to a mylar film or other film. The beaded base cover or beaded flexible jacket may be referred to as an anti-marking surface having a plurality of projections. The projections may, for example, be provided by a plurality of small beads, small bodies, or other small particles having any of a variety of geometries coupled to the anti-marking surfaces. For example, the small bodies may comprise spherical beads, egg-shaped beads, oblong beads, hemispherical beads, toroidal shaped beads, rounded pyramid shaped beads, polygonal shaped beads, and other shaped beads or particles. In an embodiment, the projections are comprised at least in part of plastic material, glass material, silicon material, and/or ceramic material. Alternatively, the projections may be formed by a process that does not entail coupling beads, bodies, or particles to the anti-marking surface. For example, the projections may be formed by removing material from the anti-marking surface to leave projections separated by gouged out or cut out areas such as holes and/or grooves. Alternatively, the projections may be formed by stippling the anti-marking surface. For further details on a beaded base cover or beaded flexible jacket, see U.S. patent application Ser. No. 13/018,107, filed Aug. 2, 2011, entitled “Reversible Anti-marking Jackets and Methods of Using,” by Howard W. DeMoore, et al., which is incorporated by reference in its entirety.
In an embodiment, the adhesive, of a tape, or of a roller having an adhesive surface described above may be used to clean a flexible jacket comprising a backing material, a barrier layer above the backing material, projections (for example, beads, adhered above the barrier layer, and a coating over the beads which coats the high points of beads lightly and fills in the troughs between the beads more fully, thereby leaving an irregular surface. This jacket may be installed over the transfer cylinder without any other flexible jacket being installed over it. The tape and/or roller having an adhesive surface may be scored and/or perforated at periodic intervals to promote ease of removal of used portions of the tape, for example portions of the tape that have collected ink or other surfactants, to expose fresh unused adhesive portions. Removing a portion of the tape that has collected ink or other surfactants may expose portion of the adhesive covered backing or tape that is clean, thereby restoring the cleaning effectiveness of the adhesive surface and/or roller. The scoring and/or perforating may be placed at distances corresponding to the circumference of the roller at that place in the roll. It is understood that the circumference of the roller will vary as the diameter of the roller varies, for example going inwards into the roll. The scoring and/or perforating may be placed at distances corresponding to the circumference of the roller at that place in the roll. It is understood that the circumference of the roller will vary as the diameter of the roller varies, for example going inwards into the roll.
The projections project above an average surface height of the anti-marking surface of the flexible jacket or project above the low points of the anti-marking surface of the flexible jacket. The projections may comprise any of a variety of small beads, bodies or particles of a variety of geometries that are coupled to the anti-marking surface. For example, the projections may comprise spherical beads, egg-shaped beads, oblong beads, hemispherical beads, toroidal shaped beads, rounded pyramid shaped beads, polygonal shaped beads, and other shaped beads or particles.
In an embodiment, the principles and implementations of cleaning using an adhesive surface to contact and lift ink, dried ink, lint, dirt, and other surfactants described above may be extended to other components in the offset printing environment. For example, the adhesive surface may be used to clean printing plates and/or printing blankets. One skilled in the art understands that in an offset printer may comprise a printing plate mounted to a plate cylinder, a blanket attached to a blanket cylinder, and an impression cylinder. The printing plate is inked and rotates to contact the blanket cylinder and leave a mirror image of the text and/or figure of the printing plate on the blanket. The blanket rotates to contact a printing substrate that is presented between the blanket and the impression cylinder. The blanket may be a pad of rubber or rubber-like material that tends to hold ink, thereby promoting transferring the inked image from the printing plate to the substrate such as sheet of paper or sheet of card stock.
The printing plate may be cleaned of unwanted ink, including dried ink, and other surfactants by contacting with the adhesive surface as described above with reference to flexible jackets. The adhesive surface may remove surfactants from both polyester printing plates using silver emulsion technology and from metal printing plates. The adhesive surface may remove surfactants from blankets. The adhesive surface may remove surfactants from impression cylinders. The adhesive surface may remove surfactants even in the presence of water and may remove surfactants better in the presence of water.
It may be easier to clean printing plates promptly after completing a printing run and/or after stopping the press to evaluate print quality during the middle of a printing run, rather than waiting to clean until later, for example rather than waiting until the next day of printing operation or waiting until the next printing job is set-up and ready to begin printing. It may be desirable, under some circumstances, to introduce water to the surfaces to be cleaned using the adhesive surface, for example by an operator spraying water or misting water onto the printing plate, the blanket, the impression cylinder, the transfer cylinder, or other cylinder of the printing press to be cleaned. Alternatively, water may be introduced by contacting a dampener apparatus or by operation of a dampener apparatus to or upon the subject surface to be cleaned before contacting the surface with the adhesive surface. Alternatively, an apparatus may be coupled to the printing press and selectively engaged to contact or approach proximate to the subject surface and to spray or mist water onto the surface prior to contacting with the adhesive surface. Introducing water to the printing plate may desensitize the printing plate in some cases and/or loosen ink prior to ink removal using the adhesive surface, hence promoting improvement of the cleaning process.
In an embodiment, the adhesive surface may be contacted to the surface to be cleaned without relative motion. For example, the adhesive surface may be rolled over the surface to be cleaned, whereby the adhesive surface does not slide or scrape over the surface to be cleaned when it is in contact. In an alternative embodiment, however, the adhesive surface may be contacted to the surface to be cleaned with relative motion, for example using a scuffing action or a scraping action. It is contemplated that the tack of the adhesive surface may be adapted to cleaning processes depending on whether water is or is not present, whether relative motion is or is not used for contacting the adhesive surface to the surface to be cleaned. Additionally, it is contemplated that the tack of the adhesive surface may be adapted to the kind of surface being cleaned. For example, a different degree of tack may be suitable for cleaning a metal printing plate from the degree of tack that is suitable for cleaning a blanket, for cleaning an impression cylinder, or for cleaning a flexible jacket comprising polytetrafluoroethylene (PTFE). Further, different combinations of adhesives may be chosen to reduce or eliminate adhesive residue left behind on the various surfaces using the various described techniques and devices.
Again referring to the flexible jacket, in an embodiment, the projections are comprised at least in part of plastic material, glass material, silicon material, and/or ceramic material. Alternatively, the projections may be formed by a process that does not entail coupling beads, bodies, or particles to the anti-marking surface. For example, the projections may be formed by removing material from the anti-marking surface to leave projections separated by gouged out or cut out areas such as holes and/or grooves. Alternatively, the projections may be formed by stippling the anti-marking surface.
In an embodiment, a coating is applied over the projections using an applicator roller. The coating is applied in such a way that at least some of the cusps of the projections are substantially free from the coating. For example, as the applicator roller applies the coating to the anti-marking surface, pinch points occur between the applicator roller and the high points of at least some of the projections, thereby reducing the initial amount of coating in contact with those high points. Further, the coating tends to flow down off the high points of the projections and into troughs or valleys that are formed between the projections.
The amount of coating material that is distributed across the anti-marking surface during manufacturing may be limited so that the coating does not cover the cusps of all of the projections. By controlling the amount of coating material distributed across the anti-marking surface, the anti-marking properties of the projections may be retained. It is thought that excess coating material tends to make the anti-marking surface smoother and more prone to marking. During printing operation, ink from printed substrates that contact the anti-marking surface attached to the transfer cylinder of the printing press may collect in the low points or valleys between the projections, hence avoiding marking the printed substrates with the ink. If the anti-marking surface were smoother, these valleys or low places would be reduced in size or eliminated entirely, and then ink deposited onto the anti-marking surface would be more likely to transfer back to printed substrates, marring these printed substrates. The coating may further reduce the interaction of solvents applied to clean the anti-marking surface with an adhesive, a resin that bonds on curing, or other bonding material coupling the projections, for example glass beads, to a film sheet of the flexible jacket.
In an embodiment, the coating applied over the projections is an ultraviolet curable coating. The ultraviolet curable coating is cured after application by exposure to ultraviolet light. This ultraviolet coating resists bonding to ultraviolet curable inks that may be used in the printing press to print substrates. As a consequence, the ultraviolet coating is easily cleaned and even allows relatively easy cleaning when the ultraviolet ink has dried on the anti-marking surface. In this case, the dried ultraviolet ink readily peels off or sloughs off during cleaning, for example by rolling an adhesive surface of the roller described above across at least a portion of the outer surface of the flexible jacket. It is thought that cleaning the anti-marking surface that has been coated with an ultraviolet coating as described above reduces damage to and/or removal of the projections coupled to the film sheet, because press operators are able to adequately clean the anti-marking surface using less physical pressure and less aggressive scrubbing action. The removal of the projections and/or beads in known anti-marking surfaces may further increase the difficulty of cleaning those anti-marking surfaces, as the place of removal becomes a relatively deep cavity that collects and holds ink, resisting cleaning
In an embodiment, the flexible jacket is further comprised of a backing sheet that is coupled to a barrier layer. The barrier layer is further coupled to a film sheet, where the projections of the anti-marking surface are coupled to the film sheet. The backing sheet is in contact with the transfer cylinder. As cleaning solvents and other solvents in the press contact the backing, for example at the outer edges of the backing, the solvents may be wicked up or drawn further into the backing, away from the edges. The barrier layer reduces or blocks propagation of the solvent away from the backing, up into the film sheet. If the solvent were able to propagate above the barrier layer, the solvent may degrade adhesive material, resin material, or other bonding material that couples the barrier layer to the film sheet. If the solvent were able to propagate above the barrier layer, the solvent may degrade adhesive material, resin material, or other bonding material that couples the projections, for example glass beads, to the film sheet. In an embodiment, the resin material bonds on curing.
For further details on a flexible jacket comprising a backing material, a barrier layer above the backing material, beads adhered above the barrier layer, and a coating over the beads which coats the high points of beads lightly see U.S. patent application Ser. No. 13/462,431, filed May 2, 2012, entitled “Beaded Partially Coated Anti-marking Jackets,” by Howard W/DeMoore, et al., which is hereby incorporated by reference in its entirety.
In an embodiment, the base cover has an outwards facing surface (i.e., the surface faces outwards away from the transfer cylinder when the base cover is installed over the transfer cylinder) encrusted with glass beads and/or ceramic beads that are adhered to the base cover. The surface encrusted with glass and/or ceramic beads in an embodiment may be coated and/or covered with silicone, with a fluoropolymer, or other material effective to reduce friction. In an embodiment, the base cover having a bead encrusted surface may be relatively thinner than alternative base covers. In one embodiment, for example, the base cover having a bead encrusted surface may be about 5 thousandths (0.005) inch thick (about 0.127 mm thick). In other embodiments, however, the thickness of the base cover having a bead encrusted surface may have a different thickness, depending on the size of the beads. The relative thinness of the base cover having a bead encrusted surface may have advantages in some printing environments, for example when the clearance between the transfer cylinder and other moving parts of a printing unit, for example an impression cylinder, is limited. In some circumstances, the thinness of the base cover having a bead encrusted surface may promote the installation of two flexible jackets over the base cover. In an embodiment, use of the base cover having a bead encrusted surface may support operating a press unit with only the base cover having a bead encrusted surface on the transfer cylinder, without a flexible jacket, for example when a flexible jacket has been damaged and no replacement flexible jacket is in stock.
As discussed above, in some embodiments the flexible jacket may be intended to provide a yieldable, cushioning support for the freshly printed side of a substrate. To achieve this yieldable, cushioning support it is desirable that the flexible jacket be installed and/or adjusted to have an effective amount of slack, looseness, and/or free play with respect to the base cover and/or the transfer cylinder. In other embodiments, however, the flexible jacket may be attached snuggly, attached tautly, and/or attached without free play to the transfer cylinder.
In an embodiment, the flexible jacket and/or the base cover (when a base cover is employed) may be provided with means for visual alignment to promote adjustment of the effective amount of free play of the flexible jacket. In another embodiment, however, the flexible jacket may not have means for visual alignment. In another embodiment, the base cover may not have means for visual alignment. For further details about visual alignment means in the flexible jacket and/or the base cover, see U.S. Pat. Publication No. 2010/0101441 A1 published on Apr. 29, 2010, and entitled “Offset Printing Transfer Cylinder Base Cover with Alignment Stripes for Precision Installation of a Flexible Jacket Cover also with Alignment Stripes” by Howard DeMoore, which is hereby incorporated by reference in its entirety.
The optional means for visual alignment on the flexible jacket and the optional means for visual alignment on the base cover (when a base cover is employed), singly or in combination, may promote repeatable adjustments based on experience. Additionally, the optional means for visual alignment on the flexible jacket and the optional means for visual alignment on the base cover (when a base cover is employed), singly or in combination, may promote ease of conveying instructions from a first experienced press operator to a second less experienced or inexperienced press operator, for example from a remote support center via a telephone call. In some embodiments, a flexible jacket with means for visual alignment may be installed over the transfer cylinder with no intervening base cover, and in this case the visual alignment means on the flexible jacket may be used on their own to promote adjustment of an effective amount of free play.
In an embodiment, a plurality of means for visual alignment may be disposed horizontally on the base cover. As used herein, horizontal indicates that the means for visual alignment on the base cover are substantially parallel to the axis of the transfer cylinder when the base cover is installed over the transfer cylinder. In an embodiment, the means for visual alignment on the base cover are set off from each other at substantially equal distances, for example by about ¾ inch (about 1.9 cm). In other embodiments, however, the means for visual alignment on the base cover may be set off from each other at equal distances but different from about ¾ inch (about 1.9 cm). In an embodiment, a plurality of means for visual alignment may be disposed horizontally on the flexible jacket. As used herein, horizontal indicates that the means for visual alignment on the flexible jacket are substantially parallel to the axis of the transfer cylinder when the flexible jacket is installed over the transfer cylinder. In an embodiment, the means for visual alignment on the flexible jacket are set off from each other at substantially equal distances, for example by about ¾ inch (about 1.9 cm). In other embodiments, however, the means for visual alignment on the flexible jacket may be set off by equal distances but different from about ¾ inch (about 1.9 cm). In other embodiments, the means for visual alignment may be offset by about the same amount for both the base cover and the flexible jacket. The means for visual alignment, of both and/or either of the base cover and the flexible jacket, may be continuous or interrupted. The means for visual alignment may extend horizontally substantially across the whole of the base cover and/or flexible jacket. Alternatively, the means for visual alignment may extend only partially horizontally across the base cover and/or flexible jacket.
The optional means for visual alignment on the base cover may be referred to as visual stripes. The visual stripes on the base cover may be applied as a line segment or a series of line segments (e.g., a dotted line) on the base cover, for example by painting, by lithography, by silk screening, and/or by laser induced marking or scoring, to positively define visual stripes horizontally disposed on the base cover. In another embodiment, different colored threads may be employed to positively define visual stripes horizontally disposed on the base cover. For example, the visual stripes may be defined by periodically weaving in one or more threads having a color that contrasts with the color of the majority of threads making up the woven material of the base cover. In another embodiment, the visual stripes may be defined by periodically weaving in one or more threads having a different diameter than the majority of threads making up the woven material of the base cover. In another embodiment, the base cover may be woven in a lattice pattern that creates substantially horizontal visual stripes in the base cover fabric, for example a herringbone pattern, a checkerboard pattern, a basket weave pattern, and other lattice patterns. As used herein, the term fabric may refer to a woven material constructed of natural fibers and/or synthetic fibers.
Alternatively, the visual stripes on the base cover may be provided by omitting one or more threads from the woven material of the base cover, for example by omitting one or more weft threads or by omitting one or more warp threads from a woven base cover. Removing one or more threads from a woven base cover may be said to negatively define visual stripes. The absence of threads from the woven base cover may be discerned by a print operator by seeing a greater portion of the underlying transfer cylinder through the base cover at the location of the missing threads, for example when the transfer cylinder is a bright metal material such as stainless steel. In some embodiments, a backing strip or backing sheet may be adhered to one side of the base cover to promote discernment by a print operator of the visual stripes. Alternatively, a packing sheet that promotes discernment of the visual stripes may be placed around the transfer cylinder beneath the base cover. The backing strips, backing sheet, and/or packing sheet may have a yellow color, an orange color, a red color, or other color which can be more readily discerned through the negatively defined visual stripe. The backing strips, backing sheet, and/or packing sheet may be a shiny, metallic material. In an embodiment, the transfer cylinder may be painted a color that promotes discernment of the visual stripes by a print operator.
Likewise, the optional means for visual alignment on the flexible jacket may be provided as for the base cover. The means for visual alignment on the flexible jacket may be referred to as visual stripes. The visual stripes on the flexible jacket may be applied as a line segment or a series of line segments (e.g., a dotted line) on the flexible jacket, for example by painting, by lithography, by silk screening, and/or by laser induced marking or scoring, to positively define visual stripes horizontally disposed on the flexible jacket. In another embodiment, different colored threads may be employed to positively define visual stripes horizontally disposed on the flexible jacket. In another embodiment, different diameter threads may be employed to positively define visual stripes horizontally disposed on the flexible jacket. In another embodiment, the flexible jacket may be woven in a lattice pattern that creates substantially horizontal visual stripes in the flexible jacket woven material, for example a herringbone pattern, a checkerboard pattern, a basket weave pattern, and other lattice patterns.
Alternatively, the visual stripes on the flexible jacket may be provided by omitting one or more threads from the woven material of the flexible jacket, for example by omitting one or more weft threads or by omitting one or more warp threads from a woven flexible jacket. Removing one or more threads from a woven flexible jacket may be said to negatively define visual stripes. The absence of threads from the woven flexible jacket may be discerned by a print operator by seeing the base cover through the flexible jacket, for example by seeing a visible stripe on the base cover through the flexible jacket at the area of the missing thread, or by seeing the transfer cylinder through the flexible jacket at the area of the missing thread.
Turning now to
Other alternative configurations of flexible jacket 100 will be readily apparent to those skilled in the art based upon the description herein, and these alternative configurations are also contemplated by the present disclosure. Other embodiments of flexible jackets useful in practicing the present invention are disclosed in U.S. Pat. Nos. 5,907,998; 5,979,322; 6,119,597; and 6,244,178, referenced previously and owned by Printing Research Inc. of Dallas, Tex., U.S.A.
In an embodiment, the flexible jacket 100 may be manufactured in a one-step process, wherein the flexible jacket 100 is woven so as to periodically omit one of either one or more of a weft thread or one or more of a warp thread from a continuous sheet of woven material. For example, the process may omit one or more weft threads every about ¾ inch (about 1.9 cm). As another example, the process may omit one or more warp threads every about ¾ inch (about 1.9 cm). Other spacings between omitted threads may be employed. The process may involve weaving the flexible jacket 100 from threads comprising PTFE, for example threads coated with PTFE or threads consisting essentially of PTFE. The process may further include cutting the continuous sheet of woven material into separate sheets sized appropriately to form the flexible jacket 100, which may be referred to as precision cutting the flexible jacket 100. In an embodiment, the process may include coating the woven material with PTFE. The PTFE coating may be applied to the woven material while it is in the continuous form or may be applied to the separately cut sheets of flexible jacket 100.
For exemplary purposes, the flexible jacket 100 and the optional base cover will be described with reference to the processing of sheet substrates. However, it will be understood that the principles of the disclosure are equally applicable to web substrates. The flexible jacket 100 of the present disclosure and the optional base cover may be used in combination with high-speed printing press equipment of the type used, for example, in offset printing.
Use of the present disclosure, in combination with the transfer cylinder 10 at an interstation transfer position (T1, T3) or at a delivery position (T4) in a typical rotary offset printing press 12, is believed to be readily understandable to those skilled in the art. In any case, reference may be made to U.S. Pat. Nos. 3,791,644 and 4,402,267, which disclose details regarding the location and function of a sheet support cylinder in a typical multistation printing press. The present disclosure may, of course, be utilized with conventional printing presses having any number of printing units or stations.
Referring to
As illustrated in
The freshly printed sheets S are transferred to the sheet stacker 18 by a delivery conveyor system, generally designated 30. The delivery conveyor system 30 is of conventional design and includes a pair of endless delivery gripper chains 32 carrying transversely disposed gripper bars, each having gripper elements for gripping the leading edge of a freshly printed sheet S as it leaves the impression cylinder 26 at the delivery position T4. As the leading edge of the printed sheet S is gripped by the grippers, the delivery gripper chains 32 pull the gripper bars and sheet S away from the impression cylinder 26 and transport the freshly printed sheet S to the sheet delivery stacker 18.
Referring to
Referring now to
The hubs 40, 42, and 44 are connected to the cylindrical rim 34 by webs 46, 48 and 50, and support the transfer cylinder 10D for rotation on the delivery shaft 36 of the printing press 12 in a manner similar to the mounting arrangement disclosed in U.S. Pat. No. 3,791,644. In the embodiment shown in
Referring to
The function and operation of the transfer cylinders 10 and associated grippers of the printing units 20 are believed to be well known to those familiar with multi-color sheet fed presses, and need not be described further except to note that the impression cylinder 26 functions to press the sheets against the blanket cylinders 24 which applies ink to the sheets, and the transfer cylinders 10 guide the sheets away from the impression cylinders 26 with the wet printed side of each sheet facing against the support surface of the transfer cylinder 10. Since each transfer cylinder 10 supports the printed sheet with the wet printed side facing against the transfer cylinder support surface, the transfer cylinder 10 is provided with the flexible jacket 100 and the optional base cover as described herein. The flexible jacket 100 and the optional base cover are releasably attached to the transfer cylinder 10 by means for releasably attaching the flexible jacket 100 and the optional base cover to a transfer cylinder 10. In an embodiment shown in
In an embodiment, when installed over the transfer cylinder 10, the flexible jacket 100 may extend across the entire width of the transfer cylinder 10, for example from an operator edge to a gear edge of the transfer cylinder 10. In another embodiment, when installed over the transfer cylinder 10, the flexible jacket 100 may extend across the entire width of the transfer cylinder 10, for example from the operator edge to the gear edge of the transfer cylinder 10, and around behind the operator edge and the gear edge, for example to attach to a hook-and-loop fabric strip adhered on to the inner diameter of the transfer cylinder 10. In another embodiment, when installed over the transfer cylinder 10, the flexible jacket 100 may not extend across the entire width of the transfer cylinder 10, for example from the operator edge to the gear edge of the transfer cylinder 10, but may leave an uncovered margin along one or both of the operator edge and the gear edge of the transfer cylinder. In an embodiment, the base cover 300, likewise, may not extend across the entire width of the transfer cylinder 10, for example from the operator edge to the gear edge of the transfer cylinder 10, but may leave an uncovered margin along one or both of the operator edge and the gear edge of the transfer cylinder 10. In an embodiment, an assembly of the flexible jacket 100 and the base cover 300 may be provided, and the assembly of the flexible jacket 100 and the base cover 300 may not extend across the entire width of the transfer cylinder 10. The narrowing of the flexible jacket 100 and/or the base cover 300 may provide manufacturing cost savings while still providing the desired support for printed substrates as they pass through the printing unit 20. The width of the flexible jacket 100 and/or the base cover 300 may be selected to work with the widest substrates that may be printed by the printing unit 20.
The provision of an uncovered margin along one or both of the operator edge and the gear edge of the transfer cylinder 10 may reduce and/or attenuate accumulation of ink, grease, oil, and/or other soiling materials on the flexible jacket 100 and/or the base cover. In some printing units 20, transfer cylinders 10 may throw off and/or accumulate ink, grease, oil, and/or soiling materials, for example by ink propagating from the flexible jacket 100 and/or the base cover 300 and by grease or oil exuding from bearings of the transfer cylinders 10 and/or other moving parts of the printing unit 20. This ink, grease, oil, and/or soiling material may accumulate along the operator edge and/or the gear edge of the transfer cylinder 10. By leaving an uncovered margin, the accumulation of ink, grease, oil, and/or soiling material along the operator edge and/or the gear edge of the transfer cylinder 10 avoids the fouling of the flexible jacket 100 and/or the base cover and saves the trouble of cleaning and/or replacing the flexible jacket 100 and/or the base cover. Additionally, by reducing exposure of the flexible jacket 100 and/or the base cover, the service life of the base cover 100 and/or the base cover may be extended as a result of reduced degradation from contact with damaging compositions, such as ink, grease, and/or soiling material.
In an embodiment, the uncovered margins of the transfer cylinder 10 may be treated to attenuate the movement and/or propagation of the ink, grease, oil, and/or soiling materials inwards from the operator edge and/or the gear edge of the transfer cylinder 10 towards the flexible jacket 100 and/or the base cover 300. This treatment of the transfer cylinder 10 may also attenuate the movement and/or propagation of the ink, grease, oil, and/or soiling materials outwards to the operator edge and/or the gear edge of the transfer cylinder 10 and attenuate release of the ink, grease, oil, and/or soiling materials to contaminate the floor and/or the air of the pressroom. In an embodiment, the uncovered margins of the transfer cylinder 10 may be abraded or otherwise provided with a rough and/or unsmooth surface to attenuate propagation of ink, grease, oil, and/or soiling materials inwards from the operator edge and/or the gear edge of the transfer cylinder 10. In embodiment, the uncovered margins of the transfer cylinder 10 may be provided with grooves or scoring that comprises troughs and lands, wherein incident ink, grease, oil, and/or soiling materials tend to be constrained within the troughs.
In an embodiment, the uncovered margins of the transfer cylinder 10 may be provided with a surface coating and/or surface treatment that tends to attract and/or retain the ink, grease, oil, and/or soiling materials and to attenuate the propagation of the ink, grease, oil, and/or soiling materials inwards from the operator edge and/or the gear edge. This surface coating and/or surface treatment of the transfer cylinder 10 may also attenuate the movement and/or propagation of the ink, grease, oil, and/or soiling materials outwards to the operator edge and/or the gear edge of the transfer cylinder 10 and attenuate release of the ink, grease, oil, and/or soiling materials to contaminate the floor and/or the air of the pressroom. For example, the uncovered margins of the transfer cylinder 10 may be provided with a surface coating of an oleophilic material. At least some of the inner portions of the transfer cylinder 10 may be provided with a surface coating of oleophobic material. For example, the outermost portion of the uncovered margin of the transfer cylinder 10 may be provided with a surface coating of an oleophilic material while an inner portion of the uncovered margin may be provided with a surface coating of an oleophobic material. The flexible jacket 100 and/or the base cover may be installed over the transfer cylinder 10 inside of outer margins of the transfer cylinder 10 defined by both the oleophilic surface and the oleophobic surface.
In an embodiment, the base cover may be about as wide as the transfer cylinder 10, for example extending from the operator edge to the gear edge of the transfer cylinder 10, while the flexible jacket 100 does not extend from the operator edge to the gear edge of the transfer cylinder 10. The outer edges of the base cover, for example the portions of the base cover not covered by the flexible jacket 100, may have a different composition or a different structure from the portion of the base cover that is covered by the flexible jacket 100. For example, the outer margins of the base cover may be effective to attract and/or to retain ink, grease, oil, and soiling materials and to attenuate the propagation of the same inwards towards the flexible jacket 100. The outer margin of the base cover may comprise an outermost portion of oleophilic surface material. In an embodiment, the outer margin of the base cover may comprise an outermost portion of oleophilic surface material and an inner margin of oleophobic surface material. The outer margin of the base cover may have a rough surface and/or a surface comprising pits, valleys, or other surface irregularities that tend to attenuate the migration and/or propagation of ink, grease, oil, and/or soiling materials inwards to the flexible jacket 100.
Turning now to
At block 208, the flexible jacket 100 is rinsed to remove solvent from the flexible jacket 100 and to flush away loosened ink and soiling matter. In an embodiment, the flexible jacket 100 may be rinsed by being removed from a first vessel containing the solvent and placed in a second vessel containing a substantially clean solution, for example water. The clean solution in the second vessel optionally may be agitated to cause the flexible jacket 100 to flex and work the clean solution over and/or through the flexible jacket 100. In another embodiment, however, the flexible jacket 100 may be treated with a flow of substantially clean solution, for example water, for a period of time. Other rinsing fluids other than water may be used in some embodiments. In an embodiment, the rinsing of block 208 may be repeated an effective number of times to incrementally remove solvent from the flexible jacket 100 and to flush away loosened ink and/or soiling matter. It will be appreciated that the blocks 204, 206, and 208 may be referred to as washing the flexible jacket 100. In an embodiment, the flexible jacket 100 may be washed in a conventional clothes washer, such as may be found in many private residences for washing clothing. At block 210, the flexible jacket 100 is dried. In an embodiment, the flexible jacket 100 may be air dried, such as by hanging up from a line exposed to freely moving air. In another embodiment, the flexible jacket 100 may be dried in a conventional clothes dryer, such as may be found in many private residences for drying clothing. In an embodiment, the flexible jacket 100 comprised of fluoropolymer may be able to withstand temperatures of about 400 degrees Fahrenheit.
At block 212, a first edge of the flexible jacket 100, now washed and dry, is attached to the transfer cylinder 10, for example to the gripper edge of the transfer cylinder 10. At block 214, the free play of the flexible jacket 100 is adjusted. As described above, in an embodiment, an effective amount of looseness in the fit of the flexible jacket 100 over the transfer cylinder 10 is preferred to promote the slight adhesion of the flexible jacket 100 to printed substrates as they transfer through the printing press 12, to promote the flexible jacket 100 moving with the printed substrates without sliding contact, thereby avoiding marking the printed substrate. In an embodiment, alignment means on at least one of the flexible jacket 100 and the optional base cover, for example horizontal visual stripes or partial horizontal visual stripes, may be used to determine the desired amount of free play in the flexible jacket 100. As described above, visual stripes may be provided in a positive manner by painting, silk screening, lithography, or laser induced marking processes or by using a different colored thread woven into the flexible jacket 100 and/or optional base cover. Alternatively, visual stripes may be provided in a negative manner by omitting a thread from the weaving of the flexible jacket 100 and/or optional base cover. At block 216, a second edge of the flexible jacket 100 is attached to the transfer cylinder 10, for example a tail edge of the transfer cylinder 10. The printing press 12 may now be returned to service. Alternatively, in an embodiment, the flexible jacket 100 is attached to the transfer cylinder 10 snuggly, tautly, and/or without free play.
Alternatively, in some embodiments, the flexible jacket 100 may be washed in place, while remaining attached to the transfer cylinder 10. For example, the flexible jacket 100 may be washed with common pressroom solvents and/or chemicals, for example blanket wash and/or roller wash. In an embodiment, the flexible jacket 100 may be washed with alcohol, acetone, benzene, toluene, xylene, and other known cleaning solvents. Alternatively, in an embodiment, the flexible jacket 100 may be cleaned without washing by lifting ink and/or contaminants from the flexible jacket 100 by applying and removing an adhesive surface. For example, a roller with an adhesive surface as described above, where the roller is coupled to an axle that is coupled to a handle, may be rolled back and forth across the flexible jacket 100 to remove contaminants and/or ink spots. The tape may also be separately applied to and removed from the surface to be cleaned as strips.
Turning now to
In some embodiments, the flexible jacket 100 and the optional base cover of the present disclosure may be packaged together and sold as an anti-marking kit for transfer cylinders, for example in a package containing at least one flexible jacket 100 and at least one base cover. In other cases, one base cover may be combined in a package with a plurality of flexible jackets 100, for example six flexible jackets 100, and sold as a kit. In another embodiment, one base cover may be combined in a package with a plurality of flexible jackets 100, for example two flexible jackets 100, three flexible jackets 100, four flexible jackets 100, five flexible jackets 100, or more than six flexible jackets 100.
Turning now to
The anti-marking device 301 is for installation on the transfer cylinder 10 for supporting a printed substrate during transfer through the printing press 12. When installed over the transfer cylinder 10, the base cover 300 of the anti-marking device 301 is facing the transfer cylinder 10 and the flexible jacket 100 of the anti-marking device 301 is facing outwards towards the printed substrate. The anti-marking device 301 has a gripper edge 302 and opposing tail edge 304. The anti-marking device 301 has an operator edge 306 that is positioned towards the operator side of the printing press 12 when installed and opposing gear edge 308 that is positioned towards the gear side of the printing press 12 when installed. The anti-marking device 301 may be produced in a variety of sizes and shapes, most often corresponding to the dimensions of the wide variety of commercial transfer cylinders 10 available. The anti-marking device 301 is typically rectangular in shape.
The flexible jacket 100 may be attached and/or coupled to the base cover 300 in a variety of ways. The flexible jacket 100 may be attached to the base cover 300 along only one edge, for example along only the gripper edge 302 or along only the tail edge 304. The flexible jacket 100 may be attached to the base cover 300 along two edges, for example along the gripper edge 302 and the tail edge 304 or along the gear edge 308 and the operator edge 306. Alternatively, in another embodiment, the flexible jacket 100 may be attached to the base cover 300 by three or four of the gripper edge 302, the tail edge 304, the operator edge 306, and the gear edge 308. The attachment along one or more of the edges may be partial, that is the points of attachment may extend along a portion of an edge and not extend from end-to-end of an edge.
The several alternative configurations may have different advantages that recommend their selected use in different environments. The anti-marking device 301 wherein the flexible jacket 100 is permanently attached to the base cover 300 at least partially along one edge only, for example, may promote ease of cleaning the base cover, for example when an unwanted solvent is spilled on the anti-marking device 301. For example, in the event of a solvent spill, the unattached edge of the flexible jacket 100 of the anti-marking device 301 may be lifted free of the base cover 300 and the transfer cylinder 10, providing access to clean the base cover 300. After cleaning the base cover 300, the flexible jacket 100 may be reattached to the transfer cylinder 10 with the effective amount of free play. Alternatively, the flexible jacket 100 may be reattached to the transfer cylinder 10 snuggly, tautly, and/or without free play. The unattached edge of the anti-marking device 301 may be secured to the transfer cylinder 10 by hook and loop fasteners, for example VELCRO®, or other attachment means.
The anti-marking device 301 wherein the flexible jacket 100 is attached to the base cover 300 at least partially along two opposing edges, for example along the gripper edge 302 and along the tail edge 304, may promote cleaning the flexible jacket 100. In an embodiment, the flexible jacket 100 may be permanently attached to the base cover 300. For example, a non-porous material may be inserted from an unattached edge, for example from the operator edge 306 or the gear edge 308, between the flexible jacket 100 and the base cover 300 and the flexible jacket 100 may be washed in place over the transfer cylinder 10 with any appropriate cleaning agent or pressroom solvent. For example, the flexible jacket 100 may be washed with common pressroom solvents and/or chemicals, for example blanket wash and/or roller wash. In an embodiment, the flexible jacket 100 may be washed with alcohol, acetone, benzene, toluene, xylene, and other known cleaning solvents. The flexible jacket 100 may be washed with a mixture of soap and water. The non-porous material may reduce the chances that the cleaning agent and/or pressroom solvent may soil and/or damage the base cover 300.
In an embodiment, a method of operating the printing press 12 having a transfer cylinder 10 comprises printing a first substrate and supporting the first substrate during at least a portion of the transfer of the first substrate through the printing press 12 with the anti-marking device 301 comprising the flexible jacket 100 comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder 10 and the base cover 300 attached to the flexible jacket 100 at two edges, for example at the gripper edge 302 and at the tail edge 304, to promote an effective amount of free play of the flexible jacket 100 when the anti-marking device 301 is installed over the transfer cylinder 10. The method also comprises inserting a non-porous material between the flexible jacket 100 and the base cover 300 from an unattached edge of the anti-marking device 301, for example from one of an operator edge 306 and a gear edge 308, and, while the anti-marking device 301 remains installed over the transfer cylinder 10, cleaning the flexible jacket 100 with one of a cleaning agent and a pressroom solvent. The method also comprises, after cleaning the flexible jacket 100, printing a second substrate and supporting the second substrate during at least a portion of the transfer of the second substrate through the printing press 12 with the anti-marking device 301.
In an embodiment, the flexible jacket 100 may be attached to the base cover 300 by stitching, adhesive, thermal bonding, crimp strips, male-female fasteners, brads, rivets, tension strips, staples, or combinations thereof. The flexible jacket 100 may be attached to the base cover 300 so as to provide the desirable effective amount of free play in the flexible jacket 100 when the anti-marking device 301 is installed on the transfer cylinder 10, thereby relieving an operator and/or a pressman of the need to adjust the free play of the flexible jacket 100 when attaching the flexible jacket 100 to the transfer cylinder 10 as described above. The anti-marking device 301 may speed the replacement of the flexible jacket 100 by relieving the operator and/or pressman of the step of adjusting the free play of the flexible jacket 100. Additionally, the anti-marking device 301 may overcome the problem of an inexperienced, and/or an inattentive operator, and/or pressman installing the flexible jacket 100 with either excessive or insufficient free play.
In an embodiment, two or more flexible jackets 100 may be attached to the base cover 300 of the anti-marking device 301. As the top-most flexible jacket 100 wears out, the top-most flexible jacket 100 may be removed from the anti-marking device 301 and then printing using the next layer of flexible jacket 100 may resume. Further details of multiple layer jackets may be found in U.S. Pat. No. 8,220,388 issued Jul. 17, 2012, entitled “Multiple Layer Anti-marking Jackets and Methods of Using in Offset Printing,” by Howard DeMoore, et al., which is hereby incorporated by reference in its entirety.
Turning now to
It is contemplated that the blanket cleaning mechanism 400 may be controllably activated by a press operator when the press is off-impression or not engaged in printing substrates, for example when the blanket cylinder 410 is rotated at a very slow rate, for example at a rate of about 5 revolutions per minute. The feed cylinder 402 and the take-up cylinder 404 may be synchronized with the slowly rotating blanket cylinder 410 to achieve contact between the adhesive surface of the continuous tape 406 and the blanket and/or blanket cylinder 410 either with or without relative motion. When the adhesive surface of the continuous tape 406 makes contact without relative motion with the blanket, the adhesive surface of the continuous tape 406 and the blanket cylinder 410 move in the same direction, as illustrated by the arrows in
In an embodiment, one of the take-up cylinder 404 or feed cylinder 402 may contact the blanket or blanket cylinder 410 to be cleaned or press the adhesive surface of the continuous tape 406 into contact with the blanket or blanket cylinder 410 to be cleaned. In an embodiment, the blanket cleaning mechanism 400 may comprise a drive component 408 that couples to the blanket cylinder 410 and mechanically drives the feed cylinder 402 and the take-up cylinder 404 in synchronization with the blanket cylinder 410. The drive component 408 may automatically adapt the rate of rotation of the take-up cylinder 404 and of the feed cylinder 402 to compensate for diameter change of the respective cylinders 402, 404 as the continuous tape is paid out by the feed cylinder 402 and is taken up by the take-up cylinder 404, whereby to maintain the desired motion of the continuous tape with reference to the blanket and/or blanket cylinder 410, e.g., either without relative motion or with appropriate relative motion of the continuous tape versus the blanket.
In an embodiment, the blanket and/or blanket cylinder associated with excess marking material is contacted by continuous tape 406 to clean the blanket without the use of a fluid. In an embodiment, the blanket associated with excess marking material is contacted by the continuous tape 406 to clean the blanket using water but no other solvent. The continuous tape 406 that has contacted the blanket is taken up on a take-up roller 404 and then disposed. This blanket cleaning mechanism 400 may replace existing blanket cleaning mechanisms that rely upon spraying solvent over a consumable fabric which engages and cleans the blanket and/or blanket cylinder 410. The solvent of the known blanket cleaning mechanisms must be replenished periodically and the solvent treated consumable fabric must be properly disposed of. The solvent dispensing jets may be subject to clogging and may need to be periodically maintained by the press operator. The solvent may be subject to handling under hazardous materials processing regulations. Failures of the known blanket cleaning mechanisms may result in solvent spills and/or damage to the press. The new blanket mechanism 400 disclosed herein may eliminate many of these hazards and maintenance activities. Additionally, the known solvent and consumable fabric blanket cleaning mechanism may not efficiently of effectively clean dried ink from the blanket and/or blanket cylinder 410, but the blanket cleaning mechanism 400 using the continuous adhesive tape is able to remove dried ink from the blanket and/or blanket cylinder 410. While the blanket cleaning mechanism 400 is described above specifically with reference to cleaning blankets, the present disclosure contemplates using a similar mechanism and/or structure for engaging with and cleaning other cylinders, for example for cleaning one or more of a transfer cylinder, a delivery cylinder, an impression cylinder, a printing plate installed on a cylinder, and other cylinders of the printing press, either with the introduction of water as a solvent or without introduction of water as a solvent.
In an experimental execution of the disclosed system and method, the adhesive surface has been found to clean offset metal plates, removing for example dried ink, wet ink, and/or hickeys (also referred to in some contexts as ‘donuts’) from the printing plate. The adhesive surface was found to remove ink from choked up half-tones. While traditional cleaning procedures using known plate cleaners may weaken or diminish the life of the printing plate, the adhesive surface was found to remove surfactants, dried ink, and/or wet ink with no observed degradation of the image of the printing plate.
The adhesive surface may be used to clean flexo presses and letter presses. The use of the adhesive surface may replace the use of chemical cleaning agents (e,g, solvents, plate cleaners) which may reduce or eliminate chemical hazards. As discussed further above, the cleaning the printing plate or other printing cylinder may be promoted by treating the surface to be cleaned with dampness or with water and then applying the adhesive surface to clean. It may be advantageous to perform the cleaning using the adhesive surface promptly after completing a printing operation, for example to ease the process of removing ink in part due to residual moisture. Additionally, it may be suitable to leave dampeners engaged while cleaning with the adhesive surface. If sufficient time has passed that the loose ink or surfactants have dried, the cleaning process may be improved by adding back moisture by a separate sprayer or a sprayer built into whatever tool is providing the adhesive surface. Leaving the dampener engaged as discussed above may provide similar benefits.
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented.
Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
The instant application is a continuation-in-part of and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 13/646,657, filed Oct. 5, 2012, entitled “Anti-marking Jackets Comprised of Fluoropolymer and Methods of Using in Offset Printing,” by Howard W. DeMoore, et al., which is hereby incorporated by reference for all purposes.
Number | Date | Country | |
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Parent | 13646657 | Oct 2012 | US |
Child | 13771554 | US |