Offset printing apparatus for applying a substance

Information

  • Patent Grant
  • 6698877
  • Patent Number
    6,698,877
  • Date Filed
    Friday, June 28, 2002
    22 years ago
  • Date Issued
    Tuesday, March 2, 2004
    20 years ago
Abstract
An offset print apparatus for applying a substance to a web is provided. The offset print apparatus has a transfer roll that is capable of being rotated. An ink jet printer is present and has a print head that is located proximate to the transfer roll. The print head has a plurality of orifices from which the substance is dispensed onto the transfer roll. The distance between the surface of the print head and the transfer roll is defined as a throw distance. A web is present and contacts the transfer roll. The substance is dispensed onto the transfer roll and is transferred to the web through contact of the transfer roll and the web. The web has an amount of dust laden boundary air that is formed proximate to the web when the web is moving. The print head of the ink jet printer is not in contact with the boundary air.
Description




BACKGROUND




Production of paper products such as paper towels, tissues, napkins, and the like often employ the use of several manufacturing steps. One of these manufacturing steps involves the application of a substance onto the web from which the paper product is made. The purpose of applying a substance onto the web is due to a desire to change the functional properties of the resulting paper product. For instance, the substance may be a strength agent, a softening agent, or a debonding agent, or any other substance which affects the functional properties of the product. Application of these types of substances to a web will result in the final paper product having desired characteristics. Typically, strengthening agents are added to a web that is made into paper towels in order to provide for a paper towel that will not disintegrate upon contact with water or other liquids. Alternatively, debonding agents are sometimes applied to a web that is made into toilet tissue such that the resulting product will break up upon contact with water. As such, the application of a substance that modifies the functional properties of a paper product is an important step in the manufacturing these products.




One method known in the art that is used to apply a substance onto a web is known as direct printing. Direct printing can employ flexographic, gravure, or ink jet technology. Ink jet technology includes a device known as an ink jet print head that has a plurality of orifices. A substance may be expelled from one or more of these orifices thus exiting the print head of the ink jet printer. Drops of the substance then travel a throw distance between the print head and the web or other surface onto which the substance is to be applied. The orifices of the print head may be aligned in a single row or may be formed having various patterns. The substance may be expelled from these orifices either simultaneously or through selected orifices at any given time. Although ink jet technology is commonly used in ink printers which apply printing to a paper, ink jet technology is also known in the art as a method of applying substances to a paper in order to effect the functional properties of the paper.




Direct printing may sometimes employ a guide roll onto which the moving web is contacted. The ink jet print head may then apply the substance onto the web as the web is rolled over the guide roll. Alternatively, a transfer roll may not be present in direct printing. Here, the ink jet print head applies the substance to a moving web that is stretched in between two points, for instance two other rolls. The moving web may create a layer of boundary air that is approximately one-half inch to one inch in distance from the surface of the moving web. Although, it is to be understood that in the present invention that any size of boundary air may be present and the invention is not limited to any particular distance. This boundary air is a turbulent airflow that has a significant amount of dust present. The dust is formed by the particles that create the web. In ink jet printing, the throw distance from the print head to the surface onto which the substance is applied is typically less than fifteen millimeters, and is commonly less than five millimeters. Therefore, in direct printing the print head is typically within the boundary air. It is often the case that the dust will build up on the print head of the ink jet printer due to static effects. This buildup of dust on the print head can significantly impact the dispensing of the substance from the ink jet printer. For instance, several of the orifices can become jammed or partially clogged therefore preventing the desired distribution of the substance onto the web. Additionally, a reduced amount of substance can be applied from that which is desired.




The production of paper products typically occurs at a fast rate. Therefore, the web is moved at a high rate of speed producing boundary air which is also moving at an elevated speed. Due to the fact that ink jet technology propels drops of the substrate onto the web, this fast moving boundary air can potentially cause problems. For instance, the boundary air may act as a barrier to prevent the drops of the substrate from reaching the web. In addition, the boundary air may effect the location onto which the substance is placed on the web causing a buildup on some parts of the web and leaving other parts of the web with none or a reduced amount of the substance. In most circumstances, such an uneven dispersion of the substance is undesired. Additionally, the buildup of dust on the ink jet print head can cause the formation of satellite drops which are smaller drops of the chemistry that are formed due to drop break-up upon impact with dust or due to improper drop formation. These satellite drops are smaller and have a greater potential of being swept away by the boundary air and/or being inhaled by a person in the proximity of the printing equipment. These problems exist at relatively low speeds of a moving web, such as speeds less than 500 feet per minute, but become worse at higher speeds.




Although it is possible to move the ink jet print head away from the boundary air such that the problem of dust buildup is not as severe, this modification causes other side effects. First, the ink jet print head is designed to operate at relatively small throw distances. Having a larger throw distance will result in a loss of resolution of the substance applied to the web. For instance, more overlapping of the substance applied to the web will occur. Additionally, the substance has a greater chance of being swept away due to the boundary air. The exact placement of the substance onto the web will not be controllable since the distance the drop of the substance is thrown will be great and will be through a turbulent airflow.




SUMMARY




Various features and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the present invention.




The present invention provides for an offset print apparatus for applying a substance to a moving web. The offset print apparatus includes a transfer roll that is capable of being rotated. A moving web is provided and is in contact with a first circumferential portion of the transfer roll. The moving web moves over or under the transfer roll and stays in contact with the first circumferential portion of the transfer roll while moving over the transfer roll. A dispenser is located proximate to a second circumferential portion of the transfer roll and has at least one orifice. A substance may also be present and be dispensed from the dispenser through the at least one orifice. The substance is dispensed onto the transfer roll without having the dispenser contact the transfer roll. The transfer roll rotates the substance into engagement with the moving web such that at least a portion of the substance is applied to the moving web.




The present invention also provides for an offset print apparatus for applying a substance to a web that includes a transfer roll. An ink jet printer is provided that has a print head located proximate to the transfer roll. The print head has a plurality of orifices from which the substance is dispensed onto the transfer roll. The distance between the surface of the print head and the transfer roll is defined as a throw distance. A web contacts the transfer roll such that the substance that is dispensed onto the transfer roll is transferred to the web through contact of the transfer roll and the web. The web has an amount of dust laden boundary air that is formed proximate to the web when the web is moving. The print head of the ink jet printer need not come into contact with the dust laden boundary air that is formed when the web is moving.




The present invention also encompasses an apparatus as discussed above where the substance is applied to affect the functional properties of the web.




A further exemplary embodiment of the present invention is provided as an apparatus as immediately discussed where the substance is selected from the group that consists of but is not limited to strength agents, softening agents, and debonding agents.




A further exemplary embodiment of the present invention exists in an apparatus as previous discussed where the dispenser is an ink jet printing apparatus.




Alternatively, the present invention includes an offset print apparatus as previously discussed which further has a doctor blade that is located proximate to the transfer roll. The doctor blade removes any of the substance that remains on the transfer roll after engagement of the substance with the moving web.




Alternatively, the present invention includes an apparatus as set forth above where the moving web is moving at a speed of between about 5,000 feet per minute and about 8,000 feet per minute in one exemplary embodiment, and a speed between about 500 and 3,000 feet per minute in another exemplary embodiment.




Additionally, the present invention includes an exemplary embodiment of an offset print apparatus as discussed above where the throw distance is between about 2 and about 3 millimeters in one exemplary embodiment, and can be between 1 and 20 millimeters in other exemplary embodiments.




Another exemplary embodiment of the invention exists where the print head is spaced away from and not in contact with the boundary air that is formed by the moving web.




The present invention also encompasses a method for applying a substance to a moving web. The method includes the step of rotating a transfer roll. A web is moved over or under a first circumferential portion of the transfer roll. The web stays in contact with the first circumferential portion while being moved over or under the transfer roll. A dispenser is located proximate to a second circumferential portion of the transfer roll. The dispenser is located such that boundary air from the moving web is substantially remote from the dispenser. A substance is dispensed from the dispenser onto the transfer roll at the second circumferential portion. The substance is rotated into engagement with the moving web so that at least a portion of the substance is applied to the moving web.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an elevation view of an exemplary embodiment of an offset print apparatus in accordance with the present invention. The offset print apparatus is shown having a dispenser that is an ink jet printer.





FIG. 2

is an elevational view of an exemplary embodiment of an offset print apparatus in accordance with the present invention. The offset print apparatus has a doctor blade that is present to remove any remaining substance that is on the transfer roll after the substance comes into contact with the moving web.





FIG. 3

is a perspective view of a print head in accordance with one exemplary embodiment of the present invention. The print head is shown having a plurality of orifices from which a substance may be dispensed.





FIG. 4

is a detailed elevational view of a transfer roll and a print head in accordance with one exemplary embodiment of the present invention. The drawing shows the throw distance being the distance between the transfer roll and the print head.





FIG. 5

is an elevational view of a direct print apparatus. The direct print apparatus makes use of a print head that prints directly onto the web.





FIG. 6

is a detailed view of the guide roll and the print head of a direct print apparatus. A layer of boundary air is shown being formed above the moving web.





FIG. 7

is a detailed view of a direct print apparatus. The drawing shows the web moving underneath a print head. In this drawing, the moving web has just begun moving and a substance is shown being applied by the print head to the moving web.





FIG. 8

shows a detailed view of the direct printing apparatus shown in FIG.


7


. Here, the drawing shows the print head shortly after the print head shown in FIG.


7


. An amount of dust has accumulated on the print head.





FIG. 9

is an elevation view of an exemplary embodiment of an offset print apparatus in accordance with the present invention. Two transfer rolls and print heads are present in order to apply a substance to both sides of a web.











DETAILED DESCRIPTION




Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.





FIG. 1

shows an exemplary embodiment of an offset print apparatus


10


in accordance with the present invention. The offset print apparatus


10


is shown having a transfer roll


12


being present. The transfer roll


12


is rotationally mounted onto a frame


46


via a shaft


44


. The transfer roll


12


may be cylindrical in shape and have a smooth outer surface. However, it is to be understood that other exemplary embodiments of the present invention will have a transfer roll


12


that does not have a smooth outer surface. The transfer roll


12


may be any type of roll known in the art in other exemplary embodiments of the present invention, for instance, one such roll is disclosed in U.S. Pat. No. 6,257,138 B1 which is incorporated by reference in its entirety for all purposes. The transfer roll


12


may be made of any type of material, for instance, steel. Also, the transfer roll


12


may have a smooth, textured, or patterned surface. Additionally, an elastomeric coating may or may not be present on the transfer roll


12


. The transfer roll


12


may be a vacuum roll in certain exemplary embodiments of the present invention. A vacuum roll is a roll that has a vacuum applied to the interior thereto such that a web


14


is securedly pulled against the vacuum roll. However, it is to be understood that in other exemplary embodiments of the present invention, the transfer roll


12


is not a vacuum roll. Additionally, in other exemplary embodiments of the present invention the transfer roll


12


may be replaced by a belt having or not having a vacuum present underneath. As such, it is to be understood that as used herein and in the claims the term “transfer roll” is broad enough to be an element capable of transferring substance.




A moving web


14


is present in the offset print apparatus


10


. The moving web


14


moves in the direction of arrow A from an upstream manufacturing process


48


. The web


14


employed in

FIG. 1

may be, for example, a tissue. However, it is to be understood that the web


14


may be used to form other products besides a tissue in other exemplary embodiments of the present invention. For instance, the web


14


may be used to form paper towels, paper napkins, hand wipes, toilet tissues, or the like. The offset print apparatus


10


is not limited to using a particular type of web


14


.




The web


14


moves around an upstream directional roll


32


from which the direction of web


14


is changed. At this point, the web


14


contacts a first circumferential portion


16


of the transfer roll


12


. The web


14


may be moved at speeds of between 500 and 8,000 feet per minute in certain exemplary embodiments of the present invention.




The transfer roll


12


is also provided with a second circumferential portion


20


. The second circumferential portion


20


is located next to a substance delivery system (dispenser)


18


. The substance delivery system


18


shown in

FIG. 1

is an ink jet printer


34


. The ink jet printer


34


is a device commonly known in the art. A print head


36


is present on the ink jet printer


34


and is located proximate to the second circumferential portion


20


of the transfer roll


12


. In certain exemplary embodiments of the present invention, the print head


36


may be heated. The print head


36


may be any type of print head commonly known in the art. For instance, U.S. Pat. Nos. 6,000,787 and 6,084,609 show two typical ink jet print heads that are commonly used in ink jet technology. However, it is to be noted that the ink jet print heads shown in these two references are used for placing ink onto a paper surface and not a substance that modifies the chemical properties of the paper or web as is the case in certain exemplary embodiments in the present disclosure.




The ink jet printer


34


of

FIG. 1

is provided with a positive pressure enclosure


28


. The function of the positive pressure enclosure


28


is to keep the area surrounding the print head


36


and the ink jet printer


34


clean. The positive pressure enclosure is not limited to a particular size or shape. As stated, an amount of dust or lint may build up on the print head


36


during use. It is important to keep the print head


36


along with the ink jet printer


34


free from dust and lint in order to ensure for a long lasting life of these components and for proper functioning of the offset print apparatus


10


. The positive pressure enclosure


28


is provided with an air intake


30


that receives clean air from a blower at a pressurized air source (not shown). This clean air is used in part to prevent the accumulation of dust and lint onto the print head


36


and the ink jet printer


34


, and also to help prevent boundary air


40


(shown in a direct print apparatus


50


in

FIG. 6

) from contacting the print head


36


.




The print head


36


may be configured as shown in

FIG. 3

in one exemplary embodiment of the present invention. Here, a series of orifices


22


are present on the surface of the print head


36


. As used in the art, the orifices


22


are sometimes referred in ink jet technology as being “jets”. A substance


24


that effects the functional properties of the web


14


once placed onto the web


14


is dispensed through the orifices


22


of the print head


36


. The substance


24


is shown in

FIG. 3

as being dispensed through several but not all of the orifices


22


, however it is to be understood that in other exemplary embodiments of the present invention the substance


24


may be dispensed through any number or all of the orifices


22


. In addition, the substance


24


may be dispensed in unequal amounts through different orifices


22


. Any type of configuration of dispensing known in the art is to be covered under the scope of the present invention.




The substance


24


is shown as being in the form of a series of drops. Again, the print head


36


may be modified such that the substance


24


is dispensed in a steady stream or a configuration of drops which takes various shapes. In one exemplary embodiment of the present invention, it may be desired to apply a substance


24


onto the web


14


such that the resulting product has desired hydrophilic properties. The substance


24


may be a material that changes the functional properties of the web


14


or may simply be a material such as ink that marks or writes on the web


14


in other exemplary embodiments. The substance


24


may be a strengthening agent, a softening agent, and/or a debonding agent.




The substance


24


is dispensed in a desired amount from the print head


36


.

FIG. 4

shows the distance between the print head


36


and the transfer roll


12


as being a throw distance


38


. The substance


24


traverses this throw distance


38


either along a substantially straight line or along some other path in order to contact the transfer roll


12


at the second circumferential portion


20


of the transfer roll


12


. Referring back to

FIG. 1

, the transfer roll


12


moves in the direction of arrow B. The substance


24


on the surface of the transfer roll


12


therefore is moved in the direction of arrow B from the second circumferential portion


20


to the first circumferential portion


16


of the transfer roll


12


. At this point, the web


14


contacts the first circumferential portion


16


of the transfer roll


12


such that the substance


24


is transferred to the web


14


. The substance


24


is then applied to the web


14


so that the functional properties of the web


14


is modified to a desired state. The web


14


is then moved over a downstream directional roll


42


and moved to a subsequent manufacturing stage. A backing roll


15


may be present and form a nip with the transfer roll


12


into which the web


14


is drawn. The backing roll


15


may be either independently driven or driven by the transfer roll


12


. The backing roll


15


in some exemplary embodiments aids in the transfer of the substance


24


onto the web


14


.




Ink jet printing technology makes use of throw distances


38


that are usually less than fifteen millimeters and commonly are less than five millimeters. In addition, is also very common to have a throw distance


38


that is between about two and three millimeters. As can be expected, with such small throw distances, dust from the web


14


may buildup on the print head


36


very rapidly due to static effects.





FIG. 2

shows an alternative exemplary embodiment of an offset print apparatus


10


in accordance with the present invention. Here, the offset print apparatus


10


is substantially similar to the one disclosed in FIG.


1


. However, the offset print apparatus


10


shown in

FIG. 2

has a doctor blade


26


being present and contacting the transfer roll


12


. The purpose of doctor blade


26


is to remove any extra substance


24


that remains on the transfer roll


12


after the substance


24


contacts the web


14


. This is done in order to ensure that an even distribution of the substance


24


is attained on the web


14


. If the substance


24


were allowed to remain on the transfer roll


12


, an uneven distribution would occur once the new amount of substance


24


were applied to the transfer roll


12


and moved into contact with the web


14


. In some applications, a doctor blade


26


is not necessary since all of the substance


24


is transferred onto the web


14


. In addition, in other applications it may be desirable to have an uneven distribution of the substance


24


onto the web


14


such that the doctor blade


26


is not needed. Further, the substance


24


may change the color of the web


14


or may print a design or writing onto the web


14


. Additionally, the substance


24


may be an odor control agent that is used to change the odor of web


14


.





FIG. 5

shows a direct print apparatus


50


. The most substantial difference between the direct print apparatus


50


of FIG.


5


and the offset print apparatus


10


of

FIG. 1

is that the print head


36


of the direct print apparatus


50


dispenses the substance


24


directly onto the web


14


. Although a guide roll


13


is shown in

FIG. 5

, the ink jet printer


34


and the print head


36


do not dispense the substance


24


directly onto the guide roll


13


to be later transferred to the web


14


as is the case in the offset print apparatus


10


of FIG.


1


. The direct print apparatus


50


of

FIG. 5

has the moving web


14


being turned around the guide roll


13


. At essentially the same time, substance


24


from the print head


36


is applied to the web


14


.





FIG. 6

shows a detailed view of the direct print apparatus


50


of FIG.


5


. Here, the web


14


is shown being moved around the guide roll


13


with the print head


36


being proximate to the guide roll


13


. The web


14


is made of material that when moved creates a layer of boundary air


40


proximate to the web


14


. Typically, the moving web


14


will create a layer of boundary air that is approximately one-half inch to one inch away from the surface of the web


14


. The layer of boundary air


40


is laden with dust and other particles that make up the web


14


. Additionally, other particles may also be present in the boundary air


40


that are not part of the web


14


. The boundary air


40


is a turbulent flow that has a significant amount of dust contained therein. As can be seen in

FIG. 6

, the print head


36


is located inside of the boundary air


40


. The print head


36


therefore acts to disrupt the turbulent airflow of the boundary air


40


and create an even greater agitation of dust and other particles at the print head


36


and the area between the print head


36


and the guide roll


13


.





FIG. 7

shows the direct print apparatus


50


as the web


14


begins moving from an at rest position. The substance


24


is shown being dispensed from an orifice


22


of the print head


36


. The web


14


contacts the guide roll


13


on one end and on the other end is applied with the substance


24


from the print head


36


. The web


14


is moving in the direction of arrow A as indicated in FIG.


7


. As can be seen, once the web


14


begins moving, immediately afterwards the dispensing of the substance


24


is normal since there is no dust buildup on the print head


36


.





FIG. 8

shows the direct print apparatus


50


of

FIG. 7

after some period of time has elapsed between the starting of the web


14


shown in FIG.


7


. Here, an amount of dust


52


has accumulated on the print head


36


. This dust


52


is also present within the orifice


22


from which the substance


24


is dispensed. The dust


52


interferes with the dispensing of the substance


24


such that the substance


24


is not evenly dispensed on the web


14


. An uneven distribution of the substance


24


on the web


14


is undesirable in some applications because the resulting product will have inconsistent properties throughout.




Again, the accumulation of dust


52


onto the print head


36


is undesirable in that it impedes the proper functioning of the dispensing of the substance


24


from the print head


36


. In some cases, the dust


52


may completely clog or jam the orifices


22


, shown in

FIG. 3

, and prevent any of the substance


24


from being dispensed. In other instances, the dust


52


may impede the flow of the substance


24


such that satellite drops of the substance


24


are formed. These satellite drops are smaller drops which have been removed from the main drop of the substance


24


. Also, these satellite drops may be so small and have a smaller weight such that they are swept away by the fast moving boundary air


40


. Such a result is undesirable in that the satellite drops will be blown to an unknown location either on the web


14


or off of the web


14


. In such circumstances, the application of the substance


24


onto the web


14


cannot be controlled or predicted with any regularity.




In the offset print apparatus


10


of

FIG. 1

, the print head


36


does not have dust or lint accumulation as does the direct print apparatus


50


because the air between the print head


36


and the transfer roll


12


in the area of the second circumferential portion


20


of the transfer roll


12


is not laden with dust. As can be seen in

FIG. 1

, the web


14


moves some distance away from the print head


36


and the offset print apparatus


10


. A boundary air


40


(shown in

FIG. 6

) will be present next to the web


14


in the offset print apparatus


10


, however the boundary air


40


does not come into close proximity with the print head


36


. Dust or other particles from the boundary air


40


may be transferred upwards due to the rotating motion of the transfer roll


12


, however, this type of dust transfer from the web


14


to the print head


36


is minimal as compared to that displayed in the direct print apparatus


50


. By use of an offset print apparatus


10


, the boundary air


40


that contains lint and dust


52


will be prevented from contacting the surface of the transfer roll


12


proximate to the print head


36


. The print head


36


may then be positioned next to the transfer roll


12


such that a small throw distance


38


is present. By making use of a small throw distance


38


, the concerns with the boundary air


40


issues are minimized and/or eliminated. In addition, the doctor blade


26


as shown in

FIG. 2

may also be used to prevent dust from being transferred from the web


14


to the print head


36


. As stated, the doctor blade


26


may also be provided for the function of removing any excess substance


24


from the transfer roll


12


.




The offset print apparatus


10


may therefore have a print head


36


that is located very close to the transfer roll


12


. Having such a short throw distance


38


provides for a better resolution of the substance


24


dispensed onto the transfer roll


12


. Less overlapping will therefore occur with the offset print apparatus


10


. In addition, the speed of the web


14


and the transfer process of the substance


24


onto the web


14


can be maximized. The web


14


may be run at a speed of between about 500 and 8,000 feet per minute with the use of an offset print apparatus


10


even if a significant boundary air


40


with dust


52


is present. However, the present invention is not limited to a particular speed of the web


14


. For instance, in other exemplary embodiments the speed of the web


14


may be less than 500 feet per minute and/or greater than 8,000 feet per minute.




The present invention also encompasses an exemplary embodiment of an offset print apparatus


10


in which the substance


24


used is a wax chemistry. In such an instance, the print head


36


is typically heated such that the wax chemistry substance


24


does not solidify on the transfer roll


12


. A heated transfer roll


12


is incorporated in order to prevent the solidification of the wax chemistry substance


24


. Alternatively, a heated transfer roll


12


may be used when the substance


24


is a viscous liquid in order to keep the viscosity low enough for an optimal transfer to the web


14


. A heated transfer roll


12


is also advantageous in helping to reduce cooling problems that are associated with printing at high speeds. When the transfer roll


12


revolves at a high rate, air will be blown across the print head


36


such that the print head


36


is cooled which could cause the evaporation of, or an increase in, the evaporation rate of the substance


24


located in the print head


36


or could make the substance


24


inside of the print head


36


more viscous. Additionally, the surface of the transfer roll


12


can become cooled due to a faster movement of air around the transfer roll


12


. In all of such instances, a heated transfer roll


12


can help to reduce the cooling effect of the rotating transfer roll


12


and increase the efficiency of the transfer between the substance


24


and the web


14


and maintain consistent properties of the substance


24


.





FIG. 9

shows another exemplary embodiment of the present invention. Here, a second transfer roll


160


is positioned proximate to the transfer roll


12


in order to form a nip


106


into which the web


14


may be drawn. A second dispenser


104


(shown as a print head) is present and located a second throw distance


102


from the second transfer roll


100


. The second throw distance


102


may or may not be the same distance as the throw distance


38


. Additionally, the second transfer roll


100


may or may not be of the same size, or have the same surface configuration as the transfer roll


12


. The second print head


104


may apply the substance


24


onto the second transfer roll


100


along the same lines as discussed above in regards to the transfer roll


12


and the print head


36


.




The second transfer roll


100


may be rotated in a direction opposite to the transfer roll


12


, causing the substance


24


to be applied to the web


14


at a location at or proximate to the nip


106


. The application of the substance


24


by the second transfer roll


100


is on an opposite side of the web


14


than that applied by the transfer roll


12


. As such, the arrangement in

FIG. 9

allows for application of the substance


12


on both sides of the web


14


. Such an application may provide for desired changes in the functional properties of the web


14


. In other exemplary embodiments, the direct print apparatus


50


may be used along with the offset print apparatus


10


to obtain a desired application. The substance


24


applied onto either side of the web


14


may or may not be the same substance


24


and may or may not be applied in the same amount. As used in the claims, the word “substance” may be the same or different substance


24


when applied on either side of the web


14


.




In one exemplary embodiment of the present invention, the substance


24


is a lotion. The lotion can be water-based or oil-based. Suitable water based compositions include, but are not limited to, emulsions and water-dispersible compositions which can contain, for example, debonders (cationic, anionic or nonionic surfactants), or polyhdroxy compounds such as glycerin or propylene glycol. The web


14


could be treated with a bi-component system comprising a debonder and a polyhydroxy compound. Both components can be added separately or mixed together prior to being applied to the web


14


.




Oil-based compositions can include combinations of oil and wax. In particular embodiments, the products into which the web


14


is formed are made by applying, on the surface(s) of the web


14


, large numbers of individual deposits of a melted moisturizing/protective additive composition comprising a wax and an oil, and thereafter resolidifying the composition to form a distribution, of solid deposits on the surface(s) of the web


14


. Because the composition is a solid or a semi-solid at room temperature and rapidly solidifies after deposition, it has less tendency to penetrate and migrate into the sheet. Compared to products treated with liquid formulations, this leaves a greater percentage of the lotion on the surface of the web


14


where it can contact and/or transfer to the user's skin to provide a benefit. Thus, a lower add-on amount can be used to deliver the same benefit at lower cost because of the efficient placement of the composition substantially at the surface of the product.




The lotion may comprise solidified deposits of a composition comprising from about 30 to about 90 weight percent oil, and from about 10 to about 40 weight percent wax, preferably also containing from about 5 to about 40 weight percent fatty alcohol. The composition can have a melting point of from about 30° C. to about 70° C. For purposes herein, “melting point” is the temperature at which the majority of the melting occurs, it being recognized that melting actually occurs over a range of temperatures.




The amount of oil in the composition can be from about 30 to about 90 weight percent. Suitable oils include, but are not limited to, the following classes of oils: petroleum or mineral oils, such as mineral oil and petrolatum; animal oils, such as mink oil and lanolin oil; plant oils, such as aloe extract, sunflower oil and avocado oil; and silicone oils, silicone fluids, or silicone emulsions. For example, dimethicone and alkyl methyl silicones could be used.




The amount of wax in the composition can be from about 10 to about 60 weight percent. Suitable waxes include, but are not limited to the following classes: natural waxes, such as beeswax and carnauba wax; petroleum waxes, such as paraffin and ceresine wax; silicone waxes, such as alkyl methyl siloxanes; or synthetic waxes, such as synthetic beeswax and synthetic sperm wax.




The amount of fatty alcohol in the composition, if present, can be from about 5 to about 40 weight percent. Suitable fatty alcohols include alcohols having a carbon chain length of C


14


-C


30


, including acetyl alcohol, stearyl alcohol, behenyl alcohol, and dodecyl alcohol.




It should be understood that the web


14


may be any type of web known in the art, and the present invention encompasses all such types of webs. For instance, the web


14


may be a woven web in one exemplary embodiment of the present invention, and may be a non-woven web in another exemplary embodiment.




It should be understood that the present invention includes other various modifications that can be made to embodiments of the offset print apparatus


10


as described herein as come within the scope of the appended claims and their equivalents.



Claims
  • 1. An offset print apparatus for applying a substance to a moving web, comprising:a transfer roll capable of being rotated; a moving web in contact with a first circumferential portion of said transfer roll, said moving web moving over or under said transfer roll and staying in contact with said first circumferential portion of said transfer roll while moving over or under said transfer roll; a dispenser located proximate to a second circumferential portion of said transfer roll, said dispenser having at least one orifice; a substance being dispensed from said dispenser through said at least one orifice and onto said transfer roll without having said dispenser contact said transfer roll, said transfer roll rotating said substance into engagement with said moving web such that at least a portion of said substance is applied to said moving web; and a positive pressure enclosure in fluid communication with said dispenser such that said positive pressure enclosure communicates clean air to said dispenser in order to aid in preventing build-up of dust on said dispenser.
  • 2. The offset print apparatus of claim 1, wherein said substance is applied to effect the functional properties of said web.
  • 3. The offset print apparatus of claim 1, wherein said substance is selected from the group consisting of strength agents, softening agents, and debonding agents.
  • 4. The offset print apparatus of claim 1, wherein said transfer roll is a vacuum roll.
  • 5. The offset print apparatus of claim 1, wherein:said substance is a room temperature solid or semi-solid; and said transfer roll is heated.
  • 6. The offset print apparatus of claim 1, wherein said transfer roll is a heated transfer roll.
  • 7. The offset print apparatus of claim 1, wherein said dispenser is an ink jet printing apparatus.
  • 8. The offset print apparatus of claim 1, further comprising a doctor blade located proximate to said transfer roll, said doctor blade removing any of said substance remaining on said transfer roll after engagement of said substance with said moving web such that said doctor blade is capable of removing excess substance.
  • 9. The offset print apparatus of claim 1, wherein said moving web is moving at a speed of between about 500 feet per minute and about 3,000 feet per minute.
  • 10. An offset print apparatus for applying a substance to a moving web, comprising:a transfer roll capable of being rotated; a moving web in contact with a first circumferential portion of said transfer roll, said moving web moving over or under said transfer roll and staving in contact with said first circumferential portion of said transfer roll while moving over or under said transfer roll; a dispenser located proximate to a second circumferential portion of said transfer roll, said dispenser having at least one orifice; a substance being dispensed from said dispenser through said at least one orifice and onto said transfer roll without having said dispenser contact said transfer roll, said transfer roll rotating said substance into engagement with said moving web such that at least a portion of said substance is applied to said moving web; and wherein said moving web is moving at a speed of between about 3,000 feet per minute and about 5,000 feet per minute.
  • 11. An offset print apparatus for applying a substance to a moving web, comprising:a transfer roll capable of being rotated; a moving web in contact with a first circumferential portion of said transfer roll, said moving web moving over or under said transfer roll and staving in contact with said first circumferential portion of said transfer roll while moving over or under said transfer roll; a dispenser located proximate to a second circumferential portion of said transfer roll, said dispenser having at least one orifice; a substance being dispensed from said dispenser through said at least one orifice and onto said transfer roll without having said dispenser contact said transfer roll, said transfer roll rotating said substance into engagement with said moving web such that at least a portion of said substance is applied to said moving web; and wherein said moving web is moving at a speed of between about 5,000 feet per minute and about 8,000 feet per minute.
  • 12. The offset print apparatus of claim 10, wherein said moving web is a tissue web.
  • 13. The offset print apparatus of claim 1, further comprising a backing roll engaging said moving web and forming a nip with said transfer roll.
  • 14. An offset print apparatus for applying a substance to a moving web, comprising:a transfer roll capable of being rotated; a moving web in contact with a first circumferential portion of said transfer roll, said moving web moving over or under said transfer roll and staying in contact with said first circumferential portion of said transfer roll while moving over or under said transfer roll; a dispenser located proximate to a second circumferential portion of said transfer roll, said dispenser having at least one orifice; a substance being dispensed from said dispenser through said at least one orifice and onto said transfer roll without having said dispenser contact said transfer roll, said transfer roll rotating said substance into engagement with said moving web such that at least a portion of said substance is applied to said moving web; and an upstream directional roll located upstream of said transfer roll.
  • 15. The offset print apparatus of claim 1, further comprising:a second transfer roll located on an opposite side of said moving web than said transfer roll, said moving web in contact with a first circumferential portion of said second transfer roll, said moving web moving over or under said second transfer roll and staying in contact with said first circumferential portion of said second transfer roll while moving over or under said second transfer roll; a second dispenser located proximate to a second circumferential portion of said second transfer roll, said second dispenser having at least one orifice; and said substance being dispensed from said second dispenser through said at least one orifice and onto said second transfer roll without having said second dispenser contact said second transfer roll, said second transfer roll rotating said substance into engagement with said moving web such that at least a portion of said substance is applied to said moving web on an opposite side of said moving web than that applied by said transfer roll.
  • 16. The offset print apparatus of claim 15, wherein said transfer roll and said second transfer roll form a nip into which said moving web is drawn.
  • 17. The offset print apparatus of claim 1, wherein the distance between an exit of said at least one said orifice and said second circumferential portion of said transfer roll is less than about twenty millimeters.
  • 18. The offset print apparatus of claim 1, wherein said substance is applied to both sides of said web.
  • 19. The offset print apparatus of claim 1, wherein said substance changes the color of said web.
  • 20. The offset print apparatus of claim 1, wherein said substance causes a design to be printed onto said web.
  • 21. The offset print apparatus of claim 1, wherein said substance comprises an odor control agent.
  • 22. The offset print apparatus of claim 1, wherein said substance comprises at least in part water.
  • 23. An offset print apparatus for applying a substance to a web, comprising:a transfer roll capable of being rotated; an ink jet printer having a print head located proximate to said transfer roll, said print head having a plurality of orifices from which the substance is dispensed onto said transfer roll, the throw distance between the surface of said print head and said transfer roll; a web contacting said transfer roll such that the substance dispersed onto said transfer roll is transferred to said web through contact of said transfer roll and said web, said web having an amount of boundary air formed proximate to said web when said web is moving, wherein said print head of said ink jet printer is not in contact with boundary air; and wherein said web is being moved at speeds between 1000 feet per minute and less than 3,000 fee per minute.
  • 24. The offset print apparatus of claim 23, wherein said throw distance is between about two and about twenty millimeters.
  • 25. An offset print apparatus for applying a substance to a web, comprising:a transfer roll capable of being rotated; an ink jet printer having a print head located proximate to said transfer roll, said print head having a plurality of orifices from which the substance is dispensed onto said transfer roll, the throw distance between the surface of said print head and said transfer roll; a web contacting said transfer roll such that the substance dispersed onto said transfer roll is transferred to said web through contact of said transfer roll and said web, said web having an amount of boundary air formed proximate to said web when said web is moving, wherein said print head of said ink jet printer is not in contact with boundary air; wherein said throw distance is between about two and about twenty millimeters; and wherein said web is being moved at speeds of between about 5,000 feet per minute and about 8,000 feet per minute.
  • 26. An offset print apparatus for applying a substance to a web, comprising:a transfer roll capable of being rotated; an ink jet printer having a print head located proximate to said transfer roll, said print head having a plurality of orifices from which the substance is dispensed onto said transfer roll, the throw distance between the surface of said print head and said transfer roll; a web contacting said transfer roll such that the substance dispersed onto said transfer roll is transferred to said web through contact of said transfer roll and said web, said web having an amount of boundary air formed proximate to said web when said web is moving, wherein said print head of said ink jet printer is not in contact with boundary air; wherein said throw distance is between about two and about twenty millimeters; and wherein said web is being moved at speeds of between about 3,000 feet per minute and about 5,000 feet per minute.
  • 27. The offset print apparatus of claim 23, wherein said print head of said ink jet printer is heated.
  • 28. The offset print apparatus of claim 23, wherein said transfer roll is a heated transfer roll.
  • 29. The offset print apparatus of claim 23, wherein said transfer roll is a vacuum roll.
  • 30. The offset print apparatus of claim 23, further comprising:a second transfer roll capable of being rotated; a second ink jet printer having a second print head located proximate to said second transfer roll, said second print head having a plurality of orifices from which the substance is dispensed onto said second transfer roll, the distance between the surface of said second print head and said second transfer roll being defined as a throw distance; said web contacting said second transfer roll such that the substance dispensed onto said second transfer roll is transferred to said web through contact of said second transfer roll and said web on an opposite side of said web than the substance applied by said transfer roll; and wherein said second print head is not in contact with boundary air.
  • 31. The offset print apparatus of claim 23, further comprising a doctor blade located proximate to said transfer roll, said doctor blade capable of removing any of the substance remaining on said transfer roll after engagement of the substance with said web.
  • 32. The offset print apparatus of claim 23, further comprising a positive pressure enclosure located over said ink jet printer.
  • 33. An offset print apparatus for applying a substance to a web, comprising:a transfer roll capable of being rotated; an ink jet printer having a print head located proximate to said transfer roll, said print head having a plurality of orifices from which the substance is dispensed onto said transfer roll, the throw distance between the surface of said print head and said transfer roll; a web contacting said transfer roll such that the substance dispersed onto said transfer roll is transferred to said web through contact of said transfer roll and said web, said web having an amount of boundary air formed proximate to said web when said web is moving, wherein said print head of said ink jet printer is not in contact with boundary air; a downstream directional roll located downstream of said transfer roll; and an upstream directional roll located upstream of said transfer roll.
  • 34. The offset print apparatus of claim 23, wherein said throw distance is between about one millimeter and about twenty millimeters.
  • 35. An offset print apparatus for applying a substance to a moving web, comprising:a rotating transfer roll; a moving web in contact with a first circumferential portion of said transfer roll, said moving web moving over or under said transfer roll and staying in contact with said first circumferential portion of said transfer roll while moving over or under said transfer roll; an ink jet printer having a print head located proximate to a second circumferential portion of said transfer roll, said print head having a plurality of orifices from which a substance is dispensed onto said second circumferential portion of said transfer roll, the throw distance between said print head and said second circumferential portion is less than about twenty millimeters in length; and a substance being dispensed from said print head and onto said second circumferential portion of said transfer roll, rotation of said transfer roll moving said substance into contact with said moving web and transferring said substance onto said moving web; wherein movement of said web creates an amount of dust laden boundary air proximate to said moving web, said print head being spaced away from and not in contact with the boundary air formed by said moving web; and a positive pressure enclosure in fluid communication with said ink jet printer such that said positive pressure enclosure communicates clean air to said print head in order to aid in preventing build-up of dust on said print head.
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Number Name Date Kind
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5209953 Grupe et al. May 1993 A
5353105 Gundlach et al. Oct 1994 A
5471233 Okamoto et al. Nov 1995 A
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6000787 Weber et al. Dec 1999 A
6084609 Manini et al. Jul 2000 A
6257138 Bialek Jul 2001 B1
6557979 Ohsawa et al. May 2003 B2
Non-Patent Literature Citations (1)
Entry
KCX-119 Application entitled Modified Siloxane Yielding Transferring Benefits from Soft Tissue Paper; Dale A. Burghardt et al. Application No. 09/742,666.