Patent Application
20150101740
The invention disclosed herein relates to methods, ink formulations, systems and apparatuses for using an offset printing press in combination with a high-speed corrugation machine.
Printed corrugated paperboard is a popular packing material for a wide variety of products. Corrugated paperboard typically comprises a corrugated or fluted medium and a linerboard laminated to one or both sides of the fluted medium. One or both of the linerboards can be printed to provide a decorative appearance to the final product, which is important in consumer-facing boxes made from corrugated paperboard.
As a result, methods of rapidly producing corrugated paperboard have been developed using the application of heat. For example, heat can be applied to the medium in order to allow the corrugation processes to run efficiently at higher speeds and to activate the starch-based adhesive used to adhere the layers together. The printed linerboards are then laminated to the fluted medium. Due to the heat used in the high speed corrugation process, care must be taken to ensure the ink on the printed linerboard is sufficiently dried and/or cured. If the ink is not sufficiently dried or cured, or if the ink is of improper formulation, the heat involved in high-speed corrugation may cause the ink to breakdown or smear, degrading the quality of the print.
Flexographic printing processes are generally used to print the linerboard for high speed corrugation applications. The relatively low viscosity ink used for flexographic printing allows the ink, and any applied coatings, the necessary time to dry and/or cure in a time frame appropriate for high speed corrugation applications. However, flexographic printing can be expensive and is usually considered to have inferior quality as compared to offset printing.
Offset, or lithographic, printing is known to be an efficient printing process in commercial applications, such as printing newspapers and books. However, offset printing has proven to be ineffective in high-speed continuous web corrugation applications where the linerboard is fed to the fluted medium. Offset printing requires a higher viscosity ink than flexographic printing, and therefore the ink and any applied coatings require longer drying times. Also, the repeat length of offset printing presses is often set and unchangeable. Thus, printing boxes of different sizes using web-fed offset printing process can be quite complicated. For printing operations where the same repeat length is used for long runs, such as paperboard for cereal boxes, this is less of an issue. However, for small print runs where color corrugated boxes are used for discrete or custom consumer uses, or low volume products, it would be advantageous to provide for high-speed, yet variable length printing processes and apparatus.
Therefore, there is a need in the art for methods, systems, and apparatus for offset printing processes for high-speed web-fed corrugation applications.
The present invention provides methods, systems, and apparatus for providing high quality printed corrugated webs, boxes, and the like. In various embodiments, a variable repeat length offset press is used to print a high quality printed linerboard. A coating and curing process may be performed to prevent degradation of the ink used to print the printed linerboard. The printed linerboard may be provided via a roll to a corrugation system, such as a high speed corrugation system. The printed linerboard may be bonded onto a fluted medium, a fluted medium on the open side of a single-faced web, and/or the like, resulting in a high quality printed corrugated web. The web may then be cut into box blanks or corrugated sheets and/or converted into high quality printed corrugated boxes.
According to one aspect of the present invention, a method for producing high quality printed corrugated boxes is provided. In various embodiments, the method comprises printing a linerboard web to provide ink to the linerboard web and in particular comprises using an offset printing press having a variable repeat length. The method may further comprise: rewinding the printed linerboard web onto a roll; providing the printed linerboard web to a high speed corrugation machine via the roll; laminating the printed linerboard web to a fluted medium web thereby producing a printed corrugated web. The method may further comprise applying heat to at least one of the printed linerboard web and the fluted medium which causes heating of the ink on the linerboard web printed thereon by the offset printed press.
According to another aspect of the present invention, an apparatus for producing high quality printed corrugated boxes is provided. In various embodiments, the apparatus may comprise a printing press component configured to provide ink to a linerboard web, thereby producing a printed linerboard web. The printing press component may be an offset printing press having a variable repeat length. The apparatus may further comprise: a winding component configured to wind the printed linerboard web onto a roll; an infeeding component configured to feed the printed linerboard web from the roll into a high speed corrugation component; and a laminating component configured to laminate the printed linerboard web onto a fluted medium, thereby producing a printed corrugated web. At least one of the high speed corrugation component and the laminating component are further configured to apply heat to at least one of the printed linerboard web and the fluted medium which causes heating of the ink on the linerboard web printed thereon by the printing press component.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
The present invention provides systems, apparatus, and methods for producing high quality printed corrugated boxes. An offset printing system is used to provide a high quality printed linerboard web. In various embodiments, the offset printing system may comprise a variable sleeve offset press and may rewind the printed linerboard web onto a roll such that the linerboard web may be provided to a corrugation system via the roll. Providing the linerboard web to the corrugation system via a roll simplifies the time-synchronization issues provided by the speed difference between the offset printing system and the corrugation system if the offset printing system and the corrugation system were run together inline. In various embodiments, the corrugation system may be configured to provide a fluted medium and laminate (e.g., glue, paste, and/or otherwise attach) the fluted medium to at least one linerboard web providing a high quality printed single-faced or double-faced corrugated web. In various embodiments, the corrugation system may comprise a high speed corrugator. Various embodiments of the invention are described below. The embodiments described herein are provided as non-limiting, illustrative examples.
Various embodiments of the present invention comprise an offset printing system 100.
In the example embodiment illustrated in
The ink may be dried or cured onto the printed front linerboard web B in a variety of ways depending on the formulation of the ink to be used by the offset press 120. In some embodiments, the offset printing system 100 may be configured to allow the ink to dry via absorption and/or evaporation, by providing sufficient time in acceptable conditions. In various embodiments, the offset printing system 100 may comprise a curing component 130 to assist in the setting of the ink. In various embodiments, the curing component 130 may dry the ink used by the offset press 120 to print the front linerboard web B. In some embodiments, curing component 130 may aid the evaporation and/or absorption of the ink from and/or into the front linerboard web B. In other embodiments, curing component 130 may be configured to heat cure, UV cure the ink, or cure the ink by some other mechanism.
In various embodiments, the offset printing system 100 may further comprise one or more coating applicator components 160. In such embodiments, the coating applicator component 160 is configured to apply a coating to the printed front linerboard web B. In some embodiments, the applied coating may be configured to protect the ink from degradation or smearing due to the heat used in high-speed corrugation applications. In other embodiments, the applied coating may be configured to protect the printed linerboard of the finished box from visible wear. In some embodiments, the applied coating may be configured to provide the printed front linerboard web B with a semi-gloss, gloss, high gloss, or other finish. In the illustrated embodiment of
In embodiments of the offset printing system 100 comprising coating applicator components 160, the offset printing system 100 may further comprise coating drying components 140 and 150. In such embodiments, the coating drying components 140 and 150 may be configured to dry the coatings. In other such embodiments, the coating drying components 140 and 150 may be configured to cure the coating via heat curing, UV curing, or some other curing mechanism. In some embodiments, ink curing component 130 and coating drying components 140 and 150 may be implemented as a single component located downstream from the coating applicator component 160. Some embodiments of the offset printing system 100 may not comprise a coating drying component 140/150
In various embodiments, such as the embodiment illustrated in
In various embodiments, a corrugation system may be configured to bond or laminate a printed linerboard B onto a fluted medium or the fluted medium on the open side of a single face web, and/or the like. The corrugation system may be configured to corrugate a medium web, thereby producing the fluted medium. In various such embodiments, the corrugation system 200 may comprise a high-speed corrugator, as is generally known in the art. The embodiment of a corrugation system 200 illustrated in
As noted, A linerboard web C is fed into the corrugation system 200 off of one or more rolls loaded onto unwinding stand 211. The linerboard web C is run over pre-heater roller 212 before being fed into the single-facing component 225. The pre-heater roller 212 may be configured to supply heat to the linerboard web C as appropriate for the application. The single-facing component 225 then laminates the linerboard web C to the fluted medium D, as is generally known in the art, thereby producing a single-faced web F. In various embodiments, such as that illustrated in
Once the single-faced corrugated web F is sufficiently dry, cured, and/or cool, the single-faced corrugated web F may be fed into the double-facing component 260 via pre-heater roller 262. The pre-heater roller 262 may be configured to supply heat to the single-faced web F, as appropriate for the application. The single-faced web F may then be fed through the double-backer glue machine 264 where adhesive may be applied to the exposed flute tips.
In various embodiments, as the single-faced web F is fed into the double-facing component 260, the printed front linerboard web B, which was printed by the offset printing system 100, may be fed into the corrugation system 200 from one or more rolls loaded onto roll stand 250 via printed front linerboard web infeeding component 251. Particularly, the front linerboard web B may be fed into the double-facing component 260 via a pre-heater roller 262. The pre-heater roller 262 may be configured to supply heat to the printed linerboard web B as appropriate for the application. The printed linerboard web B may then pass through the double-backer glue machine 264. In some embodiments, the double-backer glue machine 264 is configured to apply an adhesive to both the single-faced web F and the printed linerboard web B. In other embodiments, the adhesive is applied to only one of the single-faced web F and the printed linerboard web B. In various embodiments, the adhesive is a starch adhesive. The single-faced web F and the printed linerboard web B are brought into contact with each other by nip roller 266 such that the exposed flute tips of the fluted medium are in contact with the non-printed side of the printed linerboard web B.
The combined single-faced web F and printed linerboard web B are passed over hot plate section 268. The applied heat activates an adhesive, such as a starch-based adhesive, that is applied to the fluted medium. The temperature, which may be as high as 350° F., turns the adhesive into a gel consistency. The hot plate section 268 may be further configured to cure the adhesive. Thus, as the combined single-faced web F and printed linerboard web B pass over hot plate section 268, the adhesive laminates the single-faced web F to the printed linerboard web B, thereby producing a combined board web G.
As may be appreciated from the embodiment illustrated in
In various embodiments, the combined board web G is fed downstream from the hot plate section 268 to a cutting component 270. The cutting component 270 may comprise one or more rotary shears, one or more slitters, one or more scorers, one or more knife cylinders, and/or the like. The cutting component 270 may be configured to slit, score, and/or cut the combined board web G into web portions such as individual boxes, sets of boxes, and/or the like as appropriate for the application. In various embodiments, the cutting component 270 may be configured to slit, score, and/or cut the combined board web G across the width of the web and/or in the direction of advancement of the web. For example, the slitter/scorer component 271 may be configured to slit and/or cut the combined board web G in the direction of the advancement of the web. The slitter/scorer component 271 may be further configured to score the combined board web G to facilitate later folding. Cross cutting component 272 may be configured to cut the combined board web G in a direction transverse to the advancement direction of the web, thereby producing sheets of combined board. Additionally, stacking component 273 may be configured to stack the sheets of combined board. Thus, in various embodiments, the cutting component 270 may be configured to slit, score, and/or cut the combined board web G into individual box blanks that are then stacked by the stacking component 273. In various embodiments, the sheets of combined board G may be fed downstream to a converting component 280 that may receive the individual box blanks and fold them into individual boxes.
In various embodiments, the corrugation system may be configured to provide printed single-faced, double-walled, or triple-walled webs, corrugated sheets, box blanks, and/or boxes. In some embodiments, the interior of the resulting box may also be printed. In order to provide a printed single-faced web, the linerboard C is replaced by printed linerboard B and the second linerboard is omitted. In some embodiments, the single-faced web may be cut into lengthy strips that may be folded onto themselves in an accordion-like manner and stacked onto a pallet or the like, rather than being cut into corrugated sheets, box blanks, or converted into boxes. To provide double-walled corrugated sheets, box blanks, and/or boxes, an additional single-facing component may be added to the corrugation system illustrated in
At step 310 an offset printing system comprising an offset press is used to print the front linerboard web B. In various embodiments, the offset press may be a variable sleeve offset press. In various embodiments, the offset press may use cold set ink, heat cured ink, UV cured ink, or some other acceptable ink. The ink may be configured to not break down or smear from the heat used in the high-speed corrugation process.
At step 320 an offset printing system 100 or other system may apply a coating to the printed front linerboard web B. In various embodiments, the coating may be formulated to protect the ink used to print the front linerboard web B from degradation or smearing during the high-speed corrugation process. In other embodiments, the coating may be configured to protect the printed linerboard of the finished box from mechanical damage, such as scratching or wear. In some embodiments the coating may be used to apply a semi-gloss, gloss, high gloss, or other finish to the printed linerboard.
At step 330 the ink and/or coating are dried. In various embodiments, the step of drying the ink or coating may comprise heat curing or UV curing the ink and/or coating. In some embodiments, the ink may dry or be cured before the coating is applied.
At step 340 the printed front linerboard web B is rewound onto a roll or the like. The front linerboard web B may then be supplied to a corrugation system 200 via the roll or the like, at step 350. By providing the front linerboard web B to the corrugation system 200 via a roll or the like, the time synchronization complications caused by the difference in speed between the offset printing system 100 and the corrugation system 200 may be circumvented. The time synchronization of the offset printing system 100 and the corrugation system 200 is particularly complicated when the offset printing system 100 comprises a variable sleeve offset press due to the variable repeat length of the pattern printed by the variable sleeve offset press.
At step 360 the corrugation system 200 laminates the printed front linerboard web B onto a fluted medium D, producing a printed corrugated web (e.g., combined board G). The printed corrugated web may then be cut and scored to create box blanks.
Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
