Patent Application
20160288558
There are a variety of methods for commercial high speed printing to produce large quantities of print material, such as books, magazines, newsprints, and brochures. In the past, traditional analog printers, such as web fed offset and gravure contact printers, were the most common type of printers for such commercial applications. In recent years, digital web fed high speed inkjet non-contact printers have become more prevalent due to 100% variable print content and multi-color printing at a relatively low cost to consumers.
While paper media typically used for more traditional analog printers can perform somewhat acceptably on high speed web fed inkjet (non-contact) printing devices, such paper media are subject to problems relating to one or more of cockle, curl, wrinkle, crease, and misregistration and other similar problems, which can detrimentally impact productivity, product quality, and cost. For example, inkjet printing has a much higher moisture level than offset and gravure printing due to the colored pigments of the inkjet ink being applied to the paper media using a generally water based liquid vehicle, which will cause non-uniform hygro-expansion that appears to be related to cockle/waviness and misregistration issues. Cockle refers to a small scale expansion in paper fiber width when wetted with water, for example from water-based inkjet inks.
As such, research and development of media continue to be sought.
Additional features and advantages of the disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the technology; and, wherein:
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the technology is thereby intended.
In accordance with examples of the present disclosure, light weight media sheets having a flatness control layer coated thereon can overcome problems of curl or cockling found in high speed printing applications, e.g. Hewlett Packard Web Press Printing. Notably, utilizing a flatness control layer interposed between a substrate and ink-receiving layer can provide recording media having improved flatness.
Examples in accordance with the technology described herein are directed to a media that is more useful in digital high speed inkjet web press printing. The media can be a light weight, coated, paper-based media in that the media comprises a paper base and a coating on one or both surfaces of the paper base that facilitates image formation on the media. The media according to the technology herein exhibits improved runnability during printing and finishing and improved flatness of final output.
The use of the flatness control layer that increases the water holding time of the media can prevent or minimize the migration of water and/or solvents into the substrate. As such, the water and/or other solvents from printed inks (and their respective ink vehicles) reside closer to the surface of the media, and therefore, can more effectively evaporate during printing and subsequent processing.
Generally, recording media can have a variety of layers including extruded layers, curl control layers, barrier layers, imaging layers, etc., and such layers often use costly additives to provide acceptable media sheets for printing. However, utilizing a flatness control layer interposed between a paper substrate and ink-receiving layer as described herein can eliminate the need for some layers, can eliminate costly additives, and/or can eliminate the amounts of materials needed in the media sheet.
With the above in mind, a light weight media sheer for high speed printing can comprise a paper substrate having a basis weight of less than 100 gram per square meter (gsm). The media can also include a first flatness control layer applied directly to a first side of the paper substrate, the flatness control layer having a coating weight from 1 to 15 gsm, wherein the first flatness control layer comprises a polymer selected from the group of a polyvinyl alcohol, a polyamide, a polyimide, a polyethylene oxide, a polyvinyl pyrrolidone, a cellulose, a starch, an acrylate, copolymers thereof, and mixtures thereof. Additionally, the light weight media sheet can also include a first ink-receiving layer applied directly to the first flatness control layer, the first ink-receiving layer having a coating weight from 1 to 40 gsm. Generally, the light weight media sheet can have a total basis weight from 40 to 150 gsm.
In one example, the media sheet can further comprise a second flatness control layer applied directly to a second side of the paper substrate, and can have a coating weight from 1 to 15 gsm. In one aspect, the media sheet can further comprise a second ink-receiving layer applied directly to the second flatness control layer, and can have a coating weight from 1 to 40 gsm. Notably, such layers can be the same or different including having the same materials, different materials, the same amounts of the same materials, different amounts of the same materials, etc. In one example, the first flatness control layer can contain the same components as the second flatness control layer. In another example, the first ink-receiving layer can contain the same components as the second ink-receiving layer.
Generally, as mentioned, the present media sheets have one or more flatness control layer. In one example, the flatness control layer can comprise a polymer including a polyvinyl alcohol (e.g., polyvinyl alcohol, a polyvinyl alcohol copolymer, a cationic polyvinyl alcohol, a polyvinyl alcohol-polyethylene oxide copolymer, a modified polyvinyl alcohol); a polyamide (e.g., a polyamide copolymer or homopolymer); a polyimide (e.g., polyimide copolymer or homopolymer); a polyethylene oxide (e.g., a polyethylene oxide copolymer or homopolymer); a polyvinyl pyrrolidone (e.g., a polyvinylpolypyrrolidone copolymer or homopolymer); a cellulose (e.g., cellulose or modified cellulose); a starch (e.g., cationic starch); an acrylate (e.g., acrylate copolymer or homopolymer); etc. In one aspect, the polymer can be a polyvinyl alcohol. In another aspect, the polymer can be a polyvinyl alcohol modified with a reactive acetacetyl group. In another example, the polymer can be blend of a polyvinyl alcohol and a polyamide. In still another aspect, the polymer can be a blend of a polyamide and a crosslinked polyvinylpolypyrrolidone.
Generally, the flatness control layer(s) discussed herein are present in the media sheet at a coating weight from 1 to 15 gsm. In one example, the coating weight can be from 1 to 10 gsm, and in one aspect, from 1 to 5 gsm. In one example, the flatness control layer can be a hydrophobic polymeric layer.
Generally, the present media sheets have at least one ink-receiving layer. The ink-receiving layer can include fixers, inorganic salts, polymers, optical brightening agents, defoamers, viscosity modifiers, organic reagents, inorganic pigment, organic pigment, etc. Generally, the ink-receiving layers discussed herein are present in the media sheet at a coating weight from 1 to 40 gsm. In one example, the coating weight can be from 1 to 20 gsm, and in one aspect, from 5 to 15 gsm.
As discussed herein, the present media sheets achieve a flatness after high speed printing without the need of expensive additives, curl control layers, or moisture barrier layers. As such, in one example, the flatness control layer can exclude additives and surface sizing agents including calcium carbonate, zeolite, silica, talc, alumina, aluminum trihydrate (ATH), calcium silicate, kaolin, calcined clay, starches and starch derivatives; carboxymethylcellulose (CMC); methyl cellulose; alginates; waxes; wax emulsions; alkylketene dimer (AKD); alkyl succinic anhydride (ASA); alkenyl ketene dimer emulsion (AnKD); emulsions of ASA or AKD with cationic starch; ASA incorporating alum. Additionally, in another example, the present media sheets can exclude curl layers or moisture barrier layers including, in one aspect, extruded hydrophobic polymer layers such as polyethylene layers.
Generally, the present media sheets comprise a paper substrate. In one example, the paper substrate can be a wood fiber substrate. Generally, the paper substrate is a light weight paper substrate having a basis weight of 30 gsm to 100 gsm. In one example, the light weight paper substrate can have a basis weight of 35 gsm to 80 gsm, and in one aspect, can have a basis weight of 40 gsm to 70 gsm. In one specific aspect, the basis weight can be from 10 gsm to 50 gsm. Additionally, while the present media sheets generally have a total basis weight from 40 to 150 gsm, such sheets can have lighter weights. In one example, the total basis weight can be from 40 to 120 gsm, and in one aspect, can be from 60 to 90 gsm.
As discussed herein, the present media sheets have exceptional flatness even when used in high speed printing applications, such as Hewlett Packard's Web Press printing technologies. Such high speed printing technologies can include those generally having a processing speed from 200 ft/min to 800 ft/min. Under such conditions, the present flatness can be quantitatively measured using an amplitude parameter, a roughness parameter, and a water holding time. Such parameters are used to provide an objective independent measurement that directly correlates to the flatness of the present media sheets. Amplitude parameter is a calculation based on the peak heights on the surface of the paper across a profile line. Roughness parameter is a root mean squared calculation of the profile line. Water holding time measures the ability of the paper to hold water on the surface thereby minimizing the water uptake by the paper substrate. As such, the amplitude parameter and the roughness parameter are measurements based on the physical structure on the surface of the paper. Water holding time is a measurement of the media sheet's ability to “hold water” on the surface, thereby allowing water/solvents to evaporate more quickly, thereby reducing curl and cockle due to the presence of these liquids in the paper substrate. These terms are defined hereinafter including the measurements to obtain them.
In one example, the light weight media sheets can have an amplitude parameter of less than 1.0. In one aspect, the amplitude parameter can be less than 0.60, and in one specific aspect, less than 0.3. In one example, the light weight media sheets can have a roughness parameter of less than 0.50. In one aspect, the roughness parameter can be less than 0.40, and in one specific aspect, less than 0.30. In one example, the light weight media sheets can have a water holding time of at least 30 seconds. In one aspect, water holding time can be at least 60 seconds, and in one specific aspect, can be at least 100 seconds.
The present media sheets can be used in conjunction with printing inks. The recording media can be applied in multiple imaging systems, non-limiting examples of which include thermal or piezo inkjet, dye-sub, thermal transfer, electrostatic, liquid electrophotographic printing (LEP), etc. In one aspect, the media sheets can be used with ink-jet inks comprising pigments and/or dyes in an ink vehicle. Typical ink vehicle formulations can include water, and can further include co-solvents present in total at from 0.1 wt % to 30 wt %, depending on the jetting architecture, though amounts outside of this range can also be used. Further, non-ionic, cationic, and/or anionic surfactants can be present, ranging from 0.01 wt % to 10 wt %. In addition to the colorant, the balance of the formulation can be purified water, or other vehicle components, such as biocides, viscosity modifiers, materials for pH adjustment, sequestering agents, preservatives, and the like.
Turning now to
In addition to the recording media described herein, the present disclosure provides for methods for manufacturing lightweight media sheets. Turning now to
In another example, as shown in
It is noted that when discussing the compositions and methods, each of these discussions can be considered applicable to each of these embodiments, whether or not they are explicitly discussed in the context of that embodiment. Thus, for example, in discussing a flatness control layer used in a light weight media sheet, such a flatness control layer can also be used in a method of manufacturing a light weight media sheet, and vice versa. Thus, the disclosure herein describing the media sheets per se also related directly to the present methods.
Regarding the present method steps, such steps can be performed in a number of sequences and are not intended to be limited to the order written. For example, the second flatness control layer can be applied before the first flatness control layer, and vice versa. Additionally, it is noted that any and all combinations of such steps or individual step may be performed sequentially or simultaneously. For example, coating the paper substrate with the first flatness control layer and the second flatness control layer may be performed sequentially or may be performed simultaneously.
Additionally, it is to be understood that this disclosure is not limited to the particular process steps and materials disclosed herein because such process steps and materials may vary somewhat. It is also to be understood that the terminology used herein is used for the purpose of describing particular examples only. The terms are not intended to be limiting because the scope of the present disclosure is intended to be limited only by the appended claims and equivalents thereof.
It is be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
As used herein, the term “wood fiber” refers to cellulosic fibers and other known paper fibers including hardwood pulps and softwood pulps as defined herein. As used herein, the term “hardwood fiber” or “hardwood pulps” refers to fibrous pulp derived from the woody substance of deciduous trees (angiosperms) such as aspen, birch, oak, beech, maple, and eucalyptus. As used herein, the term “softwood fiber” or “softwood pulps” refers to fibrous pulps derived from the woody substance of coniferous trees (gymnosperms) such as varieties of fir, spruce, and pine, as for example loblolly pine, slash pine, Colorado spruce, balsam fir and Douglas fir.
As used herein, “amplitude parameter” refers to the calculation of average height of three highest peaks from a profile line measured by Industrial Vision Camera IVC-3D Laser Profiler. The Laser Profiler generates a profile line by measuring the Z direction height change from cross direction (CD) of a media sheet.
As used herein, “roughness parameter” refers to the root mean squared roughness parameter calculated from the profile line measured by Industrial Vision Camera IVC-3D Laser Profiler. The Laser Profiler generates a profile line by measuring the Z direction height change from cross direction (CD) of a media sheet.
As used herein, “water holding time” refers to the amount of time it takes for a formic acid solution dyed green to pass through the paper as measured by a Hercules Sizing Tester as per TAPPI Test method T 530 om-2 (current version as of 2013).
As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
The following examples illustrate some embodiments of the present recording media and methods that are presently known. However, it is to be understood that the following are only exemplary or illustrative of the application of the principles of the present recording media and methods. Numerous modifications and alternative examples may be devised by those skilled in the art without departing from the spirit and scope of the present compositions and methods. The appended claims are intended to cover such modifications and arrangements. Thus, while the present recording media and methods have been described above with particularity, the following examples provide further detail in connection with what are presently deemed to be the acceptable embodiments.
The present media sheets were generally prepared by coating various paper substrates with various flatness control layers, each combination having the same ink-receiving layer. The paper substrate details are listed in Table 1. The flatness control layers were prepared by combining the components in the amounts according to Table 2. The ink-receiving layer was prepared by combining the components in the amounts according to Table 3. The materials and coating weights for each media sheet are shown in Table 4.
The media sheets of Table 4 were printed on a Hewlett Packard CM8060 Color MFP with Edgeline Technology with an A50 ink, available from Hewlett Packard, at a coverage of 60% and tested for amplitude parameter, roughness parameter, and water holding time using an Industrial Vision Camera IVC-3d Laser Profiler. The results are listed in Table 5.
As shown in Table 5, the present media sheets had better amplitude parameters, roughness parameters, and water holding times compared to the control sheets. Notably, the amplitude parameter and the roughness parameter were reduced for the present media sheets as compared to the control sheets. A lower value for these parameters indicates that the surface of the sheets is flatter; i.e., the average peak heights are smaller. Also, the water holding time was increased for the present media sheets as compared to the control sheets. A high value for the water holding time indicates that the paper was able to retain the water/solvents on the surface of the paper better. As such, the water/solvents were able to evaporate quicker allowing less water/solvents to absorb into the paper substrate. Also notably, media sheets having higher water holding times were flatter as shown by the amplitude and roughness parameters.
Furthermore, uncoated paper substrates having basis weights of greater than about 100 gsm are not as susceptible to curl and cockle because they are more substantial in their overall weight. Additionally, coated papers having basis weights of greater than about 150 gsm also do not typically exhibit excessive curl and cockle. Conversely, with thinner papers such as those shown above, reduced curl and cockle can be achieved even when the base paper and/or the total coated media thicknesses are particularly thin.
While the disclosure has been described with reference to certain embodiments, those skilled in the art will appreciate that various modifications, changes, omissions, and substitutions can be made without departing from the spirit of the disclosure. It is intended, therefore, that the present disclosure be limited only by the scope of the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US13/77053 | 12/20/2013 | WO | 00 |
