DESC:DESCRIPTION OF INVENTION
FIELD OF INVENTION
The present invention generally relates to coated papers;
Particularly, the present invention relates to a quick-drying type sublimation heat transfer paper and method of producing the same.
BACKGROUND OF THE INVENTION
Sublimation transfer paper for inkjet printing is used in printing of textiles or materials containing polyester. Ink made by dispersed dyes is printed on the sublimation transfer paper for inkjet printing usually having DX5, DX7, 5113, i3200, 4720, 6300 heads of brands like Epson or industrial heads of Ricoh/ Kyocera print heads and according to the pattern images through an inkjet printer, then the printed surface fits with the object surface of transfer printing and then is heat pressed to 170-230°C. The dye in the ink is heated and sublimated into the object of transferring, thus realizing transferring, of images and texts.
Not all sublimation transfer papers are equally suited for sublimation printing. Certain transfer papers have a tendency to absorb a large amount of sublimable ink and, as a result, require the application of large amounts of sublimable ink to provide a sufficient amount of ink available for transfer. As a result, it can be fairly expensive to use that paper. In addition, other papers may not provide a desired amount of sublimable ink transfer. In such a situation, the resulting image may not be of the quality desired.
Formulations of dye materials used in Dye Sublimation ink can result in different colour fastnesses. For example, even if enhanced colour fastness of a magenta dye is achieved, that of a cyan dye may not be achieved, resulting in poor color balance of images. In a heat transfer recording material having formed images, dyes forming yellow, magenta, cyan, black images exist in an identical layer, in which a dye with poor colour fastness is affected by the other dyes, resulting in a deteriorated image.
The stabilizing compound may be incorporated into the top layer of a coated paper, it may be incorporated into a separate element, it may be incorporated into a separate portion of a top layer with repeating areas of coating layer.
The impact full way of faster process of heat transfer Technology, from the process of " digital format file ? inkjet printing by sublimation dyes ? heat fusing ? design reproducing ", eliminates the process procedures such as the plate-making of traditional printing, printing, drying completely.
Heat sublimation transfer paper is used in the digital printing technologies and is economical, efficient, high-quality, the picture on surface printing of the products such as T-shirt, case and bag, shoes and hats, socks, gloves, household back cushion, bedding, household decorations, pottery, metal, cup (dish), mouse pad.
Efforts have been made in the related prior art to provide different solutions for providing a quick dry sublimation heat transfer paper. For example, US20160159128A1 describes a sublimation transfer paper for inkjet printing includes an ink holding layer, a paper fiber bonding layer, a base paper layer, and a back coating layer. The uppermost and lowermost layers of the transfer paper are the ink holding layer and back coating layer, respectively. The paper fiber bonding layer and the base paper layer, or a layer of mixture of a paper fiber binding agent and the base paper layer, must be disposed between the ink holding layer and the back coating layer. The paper fiber bonding layer is coated on the base paper layer using a spreader, the transfer paper of the present invention is added with dry stuffing, therefore drying quickly during printing and has a low extension rate; and during inkjet printing, such transfer paper does not arch and rub the jet nozzle of the printer after absorbing water and is easy to use.
In another example, WO2018139925A1 discloses a composition for surface treating a substrate, wherein the composition comprising a film forming agent, such as an organic polymer, preferably a cationic polymer selected from the group consisting of polyamines and polyimines, and a dye-fixing agent, said dye-fixing agent comprising a divalent metal. The composition of the present invention may be used for surface treating a substrate in order to provide a paper composition for transfer printing. The present invention further relates to a method of preparing such a composition, use of the paper composition in a transfer printing method and to a method for printing a surface of a support material other than paper by means of transfer printing using a substrate surface treated with the composition of the present invention
However, the above-mentioned prior arts have failed to solve the problems of low production efficiency, unstable production and difficult control, and unstable product quality.
Therefore, in light of foregoing discussion, there exists a need to overcome the drawbacks associated with the existing solutions. The present invention describes a quick dry sublimation heat transfer paper and a method of producing the same and aims to overcome or mitigate the aforementioned problems with the prior art.
OBJECT OF THE INVENTION
The primary object of the present invention is to provide a quick dry sublimation heat transfer paper and a method of producing the same;
Further object of the present invention is to provide a Low GSM (Grams per Square Meter) sublimation printing type transfer paper which can be used with excellent anti curl properties, ink drying properties and a strike-through preventing properties;
Another object of present invention is to provide a sublimation printing type transfer paper which is excellent in image reproducibility by transfer and efficiency of transfer with sublimation inks which have lower dye stuff content probably less than 12% or lesser and improving the Color difference (Delta E Value), color fastness (Dry and wet) of the fabric.
SUMMARY OF THE INVENTION
Embodiments of the present disclosure present technological improvements as solution to one or more of the above-mentioned technical problems recognized by the inventor in conventional practices and existing state of the art.
The present disclosure seeks to provide a quick dry sublimation heat transfer paper and a method of producing the same.
In accordance with an aspect of the present invention, the quick dry sublimation heat transfer paper comprises a base paper substrate formed from a mixture of natural fibers and synthetic fibers. The natural fibers include wood fibers, which can be obtained from hardwood, softwood, or a blend of both. Additionally, non-wood natural fibers may be used. The synthetic fibers may include materials like polyacrylic fiber, polyethylene fiber, polypropylene fiber, polylactide fiber, rayon, or nylon fiber.
In accordance with an aspect of the present invention, the base paper substrate is prepared by refining the fibers to a suitable level and incorporating a sizing agent, at a rate of at least one pound per ton of fiber, to facilitate compatibility with aqueous-based sublimable inks. The base paper substrate also undergoes a drying process to enable smooth processing through printing equipment and promote ink drying.
In accordance with an aspect of the present invention, in order to enhance the paper’s performance, various additives can be included in the wet end chemistry, such as oil-resistant additives and wet strength additives. Additionally, the base paper substrate may incorporate reclaimed fiber derived from post-consumer waste, office waste, or corrugated carton waste, contributing to sustainability.
In accordance with further aspect of the present invention,, a coating layer comprising a pigment and a water-soluble binder is applied to the base paper substrate. This layer improves the ink-receiving capacity and print quality. Furthermore, a peeling layer can be added on top of the coating layer, consisting of a binder (e.g., polyvinyl alcohol, polyvinyl alcohol-starch mixture, or carboxylmethyl cellulose) and a filler. The peeling layer assists in the easy release of the transferred image.
The quick dry sublimation heat transfer paper and its production method provide several advantages, including efficient ink drying, improved compatibility with sublimation inks, enhanced print quality, and sustainability through the utilization of reclaimed fiber. These features make it suitable for high-speed sublimation printing applications across various industries.
While the invention has been described with reference to specific embodiments, various modifications and alterations can be made without departing from the scope of the invention, as defined by the appended claims.
The objects and the advantages of the invention are achieved by the process elaborated in the present disclosure.
DESCRIPTION OF THE INVENTION
The following specification describes the invention. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
The present invention is to provide a quick dry sublimation heat transfer paper and a method of producing the same.
The production of quick dry sublimation heat transfer paper requires a base paper which acts as a carrier for paper transfer printing. The following method can be used for manufacturing of the base paper or base sheet.
The paper substrate can be prepared from natural fiber, synthetic fiber, or a mixture of natural fiber and synthetic fiber. Exemplary natural fibers that can be used to form the base sheet include wood fibers and non-wood natural fibers such as vegetable fibers, cotton, various straws (e.g., wheat and rye), various canes (e.g., bagasse and kenaf), silk, animal fiber, (e.g., wool), grasses (e.g., bamboo, etc.), hemp, corn stalks, abaca, eucalyptus, etc. Examples of synthetic fibers that could be used for the base sheet include polyacrylic fiber, polyethylene fiber, polypropylene fiber, polylactide fiber, rayon, and nylon fiber.
Wood fiber can be obtained from wood pulp, which can include hardwood fibers, softwood fibers, or a blend of hardwood fibers and softwood fibers. The pulp can be provided as cellulose fiber from chemical pulped wood, and can include a blend from coniferous and deciduous trees. By way of example, wood fibers can be from northern hardwood, northern softwood, southern hardwood, southern softwood, or any blend thereof. Hardwood fibers tend to be more brittle but are generally more cost effective for use because the yield of pulp from hardwood is higher than the yield of pulp from softwood. Softwood fibers have desired paper making characteristics but are generally more expensive than hardwood fibers.
The natural fibers can be extracted with various pulping techniques. For, example, mechanical or high yield pulping can be used for stone ground wood, pressurized ground wood, refiner mechanical pulp, and thermomechanical pulp. Chemical pulping can be used incorporating kraft, sulfite, and soda processing. Semi-chemical and chemi-mechanical pulping can also be used which includes combinations of mechanical and chemical processes to produce chemi-thermomechanical pulp. Natural fibers can be bleached or unbleached.
The pulp can include a recycle source for reclaimed fiber. Exemplary recycle sources include post-consumer waste (PCW) fiber, office waste, and corrugated carton waste. Post-consumer waste fiber refers to fiber recovered from paper that is recycled after consumer use. Office waste refers to fiber obtained from office waste, and corrugated carton waste refers to fiber obtained from corrugated cartons. Additional sources of reclaimed fiber include newsprint and magazines. Reclaimed fiber can include both natural and synthetic fiber. Incorporation of reclaimed fiber in the base can aid in efficient use of resources and increase satisfaction of the end user of the transfer paper.
In general, hard wood fibers have a tendency to enhance tightness and resistance to penetration. Soft wood fibers have a tendency to provide strength and facilitate runability of the paper substrate during formation. Although the paper substrate can be manufactured from 100% hard wood fibers or 100% soft wood fibers, it is common practice to provide a blend of hard wood fiber and soft wood fiber. The blend can be expressed in a weight percent ratio, based on the fiber content, of hard wood fibers to soft wood fibers. An exemplary weight percent ratio of hard wood fibers to soft wood fibers for an exemplary paper substrate can be at least about 0.5:1 to about 6:1, and can be about 2:1 to about 5:1. The amount of soft wood fiber in an exemplary paper substrate can be characterized as about 0% to about 80 wt. %, and the amount of hard wood fiber in an exemplary paper substrate can be provided at a level of about 0 wt. % to about 100 wt. %. The fibers used to form the paper substrate can include fiber resulting from a recycle such as, for example, a pre-consumer recycle. In general, a pre-consumer recycle refers to trimmings or fiber recovered during the paper making process.
The refining of the fibers can be selected to enhance formation and fiber development. In general, if the fibers are too refined, the resulting substrate may not exhibit sufficient porosity and, as a result, the sublimable ink may not dry quickly enough. Refining the fibers helps with formation of the paper substrate during the paper making process, and contributes to the holdout of the sublimable ink receptive coating that is applied to the paper substrate on the paper making machine. The level of refining can be selected to help direct the sublimable dye away from the base sheet and toward the sublimation printing substrate during sublimation printing. That is, by selecting the level of refining, it is believed that the movement of the sublimable dye during sublimation printing can be better directed toward the sublimation printing substrate to provide a more focused delivery onto the sublimation printing substrate and thereby provide a desired image with less dye than if the dye went in all directions equally. The level of refining can be characterized by Canadian Standard Freeness (CSF). In general, a higher Canadian Standard Freeness value refers to fiber that is less refined, and a lower Canadian Standard Freeness value refers to fiber that is more refined. The level of refining of the fibers for the sublimation transfer paper can be characterized as moderately refined whereas many products used as sublimation transfer paper can be characterized as minimally refined. An exemplary characterization of refining for fiber that can be used for forming the paper substrate can be about 100 CSF to about 600 CSF. Fiber that can be used for forming the paper substrate can have a Canadian Standard Freeness value of about 300 CSF to about 500 CSF.
The base paper sheet has following desired properties:
Paper Test Report
Unit Specification
SUBSTANCE g/m² 38.0 38.0
ACTUAL GSM g/m² 2.0% 37.7
THICKNESS micron NA 68
BULK co/gm 1.75 MIN 1.80
BRIGHTNESS_ELEP % 80.0 MIN 70
CIE WHITENESS % NA 104.0
YELLOWNESS % (-8.5 to -10) -10.1
CIE L* % 80.0 MIN 88.7
CIE A* % 5.0 to 6.0 5.1
CIE B* % (-5.0 to 6.5) -6.7
OPACITY,ELEP % 70.0 MIN 81.4
WAX OPACITY % NA
WAX PICK T No's NA
WAX PICK W No's NA
B SMOOTHNESS T ml/min 350 MAX 180
B SMOOTHNESS W ml/min NA 800
G. POROSITY sec/100ml NA 9
B. POROSITY ml/min 1500 MAX 1290
COBB 60 TOP g/m² 20.0 MAX 18.8
COBB 60 WIRE g/m² 20.0 MAX 20.0
ASH % NA 7.0%
TD CONTENT % NA
STIFFNESS MD Taber NA
STIFFNESS CD Taber NA
DOUBLE FOLD MD No's NA
DOUBLE FOLD CD No's NA
TEAR STRENGTH MD gm NA 23
TEAR STRENGTH CD gm NA 28
TEAR FACTOR MD 50.0 MIN 61
TEAR FACTOR CD 50.0 MIN 74
TEN.STRENGTH MD kg/15mm NA 2.4
TEN.STRENGTH CD kg/15mm NA 1.8
BRK.LENGTH MD meter 2200 MIN 4246
BRK.LENGTH CD meter 1800 MIN 3184
BURSTING STR. g/m² NA 610
BURST FACTOR - 14.0 MIN 16.2
KLEM ABSORBENCY mm NA

The paper substrate can be provided having a weight that enables the sublimation transfer paper to be processed through printing equipment and utilized for sublimation printing, and that facilitates drying of the ink (e.g., separation of the carrier from the dye).
The wet end chemistry can, if desired, include an oil-resistant additive, a wet strength additive, or both. Exemplary oil-resistant additives include sizing agents such as fluorochemicals. Exemplary wet strength additives include urea formaldehyde resins, melamine formaldehyde resins, polyamides, polyethyleneimine resins, wet end latexes, size press latexes, or mixtures thereof.
The amount of the sizing agent added at the wet end can be selected depending upon the sublimable ink intended to be used with the sublimation transfer paper. In the case of an aqueous-base sublimable ink, it is generally desirable to provide a sufficient amount of the sizing agent so that the water from the aqueous-based sublimable ink does not penetrate into the paper substrate too quickly. Accordingly, when the sublimation transfer paper is provided for use with an aqueous-based sublimable ink, the paper substrate preferably includes at least one pound sizing agent per ton of fiber. Sublimation transfer paper for use with sublimable inks that are organic solvent-based or oil-based can tolerate the use of a lower amount of wet end sizing agent. In general, the upper amount of sizing agent can be determined by cost and the desire for the sizing agent not to plate out during wet end chemistry.
The coating layer in which the high-speed drying sublimation heating-transfer sheet of the invention is made of the pigment 5 ~ 40 weight%, and the water-soluble binder under the viscosity modifier 1 weight%, selected from the carboxy methycellulose (CMC, carboxymethyl cellulose), Carboxy methyl starch, Poly anionic cellulose and other synthetic and natural cellulosic bonders. or the acryl class viscosity control is formed and it is manufactured. The pigment 5 ~ 40 weight% is the average particle size 0.1 ~ 15?.
The peeling layer in the invention includes the binders carboxylmethyl cellulose, the carboxylmethyl cellulose, and filler (kaolin, clay, and talc) less than 15% in these the polyvinyl alcohol or its mixture is used as the main materials. The carboxylmethyl cellulose in the conventional technology, is mentioned to the peeling layer. The carboxylmethyl cellulose tries to make the heat transfer paper for the sublimation applying the pigment most of water-soluble binders doing not only the polyvinyl alcohol or its mixture but also the starch, guar gum, casein, protein, dextrin, the binder role including the modified poly acrylamide group etc. to which sticks to and use a large amount of nano pigment as the main materials and conventionally is used for the peeling layer or the barrier layer.
Examples of suitable pigment materials include silica (e.g., amorphous silica, calcined silica, fumed silica), clays (e.g., calcined clay), calcium carbonate, talc, kaolin, and other known fillers. Silica filler is a preferred filler, and may be combined with one or more additional fillers such as clay and calcium carbonate. Amorphous silica is a preferred silica.
The supporting layer which binds paper Fibers bond layer, base paper layer and back coating, the layer of supporting ink well including polyanion cellulose and dry filler, glue by the paper fiber Knot layer adopts binding agent, and the binding agent is water-base resin, and the coating includes sucrose 1-10 parts, tetramethylolmethane 1-15 parts, forms sediment Powder 1-10 parts, cellulose 2-15 parts, aerosil 2-10 parts, polyvinyl alcohol 2-16 parts, glycerol 2-18 parts, barium sulfate 2-9 Part, hydroxymethyl cellulose 2-15 parts, antibacterial 1-10 parts, organic solvent 2-15 parts, surfactant 2-15 parts, electrodeless oxide 1-10 parts, thickening agent 1-15 parts, neutralizer 1-10 parts, tall oil fatty acid 2-15 parts, polyacrylamide 1-15 parts, polysaccharide derive Thing 1-10 parts, corrosion inhibiter 1-15 parts, ink medium adsorbent 1-10 parts.
The pigment in which the invention is not water-soluble binder the main materials is used as the minimum which is possible since it serves as dry stuffing which sticks to. And it distinguished with the prior art and the heat transfer paper development in which the drying rate was fast through the porous coating layer formation using the nano pigment which was the main materials and the reproduction of image nature was excellent but this would increase the roughness of the paper.
The present invention enhances the performance of a heat transfer paper through the use of a highly absorbent coating pigment. By incorporating pigments such as silica, calcium carbonate, clay, talc, and others in the range of 5% to 40% by weight of the ceramic solution, the resulting paper exhibits excellent porosity and facilitates rapid drying. The pigment particles, with an average size of 0.1µm to 5µm, are intentionally mixed in varying sizes to further increase porosity. Additionally, the paper is designed to withstand the load level of 450% when applied with five different ink colors, making dimensional stability a crucial requirement. To achieve this stability, the paper utilizes NBKP pulp with a freeness over 25°SR (TAPPI standard), requiring a minimum usage of 10% with no ash content. The COBB value, indicating water absorption, is preferably in the range of 10-25 g/m2, with the optimal range being 8-12 g/m2.
Through extensive experimentation, it was determined that by reducing the sizing of possible milkwort, high-speed drying can be achieved while obtaining maximum coat weight to minimize color difference (?E) values. This innovative approach allows for compatibility with various printing techniques, including inkjet printing. The preferred coating process for applying the porosity ceramic solution is the three-roll coating method, bar coating method, air curtain coating method, blade coating method, mayer bar coating method, or vary bar coating method.
To improve printability and enhance ink transferability, printability improvement agents such as amine (Polyamine) groups, poly dead film (PolyDADMAC) groups, chitosan, metal salt resins, and other known agents with excellent barrier properties are employed.
The paper substrate in various embodiments of the invention has a basis weight ranging from about 20 lb/3,000 ft2 to about 200 lb/3,000 ft2. The sublimable ink receptive coating is applied at a coat weight of approximately 3 lb./3000 ft2 to about 5 lb./3000 ft2 based on the dry weight of the coating composition.
According to embodiments of the present invention, the paper substrate comprises paper formed from fiber having a level of refining of about 100 CSF to about 800 CSF.
According to embodiments of the present invention, the sublimation transfer paper has a Hagerty Porosity of about 10 sec/100 ml air to about 1000 sec/100 ml air.
According to embodiments of the present invention, the sublimation transfer paper has a GSM of about 25-80 GSM.
,CLAIMS:CLAIMS:
We Claim:
1. A quick dry sublimation heat transfer paper, the said paper comprising:
- a base paper substrate formed from a mixture of natural fibers and synthetic fibers, wherein the natural fibers include wood fibers and non-wood natural fibers, and the synthetic fibers include polyacrylic fiber, polyethylene fiber, polypropylene fiber, polylactide fiber, rayon, or nylon fiber;
- the base paper substrate further comprising a blend of hard wood fibers and soft wood fibers in a weight percent ratio of at least about 0.5:1 to about 6:1;
- the base paper substrate having a Canadian Standard Freeness (CSF) value of about 300 CSF to about 500 CSF;
- the base paper substrate including at least one pound of sizing agent per ton of fiber for use with an aqueous-based sublimable ink;
- the base paper substrate having a weight that facilitates processing through printing equipment and enables drying of the ink;
characterized by sublimation heat transfer paper having Hagerty Porosity of about 10 sec/100 ml air to about 1000 sec/100 ml air and a GSM of about 25-80 GSM.
2. The quick dry sublimation heat transfer paper as claimed in Claim 1, wherein the natural fibers used to form the base paper substrate are obtained from wood pulp, including hardwood fibers, softwood fibers, or a blend thereof.
3. The quick dry sublimation heat transfer paper of claim 1, wherein the base paper substrate further comprises reclaimed fiber from post-consumer waste, office waste, or corrugated carton waste.
4. The quick dry sublimation heat transfer paper of claim 1, further comprising an oil-resistant additive as well as a wet strength additive in the wet end chemistry.
5. The quick dry sublimation heat transfer paper as claimed in Claim 1, wherein the paper substrate further comprises NBKP pulp with a freeness over 25°SR, requiring a minimum usage of 10% with no ash content.
6. The quick dry sublimation heat transfer paper as claimed in Claim 1, wherein the heat transfer paper has a COBB value in the range of 10-25 g/m2.
7. The quick dry sublimation heat transfer paper as claimed in Claim 1,wherein the porosity ceramic solution is coated onto the paper substrate using a three-roll coating method, bar coating method, air curtain coating method, blade coating method, mayer bar coating method, or vary bar coating method.
8. The heat transfer paper of claim 1, further comprising a printability improvement agent selected from the group consisting of amine (Polyamine) groups, poly dead film (PolyDADMAC) groups, chitosan, metal salt resins, and combinations thereof
9. A method of producing a quick dry sublimation heat transfer paper, the said method comprising the steps of:
- preparing a base paper substrate by forming a mixture of natural fibers and synthetic fibers, wherein the natural fibers include wood fibers and non-wood natural fibers, and the synthetic fibers include polyacrylic fiber, polyethylene fiber, polypropylene fiber, polylactide fiber, rayon, or nylon fiber;
- applying a coating layer on the base paper substrate;
- refining the fibers to a level of about 100 CSF to about 600 CSF;
- incorporating at least one pound of sizing agent per ton of fiber in the base paper substrate for use with an aqueous-based sublimable ink;
- drying the base paper substrate to facilitate processing through printing equipment and enable drying of the ink.
10. The method as claimed in Claim 7, wherein the coating layer comprises highly absorbent coating pigment comprising silica, calcium carbonate, clay, talc, and other materials, present in a range of 5% to 40% by weight of the ceramic solution used in the coating and a water-soluble binder.
11. The method as claimed in Claim 7, further comprising applying a peeling layer on top of the coating layer, wherein the peeling layer comprises a binder selected from the group consisting of polyvinyl alcohol, polyvinyl alcohol-starch mixture, and carboxymethyl cellulose, and a filler in a range of less than 15%.