GB2592236A

GB2592236A - Dye sublimation printing

Info

Publication number: GB2592236A
Application number: GB2002397.4A
Authority: GB
Inventors: James Buckby Adam
Original assignee: Sublique Ltd
Current assignee: Sublique Ltd
Priority date: 2020-02-20
Filing date: 2020-02-20
Publication date: 2021-08-25
Anticipated expiration: 2040-02-20
Also published as: GB2592236B; GB202002397D0

Abstract

A fabric 4 comprising natural material is coated or laminated with a polymer 6. Preferably the fabric 4 comprises woven or nonwoven cotton. The preferred coating or lamina polymer 6 comprises polyamide, polyester and/or polysulphone, a dye sublimation layer 8. The polymer may comprise an ink receiving polyester layer 6a and a polyamide adhesive layer 6b. The preferred polymer 6 is ≤ 80 µm thick and has density ≤ 50 g/m2. The preferred lamina is flexible, transparent or translucent woven or nonwoven web which is applied at ≥ 100°C and ≥ 2 bar for 5-20 seconds using a flatbed or heated roller laminator. The preferred fabric has a frangible, removable dye impermeable lining. Preferably, sublimation printing is performed at ≥ 120°C and ≥ 2 bar. The printed fabric is used as a bag, clothing, upholstery, bedding or towelling.

Description

Dye sublimation printing The present invention relates to a dye sublimation printing technique on non-conventional materials, particularly for natural fibre fabrics.

Introduction

Dye sublimation printing (sometimes referred to as dye-diffusion printing) involves placing a dispersible dye against a print surface and using heat and pressure to transfer to the dye onto the surface. When printing onto fabrics, the dye may be printed onto a heat resistant transfer paper, and then heating the transfer to transfers the dye onto the fabrics. Dye sublimation can produce brilliant colours and due to the dispersion of the dye into the fabric, the colour is permanent and does not fade over time.

Dye sublimation is only able to print onto synthetic fabrics. It is believed that during heating, the polymers become porous, and the dispersive dye is able to penetrate the pores and provide a permanent bond between the polymer and the dye. However, this phenomenon does not occur in natural fibres, such as cotton, and therefore the dye is not able to effectively bond with a cotton fabric. As such, dye sublimation printing is not used for natural fibre materials.

For printing on natural materials, screen printing using plastics, such as acrylic, is used. However, the plastic layers are prone to cracking and/or peeling, particularly after washing or strenuous use. This significantly reduces the longevity of the product, reducing the value to the consumer and exacerbating the environmental issues surrounding the production and disposal of textiles.

Furthermore, whilst screen printing can be cost-effective for smaller and/or monochrome prints, adding multiple colours to a print increases cost and complexity. Larger prints, as well as being more expensive, are also more prone to the cracking and deterioration issues discussed above. Screen printing requires a plain area of fabric and is less effective over features such as stitching, seams or the like.

A prior art solution for dye sublimation printing on cotton is disclosed in US7081324. A backing layer is 20 comprises a barrier layer 40, an image layer 10 and a polyester layer 5. As shown in figures la-c and 2 of that document, the backing layer 20 is placed onto the t-shirt 62 with the polyester layer 5 against the cotton layer 30. The backing layer 20 is then heated using an iron, and the backing layer 20 and barrier layer 40 are peeled away from the polyester layer 5, leaving it on the t-shirt. During heating, dyes in the image layer sublimate into the polyester layer 5, providing an image on the t-shirt 62.

However, such a technique requires the use of a thick polyester layer 5 in order to prevent fracture thereof as the backing layer 20 is peeled away. The thick polyester layer has a "plasticky" feel which feels unnatural to the user, and suffers from the same peeling or cracking problems as previously discussed.

It is an aim of the present invention to overcome and ameliorate one or more of the above problems, particularly to provide a means to print on natural fabrics using dye sublimation.

Statements of invention

According to a first aspect of the invention, there is provided: a method of dye sublimation printing onto a substrate comprising a non-polymeric material, comprising: applying a coating to the substrate, the coating having a polymer configured to retain a sublimation dye; and transferring the sublimation dye onto the coating such that at least a portion of the dye is retained therein.

According to a second aspect of the present invention, there is provided a method of preparing a natural fibre fabric for sublimation printing.

According to a third aspect of the invention, there is provided a method of producing a sublimation printed product.

According to a fourth aspect, there is provided a sublimation printed product derived from the method of production.

According to a further aspect of the invention, there is provided a fabric material derived from the method of the second aspect.

Preferably, fabric is formed into a product. Preferably, forming of product is provided after coating of the substrate.

The substrate could comprise one or more of: a textile and/or fibre-based material; a metal material; a wood-based material (e.g. paper or wood); a glass material; a ceramic material; or a inorganic material, such as stone or brick.

Detailed description

Figure la shows a substrate comprising a coating suitable for dye sublimation printing thereon; Figure lb shows a second embodiment of the coating comprising a discontinuous layer; Figure 2 shows a tote bag with the coating applied to select portions thereof; Figure 3 shows a flowchart of a coating and printing process; Figure 4 shows a schematic of apparatus to provide the coating process.

A fabric 2 according to the invention is shown in figure la. The fabric comprises a substrate 4. The substrate 4 comprises a natural material (i.e. a non-synthetic material). For example, the substrate comprises natural fibres, yarns, staples, filaments etc. The substrate 4 may be woven or non-woven. The fabric 2 may coloured (e.g. dyed) or non-coloured.

The natural material comprises a material sourced or derived from a natural source. For example, the material fibre is sourced from an animal, plant or mineral fibre. In another example, the natural material is derived from a fibre, such as wood pulp, to provide a semi-synthetic material. It can therefore be appreciated therefore that the natural material does not comprise hydrocarbon-based polymers (i.e. plastics). ). In some examples, the substrate 4 may comprise a small percentage of synthetic/polymer materials, e.g. a minority of synthetic/polymer materials, such that it is unsuitable for direct sublimation printing. In yet further examples, the substrate 4 could comprise a greater percentage of synthetic material but of a type that does not accept a sublimation print in a satisfactory manner.

The fibre may comprise one or more of: a cellulosic fibre; a protein fibre; or a mineral fibre. The cellulosic fibre may comprise one or more of: cotton fibre; linen fibre; wood pulp fibre; or rayon fibre. The rayon fibre may comprise one or more of: viscose fibre; modal fibre; or lyocell fibre. The protein fibre may comprise one or more of a keratinous fibre, such as: wool fibre; or silk fibre.

In a preferred embodiment, the substrate 4 comprises cotton. The substrate 4 may be pure cotton (i.e. 100% cotton). In other embodiments, the substrate 4 may comprise a high cotton content, for example, greater than 50%; greater than 60%; greater than 70%; greater than 80%; greater than 90%; greater than 75%; greater than 99% cotton (by weight).

The cotton may be blended with other natural materials.

The natural material may be mixed with synthetic materials, however, it can be appreciated that the substrate 4 typically does not comprise any synthetic material in substantial amounts that permit dye sublimation printing to be effective thereon.

The substrate 4 therefore does not typically comprise polyester or other dye sublimation suitable synthetic materials in any significant proportions.

The substrate 4 comprises a coating 6 thereon. The coating 6 provides a substrate upon which a dye sublimation layer 8 may be provided on. The coating 6 thus allows dye printing onto natural substrate 4. Although the ink layer 8 is shown as a discrete layer, it can be appreciated that the ink will typically be dispersed within the coating 6.

In some embodiments, the coating 6 comprises a polyamide (PA). The polyamide may comprise one or more of: an aliphatic polyamide; a polyphthalamide; or an aromatic polyamide. The polyamide may comprise one or more of: nylon; nylon 6; nylon 12; nylon 66; PA6T; PA6T/66; Kevlar (RTM); or Nomex (RTM).

In some embodiments, the coating 6 comprises a polysulfone. The polyamide may comprise one or more of: polysulfone (PSU); polyethersulfone (PES); reactivepolyethersulfone (R-PES); polyarylene sulfone (PAS); polybisphenol-A sulfone (PSF); or polyphenylenesulfone (PPSU).

In some embodiments, the coating 6 comprises a polyester. The polyester may comprises one or more of: an aliphatic polyester; a semi-aromatic polyester; or an aromatic polyester. The polyester may comprise one or more of: polyglycolide (PGA); polylactic acid (PLA); polycaprolactone (PCL); polyhydroxyalkanoate (PHA); polyhydroxybutyrate (PHB); polyethylene adipate (PEA); polybutylene succinate (PBS); poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PBHV); polyethylene terephthalate (PET); polybutylene terephthalate (PBT); polytrimethylene terephthalate (PTT); polyethylene naphthalate (PEN); or Vectran (RTM).

In some embodiments, the coating 6 comprises a cellulosic material. The cellulosic material may comprise one or more of: cellulose; rayon; viscose or cotton.

In some embodiments, the coating 6 comprises polyurethane. In some embodiments, the coating 6 comprises polyvinylchloride (PVC).

In some embodiments, the coating comprises one or more (e.g. mixture or blend) of the polyamide, polysuflone, polyester, cellulosic material or polyurethane.

In a first specific embodiment, the coating 6 comprises a polyamide and a polysulfone (PES). The coating 6 may comprise greater than 50% polyamide; preferably, greater than 60% polyamide. In a specific example, the polyamide comprises 65% polyamide and 35% PES.

The inventor has found that polysulfones are able to withstand the high temperatures involved in the dye sublimation process without melting or degrading. This ensures the coating 6 remains adhered to the substrate 6. The inventor has found that the addition of a polyamide provides increased toughness of the polysulfones, which prevents peeling or cracking of the coating 6. Additionally, the polyamide increases the chemical resistance of the polysulfone, thus reducing the risk of chemical degradation over time.

Therefore, that the present combination of polymers provides an optimum combination of adhesion to the substrate 4 and binding the dye sublimation ink, thus providing a vivid image that is not prone to fading, cracking or peeling.

In a second specific embodiment, the coating 6 comprises a polyester. The polyester may comprise PET. The coating may comprise greater than 30% polyester; preferably greater than 40%; preferably greater than 50%; preferably greater than 60%; preferably greater 80%; preferably greater than 90%; preferably 100% polyester.

In a third specific embodiment, the coating 6 comprises a polyester and a polyamide. The coating 6 may comprise greater than 30wr/0 polyester; preferably greater than 40wt%; preferably greater than 50wr/o; preferably greater than 60wr/o; preferably greater 80wt% polyester, e.g. with the remainder being polyamide.

The inventor has found that the use of a polyester provides excellent binding with the sublimation ink, therefore providing a vivid image. The polyamide may provide good adhesive strength onto substrate 4.

As shown in figure la, the coating 6 may comprise a plurality of discrete layers 6a,6a, with one or more of constituent polymers therein. For example, layer 6a may comprise the polymer suitable for dye sublimation printing thereon. Layer 6b may provide an adhesive for the layer sublimation layer 6a. The coating 6 thus provides optimum properties for both adhesion to the substrate 4 and printing.

In an embodiment shown in figure la, a second layer 6b is applied to select portions of the first layer 6a (i.e. the second layer 6b is intermittent or discontinuous about the surface of the first layer 6b). For example, the second layer may comprise a series of dots or other discrete regions. The dots may be arranged in an array (e.g. a hexagonal array) or grid on the first layer 6a. The dots may have a width of between 500km and 800km (e.g. mesh 28), however, it can be appreciated that dots may increase in width as the coating 6 is applied to substrate 4.

In other examples, the select portions may be provided in grid; checkerboard; wave-like (e.g. herringbone or sinusoidal); woven; or random pattern.

The select portions 6b may be provided one or both sides of the first layer 6b.

The select portions 6b may comprises a different material to the first layer 6a. The select portions 6b may provide an adhesive. In a specific example, the first layer 6a comprises a polyester and the second layer 6b comprises a polyamide.

The constituent polymers may be at least partially intermixed or intermingled, such that the boundary between layers 6a,6b is discontinuous or comprises intermediate properties of the layers 6a,6b.

In other embodiments, the constituent polymers may be blended or mixed to provide a substantially homogenous coating 6 (i.e. in terms of functional properties).

The coating 6 is sufficiently thin so as not to impede the flexibility or the natural feel of the substrate 4. Additionally, the thickness is such that the look and feel of the natural material is not significantly altered.

The coating 6 has a thickness of less than 150pm; preferably less than 120pm; preferably less than 100pm; preferably less than 80pm; preferably less than 60pm; preferably less than 50pm; preferably less than 40pm.

The coating 6 has a thickness greater than lOpm; preferably greater than 20pm; preferably greater than 30pm.

In a typical example, the coating 6 has a thickness between 20pm and 60pm.

The coating 6 has a density of less than 100gsm (grams per square metre); preferably less then 80gsm; preferably less than 60gsm; preferably less than 50gsm; preferably less than 40gsm.

The coating 6 has a density greater than 5gsm; preferably greater than lOgsm; preferably greater than 20gsm.

In a typical example, the coating 6 has a density between 20gsm and 50gsm or 25gsm and 45gsm. A coating density of approximately 35gsm, e.g. 30-40gsm has been found to be effective for a high quality print.

The coating 6 comprises a thickness and/or density (gsm) typically much lower than the substrate. For example, a typical t-shirt will have a density of 100-200gsm and a sweatshirt may have a density up to 400gsm. The coating 6 may comprise a thickness/density less than 50% of the substrate 4; preferably less 40%; preferably less 30%; preferably less than 20%; preferably less than 10%; preferably less than °70.

The coating 6 is solid/rigid at ambient temperatures. The coating may have a melting or curing temperature above 130°C, preferably above 150°C; preferably above 170°C.

The coating 6 may be provided as a solid sheet. For example, the coating 6 may comprise a woven or non-woven web. The coating 6 may comprise a plain weave.

The sheet is flexible, such the coating 6 does not peel or crack when bonded to the substrate. The use of the solid, sheet like coating 6 allows the coating 6 to be stored in the roll before application onto the substrate 4. This allows convenient handling and application onto the substrate. Additionally, this ensures an even application of the coating 6 onto the substrate 4. The coating can be easily manipulated and cut into shape (e.g. to provide selective areas of coating 6).

The coating 6 may be substantially transparent or translucent. The coating 6 therefore does not significantly alter the look of the substrate 4. Alternatively, the coating 6 may be white or a light colour.

Although the coating 6 is shown in figure 1 is only provided on a single side of the substrate 4, it can be appreciated that in other embodiments, the coating 6 is provided on both sides of the substrate 4, thereby allowing printing on both sides of the fabric 2.

As shown in figure 2, the fabric 2 may be processed into a consumer product, in this example a tote bag 10. The coating 6 may be applied to select portions of the substrate 4/product 10 (i.e. the coating 6 does not cover all of the substrate 4/product 10). Therefore, during dye sublimation printing, only the portion of the substrate 4/product 10 comprising the coating 6 is dyed.

Such an arrangement allows selective printing of portions of the product 10. This means the remainder of the product 10 can retain the natural look of the natural substrate 4. Additionally, this provides a clean boundary between the printed and non-printed areas, as any dye that is dispersed adjacent the boundary onto the non-printed portion does not bind with the substrate.

In some embodiments, the fabric 4 comprises a coating or lining to prevent deposition of dye thereonto during printing. The lining may be removable, such that the lining can be removed after printing, thus not effecting the finished product. The lining may be loosely held on the fabric 2 (e.g. by mechanical means) and/or may be attached using a peelable adhesive or the like.

In an example, the handles 12 of the bag 10 comprise a removable lining. The lining may be attached to the handles before attachment of the handles 12 to the bag. The lining may comprise a sleeve/strip configured to surround/cover the handle 12, therefore, during printing, no dye will contact the handles 12. The lining may be sown into a hem on the bag 10 in which the handles 12 are typically attached.

The lining will be substantially impermeable, for example, the lining may comprise satin or a polymer, such as polyester. The lining may comprise a perforated seam adjacent the hem, allowing the lining to be torn off at the seam. Alternatively, a perforated seam may not be provided, and the lining may be torn or cut away.

In other embodiments, the lining may comprise a number of cut-outs of the like, to provide selective areas of printing on the fabric 2. The lining may therefore provide 25 a mask.

The method of producing the fabric 2 is described with reference to figures 3 and 4.

In a first step, the coating 6 is applied to the substrate 4. As shown in figure 4, the substrate 4 and the coating 6 are provide on respective rollers 14,16. The substrate 4 and the coating 6 are unwound onto a conveyor system 18 or the like, and are brought together, such that the coating 6 overlies the substrate 4.

The coating 6 and substrate 4 are then heated under pressure using a heated press 20. The heated press comprises a plurality of opposed rollers 22. The rollers 22 are heated and biased together to apply pressure to the substrate 4. The heated press may comprise a calendar heat press.

The heat/pressure step melts and/or cures the coating 6, thus ensuring adhesion to the substrate 4. Additionally, the applied pressure ensures the coating 6 interpenetrates the fibres, weave or pores in the substrate to improve bonding strength.

The heating step may be applied at a temperature greater than 100°C; preferably greater than 120°C; preferably greater than 150°C; preferably greater than 160°C; preferably greater than 180°C. Preferably heat is applied at a temperature between 155°C and 175°C.

The applied pressure may be greater than 2 bar; preferably greater than 2.4 bar; preferably greater than 2.6 bar; preferably greater than 2.8 bar; preferably greater than 3 bar.

Pressure and/or heat may applied for greater than 2 seconds; preferably greater than 5 seconds; preferably greater than 10 seconds; preferably greater than 15 seconds.

The application of the coating 6 may be described as application of an external lining to the substrate. As well as coating/impregnating the fibres of the substrate with a sublimation-print-receiving material, the process may improve the properties of the substrate for use in a final product. The process may improve the stiffness, thickness and/or surface finish/texture of the substrate. The process may reduce the surface roughness of the fibres in the substrate, e.g. providing a smoother sheen to the substrate whilst retaining the general appearance of a natural fibre or textile product. That is to say the coating does not simply provide a layer that overlays/masks the fibres of the substrate but rather one that is applied onto and within/between the fibres.

The fabric 2 may then be cut or otherwise shaped at a cutting station 24.

The fabric 2 is left to cool for greater than 1 or 2 hours; preferably greater than 5 hours; preferably greater than 10 hours; preferably greater than 20 hours; preferably greater than 30 hours. This ensures the coating 6 is fully solidified and/or cured.

The present embodiment provides a substantially continuous or semi-continuous method of manufacturing the fabric 2. In other embodiments, a batch process may be used. For example, the substrate 2 and/or the substrate 4 may be cut to size before the coating 6 is applied. The coating 6 may then be adhered using a flatbed heat press. Where the coating is applied via flatbed, a lower pressure may be used, for example, the pressure may be between 200 and 300 mbar.

A desired image is then printed onto the coated fabric using a dye sublimation process. The process is conventional and may use conventional printing apparatus. The dye sublimation apparatus may comprise a flatbed press or a calendar press. The printing process involves heating the sublimation dye under heat and pressure, such that the dye disperses onto the coating 6. The process thus produces a pre-printed fabric.

The heating step may be applied at a temperature greater than 120°C; preferably greater than 150°C; preferably greater than 180°C; preferably greater than 200°C; preferably greater than 210°C.

Any suitable sublimation inks may be used, such as aqueous or solvent (e.g. propylene glycol) based inks. The ink may be oil based.

The fabric 2 is then cooled. Preferably, the fabric 2 is cooled to ambient temperature.

The fabric 2 may then be formed into a product. For example, the product may comprise: clothing, such t-shirts, trousers, hats, aprons or pyjamas; bed clothes, such as duvet cases, pillow cases, or blankets; towels, such as bath towels or tea towels; curtains; accessories, such as bags or tote bags; soft furnishings; or upholstery. It can be appreciated that these are merely examples of products which may be formed and any such suitable product can be provided.

In alternative embodiments, the printing step may be provided after forming of the product by directly printing onto the product. Unprinted coated products may therefore be supplied to a printer who can then print onto the product as desired. For example, this facilitates low batch number/custom printing onto the product.

In some embodiments, the coating 6 may be applied to a pre-formed product, thus allowing printing on a conventional natural material product.

In some embodiments, the coating 6 can be applied to other (i.e. non-natural) substrate materials not suitable for dye sublimation printing. For example, the coating may be applied to: metal; wood-based products (e.g. paper or wood); glass; ceramics; inorganic materials, such as stone or brick; or plastics not suitable for dye sublimation printing. The process therefore provides a universal solution for printing on materials not conventionally suitable for dye sublimation printing.

Example of the invention An example of the process is described below: Substrate: 100% Cotton Coating: Polyester and polyamide The coating was applied to substrate using a flatbed press at a temperature of 160°C and a pressure of 2.9 bar (42 psi) for 12 seconds.

The fabric was then cooled for 24 hours.

The fabric was dye sublimation printed using a flatbed press at a temperature of 200°C and a pressure of 2.9 bar (42 psi) for 20 seconds.

The printed fabric is left to cool for 1 minute.

The fabric was washed at a 60°C cycle in a consumer washing machine and dried in a consumer tumble dryer. After washing and drying the printed image was retained on fabric. The process of washing and drying was then repeated several times, and no significant degradation of the image was observed.

Advantages of the invention The present invention provides a means to effectively use dye sublimation printing on non-conventional materials, such as cotton. This provides high quality, fade-resistant printing, that retains the natural look, feel and texture of fabrics natural materials. Additionally, this mitigates the need to use acrylic coatings or the like, which have a tendency to peel or crack.

The coating is easy to handle and can be applied to the substrate in a quick and convenient manner. The solid coating allows coating in a substrate in a continuous fashion using conventional apparatus. The coating provides a high adhesion to the substrate, thereby preventing cracking or peeling thereof. The coating provides a high binding affinity to the dye sublimation inks, thereby providing a vivid and high-quality image.

The process allows selective printing onto the fabric or product. This allows a printed design to be accompanied with unprinted natural material. The process allows printing of complex geometries, such as the handles of a bag.

Claims

Claims: 1. A fabric for receiving a dye sublimated image, comprising: a substrate comprising natural material; and a coating provided on the surface of the substrate having a polymer configured to retain a sublimation dye.
2. A fabric according to claim 1, where the substrate comprises greater than 95% natural fibres.
3. A fabric according to claim 1 or 2, where the substrate comprises cotton.
4. A fabric according to claim 3, where, the substrate comprises greater than or equal to 95% cotton or consists entirely of cotton.
5. A fabric according to any preceding claim, where the coating comprises a polyamide.
6. A fabric according to any preceding claim, where the coating comprises a 20 polysulfone.
7. A fabric according to any preceding claim, where the coating comprises PES.
8. A fabric according to any preceding claim, where the coating comprises a polyester.
9. A fabric according to claim 8, where the coating comprises greater than or equal to 50wr/o polyester.
10. A fabric according to any preceding claim, where the coating comprises a first material and a second material, the second material provided on select portions of the surface of the first material.
11. A fabric according to claim 10, where the select portions are provided as an array of discrete areas or dots.
12. A fabric according to claim 10 or 11, where the second material comprises a polyamide.
13. A fabric according to any preceding claim, where the coating comprises a density of less than or equal to 50 gsm.
14. A fabric according to any preceding claim, where the coating comprises a thickness of less than or equal to 80pm.
15. A fabric according to any preceding claim, where the coating comprises a thickness and/or density less than or equal to 30% of the thickness and/or density of the substrate.
16. A fabric according to any preceding claim, where the coating is solid at room temperature before application to the substrate.
17. A fabric according to any preceding claim, where the coating is flexible.
18. A fabric according to any preceding claim, where the coating comprises a
19. A fabric according to any preceding claim, where the coating is transparent/translucent.
20. A fabric according to any preceding claim, where the coating is applied to select portions of the substrate and/or product.
21. A fabric according to any preceding claim, where the fabric comprises a removeable sublimation-dye-impermeable lining.
22. A fabric according to any preceding claim, where the lining comprises a frangible portion to allow removal thereof.
23. A fabric according to any preceding claim, where the fabric forms a product comprising: a bag; clothing or apparel; upholstery; bed clothes; or towelling.
24. A method of dye sublimation printing onto a fabric comprising natural fibres, 5 comprising: providing the fabric of any preceding claim; transferring the sublimation dye onto the coating such that at least a portion of the dye is retained therein
25. A method according to claim 24, where the dye sublimation printing is performed at greater than or equal 120°C.
26. A method according to any preceding method claim, where the dye sublimation printing is performed at greater or equal to 2 bar.
27. A method of manufacturing the fabric of any preceding claim, comprising: overlaying the coating on the substrate and applying pressure and/or heat to bond the coating to the substrate.
28. A method according to claim 27, where the coating is applied in sheet like form.
29. A method according to claim 27 or 28, where the coating comprises a solid web.
30. A method according to any one of claims 27 to 29, where heat is applied for between 5 and 20 seconds.
31. A method according to any one of claims 27 to 30, where the temperature is greater than or equal to 100°C.
32. A method according to any one of claims 27 to 31, where the pressure is greater than or equal to 2 bar.
33. A method according to any one of claims 27 to 32, where the coated substrate is cooled by greater than or equal to 12 hours before printing thereon.
34. A method according to any one of claims 27 to 29, where the coating is adhered to the substrate via a heated roller or flat-bed.