GB2251209A

GB2251209A - Transfer by heating of sublimation ink from a carrier

Info

Publication number: GB2251209A
Application number: GB9026178A
Authority: GB
Inventors: David James Lacey
Original assignee: BRAINSTORM Ltd
Current assignee: BRAINSTORM Ltd
Priority date: 1990-12-01
Filing date: 1990-12-01
Publication date: 1992-07-01
Also published as: GB9026178D0

Abstract

A printed paper sheet 3 or a printed drum has the ink transferred to a foam or cloth sheet 1 by a heated platen 5 pressed onto or slightly spaced from sheet 3 or by rolling the heated drum on the sheet 1. A temperature between 70 and 300 DEG C with a pressure between 5 and 500 psi for a period between 5 seconds and 2 minutes may be used. The ink may be transferred to a PVC film which is heat bonded to the sheet 1. The sheet 1 may be coated with an adhesive prior to printing and the heat and pressure may 1 laminate the printed sheet (15, Fig. 3) to a further foam layer (11) by a heat curing adhesive (13). A mask may assist or impede the transfer of heat to a foam so that the regions subject to less heat are less compressed and stand out in relief. <IMAGE>

Description

METHOD OF PRINTING This invention relates to a method of printing and more particularly to a method of printing onto a foam surface or onto cloth or other similar materials.

There are a number of occasions on which it would be useful to be able to print onto a foam surface or the like. These include providing decorations on foam or like surfaces or providing instructions or other matter, such as advertising etc. There are many different types of material with foam, cloth or like surfaces. These include not only materials which are made totally of foam, eg sponges, but also those materials which may have a facing or backing of such material.

Attempts have been made in the past to print on such surfaces but these have suffered from a number of disadvantages ranging from the difficulty of making the print take on the material surface to rendering the print stable and not easily rubbed or scratched off while maintaining the original character of the surface.

The present invention seeks to provide a method of printing which can be used to print onto a foam, cloth or like surface and which reduces or obviates some or all of the above disadvantages.

According to the invention, a method of printing comprises printing intially onto a print carrier, applying the carrier material with the print thereon onto the surface which is to be printed and applying heat in the vicinity of the print carrier and/or surface to be printed so as to heat the print on the carrier and transfer it from the carrier to the surface to be printed.

The heat may be applied directly to the reverse surface or the carrier or may be applied adiacent to the reverse side of the carrier out spaced therefrom.

The surtace and/or tne carrier and/or a means or applying heat to tne carrier mav be relatively mover during the printing method. Thus the carrier mav comprise a drum on which the print has first been applied and which is then rolled over the surface to oe printed to transfer the print to the surface. The drum may be internally heated so that the heat source moves with the drum. Alternatively. the carrier mav be a flat sheet and the heat source mav be a heated roller which is rolled over the carrier and surface to transfer the print. Still further. a stationarv heating element may be provided and the surface to be printed. together with the carrier are moved past the element.

Preferably the printed, ink used for the printing comprises a sublimation ink.

Suitably the printing ink on the carrier may be heated in the temperature range of 70 C to 300 0.

An adhesive may be applied to the surface to be orinted prior to or at the same time as the anolication of the carrier to the surface. The adhesive may be a liauid or a sheet adhesive. Alternatively. a sheet of plastics material may be placed on the surface to ne printed between the surface to be Drinted and the carrier to act as an adhesive.

Pressure may be applied to the carrier and surface to be printed during the heating operation and mav be in -the range 5 to 500 pounds per square inch. The duration of the heating, and pressure if applied mav be in the range 5 seconds to 2 minutes.

Tne surface being printed may comorise the uooer surface ot an upper layer which mav be laid on a lower aver with the interposition of a heat curing adhesive sucn that the t we layers are bonded together during tre printing process.

A mask may be interposed between the heat source and the carrier so as to provide variable heating of the carrier and underlying surface whereby a relief oat tern is formed on the surface. Alternatively. the same effect could be produced using a heated mask.

The invention will now be described in greater detail.

by way of example, with reference to the diagrammatic drawings, in which:- Figure 1 is an elevational view of a block of sponge material with print carrier thereon together with the location of a heating device illustrative of a first embodiment of the invention: Figure 2 is a view similar to figure 1 but illustrating a second embodiment of the invention, and Figure 3 is a view similar to figures 1 and 2 but illustrating the creation of of a laminate while printing.

Referring first lav to Figure 1, there is shown a sheet 1 of foam material on which it is intended to Drint. To this end, a sheet of carrier material 3 is first Dinted in reverse using a suitable transfer ink, preferably a sublimation ink. The carrier 3 is suitablv in the form of a DaDer sheet which may, if necessary, be orovided with a reiease coating. and is printed by anv suitable process such as litho-, offset. or screen @rinting. The suolimation ink is suitably one of a number of inch manufactured either by Coates Inks Ltd. cr Britten Inks Ltd. and are produced under BS 5665.

After printing, the carrier is placed face down on to the sheet 1 of foam material. A heating element or platen 5 is lowered on to the rear of the carrier material 3 to heat it and cause the print thereon to be transferred from the face of the carrier onto tne surface of the foam sheet where it becomes intimatelv bonded.

The heating stage is carried out at a specific temperature in dependence on the materials being used and lies within the range 7C) C to 3OC C. It is also carried out under pressure in a range of 5 to 500 pounds per square inch for a duration in the range 5 seconds to 2 minutes.

In a particular example used for printing on polyester foam, heat was applied at 190 C at 5 pounds oer scuare inch for a period of 50 seconds.

After the completion of the heat and pressure stare, the platen 5 is withdrawn and the carrier sheet removed.

In a second embodiment of the invention. illustrated in figure 2, the method is basically the same as the first embodiment except that a sheet 7 of highly plasticised material, typically PVC such as that known under the name "cling film" is placed on the surface of the foam sheet I prior to the placement of the carrier so that it is sandwiched between the carrier and the surface of the sheet 1. When the platen 5 is applied to the rear of the carrier 2, the suplimation ink Is transt erred to sheet 1 while at tne same time tne sheet ? of nighly plasticised materiai is aiso bonded to the surf ace of the sheet 1.In this wav, botn the ink and the highly plasticised material are both intimately bonded to the foam sheet 1.

A third embodiment tnot shown in the drawings@ follows the first embodiment, but instead of the carrier being applied direct lv to the surface to be printed. this surface is coated, with an adhesive prior to or at the same time as the carrier is laid in Dlace. This will assist good retention and stability of the printed surface.

In a fourth embodiment of the invention as shown in figure 3, as well as carrving out a printing operation.

the method of printing is used to form a laminate. To this end, a lower layer of foam 11 is covered by a heat curing adhesive 13 and this adhesive coating is covered in turn by an upper layer 15 of foam or cloth Providing the surface to be printed. A carrier 17 which has already been printed, is laid over this laminate, with or without the interDosition of an adhesive coating or highly plasticised sheet (not shown). The platen 19 is then brought down on to the carrier to provide pressure and hear, whereby, not only is the print transferred from the carrier 17 to the uDDer foam or cloth laver 15 but also the uooer layer 15 and the lower layer 11 are bonded together.

in a further form of the invention (not shown in the drawings), the invention is used to produce a relief on the surface to be printed. For this purpose. a mask is provided and laid over the carrier so as to be disposed between the carrier and the source of heat and pressure.

The mask has a free region or regions defining the part OT the surtace intended to lie below the remainder c the surface. The platen is then brought down tr. to the mask and heat is applied to the carrier and surface bv way of the mask, The mask has the effect of reo:Jcin- the heating in the regions covered therebv so that. while tnere is sufficient heat to transfer the ink from the carrier to the surface in all regions. the regions of greatest heat are compressed leaving the less heated regions standing out in relief.

In an alternative method of providing relief. 3 heated mask is used. In this case, the open regions of this mask are subjected to the least heat and will therefore be the regions which stand out in relief. The heat of the heated mask should be such as to ensure transfer of the ink from the carrier to the carrier surf ace even on those regions which are less heated. If desired. an additional source of heat is provide to ensure adeduate heating of the parts of the surface under tfle open regions of the mask.

In a still further embodiment of the invention. where the laminate is used, articles may be trapped between the layers or lamina of the laminate so that thev make the surface stand out in relief in shapes corresponding to the shape of the articles trapped. If this form of the invention is used as a packaging Idea. the articled trapped therein may be removed and then used to whatever purpose they were intended.

It is to be understood that relief effects can still be produced even if no printing is required as well. Thus.

the masks could be applied directly to the furnace of the foam material without the interposition of the carrier.

The invention may te used with most oven or closed cell foams and is particularly suitable for closed cell cross linked foam materials sucn as DoivnroDvlFne, colv ethylene, polystyrene, polyurethane. polyester and polyetner and those foams sold under the trade marks "PLASTAZOTE", "EVAZOTE" and "PRPO70TE".

It will be appreciated that various modifications and additions may be made to the above described embodiments without departing from the scope of the invent ion. For exampie, instead of the heat being applied direct lav to the reverse surface of the carrier, it may be applied adjacent to the reverse side of the carrier but spaced therefrom at a spacing, for example of 2 - 3 millimetres. In this case, it will be appreciated that the only pressure applied wili be atmospheric.

The surface and/or the carrier and/or a means for applying heat to the carrier may be relativelv moved during the printing method. Thus the carrier may comprise a drum on which the print has first been applied and which is then rolled over the surface to be printed to transfer the print to the surface. The drum may be internally heated so that the heat source moves with the drum. Alternatively, the drum could be mounted for rotation on a stationarv axle and the surface to be printed would then be moved therepast. Alternatively, the carrier may be a flat sheet and the heat source may be a heated roller which is rolled over the carrier and surf ace to transfer the print. Still further, a stationary heating element may be Drovided and the surface to be printed, together with the carrier are moved past the element.

From the above described embodiments, it will be seen that the invention can enable a foam, cloth or like surface to be printed with a good stability and resistance to removal by scratching provided that certain parameters are followed. The printed material in the printed regions will normally be smooth and will often be shiny.

Claims

,LAIMS

1. A method of printing which comprises printing initially onto a print carrier. applying the carrier material with the Drink thereon onto the surface which is to be printed and applying heat in the vicinity of the print carrier and/or surface to be printed so as to heat the print on the carrier and transfer it from the carrier to the surface to be printed.

2. A method as claimed in claim 1. wherein the heat is applied directly to the reverse surface of the carrier.

3. A method as claimed in claim 1, wherein the heat is applied adjacent to the reverse side of the carrier but spaced therefrom.

4. A method as claimed in claim 1, 2 or 3, wherein the surface and/or the carrier and/or a means for applying heat to the carrier are relatively moved during the printing method.

5. A method as claimed in any one of claims 1 to 4, wherein the carrier comprises a drum on which the print has first been applied and which is then rolled over the surface to be printed to transfer the prlnt to the surface.

6. A met nod as claimed in claim 5, wherein the drum is internally heated so that the heat source moves with the drum.

7. A method as claimed in any one of claims 1 to 4, wherein the carrier is a flat sheet and the heat source is a heated roller which is rolled over the carrier and surface to transfer the print.

8. A method as claimed in any one oi claims A wherein a stationary heating element is provided an the surface to be printed, together witn the carrier are moved past the element.

9. A method as claimed in any Preceding claim. wherein the printing ink used for the printing comprises a sublimation ink.

10. A method as claimed in any preceding claim. wherein the printing ink on the carrier is heated In the temperature range of 70 C to 300 C.

11. A method as claimed in any preceding claim. wherein an adhesive is applied to the surface to be orinted prior to or at the same time as the application of the carrier to the surface.

i2. A method as claimed in claim 11 wherein the adhesive is a liquid.

13. A method as claimed in claim 11. wherein the adhesive is a sheet adhesive.

14. A method as claimed in any preceding claim. wherein a sheet of plastics material is placed on the surtace to be printed between the surface to be printed and the carrier to act as an adhesive.

15. A method as claimed in any preceding claim. wherein pressure is applied to the carrier and surface to be printed during the heating operation.

16. A method as claimed in claim 15* wnerein the pressure applied is in the range 5 to 500 lbs. ter square inch.

1/. A method as claimed in any preceding claim. wherein the duration oi the heating, and pressure it if applied, is in the range 5 seconds to 2 minutes 18. A method as claimed in any preceding claim. wherein the surtace being printed comprises the udder surface of an upper layer and is laid on a lower layer with the interposition of a heat curing adhesive such that the two layers are bonded together during the printing process.

19. A method as claimed in any preceding claim. wherein a mask is interposed between the heat source and the carrier so as to provide variable heating of the carrier and underlying surface whereby a relief oat tern is formed on the surface.

20. A method as claimed in any one of claims 1 to 19, wherein a heated mask is placed on the carrier so as to provide variable heating of the carrier and underlying surf ace whereby a relief pattern is formed on the surface.

21. A method of printing as claimed in claim 1 and substantially as described herein.

22. A method of printing substantially as described wherein with reference to the drawings.

23. A printed article when produced bv the method of any preceding claim.