Patentamt Europaisches || || 1 1| || || ||| 1 1 1| || ||| || || (19) J European Patent Office

Office europeen des brevets (11) EP 0 732 440 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication: (51) int. CI.6: D06P 5/00, B41J 2/325, 18.09.1996 Bulletin 1996/38 B41 M 5/33 B41 M 5/035 (21) Application number: 96103008.7

(22) Date of filing: 28.02.1996

(84) Designated Contracting States: (72) Inventor: Price Peterson, Mary Elizabeth DE FR GB IT Delmar, New York 1 2054 (US)

(30) Priority: 13.03.1995 US 404192 (74) Representative: Schaumburg, Thoenes & Thurn Postfach 86 07 48 (71) Applicant: Gerber Scientific Products, Inc. 81634 Munchen (DE) Manchester, CT 06040 (US)

(54) A method and apparatus for a graphic on fabric

(57) A method for printing a graphic on fabric using on only those portions of the fabric covered by the a thermal transfer printer is disclosed. According to the graphic. Thermal transfer ribbons for carrying out the invention, a colorant which forms the graphic and a method of printing are also disclosed. binder for adhering the colorant to the fabric are printed

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Description those areas corresponding to the print area of the graphic. Background of the Invention It is yet another object of the invention to provide an apparatus for carrying out such a process. The present invention relates to printing graphics, 5 such as alphanumeric symbols, designs, logos and Summary of the Invention other artwork, on fabric. More particularly, the present invention relates to printing graphics on fabric using a The present invention meets these objects by pro- thermal transfer printer. viding, in one aspect, a method for printing a graphic on Typically, graphics are printed on fabric using a 10 fabric using a thermal transfer printer having a first rib- thermal transfer process. In such a process a thermal bon including a carrier layer and a layer of binder sup- transfer ribbon, including a colorant layer of pigment dis- ported on the carrier layer, and a second ribbon persed in a wax, or wax-resin vehicle, is used to including a carrier layer and a layer of a colorant sup- print the desired graphic onto a thermally stable sub- ported on the carrier layer. The thermal printer is pro- strate, such as thermal , coated with a resin 15 vided with data defining the graphic to be printed on the binder. The printed paper is then placed print side down fabric, and the printer is activated to print binder with the on the fabric, and the colorant is transferred to the fabric first ribbon onto a thermally stable according in a press by the application of heat and pressure. The to the data. Thus, a print area including the binder and resin binder is also transferred, and the resin binds the an adjacent non-print area without binder are formed on colorant to the fabric. 20 the substrate. Once the binder has been deposited on Generally, the printed graphic is defined by one or the substrate, the printer is activated to print colorant more print areas covered by the colorant and adjacent with the second ribbon onto the print area of the sub- "white" or non-print areas. However, since the entire strate according to the data. In the final step of the surface of the thermal paper is coated with the binder, method, the graphic is printed on the fabric by thermally binder transfers to the fabric throughout this adjacent, 25 transferring the binder and colorant from the substrate non-print area, as well as in the areas covered by the to the fabric and adhering the colorant to the fabric with colorant. The binder gives the non-print areas of the fab- the binder. ric an undesirable hand or texture and also seals the In the preferred embodiment of this aspect of the fabric weave together, which prevents the free passage invention, the printer has a single ribbon including a car- air and moisture through the fabric in the non-print 30 rier layer, a colorant layer supported on the carrier layer, areas. Further, the resin binder is not transparent and and a binder layer overlying the colorant layer. Accord- leaves a shadow around the graphic. The resin shadow ingly, the steps of printing the binder and printing the is particularly noticeable on colors other than white. colorant are performed simultaneously using the single Thus, the above-described method of printing is gener- ribbon. ally limited to use with white fabrics. 35 According to a second aspect, the invention pro- According to an alternative process, typically used vides a method for printing a graphic directly on fabric in in most high volume applications, the thermal transfer is which the steps of printing the binder and colorant on a prepared by screen printing or lithographically printing a thermally stable substrate and then thermally transfer- desired graphic onto a thermally stable substrate. Since ring the binder and colorant to the fabric are eliminated. both processes employ inks instead of the pigmented 40 The method taught by this aspect of the invention uti- wax or resin compounds described above in connection lizes a thermal transfer printer having a first ribbon with thermal transfer ribbons, the resin binder and its including a carrier layer and a layer of colorant sup- associated disadvantages are eliminated. However, ported on the carrier layer, and a second ribbon includ- screen printing and lithographic printing, are labor inten- ing a carrier layer and layer of binder supported on the sive processes requiring artwork, ink mixing, color sep- 45 carrier layer. The printer is provided with data defining aration, printing screens or color separation films, a UV the graphic to be printed on the fabric, and the printer is exposure step, and the use of emulsions, developers activated to print colorant with the first ribbon onto the and other chemicals in addition to the inks. Moreover, fabric according to the data. Thus, a print area including the prepared screens or films can be use to print single the colorant and an adjacent non-print area absent any size designs only. so colorant are formed on the fabric. The printer is then It is, therefore, an object of the invention to provide activated to print binder with the second ribbon onto the a method for printing graphics on fabric which requires print area of the fabric according to the data to bind the less labor and equipment than screen printing or litho- colorant to the fabric. graphic printing and which does not require the inks and In the preferred embodiment of this second aspect other chemicals used in these processes. 55 of the invention, the thermal printer has a single ribbon It is a further object of the invention to provide a including a carrier layer, a binder layer supported on the method wherein the graphic is printed using a thermal carrier layer, and a colorant layer overlying the binder printer and the final product is coated with binder in only layer. Accordingly, the steps of printing the binder and

2 3 EP 0 732 440 A1 4 printing the colorant are performed simultaneously Hobart-Macintosh, Inc., Elk Grove Villiage, II., under the using the single ribbon. trade designation "SOFTtrans", coated with a paraffin- The invention is useful for printing graphics, either based wax, or a polyethylene available directly or by means of a transfer, on a wide variety of from, for example, Lamart Corp., Clifton, NJ. fabrics including cotton, polyester, cotton-polyester s As the thermal paper passes over the platen 24, the blends, wool, nylon, silk, rayon and rayon-polyester print head is pressed downwardly onto the paper and blends. The only limitation with respect to the fabric is generally establishes a linear zone of contact between that the fabric must have sufficient thermal stability to the paper and the platen. A cassette 28 supplies a ther- withstand either the heat and pressure of the transfer mal transfer ribbon 30 which carriers a colorant and a press, or the heat of the thermal printer where the to binder. The ribbon 30 extends from a supply roll 32, graphic is printed directly on the fabric. Moreover, since between the print head 26 and the platen 24, to a take- binder is applied only to the print area of the fabric up roll 34 of the cassette. Thus, as the print head 26 according to the invention and the resin shadow typical presses down on the platen 24 with the thermal paper of the prior art is eliminated, the invention can be used and ribbon 30 interposed therebetween, the colorant with fabric of any color. ts and binder carried by the ribbon are transferred to the paper according to the data defining the graphic. Brief Description Of The Drawings A more complete description of the printer 16 may be found in coassigned patent application Serial No., Fig. 1 is a schematic diagram illustrating a system 08/007,662, filed on January 22, 1993, the disclosure of for printing graphics on fabric according to the present 20 which is incorporated herein by reference. It should be invention. understood, however, that the present invention is in no Fig. 2 is a schematic side view of a thermal printer way limited in this regard and that any one of a wide for use in the system shown in Fig. 1 . variety of thermal printers already known to those Fig. 3 is a cross-section of a transfer ribbon for use skilled in the art may be substituted. in the printer illustrated in Fig. 2. 25 Referring now to Fig. 3, in the preferred embodi- Fig. 4 is a cross-section of another transfer ribbon ment of the invention the ribbon 30 includes a carrier for use in the printer illustrated in Fig. 2. layer 36, a layer of colorant 38 supported on the carrier Fig. 5(a) is a cross-section of a transfer ribbon for layer and a layer of binder 40 supported on the colorant use with an alternative embodiment of the invention. layer. The layer 36 may comprise any material typically Fig. 5(b) is a cross-section of a second transfer rib- 30 employed as a carrier in prior art thermal transfer rib- bon for use the alternative embodiment of the invention. bons. In most ribbons the carrier is formed from polyes- ter and that is the material which comprises the carrier Detailed Description of the Invention in the illustrated embodiment. As mentioned above, the colorant layer 38 com- Figure 1 illustrates a microprocessor based system, 35 prises pigment dispersed in a wax, a resin or wax-resin generally designated 10, having apparatus for printing vehicle. Typical wax vehicles include, for example, car- graphics on fabric. To print a graphic, such as the nauba, montan, beeswax, ceresine, haze, candelila, graphic P, the system 10 includes a digitizer 12 or other spermaceti, paraffin and microcrystalline wax. Resin data input device which supplies a computer 14 with vehicles used in formulating the colorant layer include, machine readable data defining the graphic to be to for example, low molecular weight polyethylene and pol- printed. From the data defining the graphic, the compu- ystyrene, vinyl polystearate, petroleum , polya- ter 1 4 generates a printing program for operating a ther- mide resins, acrylic resins, PVC, PVA and ethylene-vinyl mal printer 16 that prints the graphic on a thermally acetate copolymers. Mixtures of these and other waxes stable substrate. The program is stored in memory 18, and resins well-known to those skilled in the art are also and when the graphic is to be printed, a controller 20 45 used to formulate the colorant layer. The colorant layer reads the program and operates the printer. Once the may further include additional compounds such a sof- graphic has been printed on the substrate, it is trans- tening agents and plasticizers. ferred from the substrate to the fabric in a thermal trans- For multi-color graphics, the ribbon may include fer step carried out in press 22. only a single pigment in the colorant layer, in which case A thermal printer useful in practicing the invention is so the cassette 28 must be changed as each color of the illustrated schematically in Fig. 2. The printer, generally graphic is printed sequentially. Alternatively, the ribbon designated 16, includes a roller platen 24 over which 30 may be formulated with a standard CMYK colorant the thermally stable substrate S passes relative to a layer set, in which case process color printing can be thermal print head 26. The substrate S is supplied in carried out with a single cassette to print the multi- sheet or strip form and may be any thermally stable 55 colored graphic on thermal paper. medium known to those skilled in the art for use in ther- Turning now to the binder for adhering the pigment mal transfer printing processes. However, in the illus- to the fabric, the layer comprises a film-forming binder trated embodiment of the invention, the substrate S is provided on the ribbon 30 in a dissolved or finely dis- either a thermal paper available from, for example persed homogeneous state. The binder must exhibit

3 5 EP 0 732 440 A1 6 sufficient printability to be printed easily and precisely 22 is entirely eliminated. The only limiting factor here is on the thermal paper by the printer 1 6, and, when even- that the fabric must be capable of withstanding the heat tually transferred to the fabric by the heat and pressure generated by the thermal printer without degrading. generated by the press 22, the binder must form a clear, Whether the ribbon is constructed in the manner colorless film of uniform thickness which encloses the 5 described in connection with ribbon 30 or ribbon 42, it is pigment and adheres it to the fibers. Synthetic polymer desirable when using a resin, a wax or a wax/resin vehi- binders based on acrylic acid and butadiene and vinyl cle for the pigment to include a release layer between acetate are preferred. Binders that have been found to the polyester carrier and the immediately adjacent layer be particularly suitable include an acrylic colloidal solu- of either colorant or binder. Any suitable release agent tion available from Johnson Polymer, Racine Wl, under jo may be utilized as long as it provides the release layer the trademark JONCRYL 91 , an acrylic aqueous solu- with a melting point which is lower than the melting point tion available from Lawter International, Inc. under the of the colorant. Figs. 5(a) and 5(b) illustrate ribbons use- trade designation HYDRO-REZ 2000, and an acrylic ful in carrying out this aspect of the invention. As shown aqueous solution available from Miles, Inc., Pittsburgh, in Fig. 5(a), the ribbon includes a carrier layer 52, a PA under the trade designation Acramin Binder GD. 75 release layer 54 supported on the carrier layer, a color- Since the pigment and its binder are provided on a ant layer 56 supported on the release layer, and a single ribbon, the graphic P can be printed on the ther- binder layer 58 supported on the colorant layer. Alterna- mal paper S in a single step for subsequent transfer to tively, the ribbon 60 shown in Fig. 5(b) includes a carrier the appropriate fabric. Furthermore, since the binder 40 layer 62, a release layer 64 supported on the carrier is carried by the ribbon 30 and is not provided as a coat- 20 layer, a binder layer 66 supported on the release layer, ing on the thermal paper, binder is transferred onto the and a colorant layer 68 supported on the binder layer. fabric according to the data comprising the printing pro- In addition to the above-described methods for gram stored in memory 18. Thus, the method of printing printing a graphic on fabric, the invention encompasses taught by the present invention eliminates the disadvan- a method wherein a thermal printer, such as the printer tages of prior art methods of printing on fabric, wherein 25 illustrated in Fig. 2, and an associated ribbon are used the entire surface of the fabric is coated with binder, to print colorant, according to data defining the graphic including the non-print areas not covered by the to be printed, onto a thermally stable substrate, such as graphic. thermal paper, coated with a film of resin binder. A com- In the most preferred embodiment of the invention, puter-controlled plotter having a cutting blade and pro- the ribbon 30 comprises a general purpose high speed 30 vided with machine-readable data defining the graphic wax ribbon available from, for example, Advent Corpo- is then used to cut around the graphic after which those ration, Ellington, CT, under the trade designation AD- portions of the resin film which are not covered with col- 102HS, coated with an acrylic binder. The Advent rib- orant are removed. Thus, according to this method, the bon includes a base or carrier layer of polyester having thermal transfer comprises the thermally stable sub- a thickness of about 4.5 urn, which supports a pig- 35 strate covered with resin and colorant only in the print mented wax ink having a melting point of about 70°C area corresponding to the graphic. and an optical density of about 1 .85. The acrylic binder In yet another embodiment of the invention, a ther- comprises 90 weight % "Acramin GD", 10 weight % mally stable substrate, such as thermal paper, is coated "Acrafix MA" (Miles, Inc., Pittsburgh, PA), and a non- with resin binder. A barrier layer which prevents release ionic surfactant added at 1 % by weight of the total solu- 40 of the binder from the substrate in the transfer press is tion. then printed onto the non-print areas of the substrate. Referring now to Fig. 4, a second ribbon 42 is Using a standard ribbon, colorant is then printed onto shown for printing a graphic directly on fabric without the the print area of the substrate according to data defining need for a thermal transfer step. According to this the graphic to be printed. Accordingly, when the graphic aspect of the invention, the ribbon 42 includes a polyes- 45 is transferred to the fabric in the transfer press, binder is ter carrier layer 44, a layer of binder 46 supported on the transferred to the fabric in the print area only. carrier layer, and a colorant layer 48 supported on the In a modification of the above-described method, a binder layer. The composition of the layers 44, 46 and dry resin is coated onto the thermally stable substrate. 48 are identical to the corresponding layers described The resin forms one part of a two-part binder system above with respect to the ribbon 30, except that the so which also includes a microencapsulated activator for positions of the binder and colorant layers are reversed the resin dispersed in the colorant layer carried by the on the ribbon 42. By forming the ribbon 42 with the pig- ribbon. After the printer applies colorant to the substrate ment in the outermost layer, and supplying the fabric according to data defining the graphic to be printed, the directly to the printer in place of the thermal paper as microcapsules are ruptured by the pressure applied in the substrate S, it has been found that the thermal 55 the transfer press, and the activator is released into the printer 16 can be used to print pigment and binder resin. Accordingly, only the print area of the substrate, directly onto the fabric according to the data comprising i.e., that portion of the resin coated substrate which is the printing program. Thus, the step of transferring the covered by the colorant, is made tacky by the activator. graphic from the thermal paper to the fabric in the press Of course, the activator does not have to be incorpo-

4 7 EP 0 732 440 A1 8 rated into the colorant layer, but instead could comprise 4. The method of claim 3 wherein step (a) is further either a separate layer on the same ribbon carrying the characterized in that the printer has a single ribbon colorant or on a second ribbon used in a second printing including a carrier layer, a binder layer supported operation. on the carrier layer, and a colorant layer overlying 5 the binder layer; Claims and wherein steps (c) and (d) are performed simultaneously using the single ribbon. 1. A method for printing a graphic on fabric, said method comprising the steps of: 5. The method of claim 2 wherein step (a) is further 10 characterized in that the ribbon further includes a (a) providing a thermal transfer printer having a release layer between the carrier layer and the col- first ribbon and a second ribbon, said first rib- orant layer. bon including a carrier layer and a layer of a binder supported on the carrier layer, and said 6. The method of claim 4 wherein step (a) is further second ribbon including a carrier layer and a 15 characterized in that the ribbon further includes a layer of a colorant supported on the carrier release layer between the carrier layer and the layer; binder layer. (b) providing the thermal printer with data defining the graphic to be printed on the fabric; 7. A method of printing a graphic on fabric comprising (c) causing the thermal printer to print binder 20 the steps of: with the first ribbon onto a thermally stable sub- strate according to the data to form a print area (a) coating a thermally stable substrate with a including the binder, and an adjacent non-print resin binder; area; (b) printing a barrier layer which prevents (d) causing the thermal printer to print colorant 25 release of the binder onto the non-print areas with the second ribbon onto the print area of of the substrate; the substrate according to the data; and (c) printing colorant onto the print area of the (e) thermally transferring the colorant and substrate according to data defining the binder printed according to the data from the graphic to be printed; substrate to the fabric to print the graphic on 30 (d) transferring the printed graphic onto the fab- the fabric. ric, wherein the barrier layer prevents transfer of the binder from the non-print area of the sub- 2. The method of claim 1 wherein step (a) is further strate to the fabric. characterized in that the printer has a single ribbon including a carrier layer, a colorant layer supported 35 8. A method for printing a graphic on fabric, said on the carrier layer, and a binder layer overlying the method comprising the steps of: colorant layer; and wherein steps (c) and (d) are performed (a) providing a thermal transfer printer having a simultaneously using the 5 single ribbon. ribbon including a carrier layer and a layer of 40 colorant supported on the carrier layer; 3. A method for printing a graphic on fabric, said (b) providing the thermal printer with data method comprising the steps of: defining the graphic to be printed on the fabric; (c) coating a thermally stable substrate with a (a) providing a thermal transfer printer having a film of binder for the colorant first ribbon and a second ribbon, said first rib- 45 (d) causing the thermal printer to print the col- bon including a carrier layer and a layer of col- orant onto the substrate according to the data orant supported on the carrier layer, and said to form a print area on the substrate including second ribbon including a carrier layer and binder and colorant and an adjacent non-print layer of binder supported on the carrier layer; area of the substrate including the binder film (b) providing the thermal printer with data 50so only; defining the graphic to be printed on the fabric; (e) removing the binder film from the non-print (c) causing the thermal printer to print colorant area of the substrate; and with the first ribbon onto the fabric according to (e) thermally transferring the colorant and the data to form a print area including the color- binder from the print area of the substrate to ant, and an adjacent non-print area; 55 the fabric to print the graphic on the fabric. (d) causing the thermal printer to print binder with the second ribbon onto the print area of 9. A method for printing a graphic on fabric, said the fabric according to the data to bind the col- method comprising the steps of: orant to the fabric.

5 9 EP 0 732 440 A1 10

(a) coating a thermally stable substrate with a a thermal transfer printer having a first rib- binder for the colorant; bon and a second ribbon, said first ribbon including (b) providing a thermal transfer printer having a a carrier layer and a layer of colorant supported on ribbon including a carrier layer and a layer of the carrier layer, and said second ribbon including a colorant supported on the carrier layer, said 5s carrier layer and layer of binder supported on the colorant layer having an activator for the binder carrier layer; dispersed therein; means for providing the thermal printer with (c) providing the thermal printer with data defin- data defining the graphic to be printed on the fabric; ing the graphic to be printed on the fabric; a controller for causing the thermal printer to (d) causing the thermal printer to print the col- 10 print colorant with the first ribbon onto the fabric orant onto the substrate according to the data according to the data to form a print area including to form a print area on the substrate including the colorant, and an adjacent non-print area, and binder, colorant and activator and an adjacent for causing the thermal printer to print binder with non-print area of the substrate; and the second ribbon onto the print area of the fabric (e) thermally transferring the print area of the 15 according to the data to bind the colorant to the fab- substrate to the fabric to activate the binder and ric. print the graphic on the fabric. 1 5. The apparatus of claim 1 4 wherein the printer has a 10. The method of claim 9 wherein the activator forms single ribbon including a carrier layer, a binder layer a separate layer on the ribbon. 20 supported on the carrier layer, and a colorant layer overlying the binder layer; 1 1 . The method of claim 1 0 wherein the activator is car- and wherein the controller causes the printer ried on a second ribbon and the method further to print colorant and binder simultaneously. includes the step of printing the activator on the substrate according to the data defining the 25 1 6. A ribbon for printing a graphic on fabric using a ther- graphic. mal printer, said ribbon comprising a carrier layer, a second layer defined by one of a colorant layer and 12. An apparatus for printing a graphic on fabric, said a binder layer supported on the carrier layer, and a apparatus comprising: third layer defined by the other of a colorant and a a thermal transfer printer having a first rib- 30 binder layer overlying the second layer. bon and a second ribbon, said first ribbon including a carrier layer and a layer of a binder supported on 17. The ribbon of claim 16 further comprising a release the carrier layer, and said second ribbon including a layer between the carrier layer and the second carrier layer and a layer of a colorant supported on layer. the carrier layer; 35 means for providing the thermal printer with 18. A ribbon system for printing a graphic on fabric data defining the graphic to be printed on the fabric; using a thermal printer, said system comprising: a controller for causing the thermal printer to a first ribbon including a carrier layer and a print binder with the first ribbon onto a thermally layer of a binder supported on the carrier layer, and stable substrate according to the data to form a 40 a second ribbon including a carrier layer and print area including the binder, and an adjacent a layer of a colorant supported on the carrier layer. non-print area, and for causing the thermal printer to print colorant with the second ribbon onto the print area of the substrate according to the data; and 45 means for thermally transferring the colorant and binder printed according to the data from the substrate to the fabric to print the graphic on the fabric. 50 1 3. The apparatus of claim 1 2 wherein the printer has a single ribbon including a carrier layer, a colorant layer supported on the carrier layer, and a binder layer overlying the colorant layer; and wherein the controller causes the printer to print binder and colorant simultaneously.

14. An apparatus for printing a graphic on fabric, said apparatus comprising:

6 u EP 0 732 440 A1

8 EP 0 732 440 A1

Patent AppBra,i°n J Europe,* EUROPEAN SEARCH REPORT Office EP 96 10 3008

DOCUMENTS CONSIDERED TO BE RELEVANT _ . Citation of document with indication, where appropriate, Relevant CLASSIFICATION OF THE Category of relevant passages to claim APPLICATION 0nt.CI.6) A WO-A-92 00852 (SAWGRASS SYSTEMS INC) 23 1-18 D06P5/00 January 1992 B41J2/325 * 3, line 15 - line 23 * B41M5/38 * page 6, line 9 - line 12; claims * B41M5/035

A MANUFACTURING CLOTHIER INCLUDING: WOMEN'S 1-18 WEAR MANUFACTURER, vol. 72, no. 10, 1 October 1991, page 22 XP000234048 "ADVERTISEMENT" * the whole document *

A GB-A-2 189 436 (OLIVEIRA AMANDA UCHOA D) 1-18 28 October 1987 * the whole document *

A DE-A-34 22 286 (WILHELM HAMMANN GMBH & CO 1-18 KG) 19 December 1985 * the whole document *

A GB-A-2 243 332 (BROTHER IND LTD) 30 1-18 firtnhor 1QQ1 TECHNICAL FIELDS uciouer searched am.ci.6) * page 6, line 3 - line 13; claims; figures * D06P B41J A EP-A-0 496 337 (MATSUSHITA ELECTRIC IND CO 1-18 B41M LTD) 29 July 1992 D06B * page 7, column 12, line 56 - page 8, column 13, line 14 *

A US-A-5 326 622 (YAMANE MITSUO ET AL) 5 July 1994

A EP-A-0 304 378 (BASF AUSTRALIA ;DONENFELD HENRY (AU)) 22 February 1989

The present search report has been drawn up for all claims Place of March Dale of aupuum of the Karen THE HAGUE 21 June 1996 Bias, V CATEGORY OF CITED DOCUMENTS T : theory or principle underlying the invention E : earlier patent document, but published on, or X : particularly relevant if taken alone after the filing date Y : particularly relevant if combined with another D : document cited in the application document of the same category L : document cited for other reasons A : technological background O : non-written disclosure ft : member of the same patent family, corresponding P : intermediate document document

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