Methods of making stenciled screens
View Patent ↗Methods of making a stenciled screen for use in screen printing an image onto a substrate are generally disclosed. The method involves removing a portion of a transfer coating from a transfer sheet via heat transfer with a printable sheet defining a printable surface. The portion of the transfer coating removed from the transfer sheet corresponds to areas where an ink is present on the printable surface of the printable sheet. The transfer coating can then be transferred to a screen to form a stenciled screen having closed mesh areas corresponding to where the transfer coating is present. The stenciled screen can then be used to screen print an image onto any of a variety of fibrous substrates.
1. A method of making a stenciled screen for use in screen printing an image onto a substrate, the method comprising:
removing a portion of a transfer coating from a transfer sheet via heat transfer with a printable sheet defining a printable surface, wherein the portion of the transfer coating removed from the transfer sheet corresponds to areas where an ink is present on the printable surface of the printable sheet, wherein the transfer coating comprises a film forming binder and a powdered thermoplastic polymer, and wherein the transfer is performed at a first transfer temperature of about 50° C. to about 150° C.; and
transferring the transfer coating remaining on the transfer sheet to a screen at a second transfer temperature of greater than about 150° C., wherein the transfer coating transfers to the screen at the second transfer temperature to form a stenciled screen having closed mesh areas where the transfer coating is present.
2. A method as in claim 1 , wherein the powdered thermoplastic polymer has a melting point of from about 140° C. to about 220° C.
3. A method as in claim 1 , wherein the powdered thermoplastic polymer comprises a powdered polyamide copolymer.
4. A method as in claim 1 , wherein the film-forming binder comprises reactive carboxyl groups.
5. A method as in claim 4 , wherein the film-forming binder comprises an ethylene acrylic acid dispersion.
6. A method as in claim 1 , wherein the transfer coating further comprises a crosslinking agent.
7. A method as in claim 6 , wherein the crosslinking agent comprises an polyfunctional aziridene.
8. A method as in claim 6 , wherein the transfer coating further comprises a crosslinking catalyst.
9. A method as in claim 1 , wherein the transfer coating further comprises a plasticizer.
10. A method of making a stenciled screen for use in screen printing an image onto a fibrous substrate, the method comprising:
providing a printable sheet defining a printable surface;
printing a toner ink onto the printable surface of the printable sheet to form inked areas on the printable surface and areas free of ink on the printable surface;
providing a transfer sheet comprising a transfer coating overlying a release layer overlying a base sheet, wherein the transfer coating comprises a film forming binder and a powdered thermoplastic polymer;
positioning the transfer sheet adjacent to the printable sheet such that the transfer coating of the transfer sheet contacts the printable surface of the printable sheet to form a temporary laminate;
heating the temporary laminate to a temperature of about 50° C. to about 150° C.;
separating the transfer sheet from the printable sheet such that the transfer coating is transferred to the printable sheet only at the inked areas;
thereafter, positioning the transfer sheet in contact with a screen such that the remaining transfer coating contacts the screen; and
transferring the remaining transfer coating from the transfer sheet to the screen at a second transfer temperature of greater than about 150° C. to form the stenciled screen having closed mesh areas where the transfer coating is present.
11. A method as in claim 10 , wherein the powdered thermoplastic polymer comprises a powdered polyamide copolymer.
12. A method as in claim 10 , wherein the film-forming binder comprises reactive carboxyl groups.
13. A method as in claim 10 , wherein the film-forming binder comprises an acrylate latex.
14. A method as in claim 10 , wherein the transfer coating further comprises a crosslinking agent.
15. A method as in claim 14 , wherein the crosslinking agent comprises an epoxy resin.
16. A method as in claim 10 , wherein the transfer coating further comprises a plasticizer.