초록

A method of manufacturing a security item comprises extruding or casting a polymer plastics substrate and, during the forming process, introducing a security thread into the substrate. The security thread is embedded to different depths in the substrate so as to generate a windowed effect.

대표청구항 ▼

1. A method of manufacturing a security item, the method comprising forming a polymer plastics substrate and, during the forming process, introducing a security thread into the substrate, and causing the security thread to be embedded to different depths in the substrate so as to generate a windowed

1. A method of manufacturing a security item, the method comprising forming a polymer plastics substrate and, during the forming process, introducing a security thread into the substrate, and causing the security thread to be embedded to different depths in the substrate so as to generate a windowed effect in which the security thread is alternately exposed from and covered by a surface of the substrate.2. The method according to claim 1, wherein the forming process includes extrusion through an extrusion die.3. The method according to claim 2, wherein the security thread is introduced into the polymer plastics substrate downstream of the extrusion die, while the substrate is still molten.4. The method according to claim 3, further comprising selectively pushing the thread into the substrate.5. The method according to claim 4, wherein the security thread is preformed with an undulation generally corresponding with the pushing positions.6. The method according to claim 5, wherein the thread is preformed by holding the thread on a surface formed with recesses having perforated bases through which a vacuum is applied.7. The method according to claim 2, wherein the security thread is fed through the extrusion die and oscillated in a direction with a component orthogonal to the substrate thickness.8. The method according to claim 1, wherein the forming process includes casting in which the plastics polymer is supplied onto a release substrate through a nozzle.9. The method according to claim 8, wherein the thread is also supplied through the nozzle.10. The method according to claim 8, wherein the thread is oscillated in a direction with a component orthogonal to the substrate thickness.11. The method according to claim 8, wherein the release substrate has recesses corresponding to the window effect, the security thread being guided over the recesses.12. The method according to claim 8, wherein the substrate is perforated, the method further comprising applying a vacuum to the perforations in the substrate to hold the thread on the substrate.13. The method according to claim 8, wherein the release substrate is an endless belt.14. The method according claim 1, wherein the plastics polymer material is one of PVC, PET, PPT, PU, PBT, PP and PE.15. The method according to claim 1, wherein the security thread is made of substantially the same material as the substrate.