Punching die for punching machine

Abstract

A die is provided for printing through a print carrier onto an object in a hot stamping machine. The die comprises a first layer of a first material, hereinafter referred to as the base layer, the hardness of which is less than 50 shore A measured according to ISO 868 or DIN 53505, and the thickness of which is greater than 20 mm. The die includes a second layer of a second material, hereinafter referred to as the printing layer, the hardness of which is greater than 50 shore A measured according to ISO 868 or DIN 53505, and the thickness of which is less than 5 mm. The second layer is intended to be in contact with the print carrier.

Claims

1. A die for printing through a print carrier onto an object in a hot stamping machine, the die comprising: a base layer composed of a room-temperature vulcanizing (RTV) silicone having a hardness less than 50 shore A measured according to ISO 868 or DIN 53505, the base layer having a thickness greater than 20 mm; a printing layer composed of a second material having a hardness greater than 50 shore A measured according to ISO 868 or DIN 53505, the printing layer having a thickness less than 5 mm and configured to contact the print carrier; and a mounting bracket for attachment to the hot stamping machine, the mounting bracket composed of dural.

2. The die according to claim 1, wherein the hardness of the RTV silicone is between 10 and 40 shore A measured according to ISO 868 or DIN 53505, and the thickness of the base layer is between 30 mm and 60 mm.

3. The die according to claim 1, wherein the hardness of the second material is between 60 and 90 shore A measured according to ISO 868 or DIN 53505, and the thickness of the printing layer is between 1 mm and 3 mm.

4. The die according to claim 1, wherein the second material is a high-temperature vulcanizing (HTV) silicone.

5. The die according to claim 1, wherein the RTV silicone of the base layer is a two-component silicone elastomer which cures at room temperature by a polyaddition reaction.

6. The die according to claim 1, wherein the printing layer is configured to be heated by radiation or by contact with a hot surface.

7. The die according to claim 1, wherein the base layer extends from the mounting bracket to a distal end of the base layer, and the printing layer is secured on the base layer at the distal end.

8. A hot stamping machine comprising the die according to claim 1.

9. The hot stamping machine according to claim 8, further comprising the print carrier configured to couple to one or more objects to be stamped.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Some embodiments of the invention will now be described by way of example only, with reference to the attached drawings in which:

(2) FIG. 1 is a cross-sectional view of a die according to an exemplary and advantageous embodiment of the invention;

(3) FIG. 2 is a top view of the die;

(4) FIG. 3 is a side view of the die.

DETAILED DESCRIPTION

(5) FIG. 1 illustrates a cross-sectional view of a die 10 for printing through a print carrier onto an object in a hot stamping machine according to an exemplary and advantageous embodiment of the invention. Such a die 10 comprises a first layer 11 of a first material that is, for example, a room-temperature vulcanizing (RTV) silicone, such as Bluesil RTV 3428 silicone, for example.

(6) This first layer will be referred to hereinafter as the base layer 11. For example, the hardness of the base layer 11 is less than 50 shore A measured according to ISO 868 or DIN 53505 and its thickness is greater than 20 mm. Advantageously, the first material has a hardness comprised between 10 and 50 shore A measured according to ISO 868 or DIN 53505, and a thickness comprised between 20 mm and 100 mm. According to an exemplary embodiment of the invention, the first material has a hardness comprised between 10 and 40 shore A measured according to ISO 868 or DIN 53505, and a thickness comprised between 30 mm and 60 mm.

(7) Such a die 10 also comprises a second layer 12 of a second material that is, for example, a high-temperature vulcanizing (HTV) silicone, for example, one of Thermosil and Ultrasil silicones.

(8) This second layer will be referred to hereinafter as the printing layer 12. For example, the hardness of the printing layer 12 is greater than 50 shore A measured according to ISO 868 or DIN 53505 and its thickness is less than 5 mm. Advantageously, the second material has a hardness comprised between 50 and 95 shore A measured according to ISO 868 or DIN 53505, and a thickness comprised between 1 mm and 5 mm. According to an exemplary and advantageous embodiment of the invention, the second material has a hardness comprised between 60 and 90 shore A measured according to ISO 868 or DIN 53505, and a thickness comprised between 1 mm and 3 mm.

(9) This printing layer 12 is intended to be in contact with a print carrier.

(10) FIG. 2 is a top view of the die 10 and FIG. 3 is a side view of the die 10.

(11) The colors of the first and second materials can be chosen by adding colorants without changing the mechanical properties of these materials.

(12) According to an exemplary embodiment of the invention, the printing layer must be heated to a temperature comprised between 100 C. and 200 C., for example to 160 C. The printing layer can be heated, for example, by radiation.

(13) It can also be heated by contact, by placing the pad on a hot surface such as a metal block heated by a heating resistor.

(14) The advantage of this die according to the invention is that it can retain the heat required for hot stamping in the working area (printing layer), while enabling it to adapt to objects with complex shapes and facilitating the application of the carrier.

(15) The difference with a typical die with a metal base layer and a silicone printing layer is that the first material used in the present application is more flexible than hot stamping silicones (minimum 40 shore A measured according to ISO 868 or DIN 53505). Moreover, pad printing silicone is not thermally conductive, which enables the temperature to be maintained at the surface of the pad.

(16) The die 10 is designed to be installed, for example, on a hot stamping machine that has a print carrier and on which one or more object(s) to be stamped are installed for stamping.

(17) Advantageously, the die 10 also comprises a mounting bracket 13 for attachment to the hot stamping machine, for example made of dural. Of course, the mounting bracket may be made of any other material. For example, it may be made of steel.

(18) A person skilled in the art will be aware that several variants of the aforementioned embodiments are conceivable without departing from the scope of the invention.