METHOD AND APPARATUS FOR EMBOSSING A PATTERN ON A SUBSTRATE COATED WITH A VARNISH

Abstract

A method and an apparatus for embossing a pattern into a varnish on a sheet-like substrate are provided. The method applies a planar stamp using a roller, while the apparatus includes a roller having a planar stamp.

Claims

1. An apparatus for embossing a pattern on a substrate coated with a varnish, comprising: a table for supporting the substrate; a planar stamp having one end fixed relative to the table; and a roller adapted to apply the planar stamp onto the substrate when supported by the table by lowering the planar stamp in an application direction towards another end of the table.

2. The apparatus of claim 1, further comprising a lamp adapted to cure the varnish through the planar stamp.

3. The apparatus of claim 1, further comprising a holder configured to hold the planar stamp at an end opposite to the fixed end, the holder being adapted to hold a portion of the planar stamp at an angle of more than 45° relative to the table.

4. The apparatus of claim 3, wherein the angle is more than 80°.

5. The apparatus of claim 1, further comprising a drive that drives the roller.

6. The apparatus of claim 5, wherein the drive that drives the roller in the application direction.

7. The apparatus of claim 6, further comprising a second drive that drives the roller in a peripheral direction that is opposite to the application direction.

8. The apparatus of claim 1, wherein the table is displaceable for feeding substrates thereon.

9. An apparatus for embossing a pattern on a substrate coated with a varnish, comprising: a table for supporting the substrate; a planar stamp having a first end fixed relative to the table; and a roller driven in an application direction and a peripheral direction opposite to the application direction, wherein the roller, when driven in the application direction, applies the planar stamp onto the substrate when supported by the table by lowering the planar stamp at an advance rate in the application direction towards a second end of the table that is opposite the first end, and wherein the roller, when driven in the peripheral direction, has a peripheral speed in the application direction that is lower than the advance rate.

10. The apparatus of claim 9, further comprising a drive that drives the roller in the application direction.

11. The apparatus of claim 10, further comprising a second drive that drives the roller in the peripheral direction.

12. The apparatus of claim 9, wherein the planar stamp is made of a material selected from a group consisting of polymer, silicone, two-component silicone rubber, and polyolefin elastomer.

13. The apparatus of claim 12, wherein the roller, when driven in the peripheral direction at the peripheral speed in the application direction that is lower than the application rate, is configured to compensate for elongation of the planar stamp.

14. The apparatus of claim 9, wherein the roller is configured to compensate for elongation of the planar stamp.

15. The apparatus of claim 9, further comprising a lamp adapted to cure the varnish through the planar stamp.

16. The apparatus of claim 15, wherein the lamp is adapted to follow the roller in the application direction.

17. The apparatus of claim 9, further comprising a holder configured to hold the planar stamp at the second end, the holder being adapted to hold a portion of the planar stamp at an angle of more than 45° relative to the table.

18. The apparatus of claim 17, wherein the angle is more than 80°.

19. The apparatus of claim 9, wherein the table is displaceable for feeding substrates thereon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0084] FIG. 1 schematically illustrates a side view of an apparatus for embossing a pattern;

[0085] FIG. 2 is a perspective view of one of the two levers on which a roller is mounted; and

[0086] FIG. 3 is a perspective view of a roller with gears.

DETAILED DESCRIPTION

[0087] The subject matter of the invention will now be described by way of the drawings of FIGS. 1 to 3 with reference to an exemplary embodiment schematically illustrated therein.

[0088] FIG. 1 schematically illustrates a side view of an apparatus 1 for embossing a pattern.

[0089] The apparatus comprises a table 2 which is configured to be displaceable and can be moved into the apparatus from the right in this view. Means for displacing a table are known to persons skilled in the art and are not illustrated.

[0090] A substrate 3, in particular in the form of a glass or glass ceramic sheet, rests on table 2 and is coated with a varnish (not shown).

[0091] For embossing a pattern, apparatus 1 comprises a planar, i.e. sheet-like stamp 4.

[0092] This view illustrates the position of stamp 4 at the start of the embossing operation.

[0093] Stamp 4 is fixed at one end by means of a stamp holder 12 as a stamp fixture. It may for instance be clamped or may have recesses into which engaging members of the stamp holder (not shown) engage.

[0094] During the embossing process, table 2 is locally fixed in the apparatus. Thus, stamp 4 is fixed at one end relative to substrate 3 by means of stamp holder 12.

[0095] The apparatus further comprises a roller 5 by means of which the stamp 4 may be applied onto the substrate 3.

[0096] For application of the entire surface of the sheet, a stamp holder 8 is provided which in this embodiment is equipped with a spring that allows for a movement of the stamp holder 8 in vertical direction.

[0097] During an embossing operation, roller 5 is advanced to the right, in the horizontal direction, by a drive 6.

[0098] Stamp holder 8 is also moved to the right, in a manner so that the angle between the stamp surface area not yet applied and the substrate 3 remains constant during the application process.

[0099] Arrow 9 symbolizes the movement direction of the advancing roller to the right.

[0100] As the stamp is applied, stamp holder 8 is moved vertically downwards, in a movement direction symbolized by arrow 10.

[0101] The movement of the upper edge of stamp 4 resulting therefrom is symbolized by arrow 11, running in a straight line towards a right edge of substrate 3.

[0102] Roller 5 can be lifted by means of a lifting mechanism 14.

[0103] A UV lamp which follows the movement of the roller is not illustrated in this view.

[0104] Preferably, the varnish applied on substrate 3 is cured through stamp 4 once the stamp 4 has been applied.

[0105] Then, roller 5 is lifted by lifting mechanism 14 not shown in more detail here, and the stamp is lifted substantially in the opposite movement direction, i.e. opposite to arrow 11.

[0106] Then, substrate 3 may be retracted from the apparatus by means of table 2 and may be subjected to further processing steps.

[0107] Roller 5 is mounted on pivotable levers 7 which are connected to the apparatus or lifting mechanism 14 via a vibration damper 15.

[0108] Furthermore, the roller is driven by an active drive 13. The peripheral speed of roller 5 is adjustable, in particular such that it might be slightly less than the advancing rate when applying the stamp 4.

[0109] Stamp 4 should be applied in a manner so that the angle of the not yet applied portion of stamp 4 (except for the portion that directly engages the roller) and the substrate 3 is more than 45°, preferably more than 75°.

[0110] Preferably, the roller has a diameter between 3 and 50 cm.

[0111] Details of the roller mechanism will now be explained with reference to FIG. 2 and FIG. 3 which are perspective views of components of the apparatus.

[0112] FIG. 2 illustrates one of the two levers 7 on which the roller is mounted.

[0113] It shows the shaft 16 of the roller and gears 17 and 18 through which the roller is actively driven.

[0114] Moreover, a belt 19 can be seen, which serves to drive gear 18 by which the roller is driven through gear 17.

[0115] It goes without saying that the drive mechanism illustrated herein may as well be configured in any other manner.

[0116] Levers 7 are pivotally arranged on a bearing 21 so that roller 5 can be raised to be relieved when the stamp is lifted.

[0117] FIG. 3 shows roller 5 with gears 17.

[0118] Shaft 16 of roller 5 is mounted in ball bearings 20 which are inserted into the levers (7 in FIG. 2).

[0119] The invention permits patterning of highly viscous varnishes with high pattern fidelity, reduced number of defects, and high processing speed.

TABLE-US-00001 LIST OF REFERENCE NUMERALS 1 Apparatus for embossing a pattern 2 Table 3 Substrate 4 Stamp 5 Roller 6 Drive 7 Lever 8 Stamp holder 9 Movement direction of advancing roller 10 Movement direction of stamp holder 11 Movement of stamp upper edge 12 Stamp holder 13 Active drive 14 Lifting mechanism 15 Vibration damper 16 Shaft 17 Gear 18 Gear 19 Belt 20 Ball bearing 21 Bearing