MOLD FOR INJECTION MOLDING

Abstract

A Mold is provided for injection molding, for example for injection molding of optical components of automotive lighting devices. The mold includes a mold body with a coating applied on a surface of the mold body. The coating comprises electroless nickel.

Claims

1. A mold for injection molding comprising: a mold body having a surface; a coating applied on the surface of the mold body, wherein the coating comprises electroless nickel.

2. The mold according to claim 1, wherein the coating has a thickness in the range of 2 μm to 50 μm.

3. The mold according to claim 1, wherein a surface of the coating features a lower roughness level compared to the surface of the mold body.

4. The mold according to claim 3, wherein the surface of the coating features a lower nanoscopic roughness level and/or a lower microscopic roughness level compared to the surface of the mold body.

5. The mold according to claim 3, wherein the surface of the coating has a root-mean-squared profile roughness in a range of 0.001 μm to 0.02 μm.

6. The mold according to claim 3, wherein the surface of the coating has an average absolute profile slope in a range of 0.01° to 0.5°.

7. The mold according to claim 3, wherein the surface of the coating has a lower waviness level compared to the surface of the mold body.

8. The mold according to claim 1, wherein the electroless nickel comprises phosphorus at a portion in the range of 3 at. % to 14 at. %.

9. The mold according to claim 1, wherein the coating features a hardness in the range of 30 HRC to 80 HRC.

10. The mold according to claim 1, wherein the mold body comprises a metallic material.

11. The mold according to claim 1, wherein the mold body has a hardness in the range of 20 HRC to 70 HRC.

12. The mold according to claim 1, wherein the electroless nickel comprises phosphorus at a portion in the range of 6 at. % to 9 at. %.

13. The mold according to claim 1, wherein the coating features a hardness in the range of 65 HRC to 75 HRC.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

[0019] FIG. 1 is a cross-section of a first embodiment of a mold.

[0020] FIG. 2 is a cross-section of a second embodiment of a mold.

DETAILED DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 and FIG. 2 show cross-sections of segments of inventive molds 100 each comprising the mold body 1 with the electroless nickel coating 2 applied to the surface 11 of the mold body 11. The surface 11 of the mold body 1 features both microscopic asperities 12 and nanoscopic asperities 13 representative of different orders of the surface roughness. Such different roughness orders stem for example from different machining processes applied to the mold body 1, e.g. milling or electrical discharge machining and/or subsequent grinding or manual polishing. Alternatively, the microscopic asperities 12 can be part of a dedicated surface pattern, which is intendedly structured into the surface 11 in order to generate a corresponding surface pattern on the molded part, e.g. for optical elements with light diffusing or light diffracting properties. The coating 2 yields a mirroring, high-gloss surface appearance of the mold 100.

[0022] The thickness 20 of the coating 2 is chosen according to the desired, application-specific surface topography of the coating 2 and/or the functionality of the coating 2 regarding the protection of the mold body 1 from mechanical wear and/or corrosion.

[0023] The embodiment of the mold 100 shown in FIG. 1 features a comparably thick coating 2, e.g. with a thickness 20 of about 10 μm to 50 μm, which exhibits a basically flat surface 21, thus smoothing the roughness of the underlying surface 11 of the mold body 1. The surface 21 of the coating essentially defines the surface quality of the parts injection-molded by the inventive mold 100 and the smooth surface 21 depicted in FIG. 1 is therefore especially appropriate for the manufacturing of optical components with even surfaces, e.g. base bodies for reflectors and decorative elements with thin metallic mirror coatings or for highly transparent lenses or covers panes.

[0024] FIG. 2. shows an embodiment of the mold 100 with a coating 2 of much lower thickness 20, e.g. about 2 μm to 20 μm. The coating 2 flattens the nanoscopic asperities 13 of the surface 11 of the mold body, but essentially preserves the contour of the microscopic asperities 12. The mold 100 is therefore dedicated for injection molding of optical components with patterned surfaces, e.g. diffusors or diffractive or holographic elements.

[0025] The present invention is not limited by the embodiment described above, which is represented as an example only and can be modified in various ways within the scope of protection defined by the appending patent claims.

LIST OF NUMERALS

[0026] 100 mold [0027] 1 mold body [0028] 11 surface (of the mold body) [0029] 12 microscopic asperity [0030] 13 nanoscopic asperity [0031] 2 coating [0032] 20 thickness (of the coating) [0033] 21 surface (of the coating)