Product and method for protecting metal during etching

Abstract

The present invention is directed to a method and apparatus for etching the interior of a mold. In one implementation of the invention the interior of a mold is coated with an acid-resistant material. A photosensitive laminate is partially exposed to light, with only those areas that are to be etched being exposed. The laminate is subsequently developed to remove that portion of the laminate that has been exposed. This removed portion corresponds to the portion of the mold that is to be etched. After development the laminate is positioned in the interior of the mold over the acid-resistant coating, and then portions of the acid-resistant material are abrasively removed. The laminate is lightly wetted in some implementations in order to make it more flexible and stretchable, thereby allowing it to more readily conform to the interior surface of the mold. The intact portions of the photosensitive laminate (those portions that were not exposed to the light) provide protection to the acid-resist material, while the developed and removed portions of the photosensitive laminate provide little or no protection.

Description

FIELD OF THE INVENTION [0001] The present invention is directed to a product and process for protecting metals during etching. More specifically, the invention is directed to a product and process for selectively protecting the interior of molds during etching to create a textured surface in unprotected areas of the mold. BACKGROUND [0002] Injection molding is widely used to manufacture mass-produced materials. Many injection molds have partially texturized internal surfaces to produce texturized articles. The texture on the internal surfaces can be formed using various methods, and one known method is to mask portions of the internal surfaces that are not to be etched, and then using an acid to etch the non-masked portions. This masking method can result in very precise texturized areas. [0003] Unfortunately, existing methods for masking portions of the internal surfaces of molds have significant limitations. One widely used method involves casting a wax masking material into an et...

AI Technical Summary

Benefits of technology

[0007] The present invention is directed to a process and product for improved etching of the interior surfaces of molds, in particular for the improved etching of interior surfaces of metal molds, such as molds used in injection molding. The invention permits precise etching of selected areas of the interior of a mold by masking those portions that are not to be etched. The invention also allows rapid masking without sacrificing quality or precision of placement of the etching mask.

Problems solved by technology

This masking method can result in very precise texturized areas.

Unfortunately, existing methods for masking portions of the internal surfaces of molds have significant limitations.

Unfortunately this method is difficult to perform on large surfaces, image quality can easily be degraded during transfer, placement in the mold is often a challenge with the paper carrier, and even the heat of burnishing can cause some loss of resolution and position of the acid resist.

This method also poses significant problems, including difficulty in positioning the carrier substrate inside a mold, in particular a mold with a curved or complex interior geometry.

Also, the heat of burnishing can be a problem, as can be movement of the carrier substrate during transfer of the acid resist material to the substrate.

Yet other methods are known, but these too have problems relating to the ease and accuracy of placement of the resist on the interior of a mold, in particular the interior of irregularly shaped molds.

Also, some such methods are time consuming, involving undesirable solvents, or do not provide good, precise masks.

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