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#078 Texture and Steel Materials

Category : Technical Calculations
May13, 2011

Texture is used for providing artificial undulation patterns or texturing on the surface of molded products.

"Texture" engraves undulations on the surface of the cavity similar to "etching", or "sandblasting".

In texture, etching, an acidic corrosive liquid is made to come into contact with and erodes the surface of the steel material under managed conditions.

When carrying out texturing, the technique is to pay attention to the following points.

(1) The surface roughness of the cavity surface should be polished as finely as possible.
Further, even the extent of polishing should be as uniform as possible.
When this is done, even the state of erosion of the undulations easily becomes uniform. If there are variations in the undulation pattern, the visual beauty perceived by the human eye may appear to be of a different nature. For example, the appearance of beauty seen under sunlight may be different from the appearance of beauty seen under the light of a white fluorescent lamp.

(2) The steel material should be of the same steel type as far as possible, and should be selected from the same lot.
If the steel type is different, the state of erosion may change in a subtle way. Even if the same erosion processing is done for SKD11 and the pre-hardened steel S55C, there may be subtle differences in the state of the undulations.
In addition, even if the same steel type is used, there is the danger of the finished state after texturing being different due to differences in the lot of the material or the direction of rolling of the material.
When a mold is prepared to yield multiple pieces of the product, or when there are many locations in which the mold is manufactured, or when the mold is produced simultaneously in Japan and other countries, it has been pointed out that there is the danger of the above cases occurring.
If the state of texturing becomes different, in order to carry out texturing again, it becomes necessary to carry out polishing again of the cavity surface which can lead to a huge loss of time.

(3) Particularly careful polishing is necessary for surfaces prepared by electric discharge machining.
Surfaces that are prepared by electric discharge machining will have a machining hardened layer that may have appeared, and hence it is recommended to carry out thorough polishing of such surfaces.

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