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Texturized surface repair

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 Figure 4 - Stamped on the cast traces of mold block’s corrosion Figure 5 - The cast with a disrupted texture after mold block repair. Figure 6 - A stamp on the cast – a trace of an inaccurate surfacing.

The most accurate exploiting of moulds for plastics articles casting with a texturized surface is not able to prevent from gradual quality loss of received production’s exterior. There are a lot of reasons for it: impurity hard spots in polymer melt, minor breakages and system upset of castings pushing, bench tool use for casting’s remove, accidental damages in the process of assembling-disassembling during minor repairs. Special mention should go to the irregularity of texture as a result of moulding surface corrosion in the process of moulds’ shipping and storaging: even imperceivable ingress of moisture leads to disastrous effects for moulding surfaces. The reasons for it - is a non-use of corrosion-preventive greases, low quality of steel, which is used to manufacture moulds, as well as an extreme susceptivity of texturized surfaces to corrosion.
Texturized surfaces defects may look like different-sized dimples, disconnected guide marks, traces of corrosion in the form of “hollow ulcers” or spots with a disrupted texture (fig. 4). There may be a surface damage after using hard or abrasive tools. As a result of it, practically a working mould does not provide useful quality of produced castings. A need arises to renovate disturbed texture of shape-generating mold block surface. At first sight this problem seems not really significant and enterprises begin experimenting on elimination of occurred defects. However, not every company which deals with plastic articles’ casting has got in its staff qualified specialists in a mould repair and moreover specialists who have the necessary know-how on a texturizing technology and textures repair. Having tried by available means to renovate geometry of a shape-generating mould part using surfacing and following fitter's work and having got a negative result –enterprises apply to organizations, which deal with texturing with a request to repair this texture. But, unfortunately, inaccurately carried out actions become a draw-back for proficient renovation.
The workshop performs local complete renovation of texture. Depending on the type of a defect and matrix’s size there is a possibility to have repair works straightforwardly at the customer’s without a mould complete disassembly. In this case mounting downtime significantly reduces.