Near the Spring Festival, many manufacturers have begun to have a holiday, todayJiezheng mould, editor of the still remaining positions, to introduce the design principles of plastic mold plastic products.
A, size, precision and surface roughness
< a > size
Size is mainly meets the requirement and installation requirements, at the same time, want to consider the processing and manufacturing of mould, equipment performance, consider the liquidity of plastic.
< 2 > accuracy
Many factors influence, have precision mold manufacturing, plastic components and process conditions, etc.
< 3 > surface roughness
Determined by the mold surface roughness, the general mold rough surface is lower than products level, the mold surface to the grinding and polishing, through products require mold cavity and core surface finish to consistent Ra < 0.2 um
No tolerance requirements on plastic ring free size, the magnitude 8, generally USES the standard can standard is the tolerance for hole size, and axial size can mark each negative on a business trip. Size of center distance can brown plus or minus tolerance, cooperate parts size than not fit size.
Second, the draft
Due to the plastic parts to produce cooling in the cavity and shrinkage phenomenon, clasp plastic cavity the protruding part of the core and cavity, remove the hard plastic, forcibly removed will lead to wipe points on the surface of the plastic, hair, in order to facilitate ejection, plastics design must consider and demoulding (and axial direction parallel to the interior and exterior, enough draft design, general 1 °, 1 ° 30 `.
General core slope than big cavity, the length of the core and cavity depth, the greater the slope is reduced.
Three, wall thickness,
In accordance with the requirements of plastic parts used (strength, stiffness) and the products the requirements of the structure characteristics and molding process
Wall thickness is too small, insufficient strength and rigidity, plastic filling difficult
Wall thickness is too big, increase the cooling time, low productivity, produce bubbles, shrinkage cavity, etc.
For wall thickness as uniform as possible, otherwise due to the cooling and solidification rate caused by different stress, plastic deformation and cracking.
Note: the above information by dongguan Plastic mold factory to sort out on the Internet, welcome to reprint, indicate the source!