How good is the dimensional accuracy?
Dimensional accuracy of the material is important in ensuring that the components of industrial products function properly. In other words, how accurately can we reproduce the design dimensions in the product? Depending on the material, there will always be deviations from the design dimensions. Although there are also several other indicators, one of the superior qualities of SunForce is dimensional accuracy.
A foam with high dimensional accuracy
1Dimensional errors of molded products
The dimensional tolerance (and dimensional error) refers to the variation in the dimensions of the molded product. General foam-molded products used in shock absorbing applications etc. exhibit large shrinkage and expansion during fabrication, with consequently large dimensional tolerances.
Dimensional tolerances of molded products
Furthermore, as described above, the dimensional change at the time of fabrication is also very small, and molding at a level similar to ordinary injection molded products is possible. SunForce can be used with confidence in structures and chassis requiring dimensional accuracy.
2Coefficient of linear expansion
The linear expansion coefficient refers to the change in the dimensions of the material with temperature. The greater the value, the greater the dimensional change due to temperature. Although the numerical value for plastic is greater than for metal, SunForce assumes the characteristics of PPE plastic with its low coefficient of linear expansion in comparison with other plastics, and the effects of temperature are relatively small.
Linear expansion coefficient of various materials
3Low warpage and reduced sinkage in mold
One of the major features of foam molding. SunForce employs a method in which the mold is filled with beads which are then expanded and simultaneously fused with the heat from steam (Molding process guide). This process differs from injection molding in which plastic is poured into a mold at high temperature and high pressure, and is characterized by less warpage and sinkage even when the product incorporates large variation in wall thickness. This allows for freedom in design so that, for example, uniform wall thicknesses are not required.