Draft requirements for mould texturing 模具做皮纹时对脱模斜度的要求是多少?

One of the most common questions we are asked is “How much draft do I need for the texture that I want?”

The general rule of thumb is that you allow for 1.5 degrees of draft for each .001″ of texture finish depth. However, there are other considerations that must be taken into account due to the many new resins and polymers, molding improvements, and various other factors that come into play in modern plastic molding. Examples of situations that require additional draft are thin wall part design and high pressure molding.

Some important considerations to keep in mind are:

Is the vertical wall in question an inside or outside wall? If it is an inside wall, the part will shrink onto it during molding, so you will need more draft in order to apply a texture, or apply the texture at a lighter depth.

Certain plastics have very little shrinkage and will therefore not shrink away from outside walls as easily as other plastics. Thermosets, Ryanite, Glass Filled Nylon, Glass Filled Polypropylene, ABS, Polycarbonate, etc. will usually require more draft in order to mold parts without scuff or drag marks.

If the core is very simple, and there is nothing on the core to hold the part in place during ejection, the part will tend to hang onto the cavity, creating scuff marks. The part may require more draft, or perhaps texture could be applied to the core side. This helps hold the part onto the core during ejection. This method has been used very successfully to solve this sort of problem.