* Mold Opening Direction and Parting Line
At the beginning of the mold design, mold opening direction and parting line should be determined in the first place in order to minimize the influence of core-pulling slide and parting line on the appearance.
1. When mold opening direction is determined, product mix including ribs, locking block and flush should be designed to be in accordance with the mold opening direction to avoid that core-pulling reduces flat-fell seam, thus the mold life can be prolonged.
2. When mold opening direction is determined, appropriate parting line can be chosen to avoid that backoff exists in mold opening direction,thus appearance and performance can be improved.
*Ejection Angle
1. Proper ejection angle can avoid napping product. Ejection angle of smooth surface ≥0.5°; surface of fine grain (sand surface) ＞1°; rough surface ＞1.5°.
2. Proper ejection angle can avoid bad ejection, like whitened, deformed and broken.
3. When deep cavity structure is designed, the external surface angle ＞ the inner surface angle to ensure that the mold core is not of deviation when injection molding so that homogeneous product thickness can be gotten and to ensure the material strength of the product opening part.
*Product Stock Thickness
1. All kinds of plastics have certain stock thickness range, generally 0.5～4mm, when ＞4mm, cooling time will be overtimed and there will be problems like shrinkage; changing product structure should be considered.
2. Uneven stock thickness causes pinsink mark on surface.
3. Uneven stock thickness causes porosity and weld trace.
The article comes from China injection mold manufacturer - Mold Best Assurance Company Limited, website is www.mbamoldanddesign.com
