1. Product wall thickness
(1) All kinds of plastics have a certain range of wall thickness, generally 0.5 to 4mm. When the wall thickness exceeds 4mm, it will cause the cooling time to be too long and cause shrinkage and other problems. Consider changing the product structure.
(2) Uneven wall thickness will cause surface shrinkage.
(3) Uneven wall thickness will cause pores and weld lines.
2. Mould opening direction and parting line
At the beginning of the design of each injection product, the mold opening direction and parting line must be determined first to ensure that the core pulling slider mechanism is minimized and the impact of the parting line on the appearance is eliminated.
(1) After the mold opening direction is determined, the reinforcing ribs, buckles, protrusions and other structures of the product are designed to be consistent with the mold opening direction as much as possible, so as to avoid core pulling and reduce seam lines and prolong the life of the mold.
(2) After the mold opening direction is determined, an appropriate parting line can be selected to avoid the undercut in the mold opening direction, so as to improve the appearance and performance.
3. Demoulding slope
(1) Appropriate demoulding slope can avoid product fluffing (pulling). The demoulding slope of the smooth surface should be greater than or equal to 0.5 degrees, the surface of the fine skin (sand surface) should be greater than 1 degree, and the surface of the coarse skin should be greater than 1.5 degrees.
(2) Appropriate demoulding slope can avoid product top damage, such as top white, top deformation, and top rupture.
(3) When designing a product with a deep cavity structure, the slope of the outer surface should be larger than the slope of the inner surface as much as possible to ensure that the mold core is not deviated during injection molding, obtain a uniform product wall thickness, and ensure the material strength of the product opening.
4. Reinforcing ribs
(1) Reasonable application of reinforcing ribs can increase product rigidity and reduce deformation.
(2) The thickness of the stiffener must be ≤ (0.5~0.7) T product wall thickness, otherwise the surface will shrink.
(3) The single-sided slope of the reinforcing rib (Shanghai Mold Design Training School) should be greater than 1.5° to avoid top injury.
Post time: Sep-28-2022