Plastic Injection Molding Design Tips

plastic injection molding machine




At Tenere, we are experts in working withbob sports .We understand the complications that come with adjusting a design to complement thebob sports 制造过程。我们的Design for Manufacturability (DFM) engineers拥有数十年的经验,可以帮助客户对其设计进行修改,以确保其产品可以制造,具有成本意识,可以达到几何公差,并与所选材料合作而不会损害产品的完整性和功能。

*engineering tip: .step files are the best choice when sharing design files

We have put together 6 design tips to help engineers with designing for injection molding.

Tip 1: Do not design a part with non-uniform nominal wall thickness

  • 各个不同的壁厚会在整个过程中产生不均匀的填充cavity
  • 较薄的部分比较厚的区域更快,导致高应力的区域发生变形和扭曲
  • It is recommended to core out the thick areas to create uniform walls, which will reducecycle timeand plastic usage and improve part cosmetics
  • Depending on the type of material being used, nominal wall thickness should not vary more than 15%

Tip 2: Do identify possible sink areas and design them out

  • Sink areas are likely to occur at intersections of a rib and nominal wall where proper design guidelines are not followed
  • Rule of thumb: Ribs should be a maximum of 70% of nominal wall, but 60% is preferred
注射成型设计插图 - 水槽

Tip 3: Do create radii on all corners


  • Sharp inside corners become stressed and outside corners are difficult to fill and trap air
  • Avoid radii onparting line– causes excess expense on tool build
  • Adding radii improves fill of corners and distributes stress across a larger area
  • .030" radius minimum if possible and if radii are less than .010" they are not worth adding to design
  • 将半径放在设计树的尽头,使与DFM工程师的合作更加容易

Tip 4: Do allow at least 1° draft for part release

  • For textured surface, more draft is required – follow texture guidelines
  • If possible, more than 1° draft is better
  • 3° draft or more is needed when parting line transitions from one level to another
    • Less than 3° draft causes the steel to squeeze together when mold closes making the mold harder to pull apart and creating drag marks on the part
injection molding design illustration - draft and radius

Tip 5: Do not design bad steel conditions

  • 当设想创建零件形状所需的钢时,请避免非常锋利,高且脆弱的钢条件
    • 钢会变热并且变脆
  • 钢制条件高度应尽可能不超过宽度的4倍
  • When in a corner, one rib is better than two to allow the steel to cool better
injection molding design illustration - steel conditions

Tip 6: Do not design deep ribs with square corners

  • It will trap gas and cause short shots
  • 弹出部分会更困难