key point of injection mold design (2/2)

  2.8 one hinge

2.8.1  for PP material toughness, can be designed hinge and product to be an integration.

2.8.2 as a film hinge should be less than the size of 0.5mm, and to maintain a uniform ,

2.8.3 When integrally injection hinge design, the gate only can be designed at one side of the hinge .

 

  2.9 inserts

2.9.1 In the injection molding ,inserts increase the local strength , hardness, dimensional accuracy and setting small screw holes ( shaft )  to meet a variety of special needs. Will also increase the cost of the product .

2.9.2 Insert typically may be copper ,or other metal and plastic.

2.9.3 insert embedded in the plastic part should stop rotation and anti- pull design structure . Such as: knurled , holes , bending, flattening and so on.

2.9.4 insert should be appropriately thick plastic around to prevent stress cracking of plastic parts .

2.9.5 design inserts, should fully consider the positioning in the mold ( holes , pins, magnetic )

 

  2.10 logo

   Product identification is generally set in the relatively flat surface of the product , and the use of convex form , select the consistent face of mold opening, or may cause the part injury .

 

  2.11 precision injection molded parts

  Due to heterogeneity and uncertainty injection shrinkage , significantly lower than the metal injection molding precision parts, should Select the appropriate standard tolerances (OSJ1372-1978)

 

  2.12 deformation of injection molded parts

  Improve the rigidity of the injection of product structure, reduce deformation . Try to avoid flat structure , a reasonable set of cuffs , uneven structure. Set reasonable reinforce ribs .

 

 2.13 GAIM

2.13.1 using gas-assisted injectionmolding, can improve product rigidity and reduce distortion.

2.13.2 using GAIM avoid sink mark.

2.13.3 using gas-assisted injection molding, can save raw materials, shorten the cooling time .

 

  2.14 welding ( hot plate welding, ultrasonic welding , vibration welding )

2.14.1 welding , can improve the coupling strength.

2.14.2 welded to simplify product design.

 

3 . Reasonable to consider the contradiction between process and product performance

Must be integrated into contradiction product appearance , performance and design of injection molding processes Sometimes sacrifice some process to get a good appearance or performance.

3.1 if sometimes mold design can not avoid injection defect, try to design and make the defect on the hidden place of the parts.

 

 

Injection molding design points

1 , the direction of mold open and mold parting line

2 , draft angle

3 , thickness of the part wall

4 .ribs

5 , chamfer, rounded corners and holes

6 , core-pulling mechanism and avoid

7 , plastic deformation

8 , one hinge

9 , insert

10 , GAIM

11 , considering the technology and performance parts

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