Ejection checklist for mold design

 Checklist in Mold Design for Injection Molding, Ejection.

Usually, an ejector structure is required to remove the part from the cavity.


The following are design inspection items related to ejection of molded products.


(1) Does the formed product stay on the side envisioned in the design (usually the active side)?


(2) How many mm is the ejection stroke?


(3) Does the ejection stroke exceed the necessary ejection amount of the molded product?


(4) Is the ejection stroke larger than necessary?


(5) Is there a control mechanism for the ejection stroke? (block, etc.)


(6) In order to eject the boss, is it necessary to use a straight push tube?


(7) Are the ejector pins for ejecting the stiffener sufficient?


(8) Is the setting of the pneumatic ejector appropriate?


(9) Is the gas path of the pneumatic ejector appropriate?


(10) Has the compressed air supplied to the pneumatic ejector been dehumidified?


(11) Is it necessary to adopt a two-stage ejection structure?


(12) Is the two-stage ejection structure appropriate?


(13) Is the reset mechanism of the ejection plate appropriate?


(14) Is the reset pin properly configured?


(15) Is the strength of the return spring sufficient?


(16) Is ejection guide system required?


(17) Will there be interference between the ejector pin and the pillar of the molding machine?


(18) Have you confirmed the diameter and configuration of the ejector pin of the molding machine?


(19) Is the cross-sectional shape of the ejector pin appropriate? (round, square, shaped)


(20) Is the buckling strength of the stepped ejector pin sufficient?


(21) Is the surface roughness of the ejector pin tip surface appropriate?


(22) Is the quality of the tip edge of the ejector pin appropriate?

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