Plastic Mold Approval Checklist
Plastic Mold Approval Checklist
(OP)
I would like to have a comprehensive set of parameters that I am prompted to review when I receive a mold layout drawing for an injection molded part. Does anyone have a checklist or approval form they use upon review of the supplier's submitted drawings of the mold layout? Or can anyone supply any suggestions as to what they look for when approving the mold layout? Some things that come to mind are: Gate locations, injector pin locations, no. of cavities (economics included), location of raised characters or symbols, etc.






RE: Plastic Mold Approval Checklist
1.part design
2. number of cavities *required machince-shot size, tonage
3. type of mold
2 plate-hot runner, cold runner,
3 plate-hot runner, cold
4.placement of cavities.
5.type of gate-
6. temperature control system-surface, cores
7.ejection-pins, stripper rings
8. Vents- PL, inserts, ejector pins,
9. mold materials-base, inserts, cores
10. anticipated shrink-part design, gating, processing conditions.
Thats a good start.
Thanks gastrow
RE: Plastic Mold Approval Checklist
For context, when my company orders a plastic molded part from a supplier, we typically request an overview of the mold drawings. The idea is to look for the things that may affect our part functionally, cosmetically, or economically.
I don't pretend to understand the intricacies of mold design and development, and wouldn't begin to be able to tell the supplier how best to construct his mold.
Therefore I am interested in knowing if others have a similar method of operation, and how they approach it.
RE: Plastic Mold Approval Checklist
The performance of any given mold is determined more by external factors, like skill, process control and machinery condition, than it is to details of mold design.
Mike Halloran
Pembroke Pines, FL, USA
RE: Plastic Mold Approval Checklist
Regards
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RE: Plastic Mold Approval Checklist
As you,the most important is:try to shorten the cycle time (cooling layout)and mold size,the mold quality(hardeness,no sharpe,no impaction between mold components)!
you can also give a expexted cycle time to the mold factory for a reference!
Wish this can help for you!
RE: Plastic Mold Approval Checklist
You need to verify that the mold will fit your press, are the lifting holes right size for the weight of mold, are the KO locations correct and so on.
I would not have a mold built without having a design review done before steel is ordered.
RE: Plastic Mold Approval Checklist
I have been a tooling engineer and processing engineer for the past 15 years and I have learnt the most important things to look for are cooling circuits, gates and runners, position of ejector pins, press size, shot weight, clamp force required etc etc...
Toolmakers will always put in the least amount of cooling as possible as this creates less work. I always make sure if possible to have 4 x separate circuits per half of the tool. This enables the process engineer to set variable temp across the tool in the event of distortion on the moulded part. Gate design can normally be taken from material data sheets but always start small. If at all possible try get a MoldFlow done and send this onto the toolmaker, make sure the steel selection is of high quality steel i.e P20 or H13 tool steel. Deep ribs/bosses over the 15mm mark should be fitted with split inserts, this helps with polishing and venting. Thin blade sections should be inserted using berrilium copper or equivalent.
The list can go on but if you follow the simple points above you can't go wrong