Plastic Lid Design
Plastic Lid Design
(OP)
Guys,
I am designing a small container, ~ 4" x 2" x 1.5" that can hold liquid without leaking out. This device basically consists of a base that has a lip around the perimeter and a cover which fits over that lip making a tight seal (think of a typical plastic tote you use around the house). Before the product goes into production (injection molding) we want to ensure that the seal remains tight throughout the products use (~2 week disposable). I've found plenty of documentation on press fit designs with plastic but they typically talk about a shaft in a hole. One advantage I have is that we have prototypes made of a SLA resin, but the question is how can I ensure the design is good before spending big money on tooling.
Some of the things I'm interested in:
1. What material properties play into the lid/base fit design?
Flexural modulus, flexural strength, creep resistance....
2. What's the best way to estimate the force required to make the interference
Any guidance would be appreciated.
Thanks,
Pete
I am designing a small container, ~ 4" x 2" x 1.5" that can hold liquid without leaking out. This device basically consists of a base that has a lip around the perimeter and a cover which fits over that lip making a tight seal (think of a typical plastic tote you use around the house). Before the product goes into production (injection molding) we want to ensure that the seal remains tight throughout the products use (~2 week disposable). I've found plenty of documentation on press fit designs with plastic but they typically talk about a shaft in a hole. One advantage I have is that we have prototypes made of a SLA resin, but the question is how can I ensure the design is good before spending big money on tooling.
Some of the things I'm interested in:
1. What material properties play into the lid/base fit design?
Flexural modulus, flexural strength, creep resistance....
2. What's the best way to estimate the force required to make the interference
Any guidance would be appreciated.
Thanks,
Pete






RE: Plastic Lid Design
Mike Halloran
Pembroke Pines, FL, USA
RE: Plastic Lid Design
The closer you can make the lid to circular the better, so keep the radii in plan view as big as possible.
Regards
Pat
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RE: Plastic Lid Design