Hello group, I am not in the injection mold business but searching for answers on a hot topic in the sealing ring market. Many shops across the world are encountering problems arising from what appears to be a defective or worn injection mold and as an instructor for my industry, automatic transmissions, I am curious to get some questions answered. I have included a pic of a defective ring and welcome your questions or comments.
My searches have led me to a possibility of "flash" occurring at the "parting line" in a worn or aged mold. In what I am seeing though, this doesn't look like random etching form a worn mold, if that is even possible on a steel mold being injected with molten PEEK.
As you can see in the photo, it doesn't appear to be a simple flash, rather, almost like two mismatched mold meeting in the side wall of the ring were used together.
It's as if it is a staircased step, almost as though it was designed to be there. The trouble is, when placed into a bore, in short order, it is wearing out the soft aluminum or even steel bores it seals in and causing Honda vehicle owners, to have repeat failures after transmission repairs are made using these rings. It seals great at first for the step makes for a tighter bore, but too tight apparently, and the OEM Honda rings are not this way. My question is, what possible ways can this happen? And do any of you have or know where I can get photos makeing this matter more explainable to my customers.
Manufacturers of this ring are not willing to discuss this so I am reaching out to you guys to get answers, not to cause a ruckus, but to satisfy my curiosity. Thanks in advance
Hi, there can be several reasons for this - but the main one would be a bad mold. If the mold is worn out, then there is no chance of getting good parts. There are also considerations of mold design and its construction that can cause this issue. Not sure where you can get more info and pictures on this. If this is your mold, then the molder must give you the info that you need. Where are you based out of?
Sorry cant be of much help.
Regards,
Suhas
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