Just curious about you guys that make parts in a production shop as to how many you can cycle through a single mold in a weeks time(50-60 hrs). Lets say you have a moderately complex mold you are infusing with a room temp epoxy that might have approximately 2 sq ft of surface, and you have an oven for post cure. What’s your experience? Do you have multiple molds for some high production parts?
Jon
It is quite normal to have 1 part / mould / day. Any higher and you lose the advantage of an overnight cure.
Most high volume parts are polyester, and there are special peroxides which have the same geltime, but a faster cure than standard peroxides.
I know Mercedes has a mould where they pop out an epoxy product every 14 minutes.
what are the advantage of a overnight cure? (initial room temperature cure + post cure, instead put the piece immediately in oven after infusion)
There are many epoxy resin with a very fast cure, I have found resin with 10 min cure, 5 min and I read about a new resin with a 1 min cure (they are used with high-pressure rtm)
Im using huntsman Epoxy system that will gel in 3-5 minutes at 100*C . I usually wait till the part gels and then throw it in the oven to full cure. This can range anywhere from 3 hours to 10 hours depending on the heat I set the oven to. I usually will have molds laid up and ready for infusion the night before I leave and then in the morning I can come in, infuse, put in the oven, trim and work on the previous days cured parts and then lay up the next mold to infuse the next day.
We routinely rotate molds every two hrs. we are a pre preg and autoclave shop. I know that is not infusion but its what we do . so a normal day hustling a mold is 4-5 parts from one mold.
It all depends on temperature. If you are willing to heat the mould, anything can happen (thinking about the “PIM” system from Huntsman. PIM=parts in minutes).
With low tech polyester products, heat is not an option usually. Thatis where the overnight cure jumps in.
This can vary hugely depending upon the lay up schedule of parts, some of our more regular parts take half an hour to perform the lay up and parts can be demoulded after a few hours, other parts of not much larger size have a lay up schedule that can take 6 hours to lay up and can not be demoulded for 24 hours due to the curing schedule. Unfortunatly you can not generalise on demould times and such like, every part and every resin system id different!
I appreciate everybody’s input and the varied information offered. It’s all very helpful to see that some processes, molds and parts lend themselves to a higher production rate while others do not. Great info for a rookie like me.
Jon