Talk Composites - The Forum for Advanced Composites

Avoid Shrinkage - Resin Polyester

http://www.talkcomposites.com/Topic25209.aspx

By Dezer - 2/16/2018 10:51:58 AM

Hello friends,

I intend to make a medium-sized piece (1.35mx 0.30m) with polyester resin, but I saw that it corrodes the potential risk of shrinkage during resin curing.

- The resin has the gel time of: 30 minutes and the manufacturing process would be by Hand Layup + vacuum bag or Resin nfusion.

The doubts are as follows:

"What do I have to do to stop this from slowing down?"
Because I can not have dimensional changes due to the product accessories.

Desmoulding after 4 hours of lamination cause me problems?

We have a small production line and we need to be quick in our process.

Thanks,
Dezer
By ana - 10/12/2020 4:33:14 PM

 
Warren (Staff) - 10/12/2020 4:22:22 PM
Also, where possible, consider a filled "low shrinkage" polyester for the mould and the part. if you can reduce it with a better resin to start with then that will help and the other methods will further help.  

However low shrinkage is unlikely to mean no or negligible shrinkage.

If you really struggle, in your conditions, measure shrinkage then compensate in the pattern and mould design to account for it.  Not ideal and another added layer of complexity but can work when conditions are repeatable and known.

Tanks so much
We use cast resin in mold
This is normal resin we have with 1.5 % shirinkage .
1 hrs after gelation is normal for demolding ??