Wireless Batteryless Vacuum Measurement

The team at VacPuc have vast experience with Resin Infusion and have put together the below tips and tricks to help you with successful resin infusion.

Resin Infusion is an excellent process for reliably producing composite parts, with high fibre content and reduced mess and exposure to harmful chemicals. However, resin infusion requires careful attention to a number of factors to ensure a perfect result.

The most important factor in resin infusion is the leak integrity of the vacuum bag and mould. Performing a vacuum leak test is the most important quality control procedure in resin infusion.

How to perform a leak test:

• Place your VacPuc in a VacPuc pouch at the furthest point from the vacuum inlet.
• Scan the VacPuc.
• The vacuum level should be less than 20mbar.
• (Check the nameplate of your vacuum pump to ensure that this level of vacuum is achievable. Most resin infusion grade vacuum pumps can achieve 10mbar or less. )
• Close the vacuum inlet to isolate the vacuum bag. Monitor the leak rate – the vacuum should rise less than 10 mbar in 10 mins. Using the VacPuc history log is useful for keeping track of previous readings.

It is very unlikely that you will achieve this standard at the first attempt. Common places to look for leaks are:

• Dry fibre over the mastic sealant tape
•  Pleats
• §round fittings.

Sometimes no matter how hard you look for leaks, there is nothing obvious to find. In this case, moisture within the dry laminate is a likely cause. To remove moisture from your laminate you need to wait (often overnight) for moisture to be removed and the vacuum. Gently increasing the temperature of the environment (to say 35°C/95°F) will increase the rate at which moisture is removed.

If after an overnight hold, there is no change in leak rate, this means that it was not moisture but a leak, so you need to keep looking for the source of the leak. When the leak check has passed the limit of 10mbar/10min, you are ready for infusion.

It is important to perform a leak check on a new mould, before any mould release is applied, or any fibre laid into the mould. This way you can remedy any problems before lamination starts.

It is good practice to record the leak rate of the mould and the date of the leak check for future reference. Writing the achieved leak rate and date on the side of the mould is a good idea, for quick reference during future leak tests.

If you outsource your mould manufacture, we recommend adding a leak rate contractual requirement of the mould manufacturer. This test should be performed using VacPuc before the mould is shipped from the mould manufacturer.