How Additives Affect CIPP Resins

You don’t have to completely disavow resins that use filler, but you should know all the details of how to handle them and how they might affect your final product

How Additives Affect CIPP Resins

Interested in Rehab/Relining?

Get Rehab/Relining articles, news and videos right in your inbox! Sign up now.

Rehab/Relining + Get Alerts

“I had a supplier tell me that he was getting a ‘stronger’ resin than the regular epoxy resin for lining I typically buy and that it would be a better choice as it’s stronger. Is that true, or is this just a sales ploy to get me to buy their stuff?”

Let’s review the standards for CIPP resin as noted in the ASTM F1216 and go from there.

The standard says to use a resin/tube combination that meets a minimum 250,000 psi flexural modulus standard, a 4,000 psi flexural strength and a tensile strength of 3,000 psi. Those are the standards you should be concerned with and strive to meet or exceed. When additives or fillers are combined with the base resins, they may change the actual values of the material.

By adding talc, for example, to a weaker resin, you can increase the resin’s values to meet the standards. Usually fillers are less expensive than neat resin and are used by some suppliers to provide a lower-quality resin that meets the minimum standards outlined in the ASTM. That in itself may not cause a problem to the finished product depending on chemicals and heat that run through the lined pipe.

Calcium carbonate isn’t a good additive for sewers, as we find that hydrogen sulfide gas attacks and leaches out the materials over time, weakening the liner. Other additives may reduce the heat deflection temperature of the liner. We see many companies use a filler that will cause the liner to collapse at temperatures above 160 degrees F. Some additives require special handling, such as storage temperatures between certain levels or stirring materials before use to ensure the additives are fully mixed into the resin.

The bottom line is this: Additives are used to reduce production costs of resin. You should be paying less for a filled resin. You should know all of the effects and handling aspects of using the resin and where and when not to use it. Fillers in the resin are usually a detractor, not an enhancer.

About the author: John Heisler is the owner of Pipe Lining Supply and Quik-Lining Systems. He has more than 20 years' experience in the CIPP lining industry and over 40 years in the underground construction industry.


Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.