If you have ever opened up a glass jar with a metal lid, you might have noticed a gratifying "schlurrr-pop" sound (yep, that’s the technical term). I love this sound because it reassures me that I’m the first to open this container since it left the manufacturer. It means that I don’t have to worry whether or not the driver, shelf-stocking boy, or Suzie-Test-Before-Buying has opened my container and put their fingers or other things in my food.So, the reason for this post, other than my affection for tamper evident solutions, is to talk about Plastisol liners. Plastisol liners are one method that helps seal metal closures onto containers. Plastisol is a PVC gasket that is used in metal continuous thread and lug (sometimes called twist) closures. It is normally applied to metal lids in a ring shape on the inside of the lid at the point where it will match up with the landing of the bottle.

Plastisol material starts out as a solid. After being heated properly, Plastisol becomes liquidus and forms around the landing of the container that is being sealed. When the material cools it begins to cure, or solidifies, which then creates a tight vacuum seal that produces those comforting sounds mentioned earlier.
Now that we have established a solid foundation of knowledge in Plastisol, it would be good to discuss when it is appropriate to use this sealing method. The key temperature for Plastisol is 212° F. Plastisol can be used to seal glass containers that are hot filled up to 212° F or go through a pasteurization process up to 212° F for 1 hour. It is recommended that Plastisol Liners not be used in home pressure canning processes since the temperature goes well above 212° F, and can distort the Plastisol, and make it ineffective. The correct liner to use in pressure canning is a Retort Plastisol liner, which can resist higher temperatures.
As always, it is highly recommended that you test your product and process with this liner before purchasing a larger amount. This will provide you with the ease of mind that your product is safe and your customers—be it the general public, or grandson Billy—will know this as well.











