What is a Liner?
A liner is a soft material, usually made of urethane or white rubber, that is inserted within a chuck. The chuck with inserted liner is attached to the capping machine. The liner grips the cap during the capping process.
The grip generated by the liner is what allows the capping machine to tighten a cap onto a bottle. Liners will last for a very long time but they do eventually wear out. To replace a liner, simply pull out the old liner by hand and press fit in a new one, also by hand.
The liner plays a crucial role in capping
The amount of torque a capping machine can apply to a cap is determined by the amount of grip that the liner can generate on the cap. The greater the grip, the greater the amount of torque the capping machine will be able to apply to the cap and the greater the torque repeatability you will be able to achieve.
Durometer is the international standard for measuring the hardness of rubber, plastic and other non-metallic materials. A higher durometer rating indicates a harder material. We offer liners that range from 40 durometer to 83 durometer.
Grip vs. Wear
There is an inverse relationship between how long a liner will last and how well it grips.
- Harder liners last longer but do not grip as well as softer liners.
- Softer liners generate better grip with the cap but they do not last as long as harder liners.
When used with our Capping Machines, 55 durometer liners are the best choice for most applications
The extremely accurate clutches used on our capping machines automatically shut off the capping motor the instant the cap becomes tight. Since the liner and cap stop simultaneously, virtually no liner wear occurs for each cap the machines tighten.
Since liner wear is not a concern, our customers can use relatively soft 55 durometer liners for excellent torque generation and repeatability. We offer 55 durometer liners in both urethane and white rubber.
Provide superior gripping properties and good wear characteristics. We offer urethane liners in three durometers, 55 durometer, 70 durometer and 80 durometer. Our standard urethane liner, 55 durometer, is the best choice for most applications. The 70 and 80 durometer urethane liners are generally useful for small caps with deep serrations.
White Rubber Liners
Combine strong gripping power with a high tensile strength for excellent wear characteristics. We primarily offer white rubber liners in 55 durometer. Our standard white rubber liner, 55 durometer, is an excellent choice for most applications. We offer an 83 durometer liner in two of our most popular sizes. An 83 durometer liner is generally reserved for unusual applications or circumstances where an exceptionally hard and durable liner would be beneficial, such as applications involving highly abrasive caps.
The perfect choice for smooth caps such as metal lug caps. Made of very soft 40 durometer vinyl, these liners create almost a suction cup like grip on smooth surfaces.