Apple Rubber puts a lid on the problem of a sticking seal.

Apple Rubber specializes in custom elastomeric components and seals and maintains a diverse inventory of specialty compounds. Our expertise in these areas was the key to solving a challenging request from a manufacturer of hydration systems.

The manufacturer introduced a new, all-weather portable drinking container with a wide mouth lid that is marketed to the military, sports teams, law enforcement and outdoor enthusiasts. A seal for the lid was required to perform in a wide range of temperatures while being subjected to differing environments, from dusty, desert-like situations to wet and damp conditions.

A problem presented itself after the units were assembled and shipped to retail outlets. The seal created a bond between the lid and the container that made it very difficult for end-users to open without a lot of force. This happened when the units were placed in storage for even a short period of time, and changing temperatures and climate conditions contributed to the problem.

Uncovering the static friction problem.

Apple Rubber engineers were asked to investigate and given the challenge to re-design the seal while maintaining its robust, leak-proof properties. All the mating component gland dimensions appeared to be correct. It appeared that the static friction problem was related to the elastomer of the seal itself.

First, we confirmed a seal  size and dimensions that would be favorable under all the varying conditions identified. Then we reduced the durometer of the compound to allow for light pressure to create the seal contact. Finally, we recommended a change to the formulation of the rubber being used.

Simplicity through lubricity.

Apple Rubber's material experts began testing secondary additives that would be induced in the compound formulation itself. The additives would give lubricity to the sealing component and would be compatible with the requirements of the drinking container itself. Our solution offers a number of advantages:

• A calculated percentage  of the additives in the compound creates a slow, continuous leaching on the sealing surface.
• In this condition, the surface lubricity increases greatly, reducing the force required  to open the container lid.
• Even after long periods of storage, the seal retains its surface lubricity.
• After washing and drying of the container, the seal will self-bleed lubricant to the surface of the component, maintaining lubricity and easy-opening characteristics.

Apple Rubber offers a choice of impregnated compounds.

If you have a specialized sealing application, Apple Rubber engineers have the knowledge and resources to solve your toughest challenge, including a full line of impregnated compounds. These additives can be specified to meet any FDA, NSF, or Medical Grade Class VI requirement.