Envelope Care and Use


Instructions for Extending the Life of Your Robbins Envelopes


  • During the life of the envelope, periodically inspect the envelope for holes, tears, and cracks. Pay particular attention to the edges of the envelope, this is where many problems start.

Envelope Use:

  • Select the correct size envelope for the right tire size. See your Tire to Envelope Selection Chart.
    When installing the envelope be sure that it is centered and straight on the tire and the valve centered over the wicking pad.
  • Make sure that the valve stem is located in a position so as not to bind when hooked-up to the chamber exhaust line when the tire and envelope assembly are placed inside the curing chamber.
  • Couplers that attach to the envelope should be attached to the chamber hoses with 90° elbows.
  • Always check to be sure that exhaust valve is not blocked.
  • It is recommended that a vacuum test be performed to check the seal of the envelope and the sealing ring. NEVER insert air under the envelope to check the seal of the envelope and sealing ring. Pressurizing the envelope can pull the envelope away from the sealing ring or break the seal on inside/outside envelope systems and may create a safety hazard. Pressurizing the envelope causes distortion and stretching and will shorten envelope life.

Envelope Storage:

  • Store new envelopes and seldom-used envelopes in their original cartons off the floor and in storage racks. Organize envelopes according to size. Store them away from light and heat sources.
  • Do not store in-process envelopes on the floor.
  • Store in-process envelopes in bins or on specially designed envelope storage racks. Periodically check bins and racks for burrs and sharp edges.
  • Avoid rolling or dragging envelopes across the floor.

Envelope Lubrication:

  • The Robbins envelope has an extended life lubricant applied at the factory.
  • This extended life lubricant should prevent sticking throughout most of the envelope life; however, the number of cures you experience before sticking occurs will vary considerably depending on the condition of the tires being processed. The cleaner the tire, the better the results.
  • If sticking occurs, turn the envelope inside out and wash with a solution of liquid dishwasher soap and water. WE RECOMMEND A SOLUTION OF: 1 PART DISHWASHING SOAP TO 10 PARTS WATER. Gently scrub with a soft brush. Let the envelope dry prior to returning to service. After cleaning, the factory applied lubricant should be refreshed and eliminate further sticking. If sticking continues, apply a new coat of Robbins envelope lubricant as needed.
Robbins Envelopes

Newsletter Signup