What is the typical flash tolerance for a silicone part?

Question: What is the typical flash tolerance for a silicone part?

Answer: Silicone has a relatively low viscosity compared to other TPE (Thermoplastic elastomeric) or thermoplastic. The silicone’s viscosity enables us to more easily mold micro parts, but it also presents a challenge with flash. The typical flash tolerance for a silicone part is .005”. However, the tolerance can vary widely depending on the individual application. For example, a simple non-medical gasket may have a flash tolerance of .025” because the priority of the gasket is to provide adequate sealant in its application. On other hand, micro silicone components of a catheter may have a flash tolerance as low as .001” or less because a couple thousandths of flash or more may irritate the patient when in contact with the patient’s body parts. In addition, larger flash is a potential cosmetic defect since the components are very small. Finally, the flash tolerance can affect the cost of a part; usually the smaller the flash tolerance is, the more expensive the part is. This is due to manufacturing and inspection challenges.

This entry was posted in General Silicone on by .

About Hean

Prior to joining Albright Technologies, Hean was an intern and a part-time employee at Berry Plastics. After starting at Albright Technologies in May 2011 as an intern, he recently became a full-time employee as a Project Engineer in Training. Currently his responsibilities include, designing molds, programming codes for tools, inspecting articles, setting up a LIM machine and anything else that helps the team move forward. Hean received his Associates degree in Liberal Arts and a concentration in Physical Science from Middlesex Community College in 2008, and a Bachelors degree in Plastics Engineering with a business minor from UMass Lowell in 2011.

  • David Lee

    Here is ISO standard for the dimensional tolerance of the silicone products.

  • Silicone apprentise

    Any insights about, tolerances with RMA standards? I have on a few occasion come upon suppliers that use different toleransing than us. The iso and rma standards match poorly.

  • Michael Wilson

    Just a brief comment regarding your post. You mention that silicone has a relatively low viscosity compared to “other” TPE (materials). This statement implies that silicone is a thermoplastic elastomer itself which it is not.

    It would be better to say that silicone has a relatively low viscosity compared to TPE materials. Seems minor, but it is important that silicone is not clasified with TPE material as it is entirely different chemistry and technology.

    Thanks for your consistent work in keeping dialogue fresh in the silicone world.