RTV Technical Paper

In September of 2009, Protogenic collaborated with members of the Spectrum Plastics Group to create an in-depth technical article about RTV molding, which allows you to make more informed decisions about your own RTV molding applications, resulting in better and more useful cast urethanes.

Lead Times and RTV Molding Process 

At Protogenic, we use the process of silicone RTV (Room Temperature Vulcanization) molding to create beautiful, accurate, and functional cast urethane parts from your CAD files.

Shore A spec sheet   
Shore D spec sheet

 Here’s how the process works: 

	We take your .stl file, scale with the correct comp. for mold shrinkage, and run your SLA master. You approve your SLA master, and confirm all project-specific information with your Project manager.
Your SLA is finished to your specifications, suspended inside a box, then surrounded with silicone rubber.
	The silicone is later cut in half, your SLA master is removed, and what remains is your mold, ready for urethanes.
Your prototypes are cast in the materials and colors you specify,  ready for you to assemble, test, and show them off!

Mold Life:  Mold life will normally run from 25-35 pieces, so getting the best value from the fixed cost of each mold can be achieved by casting as many parts as possible.  Small features, thin areas, undercuts, and cavities that are deeper than they are wide can all lead to reduced mold life, please ask your Project Manager or Estimator for a mold life estimate of your file, also read more about improving mold life in the design tips area.

Appearance: Our silicone mold prices assume textured cosmetic surfaces, and include one free custom color match, per mold.  So if your project involves 4 different molds, that’s 4 color options for you to play with (additional matches are only $50).  We can approximate just about any color, and can reference your physical sample (color chip) or Pantone^® number, just tell your Project Manager what you’re looking for.  Read more about color matching in the design tips area.

Lead times: Our lead times are typically 4-5 days to your first cast part, from the day we receive your approved SLA master.  If your design has a dimension longer than 6 inches, your mold may need additional time for the silicone to reach complete shrinkage, sometimes adding another 4 days to your schedule.  Casting rates vary with material choices, averaging 2-5 parts per day.  More about lead times is found in the Protogenic Facts page.

What else…

• Any areas that require polish may have additional charges, please let your estimator know if you'd like a quote on any polished parts. 
• Threaded fasteners are installed in your cast parts upon request, again please see the threaded fastener page for our recommended boss designs for tapped threads, Helicoils^™ and threaded inserts.
• With some exceptions, several different materials can be cast in the same mold.  This can be especially useful when your project calls for rubber components, and you want to make sure the material durometer gives you “just the right feel.” Your project manager is happy to work with you on any multiple material, and/or multiple color molding projects.
• Remember to refer to the Shore A and Shore D material spec sheets in this document for a list of available cast urethanes.  Don’t see exactly what you’re looking for?  Special orders are available, just let your project manager know what your needs are, and we’ll do our best to accommodate.
  

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