Stockwell Elastomerics is a number one producer of liquid silicone rubber (LSR) based products using its extensive in-house silicone rubber molding operations. LSR is a versatile elastomer that may be molded into sheets and cast into continuous rolls for die slicing or waterjet chopping.

Stockwell Elastomerics applies acrylic stress sensitive adhesives onto LSR sheets and rolls for adhesive backed gaskets. One in every of Stockwell Elastomerics’ specialties is making use of film supported acrylic adhesives, such as 3M 9415 or Adchem 256M and 3M 467 switch movie adhesive onto .010″ and .020″ thick solid liquid silicone rubber for display gaskets and related functions requiring a really thin gasket.

Stockwell Elastomerics also injection molds custom 3D elements per buyer specifications. LSRs have a large temperature range (-58°F to 392°F) and can be made in broad durometer vary (10 – eighty Shore A) with out plasticizers. Silicone’s wonderful rebound, UV and ozone resistance makes it supreme for silicone rubber outside sealing and might be use for submerged gaskets (IP67 and NEMA 6). Stockwell Elastomerics maintains in-home stock of silicone sheet, silicone rolls and molding compounds to be injection molded for fast response times.

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Rubber Touch Brochure

Includes small samples of cured LSR supplies to touch and really feel.

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What’s Liquid Silicone Rubber?

Liquid silicone rubber (LSR) could be very low viscosity silicone that can be injection molded or forged into silicone rubber sheets. “Liquid” is express within the identify to differentiate LSRs from high consistency gum based silicone merchandise. LSRs are addition cure / platinum cure methods in contrast with most gum based mostly silicones which are peroxide cured. In its uncooked uncured form, LSR is two parts liquid which can be combined together (mixing of Half A and Part B starts the curing) and heated to speed up the curing process. Uncooked gum based mostly silicones feel and appear similar to clay. LSRs are usually injection molded or forged while gum based silicones are usually compression molded. Notice that injection molding of liquid silicone rubber is the inverse of molding thermoplastics; room temperature liquid silicone compound is injected into and cured in a hot mold vs. plastic pellets melted into sizzling liquid and pressured into a cooled mold.

Silicone Supplies Selection Information

Why Specify Liquid Silicone Rubber?

Performance properties and fast cure cycles make liquid silicone rubber a very good alternative for small molded elements. In contrast to most thermoplastic elastomers (TPRs and TPEs), LSR remains flexible and elastic right down to -58°F and retains its properties as much as 392°F. Liquid silicone rubber is an effective candidate for gaskets, seals and cushioning pads in portable communications, knowledge acquisition devices and ruggedized digital gadgets where out of doors circumstances are demanding. The cure cycles in liquid injection molding allow for a 1 or 2 cavity mold to out-produce a compression mold with a better cavity count.

Past the mechanical, chemical, and thermal properties of LSR, there are quite a few different reasons to specify this type of material. From a manufacturability standpoint, a couple of key components stand out. One of the largest reasons that customers might find yourself going with LSR materials is geometry. Any form of 3D form that can’t be fabricated in a flat configuration would require a molding course of – often with components like this, a excessive manufacturing amount degree justifies the added value of tooling that is associated with LSR molding.

Additionally, some customers might have flat gaskets, but with very tight thickness tolerance needs. If you treasured this article and you simply would like to be given more info concerning silicone products cost please visit our web site. In these cases, Stockwell Elastomerics can leverage its sheet molding capabilities to hold tighter tolerances in small sheets, which can then be used to die-minimize or waterjet cut flat gaskets and pads.

Transitioning from Flat Prototypes to Molded Manufacturing Components

Every so often, customers want to transition from flat reduce components to molded parts. As prospects work by way of small prototype runs of initial designs, Stockwell Elastomerics helps this variation with fast flip waterjet cut gaskets using molded LSR sheets. As designs develop and molding is required, the same material can be utilized. This eliminates re-testing and re-validation, since the material is the very same for the prototypes and production components.

For parts without any type of 3D geometry, molding can be a very price efficient solution at excessive quantity production, as traditional die-cutting and waterjet cutting have wasted material price. For instance, a small window gasket could also be fairly price efficient to provide in small portions as a waterjet cut half, but as production portions increase, the combined value of the wasted window cutout can add up. In circumstances like this, paying to software-up a production LSR mold creates a much more cost-effective solution trimmed piece value down the road.

Cure Catalysts – Tin vs. Platinum

In LSR materials, a catalyst is required as a part of the curing course of. Widespread cure catalysts are tin (also referred to as condensation cure) and platinum (also referred to as addition cure). All of Stockwell Elastomerics’ LSR products are platinum-cured.

Platinum-cured LSR is typically “cleaner” than tin-cured LSR – this is the reason a lot of Stockwell Elastomerics’ LSR products are suitable to be used within the medical machine trade. Platinum-cured LSR is commonly able to assembly FDA and USP Class VI certifications. Platinum-cured LSR may also survive larger temperatures when compared to tin-cured options.

Tin-cured LSR is usually found in consumer and inventor-grade materials. This material can cure using condensation from the air and does not require heat. Tin-cured LSR is often not FDA grade and is not used in more demanding functions.

Whereas tin-cured LSR is extra accessible for interest-grade and varied client purposes, it does not offer some of the distinct advantages and high-performance characteristics of platinum-cured LSR. For silicone mold this reason platinum-cured LSRs used completely – these materials greatest serve clients in core industries served by Stockwell Elastomerics.

Liquid Silicone Durometer Range

LSR is on the market in a hardness range of 10 to eighty durometer Shore A. 10 durometer LSR may be very comfortable like chewing gum and can really feel softer than some further agency silicone foam and silicone sponge products. 80 durometer LSR is harder than a heel of a shoe and is as agency as many thermoplastic elastomer merchandise. Most applications for LSR are specified within the 20 to 60 durometer Shore A variety.

Stockwell Elastomerics’ Liquid Silicone Rubber Touch Brochure can assist with choice of fabric hardness for specific applications. The tensile, elongation and tear resistance properties of liquid silicones have improved since the preliminary commercialization of LSR.

Liquid Silicone Rubber Availability

Stockwell Elastomerics offers off-the-shelf LSR sheets (12″ x 12″) and continuous cast rolls with or with out movie supported acrylic or acrylic transfer film adhesive options. The 12″ x 12″ molded sheets can be found from .032″ to .125″ thick. Stockwell Elastomerics’ on-site molding facility supplies molded and cryogenically deflashed, custom liquid silicone gaskets and quite a lot of customized elements.