Stockwell Elastomerics is a leading producer of liquid silicone rubber (LSR) primarily based merchandise using its extensive in-house silicone rubber molding operations. LSR is a versatile elastomer that can be molded into sheets and solid into steady rolls for die reducing or discuss waterjet cutting.

Stockwell Elastomerics applies acrylic stress delicate adhesives onto LSR sheets and rolls for adhesive backed gaskets. Certainly one of Stockwell Elastomerics’ specialties is making use of movie supported acrylic adhesives, comparable to 3M 9415 or Adchem 256M and 3M 467 transfer film adhesive onto .010″ and .020″ thick solid liquid silicone rubber for display gaskets and related purposes requiring a very skinny gasket.

Stockwell Elastomerics also injection molds custom 3D elements per buyer specifications. LSRs have a wide temperature range (-58°F to 392°F) and may be made in vast durometer vary (10 - 80 Shore A) without plasticizers. Silicone’s glorious rebound, UV and ozone resistance makes it very best for outdoor sealing and will be use for submerged gaskets (IP67 and NEMA 6). Stockwell Elastomerics maintains in-house stock of silicone sheet, silicone rolls and molding compounds to be injection molded for quick response instances.

Request a Free Liquid Silicone
Rubber Touch Brochure

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

Request Brochure

What is Liquid Silicone Rubber?

Liquid silicone rubber (LSR) is very low viscosity silicone that may be injection molded or cast into silicone gadget rubber sheets. "Liquid" is explicit in the name to differentiate LSRs from high consistency gum based mostly silicone merchandise. LSRs are addition cure / platinum cure techniques in distinction with most gum primarily based silicones which are peroxide cured. In its raw uncured kind, LSR is two components liquid which might be combined collectively (mixing of Half A and Part B begins the curing) and heated to speed up the curing course of. Uncooked gum based mostly silicones feel and appear similar to clay. LSRs are typically injection molded or cast whereas gum primarily based silicones are typically compression molded. Word 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 compelled into a cooled mold.

Silicone Materials Selection Guide

Why Specify Liquid Silicone Rubber?

Performance properties and quick cure cycles make liquid silicone rubber a good selection for small molded components. Not like most thermoplastic elastomers (TPRs and TPEs), LSR remains flexible and elastic down to -58°F and retains its properties as much as 392°F. Liquid silicone rubber is an efficient candidate for gaskets, seals and cushioning pads in portable communications, knowledge acquisition instruments and ruggedized digital devices the place out of doors situations are demanding. The cure cycles in liquid injection molding permit for a 1 or 2 cavity mold to out-produce a compression mold with a better cavity depend.

Beyond the mechanical, chemical, and thermal properties of LSR, there are quite a few different causes to specify this type of fabric. From a manufacturability standpoint, a few key factors stand out. One in every of the largest reasons that clients might end up going with LSR material is geometry. Any form of 3D shape that can't be fabricated in a flat configuration would require a molding process - usually with components like this, a excessive manufacturing quantity stage justifies the added value of tooling that is related to LSR molding.

Moreover, some prospects may have flat gaskets, but with very tight thickness tolerance wants. In these circumstances, Stockwell Elastomerics can leverage its sheet molding capabilities to carry tighter tolerances in small sheets, which may then be used to die-cut or waterjet reduce flat gaskets and pads.

Transitioning from Flat Prototypes to Molded Production Components

Occasionally, clients want to transition from flat cut elements to molded elements. If you are you looking for more info in regards to silicone products (browse around these guys) look at the web site. As customers work via small prototype runs of initial designs, Stockwell Elastomerics helps this variation with quick flip waterjet reduce gaskets using molded LSR sheets. As designs develop and molding is required, the same material could be utilized. This eliminates re-testing and re-validation, since the fabric is the exact same for the prototypes and production elements.

For elements with none form of 3D geometry, molding can be a very price efficient solution at excessive amount production, as conventional die-slicing and waterjet reducing have wasted materials cost. For instance, a small window gasket could also be fairly cost effective to provide in small quantities as a waterjet lower half, however as manufacturing portions improve, the combined cost of the wasted window cutout can add up. In circumstances like this, paying to device-up a production LSR mold creates a much more value-efficient solution trimmed piece value down the line.

Cure Catalysts - Tin vs. Platinum

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

Platinum-cured LSR is usually "cleaner" than tin-cured LSR - because of this lots of Stockwell Elastomerics’ LSR products are suitable to be used within the medical machine trade. Platinum-cured LSR is often 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 often present in client and silicone mold inventor-grade material. This materials can cure utilizing condensation from the air and does not require heat. Tin-cured LSR is typically not FDA grade and isn't used in more demanding purposes.

While tin-cured LSR is more accessible for passion-grade and varied consumer functions, it does not offer among the distinct advantages and excessive-performance traits of platinum-cured LSR. Because of this platinum-cured LSRs used exclusively - these materials greatest serve prospects in core industries served by Stockwell Elastomerics.

Liquid Silicone Durometer Range

LSR is available in a hardness vary of 10 to 80 durometer Shore A. 10 durometer LSR could be very comfortable like chewing gum and might feel softer than some further firm 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 products. Most purposes for LSR are specified within the 20 to 60 durometer Shore A spread.

Stockwell Elastomerics’ Liquid Silicone Rubber Contact Brochure can assist with selection of fabric hardness for particular purposes. The tensile, elongation and tear resistance properties of liquid silicones have improved since the initial commercialization of LSR.

Liquid Silicone Rubber Availability

Stockwell Elastomerics affords off-the-shelf LSR sheets (12″ x 12″) and steady solid rolls with or with out movie supported acrylic or acrylic switch movie adhesive options. The 12″ x 12″ molded sheets can be found from .032″ to .125″ thick. Stockwell Elastomerics’ on-site molding facility offers molded and cryogenically deflashed, custom liquid silicone gaskets and a wide range of customized components.