Stockwell Elastomerics is a number one producer of liquid silicone rubber (LSR) primarily based products using its in depth in-house silicone rubber molding operations. LSR is a versatile elastomer that can be molded into sheets and forged into continuous rolls for die cutting or waterjet cutting.
Stockwell Elastomerics applies acrylic strain delicate adhesives onto LSR sheets and rolls for adhesive backed gaskets. Certainly one of Stockwell Elastomerics’ specialties is making use of film supported acrylic adhesives, corresponding to 3M 9415 or Adchem 256M and 3M 467 switch movie adhesive onto .010″ and .020″ thick forged liquid silicone rubber for show gaskets and comparable functions requiring a really skinny gasket.
Stockwell Elastomerics additionally injection molds custom 3D components per customer specifications. LSRs have a wide temperature range (-58°F to 392°F) and could be made in wide durometer range (10 – 80 Shore A) without plasticizers. Silicone’s glorious rebound, UV and ozone resistance makes it preferrred for out of doors sealing and may 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 fast response occasions.
Request a Free Liquid Silicone
Rubber Touch Brochure
Contains small samples of cured LSR materials to contact and really feel.
Request Brochure
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 excessive consistency gum primarily based silicone products. LSRs are addition cure / platinum cure techniques in distinction with most gum based silicones which might be peroxide cured. In its raw uncured type, LSR is 2 elements liquid that are mixed collectively (mixing of Half A and Part B begins the curing) and heated to accelerate the curing course of. Raw gum primarily based silicones feel and appear similar to clay. LSRs are usually injection molded or forged whereas gum based mostly silicones are sometimes compression molded. Be aware 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 hot liquid and silicone gadget products compelled right into a cooled mold.
Silicone Supplies Selection Information
Why Specify Liquid Silicone Rubber?
Performance properties and fast cure cycles make liquid silicone rubber a superb choice for small molded parts. Not like most thermoplastic elastomers (TPRs and TPEs), LSR stays versatile and elastic down to -58°F and retains its properties up to 392°F. Liquid silicone rubber is an efficient candidate for gaskets, seals and cushioning pads in portable communications, data acquisition instruments and ruggedized electronic devices where outside conditions are demanding. The cure cycles in liquid injection molding enable for a 1 or 2 cavity mold to out-produce a compression mold with a higher cavity rely.
Beyond the mechanical, chemical, and thermal properties of LSR, there are quite a few other causes to specify this sort of fabric. From a manufacturability standpoint, a few key components stand out. Certainly one of the most important causes that clients might find yourself going with LSR materials is geometry. Any kind of 3D form that can not be fabricated in a flat configuration would require a molding process – often with parts like this, a high production 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 wants. In these cases, Stockwell Elastomerics can leverage its sheet molding capabilities to carry tighter tolerances in small sheets, which can then be used to die-lower or waterjet minimize flat gaskets and pads.
Transitioning from Flat Prototypes to Molded Production Parts
On occasion, customers want to transition from flat cut elements to molded parts. As prospects work by way of small prototype runs of preliminary designs, Stockwell Elastomerics supports this variation with quick turn waterjet lower gaskets utilizing molded LSR sheets. As designs develop and molding is required, the same material might be utilized. This eliminates re-testing and re-validation, since the fabric is the very same for the prototypes and production elements.
For elements without any kind of 3D geometry, molding can be a very price efficient answer at high amount production, as traditional die-reducing and waterjet cutting have wasted materials price. For instance, a small window gasket may be quite price effective to offer in small quantities as a waterjet reduce part, however as production quantities increase, the combined value of the wasted window cutout can add up. In instances like this, paying to software-up a production LSR mold creates a much more value-efficient resolution trimmed piece price down the road.
Cure Catalysts – Tin vs. Platinum
In LSR supplies, a catalyst is required as part of the curing process. Common cure catalysts are tin (also known as condensation cure) and platinum (also referred to as addition cure). All of Stockwell Elastomerics’ LSR merchandise are platinum-cured.
Platinum-cured LSR is typically “cleaner” than tin-cured LSR – this is why many of Stockwell Elastomerics’ LSR products are appropriate for use in the medical device trade. Platinum-cured LSR is often able to assembly FDA and silicone mold USP Class VI certifications. Platinum-cured LSR can even survive greater temperatures when in comparison with tin-cured options.
Tin-cured LSR is often found in shopper and inventor-grade materials. This materials can cure using condensation from the air and doesn’t require heat. Tin-cured LSR is typically not FDA grade and is not used in additional demanding purposes.
Whereas tin-cured LSR is more accessible for passion-grade and various consumer functions, it does not offer some of the distinct advantages and excessive-performance traits of platinum-cured LSR. This is the reason platinum-cured LSRs used exclusively – these materials finest serve prospects in core industries served by Stockwell Elastomerics.
Liquid Silicone Durometer Vary
LSR is accessible in a hardness range of 10 to 80 durometer Shore A. 10 durometer LSR is very gentle like chewing gum and might feel softer than some additional firm silicone gadget 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 functions for LSR are specified in the 20 to 60 durometer Shore A range.
Stockwell Elastomerics’ Liquid Silicone Rubber Touch Brochure can help with choice of material hardness for particular purposes. The tensile, elongation and tear resistance properties of liquid silicones have improved because the preliminary commercialization of LSR.
Liquid Silicone Rubber Availability
Stockwell Elastomerics affords off-the-shelf LSR sheets (12″ x 12″) and continuous 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 supplies molded and cryogenically deflashed, customized liquid silicone gaskets and a wide range of custom components.
Leave a Reply