EPDM, TPE, and silicone are three commonly-used compounds for rubber edge trim. Which elastomer is right for your sealing and insulation application?
Rubber edge trim is used to finish and protect exposed metal edges on vehicle and machine doors, kitchen equipment, and other sheet metal surfaces. Typically, these industrial rubber products are U-shaped so that the retainer section can be pressed over the metal edge. Materials of construction include solid, sponge, or dual durometer rubber. Durometer, a measure of hardness, describes a material’s resistance to compression or pressure. The higher the durometer, the harder the rubber.
Elasto Proxy keeps standard edge trims in stock, and can custom-fabricate rubber edge trim that meets your precise specifications. We can also supply edge trim where the retainer contains either a wire core or a segmented steel core to help absorb impact. For design engineers and technical buyers, choosing the right product often begins with compound selection. In this technical article from Elasto Proxy, we examine three common compounds for edge trims: EPDM, TPE, and silicone.
EPDM Edge Trim
EPDM edge trim is made of a synthetic rubber that resists moisture and withstands temperature extremes. EPDM also maintains its flexibility at low temperatures, provides a relatively high degree of electrical insulation, and exhibits superior UV resistance. EPDM rubber products resist both water and steam, and provide good resistance to alkalis, acids, and oxygenated solvents. Often, EPDM edge trim is the right choice for car door edges, machinery, and outdoor applications.
Elasto Proxy also offers fire-rated EPDM bulb trim that meets requirements for flame, smoke, and toxicity (FST). These fire-resistant rubber products are laboratory-tested and validated, and ideal for mass transit applications such as buses, subways, and rail. EPDM edge trim provides an alternative to neoprene rubber, an all-purpose material with both flame and water resistance. Unlike EPDM, however, neoprene provides only limited flexibility at low temperatures.
TPE Edge Trim
TPE edge trim is made of thermoplastic elastomers (TPE), a group of rubber-like materials that combine the processing strengths of thermoplastics with the flexibility of thermoset rubbers. TPE is less likely to break in cold temperatures than polyvinyl chloride (PVC), but has a higher material cost than other elastomers. In addition, TPE has relatively poor recovery when exposed to heat and compression. TPE’s advantages include flexibility, shock absorption, and slip, weather, and ozone resistance
Choose TPE edge trim for applications that require recyclable materials, or that require fully non-metal parts. Instead of a steel core, TPE edge trim can use a solid interior plastic. Importantly, these fully non-metallic parts can meet or comply with the requirements of the European Union’s (EU) Restriction of Hazardous Substances (RoHS) directive. You’ll find a wide variety of TPE products in Elasto Proxy’s catalog, which features numerous extruded rubber products.
Silicone Edge Trim
Silicone edge trim is used in applications that require low toxicity, low chemical reactivity, and thermal stability over a wide temperature range. A type or family of synthetic rubbers, silicones can be specially-formulated to impart particular properties. Typically, however, silicone edge trims are used in food and beverage processing, medical, pharmaceutical, and other sanitary or hygienic applications. Many silicones are available, but not all are recyclable.
Choose Edge Trims from Elasto Proxy
Elasto Proxy supplies standard and custom-fabricated edge trims for industries such as aerospace, defense, infrastructure, medical and health, and stainless steel food equipment. For over 25 years, we’ve been solving sealing and insulation challenges by providing high-quality, low-to-medium volume quantities of industrial rubber products such as edge trim. How can we help you? To learn more, contact Elasto Proxy.