What are the advantages of silicone foam over polyurethane foam?
From car seats to batteries to soundproofing your home, foams can be found everywhere; but which type is best for the purpose you seek? In this article we explore where foams are used in various industries, as well as compare the advantages of silicone foam versus polyurethane foam.
ADVANTAGES OF SILICONE FOAMS
Silicone foams are ideal for gasketing, insulation, and vibration damping, especially in applications where the sealing surface is not smooth and temperatures vary widely, due to silicone’s excellent versatility. Here we explore the unique advantages of these foams.
The closed-cell foam structure does not allow water, moisture or dust to be absorbed, making it ideal in sealing applications where water and dust need to be kept out.
- Low flammability: allows use in fire measures and glazing seals (UL94 rating)
- Low density: reducing overall weight and improving dimensional stability
- Excellent resistance to compression-rebound
- Mechanical properties remain virtually constant between -60°C and 230°C
- Maintains full flexibility over a wide range of temperatures
- Good acoustic and thermal insulation
- Highly resistant to aggressive chemicals and UV rays, with excellent weathering properties
- No release of toxic chemicals during thermal decomposition
- Excellent dielectric properties-allowing uses in electrical insulation or conduction
ADVANTAGES OF POLYURETHANE FOAMS
Polyurethane foams are used in many applications where comfort is a priority, including car seat cushions, mattresses, and the furniture industry in general. It is a durable and inexpensive material, although after it decomposes it is prone to emit harmful chemicals that could cause damage. Here we explore a range of benefits of polyurethane foam:
- Polyurethanes are harder than rubber and more flexible than plastic, leading to high strength and impact resistance
- Excellent abrasion resistance
- Extremely lightweight: helps reduce emissions in transportation applications
- Highly resistant to aggressive chemicals and oils – minimal swelling
- One of the softest foams that can be used in the furniture industry
- Excellent shock resistance due to high vibration frequency
- Structurally stable
Comparison of silicone and polyurethane foam
When it comes to technical comfort in the furniture industry, polyurethane foams have the advantage of being soft, impact-resistant, durable, and lightweight, leading to products such as the memory foam mattress. However, because of polyurethane’s tendency to emit volatile organic compounds that can cause problems , it is being phased out of the mattress and upholstery industries and replaced by more environmentally friendly materials.
When considering insulation and fire-fighting measures, closed-cell silicone foams definitely have the upper hand because they are completely flexible over a very wide temperature range and are fire retardant. As a result, they have proven useful in the thermal management of electric vehicle batteries. In addition, they can be used on any surface regardless of their environment due to silicone’s extreme weather resistance and resistance to harsh chemicals and UV rays.
Overall, silicone foams can be used in a wider range of applications than polyurethane foams, without having the adverse health effects of polyurethanes.
A silicone foam to consider
DOWSIL 3-6548 RTV silicone foam is a two-component, medium-density foam that is ideal for sealing fire crossings in systems containing cables and pipes. It can prevent the penetration of smoke and gases through seals by forming irregular and complex shapes around the components it is protecting. It is composed of two liquids that mix in a 1:1 ratio, expanding and curing at room temperature to form an elastomer. Like all silicone foams, it is non-corrosive, flame retardant, and resistant to UV rays and extreme temperatures. It also meets HL3/R22 of the railway standard EN45545, making it an excellent choice for use in the railway industry.
