The Types of Foam & Sponge Rubber: Properties, Benefits & Applications.
Foam and sponge rubber are essential materials in many industries due to their unique properties. This article will help you understand the different types of foam and sponge rubber, their benefits, and how they can be used effectively. Understanding these materials can help in selecting the right foam product for your specific needs.
What is Foam?
Foam is a lightweight material formed by trapping gas bubbles within a solid or liquid matrix, such as rubber, plastic, or other polymers. Its structure can range from soft to firm, depending on its density and composition. Foam is widely used for its cushioning, insulation, and shock-absorbing properties, making it ideal for applications in packaging, construction, automotive components, and more.
What is Sponge Rubber?
Sponge rubber is often confused with foam, but the key difference lies in the production process and cellular structure. Sponge rubber is created by adding a chemical blowing agent during the manufacturing process, causing the rubber to expand and form a spongy texture. Sponge rubber can also be open-cell or closed-cell, and it is often used for thermal insulation, weatherproofing, and soundproofing applications.
Types of Foam
Different types of foam are used across industries depending on their properties. Below, we explore various types of foam, their benefits, and applications:
Polyurethane Foam
Polyurethane foam is a highly versatile material known for its light weight and durability. Its flexible structure makes it suitable for a wide range of applications, including furniture upholstery, automotive seating, thermal insulation, and soundproofing. The density of polyurethane foam can vary, with most standard types ranging between 20-50 kg/m³, allowing for tailored solutions in cushioning and energy absorption.
AS Rubber offers a range of polyurethane foams, such as reticulated foam for filtration, reconstituted foam for impact cushioning, and polyether foam for lightweight applications. These foams are available in a variety of formats to meet the needs of industries including automotive, construction, and furniture, providing customised solutions for specific requirements.
Polyethylene Foam
Polyethylene foam is a closed-cell foam characterised by its strength, lightweight nature, and excellent shock absorption properties. It is resistant to moisture, chemicals, and UV radiation, making it ideal for protective packaging, sports equipment, building insulation, and flotation devices. Polyethylene foam has a density that typically ranges between 24-115 kg/m³, which makes it well-suited for both heavy-duty and lightweight applications.
AS Rubber offers polyethylene foams in various forms, including chemically cross-linked PE foam for enhanced thermal insulation, non-cross-linked PE foam for general-purpose protective packaging, and physically cross-linked PE foam for high-performance cushioning. Available in multiple colours and formats, these foams are tailored to meet the specific needs of various applications.
PVC Foams
PVC foams are flexible, closed-cell foams that offer excellent sealing capabilities, making them suitable for automotive, construction, and marine environments. These foams are flame retardant and resistant to chemicals, which makes them particularly useful for applications requiring enhanced safety and durability.
PVC foams provide a unique combination of flexibility and strength, making them ideal for gaskets, thermal insulation, and cushioning. They also have excellent resistance to water, air, and dust infiltration. This makes them highly effective for sealing applications.
Within our PVC Foam range we offer Fast Recovery PVC Foam, which features quick rebound properties, making it ideal for applications that require repeated compression and recovery, such as display packaging and protective padding.
Solid Rubber
Solid rubber is a dense and durable form of rubber that provides excellent resistance to wear, weather, and chemicals, making it particularly beneficial in heavy machinery applications where components are exposed to harsh conditions and require long-lasting performance. Unlike foam, solid rubber does not contain air pockets, making it highly durable and suitable for applications requiring significant resilience, such as seals, gaskets, and bumpers. Solid rubber is typically used in heavy-duty applications, such as industrial machinery mounts and heavy-duty vibration dampening pads, where high resistance to compression and environmental factors is required.
AS Rubber offers solid rubber in various formats, including sheets, rolls, and custom-cut parts, providing you with the flexibility to choose materials or have specific products created to meet your requirements.
Cellular Sponges
Cellular sponges are made from rubber compounds that are expanded to create a network of air pockets, resulting in a flexible and compressible material. Their soft and pliable nature makes them ideal for applications requiring cushioning, insulation, sealing, flexibility, and shock absorption. Our cellular sponges can be used in automotive weather stripping, industrial gaskets, and other sealing applications where flexibility and durability are essential.
Open Cell Foam
Open cell foam is characterised by its interconnected air pockets, which allow air and liquid to pass through. This type of foam is soft, lightweight, and highly compressible, making it ideal for applications like cushioning, acoustic insulation, and air filters. Open cell foam is used extensively in furniture padding, soundproofing, and automotive interiors.
Closed Cell Foam
Closed cell foam features isolated air pockets that make it more rigid and resistant to water, making it suitable for outdoor applications such as playground flooring, as well as environments with high moisture levels. It provides excellent insulation properties and is widely used for flotation devices, moisture barriers, and packaging. Closed cell foam is also known for its superior resistance to chemicals and UV radiation, making it an ideal choice for outdoor uses and industrial applications.
Our semi-closed cell EPDM sponge is a versatile option that offers excellent weather resistance, making it suitable for sealing and gasketing in outdoor environments where exposure to the elements is a concern.
Which Type of Foam Is Best For You?
| Types of Foam | Properties | Advantages | Typical Applications | Our Products |
| Polyurethane Foam | Light, flexible, variable density | Durable, versatile | Upholstery, soundproofing, insulation | Non Porous Film PU Coat - Reticulated Foam - High Resilience Polyurethane Foam - Memory Foam - Flame Retardant Foam |
| Polyethylene Foam | Closed-cell, strong, moisture resistant | Shock absorbing, chemical resistant | Packaging, insulation, flotation | Closed Cell Polyethylene Foam - Cross-Linked Polyethylene Foam - Reconstituted Foam |
| PVC Foams | Flexible, flame retardant | Good sealing, chemical resistant | Packaging, insulation, flotation | Impregnated PU Foam - PVC Nitrile Foam |
| Solid Rubber | Dense, durable | Excellent wear resistance | Seals, gaskets, bumpers | EPDM Solid Rubber - Non Porous Film PU Coat |
| Cellular Sponges | Flexible, compressible | Good for cushioning and sealing | Gaskets, weather stripping | Neoprene Sponge - Reticulated Foam |
| Open Cell Foam | Soft, interconnected cells | Lightweight, highly compressible | Furniture padding, acoustic insulation | Open Cell Polyurethane Foam - Reticulated Foam |
| Closed Cell Foam | Rigid, isolated cells | Water-resistant, good insulation | Flotation, packaging, barriers | Closed Cell PVC Foam - Impregnated PU Foam |
Choosing the right type of foam or sponge rubber depends on your specific application requirements, including properties such as flexibility, density, and environmental resistance. Whether you need foam for cushioning, insulation, or sealing, there is a type of foam that meets your needs. With 28 years of experience, AS Rubber can cater to customers in the UK and abroad, providing assistance and high-quality products. For more information and assistance in selecting the best foam product for your application, contact AS Rubber today.
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