A polymer foam is basically a polymer-and-gas mixture, which gives the material a microcellular structure. According to the cell structure, polymer foams can be divided into two types, the open cells and the closed cells (see in figure 1) [1]. Generally, polymer foam has the characteristics of light weight, resistance to impact, high thermal insulation, and damping properties. Due to these characteristics, polymer foam finds numerous applications in automotive, packing industry, electronic, aerospace, building construction, bedding, medical applications and other fields.
Fig. 1 Illustration of polymer foam cellular structures (a) closed cell type (b) open cell type
Influencing Factors
The properties of polymeric foams are affected by many factors:
Polymeric foams can be made from almost any type of polymer. The most common types of polymers are polyurethane (PU), polystyrene (PS), polyvinylchloride (PVC), polyethylene (PE) and a number of elastomers such as ABS, natural rubber and silicone.
The type of polymer determines whether the resulting foam will be hard and rigid or soft and flexible. In general, elastomers yield flexible foams, whereas rigid (glassy) polymers yield rigid foams.
According to the density, polymeric foams are generally divided into high-(0.5-1.0g/cm³), medium-(0.1-0.5g/cm³) and low density (less than 0.1g/cm³) foams. Low density foams are mainly used in insulation applications; medium density foams find their applications in the packaging, building and construction industry; high density foams have noticeably higher strength and modulus, and thus, can often replace regular plastics in applications where lower electrical/thermal conductivity, weight per volume, dielectric constant, compression modulus as well as greater flexibility and damping is needed or required.
Both open and closed cell foams have much better thermal and acoustical insulation properties than non-porous plastics. The closed-cell foam has a high plastic content and very low gas and vapor permeability. It is also stronger and more rigid than open-cell foam. Open-cell foam is softer and more flexible than closed-cell foam. It allows gas and vapor to move freely through the cells and absorbs liquid when immersed in it.
What we offer
Alfa Chemistry offers various polymer foams including:
Polyurethane (PU) Foam
PU foams are formed by the reaction between an isocyanate prepolymer and a polyol in the presence of a blowing agent, and an amine (catalyst). Closed-cell PU foams are strong, durable, rigid, do not absorb water and are used for many different purposes. Their variety of applications lend themselves to industries such as such as marine, aerospace, construction, recreation, modeling and more. Open-cell PU foams are used for load deflection applications, in industries such as aerospace, defense, automotive and others.
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Polyvinyl chloride (PVC) Foam
PVC foam is a durable, light, and flexible material which offers many advantages, such as superior impact resistance, high strength, great durability, low water absorption, high corrosion resistance, and fire resistance to name a few. These benefits provide the perfect material to withstand all types of indoor and outdoor conditions, including harsh weather. PVC foam is also a great alternative to other materials, such as wood or aluminum, and can often last 40 years without experiencing any damage.
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Polyethylene (PE) Foam
PE foam is a durable, lightweight, resilient, closed-cell material with many advantages, such as surface sensitivity, flexibility, low cost, lightweight, shock absorbing, resists mildew or mold. The most common use of the PE foam material is in applications such as air conditioning systems, hot and cold-water transmission units, freezer and chiller systems and numerous ducting systems.
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Polystyrene (PS) Foam
As a closed-cell structure with excellent heat-shielding performance, low water absorbability, good dielectric properties, and great mechanical strength, PS foam may be divided into two types: expandable and ordinary, depending on how it is prepared. PS foam is most commonly used for construction, insulation and packaging.
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Acrylonitrile-butadiene-styrene (ABS) Foam
ABS foam gives increased rigidity compared to a part made from the same weight of solid material. Injection speeds are increased and locking pressures are lower, hence relatively inexpensive moulds can be used. Tend to have a reduced tendency to sinking. It can be used in furniture, loudspeaker boxes, picture frames and knobs, telephone junction boxes, sprinkler housings, television surrounds, electric fan components, business machine housings, computer readout terminals, copying machine housings and automotive bucket seats.
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Alfa Chemistry is a leading manufacturer of polymer foams, and we can offer different polymer foams including PU foams, PS foams, PVC foams, PE foams, ABS foams and others. To place an order or request a quote, please don't hesitate to contact us.
Reference
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Mihrigul Altan. Thermoplastic Foams: Processing, Manufacturing, and Characterization. Recent Research in Polymerization, 2017.
