White Foam

Updated: 2026-07-21

Overview

Polystyrene foam, colloquially called white foam, is a versatile cellular plastic material derived from petroleum. It consists of 98% air trapped within a polystyrene matrix, giving it exceptional lightness and buoyancy. First commercialized in the 1950s, its low production cost and functional properties have made it ubiquitous in industrial and consumer applications. The material exists in two primary forms: expanded polystyrene (EPS) and extruded polystyrene (XPS). EPS is created by expanding beads with steam, while XPS is produced through continuous extrusion, resulting in different cell structures and performance characteristics. Both types share common advantages of thermal insulation and cushioning properties.

Physical and Chemical Properties

White foam exhibits a unique combination of physical properties that make it valuable across industries. Its thermal conductivity ranges between 0.032-0.038 W/(m·K), making it an effective insulator. The closed-cell structure provides moisture resistance, though prolonged water exposure can lead to absorption in EPS varieties. Chemically, polystyrene foam is inert to most acids, alkalis, and salts, but dissolves in many organic solvents like acetone and toluene. It has limited UV resistance and degrades under prolonged sunlight exposure. The material demonstrates excellent dimensional stability across a wide temperature range (-50°C to +70°C for standard grades), though it becomes brittle at lower temperatures.

Main Applications

The packaging industry accounts for approximately 40% of global polystyrene foam usage. Its shock-absorbing qualities protect fragile items during shipping, while its lightweight nature reduces transportation costs. Custom-molded EPS packaging is common for electronics and medical equipment. In construction, foam boards serve as insulation for walls, roofs, and foundations. The material's R-value (thermal resistance) makes it particularly effective in cold climates. Other applications include flotation devices, craft materials, and disposable food service items like coffee cups and takeout containers, though environmental concerns have led to restrictions in some regions.

Safety and Storage

While polystyrene foam is generally safe for intended uses, proper handling precautions are necessary. The material is classified as flammable (Class B fire rating) and should be stored away from ignition sources. During cutting or shaping, proper ventilation is recommended to avoid inhalation of fine particles. Long-term storage requires protection from sunlight (UV degradation) and solvents that may dissolve the material. Bulk storage should maintain stacking height limits to prevent compression damage. Fire-retardant grades are available for applications requiring reduced flammability, though they typically cost 15-20% more than standard grades.

B2B Procurement Guide

Industrial buyers should specify several key parameters when purchasing polystyrene foam. Density (measured in kg/m³) directly correlates with strength and insulation value - common packaging grades range from 15-30 kg/m³, while construction insulation typically uses 30-40 kg/m³. Consider whether fire-retardant additives are necessary, especially for building applications. For custom shapes, mold tooling costs and minimum order quantities apply. Lead times vary from stock items (1-3 days) to custom productions (2-4 weeks). Environmentally conscious buyers may explore recycled content options or biodegradable alternatives like PLA foams, though these currently command premium pricing.