Some knowledge of expandable polystyrene (EPS)
In 1950, BASF developed EPS. Because of its excellent thermal insulation performance, it was widely used in the construction field. Later, it was widely used in packaging because of its strong impact resistance.
When EPS raw material beads are smashed into production, foaming agent has been mixed in, generally 4-7% pentane. In the mold, high-temperature steam is used for foaming and molding, and up to 98% of the finished product can be air. Beads can be divided into flame-retardant and non-flame-retardant, and can also be divided into large, medium and small according to their radius.
The closed-cell structure allows it to cushion impact by changing and restoring deformation. The thermal conductivity is 0.033-0.043W/(m·k). Prolonged exposure to ultraviolet light will affect performance. It has no nutritional value, will not be eroded by mold, and will not decompose any water-soluble substances that pollute groundwater.
A study by the School of Packaging at Michigan State University found that when EPS is used to package fruits and vegetables, the carbon dioxide released by them will be retained, delaying maturity, and maintaining the content of vitamin C more effectively.