Foaming materials refer to aggregates formed by the dispersion of gas in solid polymers. Generally, they have the functions of being lightweight, heat-insulating, and cushioning. They are often used in fields such as daily necessities, packaging, industry, agriculture, transportation, and more.

Common foaming materials on the market include polyurethane (PUR), polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and others.

EPP is the abbreviation for expanded polypropylene and is the abbreviation for a new type of foam plastic. EPP materials have higher mechanical strength and a wider range of application scenarios. It has become one of the fast-growing environmentally friendly materials.

Production of EPP materials

EPP materials use physical foaming. Generally, the autoclave impregnation method is used.

Production principle

The production principle is to pressurize EPP beads in a pressure vessel (that is, fill the beads with a certain pressure of air), and then inject compressed air into the mold of the EPP molding machine through a spray gun. Steam is introduced to further expand the EPP beads and fuse the surfaces together to form a shape. After cooling, the mold is then stabilized at a certain temperature to obtain the EPP product.

First, through a specific ratio, PP particles of various colors are obtained. Then, through foaming treatment, PP particles of various expansion ratios are obtained. Finally, EPP products are obtained using molds in the manufacturing plant.

Properties and uses of EPP

EPP materials are lightweight, have good elasticity, are resistant to earthquakes and compression, have a high deformation recovery rate, good absorption performance, are resistant to oil, acid, alkali, and various chemical solvents, do not absorb water, are insulating, heat-resistant (-40 to 130 °C), non-toxic and odorless, can be recycled 100% without almost any reduction in performance, and are environmentally friendly foam plastics.

EPP materials are mostly used in food packaging, instrument cushioning packaging, various automotive parts such as bumpers, automotive interiors, and more.