Expanded Polypropylene (EPP) consists of extruded pellets which expand under tightly controlled conditions to become consistently shaped beads of what is referred to as expanded polypropylene foam.
EPP is a highly versatile bead foam which can be produced in various density grades for different applications. It also provides a unique range of properties, including thermal insulation, water and chemical resistance, energy absorption, and impact resistance.
EPP Comes in a Wide Range of Grades, Densities, and Colours
EPP is produced in a wide range of densities, from 15 to 200 grams per litre. The moulding process extends these densities from 18 to 260 grams per litre by adding extra beads through the moulding process to form a stronger and lightweight shape.
EPP grading is important as it indicates the suitability of the product based on the specific technical requirements of various industries. Medium to low-density EPP grades is more suitable for packaging applications and other consumer products and is offered in white, although colour options are also possible.
High-density EPP grades are ideal for energy management through better thermal insulation capabilities needed in the automotive industry, e.g. in interior passenger safety components, seating and bumpers. EPP is commonly coloured black for automotive applications.
EPP is a Good Thermal and Acoustic Insulator
The cylinder-shaped polypropylene beads of the porous EPP adds air space between the beads, which not only makes the material lightweight by reducing weight but also enhances beneficial acoustical insulating effects.
Furthermore, as seen above, EPP acts as a thermal insulator and energy absorber, particularly in its high-density grade. Its thermal insulation properties and strength are widely used in the packaging industry for food containers and beverage coolers. Furthermore, EPP does not allow microbial interference, another strong advantage.
EPP is Resistant to Water and Chemicals
Aside from its strength and exceptionally high strength to weight ratio, which makes it impact-resistant, EPP is known for its excellent water and chemical resistance. The EPP foam is virtually non-affected by alcohols, acetates and common acids, oils, petrol, and gasoline.