Polypropylene foam produced by physical expansion (EPP) also known as physically foamed polypropylene has several advantages over other rigid foams on the market. EPP is also highly versatile and offers enhanced performance characteristics that are valuable in different industries including civil engineering, automotive, and food packaging.
Advantages and Applications
When Compared to more amorphous rigid foams such as low-density polyethylene foam (LDPE foam), EPP is a much more crystalline material which allows it to replace several types of rigid foams currently on the market.
EPP also exhibits excellent physical and mechanical Properties, which enable its use in environments with high operating temperatures of up to 130 degrees Celsius. Furthermore, EPP is much more environmentally friendly than cross-linked polymers and other insulating materials, a fact that has contributed to its increasingly higher popularity among consumers.
Much to their detriment, manufacturers of physically foamed polymers are often reluctant to incorporate EPP into their productions. Lack of technological knowledge is often the reason many foam manufactures prefer to forgo the production of EPP and instead opt to produce lower quality Polyethylene foam for packaging applications. This material is often produced using inefficient single screw extruders, which are unable to produce a high-quality polypropylene foam material.
Our partners at FAP contribute greatly to the development of EPP in the global market. in conjunction with their high-performance foam machines, they offer training and a full range of services geared towards calculating production indicators, launching EPP and EPE production, and preparing all technological and technical documentation.
EPP also exhibits excellent physical and mechanical Properties, which enable its use in environments with high operating temperatures of up to 130 degrees Celsius. Furthermore, EPP is much more environmentally friendly than cross-linked polymers and other insulating materials, a fact that has contributed to its increasingly higher popularity among consumers.
Much to their detriment, manufacturers of physically foamed polymers are often reluctant to incorporate EPP into their productions. Lack of technological knowledge is often the reason many foam manufactures prefer to forgo the production of EPP and instead opt to produce lower quality Polyethylene foam for packaging applications. This material is often produced using inefficient single screw extruders, which are unable to produce a high-quality polypropylene foam material.
Our partners at FAP contribute greatly to the development of EPP in the global market. in conjunction with their high-performance foam machines, they offer training and a full range of services geared towards calculating production indicators, launching EPP and EPE production, and preparing all technological and technical documentation.
Comparing Physically foamed polypropylene (EPP) and cross-linked polyethylene foam (XLPE)
EPP and XLPE are comparable in terms of performance metrics and thus it is important to draw comparisons of different characteristics between the two to better understand the difference in performance.
As the table above indicates, PP foam is superior to XLPE in terms of thermal conductivity, elastic modulus and application temperature. But this does not mean that EPP can replace XLPE in all applications, on its own XLPE has excellent shock-absorbing properties, is much more elastic, and has similar low thermal conductivity. Moreover, XLPE has many other qualities that are essential in some industries.
With that said EPP is a much more sustainable material than physically or chemically cross-linked foams (XLPE). Recycling XLPE is difficult, expensive, and the process is poorly organized. EPP on the other hand can be recycled by a relatively simple granulation process and can be reused several times. This enables closed-loop manufacturing, which allows all production waste to be easily recycled internally by companies. Aside from environmental factors, the production process for EPP is much simpler and more efficient than that of XLPE.
As the table above indicates, PP foam is superior to XLPE in terms of thermal conductivity, elastic modulus and application temperature. But this does not mean that EPP can replace XLPE in all applications, on its own XLPE has excellent shock-absorbing properties, is much more elastic, and has similar low thermal conductivity. Moreover, XLPE has many other qualities that are essential in some industries.
With that said EPP is a much more sustainable material than physically or chemically cross-linked foams (XLPE). Recycling XLPE is difficult, expensive, and the process is poorly organized. EPP on the other hand can be recycled by a relatively simple granulation process and can be reused several times. This enables closed-loop manufacturing, which allows all production waste to be easily recycled internally by companies. Aside from environmental factors, the production process for EPP is much simpler and more efficient than that of XLPE.
EPP will soon dominate in several applications
Physically foamed polypropylene (EPP) is set to become a leading material in several applications thanks to its superior quality and characteristics. Areas where it will become prominent include:
Insulation in Construction
Insulation of car interiors
Food industry
Insulation in Construction
- Soundproofing of impact and airborne noise during the construction of multi-story buildings;
- Thermal insulation of constructions with high operating temperatures (saunas, hot water boilers, hot pipes);
- Reflective thermal insulation in the “warm floors”;
- Thermal insulation and sound insulation of metal roofing of buildings.
Insulation of car interiors
- Sound insulation of the car floor and roof structure.
Food industry
- Production of single-use tableware instead of polystyrene foam (EPS).
EPP for sound and heat insulation of “floating floor” systems under concrete screed
Most countries have established policies limiting the number of decibels that can be transmitted through a floor structure. This is why it is important to provide adequate sound insulation on floors that can minimize airborne and impact noise
The construction of a “floating floor” can involve the use of certain insulating materials, including chemically and physically cross-linked polyethylene foam, polypropylene foam, foam rubber, stone wool, as well as non-cross-linked polyethylene foam.
The construction of a “floating floor” can involve the use of certain insulating materials, including chemically and physically cross-linked polyethylene foam, polypropylene foam, foam rubber, stone wool, as well as non-cross-linked polyethylene foam.
A test revealed that physically foamed polypropylene (EPP) was the best material for floor soundproofing under cement screed. The results of the durability test "12 months under a load of 2000 N/m2", shows the change in the thickness of sound insulation from foamed polypropylene (EPP) and cross-linked polyethylene (XLPE) over 12 months.
The graph above indicates that the stabilization of the thickness of physically foamed polypropylene (EPP) occurred at the end of the third month, and the loss of thickness at the end of 1 year was 10-11% of the original. Stabilization of the thickness of the crosslinked polyethylene foam (XLPE) occurred at the end of the fifth month, but the overall thickness loss was 20%. Thus, after a year, the impact noise reduction rates for physically foamed polypropylene (EPP) decrease by approximately 4%, for cross-linked foamed polyethylene (XLPE) by 10%. Decreasing impact noise reduction results in increased sound transmission through the floor in the room.
EPP for Thermal insulation
EPP can be used at high ambient temperatures, where other polymer materials struggle to maintain their physical properties. Consequently, EPP is often used as insulation for saunas. It can also be used as a insulation for metal roofs and is especially useful in areas with large differences in average annual temperatures.
Below are the shrinkage test results of physical polypropylene foam (EPP) and cross-linked polyethylene foam (XLPE) under various temperature conditions for 48 hours.
Below are the shrinkage test results of physical polypropylene foam (EPP) and cross-linked polyethylene foam (XLPE) under various temperature conditions for 48 hours.
Please note that after the use temperature exceeds 105 °C for a long time of use, XLPE begins to deform quite severely.
As for physically foamed polypropylene (EPP), it can be used in conditions of constant high temperatures up to 125-130 °C, which gives this type of insulation additional advantages.
As for physically foamed polypropylene (EPP), it can be used in conditions of constant high temperatures up to 125-130 °C, which gives this type of insulation additional advantages.
Physically foamed polypropylene (EPP) is an excellent solution on many industries
There are several qualities that make EPP a highly attractive option. Its environmentally friendly production and recycling process set it apart from other foam materials. Furthermore, its molecular structure and various other qualities enable EPP to be produced using carbon dioxide as a foaming agent, a fact that greatly contributes to its value.