Expanded polypropylene (EPP for short) is an ultra-light, closed-cell thermoplastic foam particle based on polypropylene foam. It is black, pink or white, and the diameter is generally between φ2 and 7mm. EPP beads are composed of two phases, solid and gas. Usually, the solid phase only accounts for 2% to 10% of the total weight, and the rest is gas. The minimum density range is 20-200 kg/m3. Specifically, the weight of EPP is lighter than that of polyurethane foam under the same energy-absorbing effect. Therefore, the foam parts made of EPP beads are light in weight, have good heat resistance, good cushioning properties and excellent mechanical properties, and are 100% degradable and recyclable. All these advantages make EPP one of the most widely used materials in many fields, in every aspect of our life:
In the automotive field, EPP is the best solution to achieve lightweight components, such as bumpers, automotive A-pillar trims, automotive side shock cores, automotive door shock cores, advanced safety car seats, tool boxes, luggage, Armrests, foamed polypropylene materials can be used for parts such as bottom plates, sun visors, instrument panels, etc. Statistics: At present, the average amount of plastic used in automobiles is 100-130kg/vehicle, of which the application amount of foamed polypropylene is 4-6kg/vehicle, which can reduce the weight of automobiles by up to 10%.
In the field of packaging, reusable packaging and transportation containers made of EPP have the characteristics of heat preservation, heat resistance, corrosion resistance, insulation, long service life, etc., do not contain volatile organic compounds, and do not contain single substances that are harmful to the ozone layer or heavy metals Material packaging, digestible after heating, 100% environmentally friendly. Whether it is precision electronic components, or the transportation of food such as fruit, frozen meat, ice cream, etc., expanded polypropylene foam can be used. According to the BASF pressure level test, EPP can regularly achieve more than 100 shipment cycles, which greatly saves materials and reduces packaging costs.
In addition, EPP has excellent shock resistance and energy absorption performance, and is also widely used in the production of child safety seats, replacing traditional hard plastic and polystyrene components, and has even become the preferred material for environmentally friendly household daily necessities.
A child seat developed by Karwala in cooperation with KNOF Industries. This is the lightest child safety seat on the market, transporting children in the 0-13kg range and weighing only 2.5kg, which is 40% lower than the current product on the market.
Despite such a wide range of applications, we rarely perceive it. Why is this so? Because in the past, the surface of most EPP foam parts using mold and direct particle molding technology was not aesthetically pleasing and was often hidden behind materials such as steel, metal, sponge, foam, textile and leather. For many years, attempts have been made to improve the surface quality of standard-produced foam particle parts by adding texture to the interior of molding equipment. Unfortunately, this often results in higher scrap rates. Injection molding is temporarily considered a reasonable process, but its products are not ideal in terms of light weight, energy absorption and insulation.
In order to make the surface of particle foam parts better, you can also choose to use laser processing technology after the parts are formed, or perform lamination treatment to obtain different styles of textures. But post-processing also means additional energy consumption, which also affects the recyclability of EPP.
In this context, T.Michel GmbH, together with many top material and equipment manufacturers in the industry, launched the “In-Mold Foamed Particle Coating” (IMPFC) technology, which is spraying at the same time as molding. This process uses kurtz Ersa’s THERMO SELECT process, which individually adjusts the temperature zones of the mold, resulting in a high-quality part surface with very low shrinkage. This means that the produced mouldings can be overmolded immediately. This also enables simultaneous spraying. The sprayed coating will choose a polymer with the same structure as the foam particles, for example, EPP corresponds to sprayed PP. Due to the composite of a single-layer structure, the produced foam parts are 100% recyclable.
An industrial-grade spray gun from Nordson that disperses the paint into uniform and fine droplets for precise and efficient application to the inner layers of the mold. The maximum thickness of the coating can reach 1.4 mm. The use of the coating enables the free choice of the color and texture of the molded parts, and provides a huge space for the increase or change of the performance of the surface. For example, the PP coating can be used for EPP foam. Brings good UV resistance.
Coating thicknesses up to 1.4 mm. Compared with injection molding, IMPFC technology produces molded parts that are more than 60 percent lighter. Through this method, moldings made of foam particles including EPP will have a broader prospect.
For example, EPP foam products will no longer be hidden behind other materials or wrapped in other materials in the future, but will show their own charm openly. And, with the growing demand for electric vehicles in recent years and the favorable trend of consumers switching from traditional vehicles to electric vehicles (according to the International Energy Agency, global electric vehicle sales are expected to reach 125 million units in 2030. By 2030, China is expected to Around 70% of vehicle sales will be EVs), which will create considerable opportunities for the EPP market. Automobiles will become the largest application market for EPP. In addition to realizing the transformation and upgrading of existing auto parts and their assemblies, EPP will also be applied to more newly developed components, including but not limited to:
In the future, EPP will continue to play an important role in material lightweighting, heat insulation, energy absorption, etc. by virtue of its wide range of positive properties that cannot be met by any other material combination: low cost, excellent mechanical properties, good formability, environmental friendliness, etc. effect.
Post time: Aug-05-2022