LyondellBasell Industries announced that its heterophasic polypropylene copolymer, Moplen EP340M, has become one of the first polypropylene products to receive certification from the Association of the German Automotive Industry (VDA) for the production of collapsible pallet boxes used in automotive manufacturing. Known to be regularly used by plastic converters of small crates and large collapsible boxes, the resin is said to provide excellent resistance to low and high temperatures and good impact performance for boxes used in this demanding manufacturing environment. Since the resin shows a ductile brittle temperature of -55°C combined with a high heat deflection temperature of 80°C, pallet boxes produced using Moplen EP340M fulfill a wide range of requirements, including high impact resistance. The collapsible pallet boxes were developed by VDA experts together with the box manufacturers to optimize manufacturing chain logistics, including the reuse of the polypropylene boxes.
Relative to traditional products made with wood and steel, boxes made from polypropylene have proven to be more suitable for automotive manufacturing due to the weight and handling advantages they offer. The VDA 4520 recommendation for collapsible pallet boxes for the automotive industry stipulates the geometric requirements and testing necessary for approval, such as a dynamic vibration test which must be conducted by an independent institute. The test simulates the vibration caused by a truck during transportation. Described by the ASTM 4728, several frequencies, amplitudes and accelerations are forced onto the box while loaded with 500 kg at room temperature, at +40°C and at - 15°C. Other tests include the definition of the breaking load at room temperature, at +50°C and at -15°C. As a maximum load of up to 2800 kg can be expected on the lower box, the breaking load has to be even higher than 3 times the weight. Horizontal impact must be tested to simulate collisions by forklifts; several drop tests of a loaded carrier are conducted to complete the mechanical testing.