High Density Polypropylene (HDPP)
High density polypropylene (HDPP), also called polypropene is a thermoplastic polymer, made up of the monomer, propylene. It can be manufactured as a dense product that has high resistance to chemical cleansers but also relatively light and flexible with a low melting point between 130 and 170 degrees C.
Polypropylene (PP) is a commonly used material for packaging, automotive parts and textiles, whilst HDPP is commonly used to manufacture pipes as an alternative to high density polyethylene (HDPE). HDPE is naturally greater resistance to UV but HDPP can contain additives that increases its UV stability. HDPP can become more brittle at lower temperatures and poorer resistance to oils than HDPE.
Polypropylene (PP) including High density polypropylene (HDPP) comes under category 5 in the Resin Identification Code (RIC) system for plastic classification, where as high density polyethylene (HDPE) falls in category 2. To differentiate between the two under a burn test ,HDPP tends to smell of petroleum whilst HDPE smells more of melted candlewax.
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