HDPE suction box cover and scraper blades: HDPE is an engineering plastic that is often underestimated and althogh HDPE is popular,it is sometines confused with other engineering platics.HDPE is grade number the higher the density polyethylene and available in two main grades, 300 and 500 grade.The higher the HDPE grade number the higher the density of the plastic is which improves the performance of the product. HDPE ofters resistance to almost all acids and bases,detergents and hot water.HDPE is an excellent engineering plastic that has many unique and useful properties to offer users who need a varied and combinedrange of beneficial features.