Polypropylene (PP) has characteristics that are extremely similar to those of the HDPE that sometimes it is difficult to distinguish between the two. PP is often divided into the homo-PP and the co-PP. Although the PP density is extremely small (between 0.9 and 0.94), it is mechanically much stronger and harder than the HDPE, and has better electro-insulating properties. It is also highly chemical-resistant.
Characteristic
Low specific gravity (0.9 or lower), transparent, 95% crystalline
Often used as a hard molding material
Although it is shock-absorbent in room temperature, because it loses its strength against shock in temperatures below -5 degrees Celsius, it requires a grade that is highly shock-absorbent.
Heat-resistant, wear-resistant
Waterproof, chemical-resistant
Smells like gasoline and loses stickiness and printability when combusted.
Ages slowly under the sunlight and heat
More affordable and light-weight than the HDPE
Extremely light, insulates well, and easily workable using machines
Can be welded or fused.
Applications
Plating, chemical tank lining, gears, poller guides
