Recently, a customer asked the price of polypropylene rope, the customer is a manufacturer of fishing net exports, usually used is polyethylene rope, but polyethylene rope is more delicate, easy to loosen after knotting, and the advantage of flat wire rope is that the monofilament of the rope is rough, knotting is not easy to slip. But polypropylene is heavier than polyethylene. Theoretically, the molecular formula of propylene is CH3CH2CH3, and the molecular formula of ethylene is CH3CH3. Polypropylene has one more carbon atom than polyethylene, so the mass of polypropylene rope is heavier than polyethylene.

The structure of polyethylene is as follows:

—(CH2-CH2-CH2-CH2)n—-

The structure of polypropylene is as follows:

—(CH2-CH(CH3)-CH2-CH(CH3)-CH2-CH(CH3))n—-

It can be seen from the structure that polypropylene has a branch chain more than polyethylene. After making a rope, due to the role of the branch chain, the rope of polypropylene has a stronger tension than polyethylene, and it is not easy to slip. The density of polypropylene is 0.91 and the density of polyethylene is 0.93, so polyethylene should be heavier.

Polyethylene rope is more flexible, smoother and softer than polypropylene.