Recently, a customer consulted the price of polypropylene flat wire rope, the customer is a manufacturer for fishing net export, usually using 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 relatively rough, and the knot is not easy to slip.

However, the weight of polypropylene is larger than that of polyethylene, from theoretical analysis, the molecular formula of propylene is: CH3CH2CH3, the molecular formula of ethylene is: CH3CH3, polypropylene has one more carbon atom than polyethylene, so the mass of the rope made of polypropylene is heavier than that of polyethylene.

　　The structure of polypropylene is as follows:

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

The structure of polyethylene is as follows:

---(CH2-CH2-CH2-CH2)n----

From the structure, it can be seen that polypropylene has one more branch chain than polyethylene, and after being made into a rope, due to the role of the branch chain, the rope of polypropylene has a stronger tensile force than polyethylene, and the knot is not easy to slip.

Polyethylene rope is more flexible, smooth and feels supple than polypropylene.

The density of polypropylene is 0.91, and the density of polyethylene is 0.93, so it should be the heavier of polyethylene.