HMPE Fiber: Properties, Comparison & Applications
1.What is HMPE？
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW)，also known as high-modulus polyethylene, (HMPE), is a very tough material，the third largest high-performance fiber just after aramid fiber and carbon fiber.HMPE fiber has excellent properties，such as with high strength, high modulus, impact resistance, acid and alkali resistance, wear resistance, low density etc.Get the benefit of the advantages,HMPE is widely used in military industry, aviation technology, marine engineering and civil fields, and rope is one of the largest application fields of HMPE fiber.
2.The structure and performance of HMPE
HMPE is a type of polyolefin fiber. It is made up of extremely long chains of polyethylene with a molecular mass usually between 3.5 and 7.5 million, which all align in the same direction. It can be said that the fiber morphology of HMPE is close to the ideal fiber morphology to obtain the maximum strength and stiffness.
Such microstructure gives HMPE fiber good mechanical properties: the fiber has high strength, high modulus, high energy absorption and impact resistance along the axis; At the same time, HMPE is resistant to most chemicals, its strength will not be reduced in acid-base solution, nor will it swell and hydrolyze in seawater; At very low temperature, HMPE fiber can still remain soft without embrittlement.
3.Comparison between HMPE rope and other ropes
The high-performance rope and cable made of HMPE has many characteristics, such as high strength, light weight, wear resistance, impact resistance, low temperature resistance and so on. It is an ideal rope product for marine and industrial markets. Compared with steel wire rope:
•under the same strength, the weight of HMPE rope is only 1 / 8 of that of steel wire rope
•corrosion resistance and aging resistance, no lubrication is required during use
•the operation cost is greatly reduced and easy to maintain
•better fatigue strength and long service life
•Higher safety factor
Compared with other chemical fibers, HMPE has the characteristics of high strength, high modulus and low density. Application on HMPE rope:
•Under the same breaking strength, HMPE rope has the smallest diameter and lightest weight.
•HMPE has low density, can float in water and does not absorb water; Flexible in wet environment or underwater.
•It has strong resistance to bending fatigue and tension fatigue, and the strength retention rate is 100% after 1000 cycles of load.
4.Why do we recommend HMPE rope
With the development of society and the progress of science and technology, people have an increasing demand for ropes. Therefore, the requirements for the preparation, types and performance of ropes are also gradually improved. For example, in some special occasions, in addition to requiring rope quality and increasing strength, it is also required to have the characteristics of wear resistance, acid and alkali resistance, fatigue resistance and impact resistance. A single traditional fiber rope has been difficult to meet people's demand for special ropes. HMPE rope has become the best solution in many applications because of its excellent characteristics.
1) High strength and light weight
The strength of HMPE rope can be completely comparable to that of steel wire rope, but what is more prominent is that its weight is only 1 / 8 of that of steel wire rope. The application of HMPE rope brings great cost reduction for engineering operation, transportation and maintenance. Therefore, HMPE rope has unique advantages in mooring and hoisting applications.
2) Wear resistance
In marine engineering application, the friction between rope and winch, cable pile and fairlead is inevitable. In other industrial applications, ropes often come into contact with some rough interfaces. This will not only have a great impact on the service life of the rope, but also bring risks to the use of the rope. The rope made of HMPE fiber can greatly reduce the impact of wear.
3) Impact resistance and low elongation
Among all chemical fiber ropes, only HMPE rope have the similar elongation as steel wire rope, and HMPE rope are extremely impact resistant, which means that HMPE rope is an excellent solution in the working environment with high requirements for safety and stability.
4) Fatigue resistance
The main chain of HMPE fiber is a soft polyethylene chain with very high molecular weight, and the binding force between molecular chains is very high. Therefore, the fatigue resistance of HMPE rope is very excellent. Whether it is used under repeated cyclic loading or bending under high tension, it will not affect the service life of the rope.