UHMWPE- ultra high molecular weight polyethylene:

Ultra high molecular weight polyethylene (abbreviated as UHMWPE) is a linear polyethylene with molecular weight over 1.5 million and no branched-chain. Molecular formula is (C2H4) N, density: 0.920 ~ 0.964g/cm3. The thermal deformation temperature (0.46MPa) is 85℃, and the melting point is 130 ~ 136℃. UHMWPE high molecular weight (molecular weight HDPE are usually only 2 ~ 300000) to the use of its outstanding performance, and belongs to the moderate price, good performance of thermoplastic engineering plastic, which concentrated the advantages of all kinds of plastic, almost with ordinary polyethylene and other engineering plastics incomparable abrasion resistance, impact resistance, self-lubrication, corrosion resistance, absorb the impact energy, low temperature resistance, health, non-toxic, difficult to adhesion, small water absorption, density and so on comprehensive performance. In fact, there is no single polymer material with so many excellent properties.

Common products of ultra-high molecular weight polyethylene:

At present, UHMWPE has been widely used in textile, papermaking, packaging, transportation, writing, chemical, mining, petroleum, construction, electrical, food, medical, sports and other fields, and began to enter the conventional weapons, ships, automobiles and other fields. In medical treatment, UHMWPE has excellent physiological adaptability, approved by the United States Food and Drug Administration, the Department of Agriculture, can be used in the field of medicine and human contact, such as as the heart valve, orthopaedic surgery parts, artificial joints and birth control implants and other clinical use, is an ideal medical polymer material. The wear resistance and safety of artificial hip and knee joint composed of carpal socket and metal femur made of UHMWPE are more different than PTFE. Hundreds of thousands of people around the world have undergone this type of joint replacement. In the future, it will also be extended to the fields of aerospace and atomic energy boarding.




Ultra-high molecular weight polyethylene advantages:

  1, wear resistance, resistance to sliding friction. The wear resistance of ultra-high molecular weight polyethylene pipe is 4-7 times higher than that of ordinary steel pipe, and 27.3 times that of stainless steel. It is 17.9 times of phenolic resin, 6 times of nylon, 4 times of polyethylene, and the average annual wear rate is 0.58 ㎜, which improves the service life of the pipe.   2. Impact resistance. UHMWPE has the highest impact toughness among the existing engineering plastics, and its impact strength is more than 10 times that of PE100 at normal temperature. With the decrease of ambient temperature, its impact resistance is stronger.   3, corrosion resistance, can resist the erosion of most corrosive media and organic solvents, ultra-high molecular weight polyethylene can be used in concentration of less than 80% of concentrated hydrochloric acid, in the concentration of less than 75% of sulfuric acid, concentration of less than 20% of nitric acid performance is quite stable.   4, self-moistening, its sliding performance is better than oil lubricated steel or brass. The dry lubrication performance of UHMWPE tube is better in the place of bad environment, dust and silt. It can move freely to protect the relevant workpiece from abrasion or strain. The friction coefficient is only 0.07~0.12, which is 1/5 of ordinary PE, 1/6 of new steel pipe and 1/20 of rubber.   5, non-toxic, ultra-high molecular weight polyethylene material is the national certification of environmental protection materials, non-toxic and tasteless, anti-pollution anti-moth new thermoplastic engineering plastics. The US Food and Drug Administration (FDA) and the US Department of Agriculture (USDA) allow it to be used in contact with food and drugs. The main water supply and drainage pipes in many cities in China have been converted to ultra-high molecular weight polyethylene pipes.   6, low temperature resistance, anti-aging, ultra high molecular weight polyethylene tube can work at -269℃ to 80℃ temperature for a long time, due to the molecular chain in the unsaturated molecular group is very few, large molecular weight, high stability, aging speed is particularly slow, long service life.   7, the surface of non-adhesion, no scaling, ultra-high molecular weight polyethylene tube due to small friction coefficient and non-polarity, with a surface of non-adhesion.   8, crack resistance is the best, ultra high molecular weight polyethylene tube through tensile test proved that it has 100~300% elongation, under huge external pressure and internal pressure or bending stress can also maintain a certain deformation without breaking.

HDPE- High density polyethylene:

The English version of high-density Polyethylene is referred to as "HDPE", also known as low-pressure Polyethylene. HDPE is one of the PE and its molecular formula is (C2H4) N. High-density Polyethylene HDPE is a kind of white powder granule product, non-toxic and tasteless. High density polyethylene HDPE is a thermoplastic polyolefin with ethylene copolymerization claims. Although HDPE was introduced in 1956, this plastic has not yet reached a mature level, and this universal material is still being developed for new uses and markets. Redden porous plastic and in the development of the extraction of HDPE a small part of the use of raw materials.

High density polyethylene products:



Chemical properties of high density polyethylene:



High density polyethylene advantages:

  1. It has good heat resistance and cold resistance.   2, good chemical stability, but also has high rigidity and toughness, good mechanical strength.   3, acid and alkali resistance, organic solvent resistance, excellent electrical insulation, low temperature, still can maintain a certain toughness.   4, HDPE surface hardness, tensile strength, rigidity and other mechanical strength are higher than LDPE, close to PP, than PP toughness, but the surface finish is not as good as PP.

LLDPE- Linear Low Density Polyethylene:

The English name of Linear Low Density Polyethylene is Linear Low Density Polyethylene, abbreviated as LLDPE. Linear low density polyethylene (LLDPE) is non-toxic, tasteless, odorless milky white particles.



Chemical properties of linear low density polyethylene:

Advantages of LLDPE and LDPE: