what is the melting point of uhmw

What is the melting point of UHMWPE?

Its melting point is around 130 to 136 °C (266 to 277 °F), and, according to DSM, it is not advisable to use UHMWPE fibres at temperatures exceeding 80 to 100 °C (176 to 212 °F) for long periods of time. It becomes brittle at temperatures below −150 °C (−240 °F).

What are the properties of UHMW?

UHMW (ultra-high-molecular-weight polyethylene) offers a combination of exceptional properties. This thermoplastic material is tough with superior impact strength. It is corrosion-resistant and exhibits virtually no water absorption. It is also wear-resistant, non-sticking and self-lubricating.

How is UHMW made?

How is UHMW Made? Like most plastics, polyethylene (the base monomer of UHMW) is created by distilling hydrocarbon fuels into lighter groups known as “fractions.” Some of the extracted fractions are combined with serval catalysts to produce plastics.

What is UHMWPE?

In these blends, the UHMWPE fibers are blended with, for example, Vectran . In skydiving, UHMWPE is one of the most common materials used for suspension lines, largely supplanting the earlier-used Dacron, being lighter and less bulky.

Does UHMW melt?

UHMW-PE's high molecular weight means it will not melt or flow as a molten liquid. Processing methods are therefore derived from those of powder metal technology. UHMW-PE cannot be transformed and molded by conventional plastic processing techniques (injection molding, blow molding or thermoforming).

At what temp does UHMW melt?

For UHMWPE, its melting point is about 155°C, and the polymer powder particles can completely fuse into melt as temperature is higher than 200°C.

Can UHMW be heat formed?

Unlike most thermoplastics, UHMW plastic does not become a liquid when it is heated above its "melting point". Because of its high melt strength, it can be handled and shaped above its crystalline melting temperature of 265° F (129° C).

Which is stronger HDPE or UHMW?

UHMW and HDPE are thermoplastic polymers that have a similar appearance. The key difference between UHMW and HDPE is that UHMW contains long polymer chains with very high molecular weights whereas HDPE has a high strength-to-density ratio. UHMW stands for Ultra High Molecular Weight polyethylene.

Is UHMWPE stronger than Kevlar?

Durability. In terms of overall durability, both UHMWPE and Kevlar rank high above other industrial fibers. However, UHMWPE fibers like Spectra and Dyneema exhibit resistance five times higher than Kevlar—even using just half the number of synthetic materials.

Can you bend UHMW with heat?

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Is Delrin the same as UHMW?

UHMW has surface and chemical properties that are rare to find in high-performance polymers. It is very resistant to most chemicals, UV radiation, and micro-organisms, but doesn't have the same creep resistance as Delrin.

Is HDPE the same as UHMW?

UHMW and HDPE are made from ethylene monomers. They are both thermoplastic polymers. They both have an indistinguishable appearance. The main difference between UHMW and HDPE is that UHMW contains long polymer chains with a very high molecular weight, whereas HDPE has a high strength to density ratio.

How do you cut UHMW plastic?

eric. h... @hotmail.comUse a coarse blade when cutting UHMW. ... Unlike polypropylene, UHMW does not melt when you cut it, so the. ... UHMW does not harm the saw or blade. ... If you are cutting a thick piece of UHMW, it is best to do short. ... I always recommend that people use a carbide blade.More items...•

Does UHMW crack?

Also, even though UHMW plastic is known for its ability to withstand cold temperatures, it will become brittle at temperatures below -150 °C (or -240 °F).

Can you machine UHMW-PE?

Machining UHMWPE Thermoplastics are prone to stress cracking and premature part failure when placed under high heat and tensile load. Therefore, annealing is crucial if you want a quality, precision machined part out of the stock shape.

Does UHMW float in water?

Non-staining. FDA approved for use in food and medical applications. Low specific gravity – will float in water.

What is UHMW polyethylene?

UHMW is an acronym for Ultra High Molecular Weight Polyethylene. Most commonly referred to as UHMW. It is famous for its abrasive resistance, toughness, and low cost. It is also FDA and NSF compliant. It’s natural color is white, but is available in black and other colors at special request. Typical applications include sleeve and flanged bearings for high wear industrial and manufacturing bearing applications. Custom and standard profiles exist for conveying environments. UHMW is easily machined into custom components. Though it is easily machined with standard metal working equipment, UHMW has a very high coefficient of thermal expansion making it difficult to hold close tolerance dimensions. Its main attributes are impact and abrasion resistance. Its self-lubrication properties and low cost makes UHMW a great choice for many demanding bearing and wear applications.

Is UHMW a standard profile?

Custom and standard profiles exist for conveying environments. UHMW is easily machined into custom components. Though it is easily machined with standard metal working equipment, UHMW has a very high coefficient of thermal expansion making it difficult to hold close tolerance dimensions.

Material Information

UHMW is a thermoplastic that belongs to the polyolefin group of material. Molecular density characterizes polyethylene, with UHMW being the most dense with a molecular weight of 3.1 million or higher. UHMW is simple to machine.

Electrical

The information contained herein are typical values intended for reference and comparison purposes only. They should NOT be used as a basis for design specifications or quality control. Contact us for manufacturers' complete material property datasheets. All values at 73°F (23°C) unless otherwise noted.

What temperature does UHMWPE melt?

Its melting point is around 130 to 136 °C (266 to 277 °F), and, according to DSM, it is not advisable to use UHMWPE fibres at temperatures exceeding 80 to 100 °C (176 to 212 °F) for long periods of time. It becomes brittle at temperatures below −150 °C (−240 °F).

What is UHMWPE made of?

UHMWPE is a type of polyolefin. It is made up of extremely long chains of polyethylene, which all align in the same direction. It derives its strength largely from the length of each individual molecule (chain). Van der Waals bonds between the molecules are relatively weak for each atom of overlap between the molecules, but because the molecules are very long, large overlaps can exist, adding up to the ability to carry larger shear forces from molecule to molecule. Each chain is bonded to the others with so many van der Waals bonds that the whole of the inter-molecular strength is high. In this way, large tensile loads are not limited as much by the comparative weakness of each van der Waals bond.

How long does it take for UHMWPE to cool down?

When UHMWPE is annealed, the material is heated to between 135 °C and 138 °C in an oven or a liquid bath of silicone oil or glycerine. The material is then cooled down at a rate of 5 °C/h to 65 °C or less. Finally, the material is wrapped in an insulating blanket for 24 hours to bring to room temperature.

Why does UHMWPE feel slippery?

For the same reasons, skin does not interact with it strongly, making the UHMWPE fiber surface feel slippery. In a similar manner, aromatic polymers are often susceptible to aromatic solvents due to aromatic stacking interactions, an effect aliphatic polymers like UHMWPE are immune to.

How many monomers are in HDPE?

These molecules are several orders of magnitude longer than those of familiar high-density polyethylene (HDPE) due to a synthesis process based on metallocene catalysts, resulting in UHMWPE molecules typically having 100,000 to 250,000 monomer units per molecule each compared to HDPE's 700 to 1,800 monomers.

How many amu is a polyethylene chain?

Also known as high-modulus polyethylene, ( HMPE ), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions.

Who makes UHMWPE powder?

Polymerization of UHMWPE was commercialized in the 1950s by Ruhrchemie AG , which has changed names over the years. Today UHMWPE powder materials, which may be directly molded into a product's final shape, are produced by Ticona, Braskem, DSM, Teijin (Endumax), Celanese, and Mitsui. Processed UHMWPE is available commercially ...

What is UHMW plastic?

UHMW is quickly emerging as one of the best replacements for metallic parts in industrial facilities. In fact, this performance plastic has proven to consistently outperform alternative materials, including metals, in these applications. The versatility of UHMW has made it a popular choice for those looking for new solutions to improve their ...

What are the advantages of UHMW?

Advantages of UHMW. Some of the primary benefits of UHMW include its strength, durability, and high impact resistance. UHMW is also particularly advantageous when used in applications that need to withstand constant friction.

Is UHMW a good material?

In addition, its impact strength is high, and its chemical resistant is excellent. UHMW is a great general-purpose material because of its versatile characteristics, and it can be used in almost any environment.

Is UHMW food safe?

However, one of UHMW’s greatest advantages is its food-safe properties, making it one of the few materials that meet various regulatory compliances. UHMW is also corrosion resistant and has a very low rate of moisture absorption, making it the perfect option for applications that face unique environmental challenges.

What is the strength of UHMW?

The brands like Dyneema and Spectra have developed UHMW with a high yield strength of 2.4 GPa (2.4 kN/mm2 or 350,000 psi), making it as strong as steel. The branded plastic material is used in vehicle and personal protection armors, bowstrings, automotive winching, climbing equipment, spear lines for spearguns, cut-resistant gloves, high-performance sails, suspension lines in parachutes, and paragliders, etc.

What is UHMW insulation?

UHMW fluoropolymer insulation protection cables are extremely popular in the wires & cables industry. It contains a certain amount of ECTFE and is chemically resistant to chlorine, sulfuric acid, and hydrochloric acid. The UHMW jacketing on the cable provides great mechanical and pliable strength during installation as well as operations.

What is UHMW used for?

UHMW is used for manufacturing the mooring of ships and floating structures. The UHMW forms good contact between the floating structure and the field one. The features such as wear-resistance, which is better than steel, impact resistance, similar to steel, and self-lubrication, make it ideal for applications in facing berthing structures.

What blade to use to cut UHMW?

Ans. Using a coarse blade is the option to cut the UHMW sheet. Another option is a carbide blade which cuts well. Using Teflon spray on the sides of the blades used for cutting makes the process smoother.

When was UHMW first used?

The high-performance polymer was first introduced to medical science in 1962 by Sir John Charnley became a prominent force as a material for hip and knee replacement in the 1970s.

Who makes UHMW powder?

Today UHMW powder material is manufactured by serval manufacturers such as Mitsui, DSM, Ticona, Teijin, Celanese, Braskem. Now, it is widely available in the form of fibers, sheets, and rods.

Is HDPE the same as UHMW?

HDPE is easy to shape and weld using any thermoplastic equipment, making it ideal for applications with a specific shape. On the other side, UHMW is compatible with holding up against wear from constant friction with moving parts. It can also be fabricated and machined, but it’s not suitable for forming specific shapes.