Ultra High Molecular Weight Polyethylene Ropes (UHMWPE)
Ultra High Molecular Weight Polyethylene Ropes are considered the best ropes for marine & industrial applications, performance yachting, aquaculture, commercial fishing, mountaineering etc and they can be the ideal substitute for wire and steel in the mooring line of the Tanker vessels, pennant lines for offshore rigs, tow hawsers, ship assist lines and a lot more.
Ultra High Molecular Weight Polyethylene Ropes float in water making them significantly safer, their low stretch properties provide greater sensitivity and their low elongation combined with their low weight makes their handling easy and the manoeuvring of vessels extremely accurate especially in distress & critical times.
Ultra High Molecular Weight Polyethylene (UHMWPE) ropes are 7-9 times stronger than steel (by weight) and 3 times stronger than Polyester of equal weight. Exhibiting the highest strength to weight ration, these ropes are widely used and accepted by the major classification societies, Marine Forums and Oil & Shipping Companies in their first installation in newbuildings.
UHMWPE ropes are small in volume (due to the smaller sizes used) making them suitable for easy storage and rapid deployment in emergency cases even by a single individual.
UHMWPE ropes provide a high level of security and protection and are according to OCIMF's latest regulations & recommendations for the safe mooring of the Tanker vessels.
- Light enough to float
- High resistance to chemicals, water and ultraviolet light
- Excellent vibration damping
- Highly resistant to flex fatigue
- Low coefficient of friction
- Good resistance to abrasion
- Low dielectric constant makes it virtually transparent to radar
What is Ultra High Molecular Weight PolyEthylene?
UHMWPE (Ultra High Molecular Weight PolyEthylene), also known as HMPE (High Modulus PolyEthylene) or HPPE (High Performance PolyEthylene), is a polyolefin resin of very high molecular weight (mass) usually between 2 and 6 million g/mol with extremely long chains produced by gel spinning (wet or dry methods). The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made.
UHMWPE is odorless, tasteless, and nontoxic. It is highly resistant to corrosive chemicals except oxidizing acids, has extremely low moisture absorption (Hydrophobic), very low coefficient of friction, self-lubricating and highly resistant to abrasion, in some forms being 15 times more resistant to abrasion than carbon steel. Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of polytetrafluoroethylene (PTFE, Teflon), but UHMWPE has better abrasion resistance than PTFE. UHMWPE material floats in water thus gaining another advantage over many other materials such as Polyester, Nylon, Aramids, LCP.
UHMWPE material can be classed as a specialty engineering plastic. It is an indispensable product in world markets having an incomparable combination of abrasion resistance, surface lubricity and impact strength, combined with the excellent chemical properties of HDPE. It competes primarily with Polyacetal, Nylon, PTFE and, in fiber form, with Polyaramid, but it also has many markets that are uniquely its own.
UHMWPE ropes are increasingly replacing steel and conventional fibers in the shipping and offshore businesses of oil & gas, aquaculture, wind mills and cables and lately, experimentally, in ships’ cranes. These high performance ropes are stronger than steel and ~1/8 of the weight of comparable steel wires.
In other words, they are at least 8 times stronger than steel wire ropes on a weight-for-weight basis. Since they are thinner and lighter, they are significantly easier to handle compared to steel and conventional fiber ropes. This means more effective logistics, shorter tie-up times, reduced fuel consumption, increased speed and safety.
HMPE fiber has a melting point between 144ºC and 152ºC. The tenacity and modulus decrease at higher temperatures but increase at sub-zero temperatures. There is no brittle point found as low as -150ºC, so the fiber can be used between this temperature and 70ºC. Brief exposure to higher temperatures will not cause any serious loss of properties.
Below, there is a diagram showing the influence of temperature on HMPE fiber breaking strength (the 100% of the relative breaking strength at 21oC)
Benefits in brief:
- It practically never absorbs water.
- Has a density of as little as 0.97 (floats on Sea Water)
- Great abrasion Resistance (better than Teflon), in some forms it is 15 times more resistant to abrasion than carbon steel
- UHMWPE is self-lubricating
- UHMWPE has excellent UV resistance.
- Low Elasticity. Unlike Nylon, UHMWPE does not stretch much (3-4% at breaking load).
- Reduced Injuries
- Reduced crew fatigue
- Reduced Seasonal Hardware costs
- Increased lifetime
- Less Maintenance