UHMWPE rope, also known as HMPE (High Modulus Polyethylene), is a polyolefin fibre known for its exceptional strength relative to its weight.
This strength is due to the extremely long, overlapping polyethylene chains in the molecular structure that are aligned in the same direction.
So what are the advantages of HMPE rope:
- Strong and light: UHMWPE has an extremely high strength-to-weight ratio. This means that the rope is very strong, but at the same time remains lightweight.
- Chemical-resistant and water-resistant: UHMWPE is resistant to most chemicals, including detergents, mineral acids and oils.
However, it is susceptible to corrosion from strong oxidising agents.
Its water-repellent properties make the rope very suitable for use in wet environments. - Buoyancy: UHMWPE is light enough to float, making it a good choice for marine applications.
- Low stretch: The low stretch of UHMWPE makes it suitable for applications where shape retention is important, such as sails and rigging in yachting.
- Wear resistance: UHMWPE is highly resistant to abrasion, which extends the life of the rope.
Disadvantages of HMPE rope:
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Poor friction between yarns: The yarns in UHMWPE rope have low friction, allowing them to slide over each other without absorbing energy.
This can lead to the ‘wedge-through effect’, where the fibres fail due to too much pressure on a small point.
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Sensitive to heat: UHMWPE has a relatively low melting point, making it unsuitable for use in high-temperature environments.
Heat can also be generated by friction so take that into account too. When used for 4x4 vehicles, for example, a roller window for an HMPE winch cable is much better than a sheave window, as this creates much less frictional heat.
- Creep under load: UHMWPE can deform under long-term loading (this is called creep), which can be problematic in applications where constant load bearing capacity is important.
Factors affecting the quality of UHMWPE
The quality of UHMWPE rope is influenced by several factors in the production process, including:
- Molecular weight of the polymer
- Spinning process and temperature control
- Tensile ratio
- Coating and finishing
- Tension during winding
- Fibre diameter and strand configuration
It is going too far for this article to look at this in detail, but does indicate that the quality of the manufacturing process certainly matters for the final quality of the rope.
So if you have 2 HMPE ropes that look the same, there can still be a big difference in quality.
Dyneema® vs Spectra®
Dyneema® and Spectra® are well-known brand names for UHMWPE rope.
Dyneema® stands out for its consistent manufacturing process, using their own raw material and applying molecular engineering during production.
Spectra® offers a wide range of products with different specifications.
In terms of quality as a result of how good the production process is, brands are a good indication of the quality of the UHMWPE rope.
That way, you know you can count on the rope you use. Hence, we have our own range of Prorope HMPE rope.
Want to know more about UHMWPE rope or have any questions following this article? Then get in touch at info@prorope.com