What Is High Modulus Polyethylene (HMPE) Mooring Rope?

 Technical White Paper Based on Documented Material Properties, Comparative Charts, and Manufacturing Process Flow.

Executive Summary

HMPE mooring rope (documented as UHMWPE rope) is a high-strength fiber rope with density 0.97 g/cm³, operating temperature −125°C to 70°C, no moisture absorption, strong sunlight/UV resistance, and very good resistance to acid/alkali/chemical corrosion, with excellent abrasion and fatigue resistance.
This paper consolidates the document’s properties, comparative performance statements, durability evaluation, and manufacturing process flow into a structured, data-first technical reference.

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Table of Contents

• Definition (HMPE / UHMWPE)
• Documented Key Properties
• Strength-to-Weight Multiples (Equal Weight)
• Density & Buoyancy (Specific Gravity)
• Low-Temperature Performance
• Durability Evaluation
• Conventional Fiber Rope Reference
• Manufacturing Process Flow
• Standards & Certification Scope
• FAQ

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Definition (HMPE / UHMWPE)

In the source document, the rope material is specified as Ultra-High Molecular Weight Polyethylene (UHMWPE). In industry usage, HMPE mooring rope commonly refers to this UHMWPE-based high-modulus polyethylene fiber rope category.

Table 1 — Material Identification (Documented)

Item	Documented content
Material	Ultra-High Molecular Weight Polyethylene (UHMWPE)

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Documented Key Properties

The document lists fundamental physical and environmental properties as follows.

Table 2 — Key Properties of UHMWPE/HMPE Rope (Documented)

Property	Value / Rating (as documented)
Material	Ultra-High Molecular Weight Polyethylene (UHMWPE)
Colors	Yellow, blue, red, etc.
Density	0.97 g/cm³
Operating environment temperature	−125°C to +70°C
Moisture absorption	None
Sunlight / UV resistance	Excellent
Acid / alkali / chemical resistance	Very good
Abrasion resistance	Excellent
Fatigue resistance	Excellent
Elongation	Low; close to steel

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Strength-to-Weight Multiples (Equal Weight)

The document provides explicit comparative statements regarding strength at equal weight and weight at equal strength.

Table 3 — Strength Multiples at Equal Weight (Documented)

Compared rope type	UHMWPE/HMPE rope strength (documented multiple)
Nylon rope	3–4
Polyester rope	4–5
Polypropylene rope	4–5
Steel wire rope	6–7

Table 4 — Weight Comparison at Equal Strength (Documented Statement)

Comparison basis	Documented statement
Same strength	The document presents a weight comparison among rope types at equal strength (shown in chart form).

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Density & Buoyancy (Specific Gravity)

The document compares densities of fiber ropes and notes that UHMWPE rope density is below water, enabling flotation.

Table 5 — Density Comparison of Fiber Ropes (Documented)

Material	Density (g/cm³)
UHMWPE / HMPE rope	0.97
Polypropylene rope	0.91
Nylon rope	1.14
Polyester rope	1.38
Water (reference)	1.00

Documented implication: Rope density is the same as imported UHMWPE and lower than water, therefore it can float on water.

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Low-Temperature Performance

The document states that UHMWPE rope has excellent low-temperature performance and that fiber strength increases at low temperatures, with a minimum service temperature reaching −125°C.

Table 6 — Low-Temperature Performance Summary (Documented)

Item	Documented content
Low-temperature resistance	Very excellent
Strength behavior at low temperature	Strength increases at low temperature
Minimum service temperature	−125°C

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Durability Evaluation

The document provides a durability evaluation table covering chemical resistance, aging/weathering resistance, and mechanical durability.

Table 7 — UHMWPE Rope Durability Evaluation (Documented Ratings)

Category	Performance item	Evaluation (as documented)
Chemical resistance	Acid resistance	Excellent
Chemical resistance	Alkali resistance	Excellent
Chemical resistance	Resistance to most chemical reagents	Excellent
Chemical resistance	Seawater / freshwater resistance	Excellent
Aging resistance	Visible light / UV irradiation resistance	Excellent
Aging resistance	Weather resistance	Excellent
Aging resistance	Mold resistance	Excellent
Other	Abrasion resistance	Excellent
Other	Cut resistance	Excellent
Other	Fatigue resistance (bending / tension)	Excellent

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Conventional Fiber Rope Reference

The document includes a comparative evaluation of conventional ropes (nylon, polyester, polypropylene).

Table 8 — Conventional Fiber Rope Evaluation (Documented)

Performance	Nylon	Polyester	Polypropylene
Moisture absorption	High (4%)	Low	Very low
Minimum service temperature	−70°C	−40°C	−40°C
Acid resistance	Fair	Excellent	Excellent
Alkali resistance	Excellent	Fair	Excellent
Sunlight resistance	Fair	Good	Fair
Abrasion resistance	< New-type rope	< Nylon	< Polyester
Cut resistance	Poor	Poor	Poor

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Manufacturing Process Flow

The document outlines both conventional rope process flow and high-strength rope process flow.

Table 9 — Conventional Rope Manufacturing Process (Documented)

Step sequence (as documented)
Fiber drawing → Yarn threading → Twisting → Strand making (critical process) → Eye splicing → Rope making → Packaging → Warehousing

Table 10 — High-Strength Rope Manufacturing Process (Documented)

Step sequence (as documented)
Raw fiber → Twisting → Strand making → Braiding → Surface treatment → Drying → Packaging & warehousing

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Standards & Certification Scope

The document explicitly indicates coverage of the following items: conventional rope process flow, high-strength rope process flow, applied standards, and classification society certification scope.

Table 11 — Documented Coverage: Standards & Certification Scope

Document section coverage
Process flow (conventional rope)
Process flow (high-strength rope)
Applied standards
Classification society certification scope

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Conclusion

Based strictly on the provided document, UHMWPE/HMPE rope is characterized by:

• Density 0.97 g/cm³ and buoyancy below water reference
• Operating range −125°C to +70°C and documented low-temperature strength increase
• Strength multiples at equal weight vs. nylon/polyester/polypropylene/steel wire rope
• Excellent durability ratings across chemical, UV/weathering, abrasion, cut resistance, and fatigue
• Documented manufacturing process flows for conventional and high-strength rope production

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FAQ

What material is HMPE mooring rope made from?

The document specifies the material as Ultra-High Molecular Weight Polyethylene (UHMWPE).

What is the documented density of UHMWPE/HMPE rope?

The documented density is 0.97 g/cm³.

What is the documented operating temperature range?

The document states −125°C to +70°C, and notes minimum service temperature can reach −125°C.

How does HMPE/UHMWPE rope compare in strength at equal weight?

According to the document, when compared on an equal-weight basis, UHMWPE/HMPE rope delivers 3–4× the strength of nylon rope, 4–5× the strength of polyester rope, 4–5× the strength of polypropylene rope, and 6–7× the strength of steel wire rope.

About the Publisher (KNKT)
This technical white paper is published by KNKT, a professional mooring rope supplier and manufacturer focused on high-strength ropes and related lifting/mooring solutions, providing documented product knowledge and practical manufacturing insights for industrial and marine applications.

References (external): ISO 9554: Fibre ropes — General specifications; OCIMF Mooring Equipment Guidelines (MEG4).