Polyamide, polyester, polypropylene, aramid, polyethylene, linen or cotton: each strap material has its own strength profile. None is ‘the best’ in absolute terms. It all depends on the intended use.
The material of a webbing strap determines its tensile strength, heat resistance, ability to withstand moisture or UV exposure, and its durability in the field. Two webbing straps of the same width and weave may behave completely differently depending on whether they are made of polyamide or polypropylene.
This difference comes down to several technical criteria: mechanical strength, behaviour when exposed to heat and fire, sensitivity to certain chemicals, buoyancy, and performance when stored in damp conditions. Choosing the wrong material means running the risk of a strap that deteriorates too quickly, or worse, that fails at the wrong moment.
Eurosandow has been manufacturing straps from all of these materials for nearly a century at its workshop in Saint-Étienne. This expertise enables us to help you make the right choice based on your specifications.
The 5 criteria for choosing the right webbing material
The load to be borne and the breaking strength
It all starts with the breaking load (the maximum load a strap can withstand before breaking, expressed in kilonewtons (kN) or kilograms) and the working load specified in the technical specifications, which are often governed by an industry standard. Based on this criterion, aramid and polyethylene are the leading materials, followed by polyamide and polyester
Heat resistance and flammability
Each polymer has its own softening point and melting point. Polypropylene is the most heat-sensitive. Polyester performs significantly better and remains usable in most industrial environments. Aramid is the benchmark for applications requiring high heat resistance. This material remains functional even under extreme conditions, with temperatures ranging from -70 °C to +200 °C. Its non-melting and non-combustible nature makes it a safe and reliable material for the most demanding industries.
UV and moisture resistance
The lifespan of a strap used outdoors depends largely on the sensitivity of its polymer to UV light. Polyester and polyethylene are highly resistant to sunlight, whilst polypropylene and polyamide degrade more quickly. As for natural fibres such as cotton and linen, they retain more moisture than synthetics, which improves comfort and feel, but encourages mould growth and deterioration when stored in damp conditions.
Abrasion resistance and flexibility
The intensity of the friction to which a strap is subjected (pulleys, crimping, manual handling) determines the level of abrasion resistance expected of its outer layer. Polyamide is the gold standard in this category. Kevlar, on the other hand, offers great strength but tends to fray when subjected to prolonged friction. For the lining, which requires flexibility and quiet operation, polyester and cotton remain the best choices.
The context of use and the environment
The choice of a strap can never be made in isolation from its intended environment of use: each sector imposes its own mechanical, climatic and regulatory constraints. In the automotive sector, straps must withstand continuous vibrations and temperature fluctuations under the bonnet or in the passenger compartment, and must be integrated into high-speed production processes, which demands impeccable manufacturing consistency. The rail sector adds requirements for fire resistance, durability spanning several decades and resistance to repeated friction, in a context where passenger safety is paramount. In the aerospace sector, the criteria are even stricter: lightness, resistance to high elongation, resistance to UV light and pressure fluctuations, with full traceability of materials required by the sector’s certifications. For interior fittings, straps must above all combine aesthetic discretion, comfort of use and resistance to repeated daily use, with a polyester or polypropylene covering suited to the desired visual finish.
In industry in the broadest sense, resilience to harsh environments — dust, oils, moisture — and the ability to withstand heavy loads continuously take precedence over all other considerations. Finally, for sports applications, controlled elasticity, lightness and abrasion resistance are the key factors in the choice, with particular attention paid to the end-user’s comfort and safety. Accurately identifying the target environment thus enables the selection of the most suitable raw material (natural latex, polyester, polypropylene), coverage and elongation rate.
| Criteria | Polypropylene | Polyamide | Polyester | Polyethylene | Aramid | Linen | Cotton |
|---|---|---|---|---|---|---|---|
| Tensile strength | Suitable | Very suitable | Very suitable | Perfectly suited | Perfectly suited | Very suitable | Suitable |
| Heat resistance | Not particularly suitable | Suitable | Suitable | Not particularly suitable | Perfectly suited | Suitable | Not particularly suitable |
| Abrasion resistance | Not suitable | Very suitable | Very suitable | Perfectly suited | Perfectly suited | Suitable | Not particularly suitable |
| UV resistance | Very suitable | Suitable | Suitable | Suitable | Not suitable | Suitable | Suitable |
| Moisture resistance | Suitable | Perfectly suited | Perfectly suited | Perfectly suited | Perfectly suited | Very suitable | Perfectly suited |
| Flexibility | Suitable | Very suitable | Very suitable | Suitable | Perfectly suited | Perfectly suited | Perfectly suited |
| Buoyancy | Yes | No | No | Yes | No | No | No |
| Storage in a damp environment | Suitable | Suitable | Very suitable | Perfectly suited | Very suitable | Not particularly suitable | Not particularly suitable |
Polypropylene, a lightweight material
Polypropylene is the most cost-effective material on the market. It is lightweight and floats on the surface of the water, making it a good choice for straps used occasionally in nautical or damp environments.
Its weaknesses are heat and abrasion. It softens at 100°C and melts at 160°C. A polypropylene strap that rubs continuously against an edge or a rough surface will wear out quickly. It is also susceptible to chlorinated solvents at high temperatures and to aromatic compounds, which can dissolve it.
In summary: ideal for light-duty, low-cost applications where the material is exposed to moisture, but should be avoided in applications subject to repeated friction or heat sources.
Polyester: stability and UV resistance
Polyester performs similarly to polyamide in terms of tensile strength and abrasion resistance, with one clear advantage: it is more resistant to moisture and is less prone to deformation over time. It is the most dimensionally stable material, which explains its popularity for lashing straps and outdoor applications.
Its melting point, between 255 and 260°C, makes it one of the most heat-resistant synthetic materials amongst the four main families of common plastics. It does not float and is susceptible to strong alkalis, certain phenols, benzyl acetate and nitrobenzene.
Polyethylene, which is moisture-resistant
Polyethylene combines two rare qualities: excellent tear and abrasion resistance, whilst also floating on water. It withstands storage in damp conditions perfectly, without any noticeable deterioration.
Its main weakness remains heat. It softens at around 120°C and melts at around 130°C, which means it falls short of polyamide or polyester in this respect. It remains susceptible to chlorinated hydrocarbons when heated. For webbing intended for nautical use or in damp outdoor environments, without exposure to a heat source, it is a robust material.
Aramid: a high-performance engineering material
Aramid (the best-known form of which is Kevlar) ranks at the top of the list for almost all mechanical criteria: tensile strength, heat resistance, abrasion resistance and moisture resistance. It does not burn, does not melt, and only carbonises at around 500°C.
Its only weakness but it is a significant one is UV radiation. Prolonged exposure to sunlight significantly reduces its performance if the fibre is not protected. It is also susceptible to concentrated mineral acids and strong alkalis at high temperatures. It is a material reserved for demanding technical applications (protection, aerospace, emergency services), and is significantly more expensive than other synthetic materials.
Polyamide: strength and elasticity
Polyamide, better known as nylon, combines good tensile strength with very good abrasion resistance. It absorbs some of the energy before breaking, making it a suitable choice for applications subject to impact loads.
It does not float and its melting point lies between 215 and 260°C, well above that of polypropylene. It is not readily flammable and does not support combustion. Its vulnerability lies in its chemical properties: concentrated mineral acids, formic acid and acetic acid, as well as certain phenols, can attack it.
Polyamide is well suited to demanding applications where the strap must withstand repeated stress without tearing.
Natural fibres: linen and cotton
Linen and cotton are still used for certain specific purposes, often for aesthetic, heritage or tactile reasons (leather goods, ready-to-wear). They offer excellent suppleness, thanks to their low density
These two fibres share a common weakness: they are flammable and begin to break down at 160°C, and can never match synthetic materials in terms of heat resistance. Cotton withstands moisture better than linen in everyday use, but neither copes well with prolonged storage in damp conditions, unlike polyester or polyethylene. Cotton is particularly susceptible to sulphuric acid and concentrated cupro-ammoniacal liquor.
For technical applications or those subject to high mechanical stress, these natural materials are not the first choice. They remain suitable for products where the appearance, feel or image of the material are just as important as performance.
Need help choosing the right material?
Every project has its own constraints: load-bearing requirements, environmental factors and applicable regulations. Personalised advice can help you avoid costly material choices in the long run. Please do not hesitate to contact our teams to confirm the most suitable material.
Our range covers all the materials featured in this guide: polyester, polypropylene, polyamide, polyethylene, aramid (Kevlar, Technora), cotton, linen, as well as technical materials such as fibreglass and carbon fibre. Urosandow also offers a biodegradable webbing woven from maize fibres on a latex core, designed for programmes committed to a CSR approach.
This expertise, from design through to manufacture, enables our teams to guide each client towards the right material, in line with the project specifications.