Tensile Testing of Webbing Materials

Webbing specimens are flat strips of high-strength woven material used in various applications ranging from sporting goods to military apparel and seat belts. Modern webbing is typically made from nylon and polyester fibers or high performance aramids (Kevlar) and ultra-high-molecular-weight polyethylene (Dyneema). The woven design results in a lightweight and high strength product.

When used in safety applications such as seat belts or harnesses, it is essential that tensile properties of webbing materials are understood. For example, the material should not have excessive elongation and should have consistent tensile strength properties.

Unfortunately, the very same properties that make webbing so desirable also present significant challenges when it comes to testing their mechanical properties. These materials can be challenging to grip without the proper equipment. Simple side-action grips often do not provide sufficient clamping force to hold the specimen firmly during testing, while hydraulic grips, with their greater clamping force, can cause premature jaw breaks.

Instron’s capstan webbing grips are designed for high-strength webbing specimens, and allow for testing without inducing jaw breaks or specimen slippage. Instron capstan webbing grips are offered in capacities up to 50 kN.

The challenges of testing to this standard are:

• Specimen gripping

• Capstan webbing grips allow testing of high-strength webbing material without slippage or jaw breaks while maintaining high throughput