Featuring technology from ZwickRoell  Material Testing in Ski Development at Stöckli

As part of its ski development process, Stöckli conducts mechanical material testing in its own laboratory. The goal is to quantitatively evaluate material properties, bonded joints, and the structural strength of composite systems and finished skis. The company uses a universal testing machine from ZwickRoell. 

A ski is bent, loaded, and twisted thousands of times during use. Every descent affects the composite material, and every turn affects the adhesive layers, core materials, and outer layers. To reliably evaluate and compare new materials and composite structures, their mechanical properties and bonds must be quantitatively tested. 

This is precisely where material testing comes into play in the ski development process at Stöckli Swiss Sports AG. Mechanical tests conducted in the company’s own laboratory provide the data needed for design, further development, and quality assurance.

When Composite Materials Are Key in Ski Manufacturing

Skis consist of complex composite systems made of wood, fiber composites, metals, and adhesives. The reliable bonding of these materials is a key factor in performance, safety, and service life. New materials, modified layer structures, and different adhesive systems require testing methods that quantitatively evaluate not only individual materials but also complete composite systems.

For Stöckli, the challenge was to conduct these tests in-house in a reproducible manner and under consistent conditions. The goal was to base development decisions on reliable measurement data and to reduce the need for external testing.

Quantitative Adhesion and Strength Analyses

In the laboratory, a ZwickRoell Z020 AllroundLine universal testing machine is used for this purpose. It is used to perform peel tests to evaluate the adhesive strength between material layers. In addition, tensile and compression tests are performed on components and composite structures.

In addition, pull-out tests are used to evaluate the stability of critical joints as well as the bond strength within the overall system. These test methods provide quantitative parameters that allow for direct comparisons of different material combinations, adhesive-backed nonwoven types, and structures.

From the Material Structure to the Finished Ski

In addition to material and composite testing, Stöckli also examines the mechanical behavior of complete skis. To do this, the company uses 3-point bending tests to evaluate the flexural strength and the interaction of all layers in the finished product.

Several testing methods are used in the Stöckli Laboratory:

• Drum peeling tests for the quantitative evaluation of the adhesion strength between material layers

• Tensile and Compression Tests on Components and Composite Structures

• Pull-out tests to examine critical joints and bond strength

• 3-Point Bending Tests to Evaluate the Bending Strength of Complete Skis

The tests are conducted in a reproducible manner under defined conditions and provide comparable performance characteristics for different material combinations and types of adhesive nonwovens.

The findings are directly incorporated into ski development. Among other things, the durability of various types of adhesive nonwovens at room temperature is examined, and their failure behavior is systematically analyzed. Material testing is thus an integral part of the development process and not merely a tool for quality assurance.

Accelerated Development

Structured in-house testing makes it possible to detect deviations in adhesion, strength, or stability at an early stage and evaluate them before mass production begins. At the same time, development times are shortened because relevant tests are available at any time and test series can be conducted and evaluated efficiently.