The performance of composite materials greatly depends on how well fibres adhere to the matrix. To address this, Textechno developed the FIMATEST system with the Leibniz Institute of Polymer Research Dresden (IPF) and the Faserinstitut Bremen (FIBRE). As a result, a versatile and reproducible micromechanical single-fibre pull-out test is available worldwide for quantitative assessment of fibre–matrix adhesion.

The FIMATEST system includes two key devices:

• FIMABOND embedding station, a partially automated unit capable of processing all types of fibres and matrices with precise control
• A high-precision pull-out device serving as an accessory to Textechno’s FAVIMAT+ tester

The FIMATEST system is suitable for all fibre/matrix combinations, including thermoplastic, thermoset and cementitious (inorganic) matrices, with processing temperatures up to 400 °C.

FIMABOND Embedding Station

Reproducible Embedding for Reliable Adhesion Data

To obtain reproducible pull-out results, the fibre must be embedded exactly in the center of the matrix droplet to prevent unwanted shear forces during testing. The FIMABOND embedding station ensures precise placement and controlled specimen formation.

Subsequently, the prepared specimen is clamped in the pull-out device installed in FAVIMAT+. The pull-out test is performed and the recorded force/displacement curve is used to determine all relevant interfacial parameters.

The FIMATEST system received the JEC World 2016 Innovation Award. Furthermore, the testing method implemented in FIMATEST is internationally standardized as ISO 19375 “Measurement of interfacial shear strength by means of a micromechanical single-fibre pull-out test”.

Single-Fibre Contact Angle Measurement

Optical Single-Fibre Contact Angle Measurement

As an optional extension of the FIMABOND embedding station, the contact angle between the individual fibre and matrix can be measured directly during specimen preparation for the single-fibre pull-out test. During embedding, a high-resolution camera positioned at 90° to the fibre axis records the wetting meniscus in real time.

The integrated image analysis continuously detects the three-phase line (fibre–matrix–gas) and automatically evaluates the contact angle on both sides of the fibre (measurable up to approx. 90°). This provides quantitative wetting data under realistic processing conditions.

Key advantages of the integrated optical contact angle measurement are:

• Measurement directly on the actual fibre/matrix combination
• Performed at the relevant process temperature (thermosets during impregnation, thermoplastics in molten state, e.g. carbon fibre in molten PEEK above 340 °C)
• No need for flat reference substrates or substitute probe liquids
• Real-time detection of the three-phase line during embedding
• Automatic evaluation of contact angles on both sides of the fibre