# Quantitative Measurement of the Tack for Carbon Fiber Reinforced Epoxy Prepreg by Using a Compression-to-Tension Method

## TL;DR

This paper introduces a new method to quantitatively measure the tack of carbon fiber reinforced epoxy prepregs using a compression-to-tension approach.

## Contribution

The study proposes a novel Compression Tack Index for accurate and repeatable evaluation of prepreg tack.

## Key findings

- The compression-to-tension method shows good repeatability and stability for testing unidirectional and fabric prepregs.
- The Compression Tack Index better reflects tack formation and separation than traditional methods.
- Slitting prepregs without polyethylene film coating have lower tack than mother prepregs with the coating.

## Abstract

Prepreg tack is an important process quality parameter for prepregs during laying. Aiming at the current lack of standardized testing for prepreg tack, this paper established a quantitative testing method for prepreg tack—a compression-to-tension method—and proposed a parameter of Compression Tack Index as a quantitative evaluation index for prepreg tack. The prepreg/prepreg tack and prepreg/metal tack of carbon fiber reinforced epoxy prepregs were evaluated and the applicability of this compression-to-tension method was verified, comparing it with the qualitative testing method by vertical metal plates. The results show that the compression-to-tension method is suitable for quantitative testing of the tack for unidirectional prepregs and fabric prepregs, with good repeatability and stability of test results, and is not affected by personnel changes. Considering that tack characterization based only on the separation process cannot accurately evaluate the tack of different materials, Compression Tack Index is an accurate parameter that characterizes the prepreg tack because it can reflect the process of tack formation and tack separation. Compared with the vertical metal plate method, the discrimination of the test results by the compression-to-tension method is significant. The tack of the slitting prepreg without polyethylene film coating is lower than that of the mother prepreg (one-meter-width prepreg) with polyethylene film.