COMPOSITE PULTRUSION PREPRESS

FRP & Carbon Fiber Pultrusion Die Vector Prepress Guide

Pultrusion is a continuous composite manufacturing process wherein roving fibers and stitched mats are pulled through a liquid resin wet-out bath and a precision-machined heated steel die to produce high-strength structural profiles (rebar, grating, utility poles, I-beams).

1. Fiber Creel Roving Hydraulics & Compaction

The total number of roving strands pulled into the die must match the profile area $A$ and target volume fraction $V_f$ via $N = \frac{V_f \cdot A \cdot \rho_{\text{fiber}}}{\text{TEX} \times 10^{-4}}$. The heated die entrance features a $1.0^\circ - 2.5^\circ$ bellmouth taper to compact roving bundles while purging trapped air bubbles.

2. Engineering Specifications & Tolerances

3. CNC Pultrusion Die Machining & Vector Prepress

• Surface Roughness & Mirror Polish: Die internal surfaces must be hard chrome plated (70 HRC, 0.05mm thick) and hand-polished to Ra < 0.1 µm along the pulling axis.
• Thermal Expansion Offset: Steel die cavities expand at 180°C operation. Apply -0.25% thermal compensation to cold CNC milling vector paths.
• Roving Creel Card DXF: Creel guide plates require laser-cut ceramic eyelet matrices in 1:1 DXF format to prevent roving crossover snagging.