Polymer Melt Impregnation of Glass Roving

Abstract

Much attention has been recently focussed on the melt impregnation of thermoplastic polymers as a consequence of the difficulty involved in driving viscous polymer melt into a tightly packed fiber bundle. This work studies an impregnation process consisting a series of staggered cylindrical pins in a melt pool. A numerical model for evaluating the pressure generation in the wedge region between the roving/pin, the impregnation velocity of the melt through the glass mesh, and the resulting impregnation depth along the wedge is developed using relationships for pressure build-up in foil bearings and Darcy's law. The model results are compared with experimental melt impregnation data. The model adequately predicts the effect of melt impregnation process conditions on impregnation quality.

A novel model for resin infiltration in pin‐assisted pultrusion

“…b) decreases the infiltration depth for all pulling speeds. This behavior is also in agreement with the experimental observations reported in .…”

“…The efficacy of resin infiltration can also be expressed through an Infiltration Degree , defined as D f = L f / H , where H is the total thickness of the porous substrate ( D f = 1 would indicate complete saturation of the substrate). Results are shown Fig.…”

“…. In V = 0.1833 m/s and we have assumed T = 20 N, μ = 100 Pa s, W = 10 mm, and δ = 0.5 and K = 10 −9 m 2 . The latter values are not reported in but are typical of those used in earlier studies by the same authors—thus we use them in all subsequent comparisons.…”

“…In V = 0.1833 m/s and we have assumed T = 20 N, μ = 100 Pa s, W = 10 mm, and δ = 0.5 and K = 10 −9 m 2 . The latter values are not reported in but are typical of those used in earlier studies by the same authors—thus we use them in all subsequent comparisons. Since some value for the total thickness of the substrate H has to be assumed in order to compare with the results of , we assume that for for R = 2.5 mm full impregnation ( D f = 1) is accomplished for N = 8.…”

Continuous Consolidation of Commingled Glass and Polypropylene Roving

“…A nominal value of 50% has been chosen for these calculations. The Kozeny constant for transverse flow through the fiber bundle is assumed to have a value of 0.7 as suggested by Bates [7] and is consistent with the value found by Gutowski [36]. Figure 11 shows the estimated value of the distance penetrated by the polymer melt as a function of pulling speed for both a three and five pin system.…”