Affecting glass fibre surfaces and composite properties by two stage sizing application

Abstract

Abstract. The influence of sizing constituent distribution on the properties of sized glass fibres (GFs) and corresponding polypropylene (PP) composites was studied by two-stage sizing application, i.e. applying silane coupling agent and polymeric film former at separate stages and with different sequences, in comparison with one-stage sizing application usually used. Surface properties of sized GFs and transverse tensile strength of unidirectional GF reinforced composites were studied using various surface and interface analysis methods and tensile testing, respectively. Two-stage technology achieved sized GFs with lower loss-on-ignition (LOI) and resulted in poor fibre-matrix adhesion strength. However, applying silane coupling agent at the first sizing stage with an increased roller speed achieved sized GFs with lower LOI but composites with mechanical properties quite close to those of composites based on one-stage technology. Moreover, the difference in surface properties of sized GFs is discussed in terms of the wetting ability difference of sizing constituents and the interactions between sizing components.

Fiber-Matrix Interface Characterization through the Microbond Test

“…The IFSS determined for different fiber sizings for glass fiber-epoxy systems agreed well with the macroscopic composite properties through transverse tensile and compression shear tests [8]. The adhesion strength between glass fibers and a polypropylene matrix was found to be largely influenced by both the sizing and the conditions and manner in which it was applied, as shown by Zhuang et al [9]. Several other researchers have alluded to the large influence of fiber-matrix interface strength on the mechanical properties of a textile composite [10][11][12][13][14][15][16][17].…”

NaBF4 as a hygrothermal durability enhancer for glass fibre reinforced polypropylene composites

“…Correspondingly, the R q and R max of differently sized GFs -8 -exhibited no difference and were in the range of 9.2−12.9 nm and 93.1−121.2 nm, respectively (Table 1). In addition, the R max values are close to the mean particle size of PP film former [23], this suggests that the aggregates were mainly made of PP particles.…”

“…Table 1 Taking into consideration the similar topography and surface roughness for all four sized GFs, the lower θ r for GF-32 is most likely attributed to its higher sizing uptake, since it was noted previously that the GFs sized only with the same PP film former used here exihibited low θ r of 41.6 o [23]. This will be further described in next part.…”

“…Here, Ca atom is used as reference instead of Si atom because of the "island in sea" topography and low LOI of sized GFs [23,24]. It is noted that the reference fibre GF-00 was free of F atom as expected; meanwhile the Na at% was relatively low and in the range of normal E-GF.…”

A review of the analysis and characterisation of polymeric glass fibre sizings

“…They also correlated fibre tensile strength and surface roughness with Griffith fracture predictions. Zhuang et al [104] have reported on the application of PP compatible sizing using dual applicators.…”