Molding method and molding apparatus of composite material toughened thin rod

Abstract

The invention discloses a molding method and a molding apparatus of a composite material toughened thin rod. The molding method comprises the steps that: first, a resin-impregnated fiber bundle penetrates a primary molding mold, such that fiber bundle primary molding body with a shape same as that of an axial primary molding mold through hole mold cavity cross-section is produced; second, the primary molding body fiber bundle is heated for a first time, wherein the temperature is an initial reaction temperature of the resin; third, the fiber bundle is delivered into a second heating process, wherein the heating temperature is the resin gelatinization temperature; then, the fiber bundle is delivered into a molding mold, wherein the middle part of the molding mold is an equal-cross-section axial molding through hole mold cavity; and finally, the fiber bundle discharged from the molding mold is delivered into a third heating process, wherein the heating temperature is controlled at a value between the exothermic peak temperature of the resin and the reaction stopping temperature of the resin. Therefore, the thin rod reaches a curing degree above 70%, such that the resin-containing fiber bundle is solidified into the thin rod product. The heating durations in the three heating processes are determined according to the dimension of the thin rod and the thermal performance of the resin.

Description

technical field [0001] The invention relates to a composite material preparation technology, in particular to a molding method and device for a composite material toughened thin rod, and the composite material toughened thin rod is mainly used for toughening composite material laminated boards. Background technique [0002] Traditional two-dimensional laminated composite materials have good in-plane mechanical properties, but there is no fiber reinforcement between the layers, and only the matrix resin plays the role of bonding and transmitting loads, so it is perpendicular to the direction of the layup and between the layups. performance is relatively weak. When subjected to external loads, the laminated composite material often produces interlaminar damage first, and the low interlaminar strength of the composite material also leads to poor damage resistance of the composite material. In order to improve these shortcomings of laminated composites, many techniques for impr...

AI Technical Summary

Problems solved by technology

However, this technology is complex, and due to the strong adhesion of the resin and the low shrinkage of the thin rod, it is difficult to release the thin rod from the mold, and the surface of the product is prone to defects

In order to solve this problem and improve the surface quality of the product, it is often necessary to increase the amount of internal release agent, but this method will leave the internal release agent on the surface of the thin rod. When the thin rod is implanted into the composite laminate After that, it will affect the bonding performance of thin rods and laminates

In addition, the cross-sectional diameter of thin rods is generally between 0.2 and 1.0mm. For composite products of this fineness, the traditional pultrusion technology requires a larger mold size and higher cost, and the processing of pultrusion molds also has quite difficult

In addition, due to the high frictional resistance of the thin rod in the mold, a large traction force is required to pull the thin rod out of the mold, and a large traction force is likely to cause the toughening fiber to break and affect the quality of the product

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