Preparation method of coarse denier polyester monofilaments, engineering composite material wrapped stiffener and preparation method thereof

Abstract

The invention discloses a preparation method of coarse denier polyester monofilaments, an engineering composite material wrapped stiffener and a preparation method thereof. Viscosified polyester chips are fused through a screw after dried, are squeezed by parallel porous spinneret plates, are cooled and extended through a cooling bath after extruded and adhered by spray mouths, and are shaped and wound under low temperature after a post extension outside the cooling bath, after the prepared coarse denier polyester monofilaments are preliminarily wrapped in the outer surface of an engineering composite material, the composite material slowly passes through a high-temperature setting stretcher, wherein high temperature can result in reaction of binding material in the composite material and a great amount of dissipated heat, the wrapped coarse denier polyester monofilaments shrink after heated and can tightly wrap the surface of the composite material and form uniformly spiral grooves on the surface of the composite material. The coarse denier polyester monofilaments have greater thermal shrinkage, stresses among fiber molecules can release under a heating condition in wrapping the engineering composite material, so as to form larger shrinkage force and enlarge the surface concave-convex property and the friction force of the engineering composite material.

Description

technical field [0001] The invention relates to a method for preparing a coarse-denier polyester monofilament, in particular to a method for preparing a multi-curved high-shrinkage polyester monofilament. [0002] The present invention also relates to a preparation method of the engineering composite material wrapped reinforcing rib containing the above-mentioned coarse denier polyester monofilament, and the prepared engineering composite material wrapped reinforcing rib. Background technique [0003] Existing monofilament technologies for engineering composites include: [0004] (1) Round ordinary coarse denier polyester monofilament has the defects of smooth surface, insufficient friction as a composite material, and insufficient gripping force with the substrate. It must be processed by high-temperature hot roller indentation, but it will reduce the monofilament intensity and consume energy, increasing production costs. [0005] (2) Rectangular thick-denier polypropylen...

AI Technical Summary

Problems solved by technology

[0004] (1) Round ordinary coarse denier polyester monofilament has the defects of smooth surface, insufficient friction as a composite material, and insufficient gripping force with the substrate. It must be processed by high-temperature hot roller indentation, but it will reduce the monofilament intensity and consume energy, increasing production costs

[0005] (2) Rectangular thick-denier polypropylene monofilament has the disadvantage of poor heat resistance, and the use temperature is lower than 180°C, otherwise it will melt, and the low strength cannot significantly enhance the reinforcing effect on the substrate;

[0006] (3) The disadvantage of other polymer monofilaments with different cross-sections is that the shrinkage rate is small, and it cannot be shrunk at high temperature to achieve the effect of increasing the grip force

[0007] The monofilament of engineering composite materials must have the characteristics required as a reinforcing material, such as high strength, good heat resistance, suitable shrinkage and chemical stability. For example, the coarse denier monofilament fiber used in FRP requires high Strength (>400MPa), heat-resistant temperature at 200°C, high shrinkage (>20%), good chemical stability and grooves along the fiber direction, which can increase the grip between the fiber and the substrate Wrapping force to improve pull-out work, while the traditional coarse denier PP monofilament is insufficient in strength and heat resistance, the traditional coarse denier PET monofilament has a circular cross section, and the grip force with the substrate is insufficient, requiring post-processing to affect the material strength And increase the cost, not suitable for mass production