A z-directional reinforcement method suitable for dry fiber preforms

Abstract

The invention belongs to the liquid molding technology of resin-based composite materials and relates to a Z-direction reinforcement method suitable for dry fiber preforms. The Z-Pin implant preform is composed of Pin needles and a foam layer. The foam layer is placed between a porous plate and an adhesive coating. The thickness of the porous plate is 1mm~3mm, the pore diameter is 0.3mm~1mm, and the hole spacing is 3mm~5mm, the porous plate [2] is made of metal. The present invention proposes a Z-Pin implantable preform suitable for dry fiber preforms. By replacing the high-density foam layer in the existing Z-Pin implanted preform with an adhesive coating, and adding A layer of porous plate is added under the low-density foam layer to increase the support for the tail end of Pin needle implantation and the guidance of the initial implantation section, which solves the problem of the existing Z-Pin implant prefabricated foam carrier’s support and The guiding effect is poor, and the Pin deflects when cutting and removing the foam carrier after implantation.

Description

technical field [0001] The invention belongs to the liquid forming technology of resin-based composite materials, and relates to a Z-direction reinforcing method suitable for dry fiber preforms. Background technique [0002] Z-Pin three-dimensional reinforcement technology is a new three-dimensional reinforcement technology developed on the basis of discontinuous suture technology. Its reinforcement mechanism is to introduce Pin needles in the thickness direction of the composite material, so that the layers of the material are combined, thereby improving the layer quality of the workpiece. performance and interfacial connection strength. [0003] Due to the small diameter of the Pin needle, it is very difficult to directly implant the Pin needle into the uncured composite material, and the efficiency is low. Transfer and implant the Z-Pin into the preform into the uncured prepreg. [0004] The Z-Pin implanted prefabricated body currently suitable for prepreg reinforcement...

AI Technical Summary

Problems solved by technology

Because foam often contains tiny closed cells, high-density foam can provide certain sidewall support and guidance for the end of Pin needle implantation, but the effect is limited

The low-density foam basically has no guiding effect on the initial implantation section of the Pin needle.

If this kind of Z-Pin is implanted into the preform for the reinforcement of dry fiber, due to the existence of non-viscous resin in the dry fiber preform, the friction between the laminates is small, and the Pin needle during the implantation process of the Pin needle is small. The initial implanted section and the tail end, especially the initial implanted section are basically in a free, unfixed and unrestrained state, the pin guide effect is poor, and it is more likely to be unstable and tilted

Furthermore, after the Pin is implanted, when the foam layer is removed with a special cutter, the friction between the dry fiber laminate and the Pin is difficult to eliminate or counteract part of the cutting shear force of the cutter on the Pin, which may easily lead to implantation. Pin deflection after entering

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