Research On The Influence Of Z-Pin’s Curing Degree On The Properties Of Composites

In this paper, the curing degree of Z-pin is studied, regarding Z-pin as a new material. Theresearch starts with the preparation of partly-cured Z-pin, the partly-cured Z-pin technology ofepoxy resin was explored firstly, then its mechanism was analyze d through some simple data, andfinally summarized was the influence law of Z-pin’s curing degree on the laminates’ propertiesthrough a large number of experiments of the BMI matrix Z-pin reinforced laminates.Partly-cured Z-pin that can be used for implantation was produced by adjusting the pultrusionspeed, die temperature and curing tunnel temperature of the pultrusion process, and the minimumcuring degree and the pultrusion process parameters of the BMI and epoxy resin Z-pin meeting forimplantation demand were obtain. As Z-pin of FW-125epoxy resin matrix, the minimum curingdegree meet the requirements of the implantation is69.94%, and the corresponding pultrusionprocess parameters are: die temperature of99℃, curing tunnel temperature of99℃, pultrusionspeed of10mm/s; for the Z-pin of NHZP-1BMI resin matrix, the minimum curing degree meetthe requirements of the implant is78.56%, the corresponding parameters for the pultrusionprocess are: glue tank temperature of89℃, die temperature of120℃, curing tunnel temperatureof220℃, pultrusion speed of3.3mm/s.The influence mechanism of Z-pin’s curing degree on the properties of laminates wasanalyzed by experiment data, the curing degree of Z-pin affects the chemical combination of theinterface between Z-pin and laminates to determine the interlaminar properties of laminates, thefirmer interface owing to the co-curing reaction between uncured resin carries by Z-pin and theprepregs. When the reinforced mode is the breakage of the interface between Z-pin and laminatesand Z-pin’s pull-out from laminates, the curing degree of Z-pin has an notably effect on theinterlaminar properties, and the laminates reinforced by Z-pin with lower curing degree had agreater improvement up to38%; however, if Z-pin was fractured under shear conditions, theimpact performance of the Z-pin’s curing degree on the interlaminar properties of the laminateswould be greatly reduced.The influence of the Z-pin’s curing degree on the in-plane properties of laminates is verysmall. It would not improve the in-plane of laminate, but would increase the difficulty ofpreparation of Z-pin greatly by changing the Z-pin’s curing degree. It’s a nonlinear relationshipbetween Z-pin’s curing degree and the properties of laminates, the improvement extent declinesgradually as the Z-pin’s curing degree declining, until it goes down to no effect approximately.