Research On Pretreatment Technology Of ADP Process For Half Lenticular Tube

Composites lenticular tube, which can be widely applied in spatial deployable structures, is a hotspot in the field of spaceflight recently. Advanced pultrusion,also can be named as ADP, which works highly automated and low-costing, is a suitable method to form composite lenticular tube and has been employed by Nanjing University of Aeronautics and Astronautics. To improve the quality of lenticular tube, and decrease defects such as fiber distortion, stepping trace and short of thickness, the pretreat technology has been proposed, the parameters of pretreat process has been determined, and the influences on the properties of lenticular tube of pretreat process have also been discussed, and finally, the pretreat technology has been applied in ADP process with which high performance lenticular tube has been produced The main work includes the following aspects:(1) The resin flow model was applied to analysis the reasons which may cause the defects. The pretreat process was proposed, with which the prepreg would be heated to raise the viscosity of the resin and to control the flow of the resin under pressure. According to the requirement of thickness, the target of pretreat process was set to keep the resin from flowing within 2.3%.(2) Parameters of pretreatment process were determined through experiments. DSC and viscosity experiments were conducted, and suitable temperature for pretreatment was selected as: 100 oC, 105 oC, and 110 oC under the consideration of the processing cost and efficiency To simulate the pretreatment and hot pressing of the ADP process, pre-heating and pressing experiment was conducted under the temperature with an oven and a hot pressing device, three groups of process parameters were determined: 48 min under 100 oC, 42 min under 105 oC, 23 min under 110 oC, with the target to keep the lost resin within 2.3%.(3) Laminates were made under different pretreat parameters. The test of resin content and thickness of the lenticular tube was carried out, and it showed pretreat process had a good effect on the control of the resin content and thickness of lenticular tube. After axial and inter-laminar tensile examinations, the pretreat process was found to have no negative influence on the mechanical property of the lenticular tube. Above all, there was no obvious reduction in using performance of the laminates which were treated by pretreatment process.(4) The pretreat device was designed and installed on the ADP system. With this ADP equipment system, the experiment to produce half lenticular tube was carried out. In the experiment, the pretreatment parameter was set to be heated under 100 oC for 48 minutes, and lenticular tube was formed with the ADP process. The surface quality of the lenticular tube was perfect, no stepping trace or fiber distortion could be found. After detection, it was found that the thickness and resin content were precisely controlled, which were very close to the designation, and the axial tensile and inter-laminar tensile can also fulfil the needs of lenticular tube.