發(fā)布時間：2018-04-13 17:29

  本文選題：三維打印 + 熔體微分　； 參考：《中國塑料》2017年07期

【摘要】：提出一種可實現(xiàn)多種塑料顆粒直接打印的閥控式熔體微分三維(3D)打印機(jī),運用多相流及動網(wǎng)格技術(shù)對閥腔內(nèi)非牛頓流體的擠出過程進(jìn)行數(shù)值模擬。結(jié)果表明,擠出流量與閥針下移速度、閥針/閥腔直徑比均呈正相關(guān)關(guān)系,且閥針距噴嘴越近、直徑比越大,流量波動越大;最佳閥針最大運動距離為0.5~1mm;閥針運動速度/閥腔背壓比大于0.5時,熔體出現(xiàn)倒流現(xiàn)象;精確控制各工藝參數(shù)可實現(xiàn)穩(wěn)定按需擠出,提高成型件精度。
[Abstract]:A valve controlled melt differential 3D (3D) printer for direct printing of various plastic particles is proposed. The extrusion process of non-Newtonian fluid in the valve cavity is numerically simulated by means of multiphase flow and dynamic grid technology.The results show that the extrusion flow rate has a positive correlation with the speed of the valve needle moving down and the ratio of valve needle to valve cavity diameter, and the closer the valve needle is to the nozzle, the bigger the diameter ratio is, and the greater the flow fluctuation is.The maximum moving distance of valve needle is 0.5mm, when the ratio of valve needle motion velocity to valve cavity back pressure is greater than 0.5, the melt reverse flow phenomenon appears. The precise control of each process parameter can realize stable extrusion on demand and improve the precision of forming parts.
【作者單位】： 北京化工大學(xué)機(jī)電工程學(xué)院;北京衛(wèi)星信息工程研究所;
【基金】：國家自然科學(xué)基金青年基金資助項目(51403014) 廣東省省級科技計劃項目(2016B090915001)
【分類號】：TP334.8;TQ320.5
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本文編號：1745504