化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2015年
6期
2329-2335
,共7页
熔体%偏移%注射速度%微注塑
鎔體%偏移%註射速度%微註塑
용체%편이%주사속도%미주소
melt%offset%injection rate%micro injection
采用集成式热电偶传感器温度测量系统和可视化全息示踪技术,对多型腔微注塑成型过程熔体流动前沿在型腔内的偏移现象进行观察和分析。结果表明,当注射速度为140~220 mm·s?1时,主流道内的塑料熔体前沿呈“U型流”状态分布,分流道内塑料熔体前沿向上侧偏移;当注射速度为10~70 mm·s?1时,主流道塑料熔体前沿呈“喷泉流”状态分布,分流道熔体前沿向下侧偏移;当注射速度为80~120 mm·s?1时,主流道和分流道熔体前沿均没有明显的偏移。说明微注塑时注射速度不同,产生的剪切热也不同,熔体前沿偏移情况也不同。为此,引入非平衡流动系数λ,来判断熔体前沿的流动和偏移情况。
採用集成式熱電偶傳感器溫度測量繫統和可視化全息示蹤技術,對多型腔微註塑成型過程鎔體流動前沿在型腔內的偏移現象進行觀察和分析。結果錶明,噹註射速度為140~220 mm·s?1時,主流道內的塑料鎔體前沿呈“U型流”狀態分佈,分流道內塑料鎔體前沿嚮上側偏移;噹註射速度為10~70 mm·s?1時,主流道塑料鎔體前沿呈“噴泉流”狀態分佈,分流道鎔體前沿嚮下側偏移;噹註射速度為80~120 mm·s?1時,主流道和分流道鎔體前沿均沒有明顯的偏移。說明微註塑時註射速度不同,產生的剪切熱也不同,鎔體前沿偏移情況也不同。為此,引入非平衡流動繫數λ,來判斷鎔體前沿的流動和偏移情況。
채용집성식열전우전감기온도측량계통화가시화전식시종기술,대다형강미주소성형과정용체류동전연재형강내적편이현상진행관찰화분석。결과표명,당주사속도위140~220 mm·s?1시,주류도내적소료용체전연정“U형류”상태분포,분류도내소료용체전연향상측편이;당주사속도위10~70 mm·s?1시,주류도소료용체전연정“분천류”상태분포,분류도용체전연향하측편이;당주사속도위80~120 mm·s?1시,주류도화분류도용체전연균몰유명현적편이。설명미주소시주사속도불동,산생적전절열야불동,용체전연편이정황야불동。위차,인입비평형류동계수λ,래판단용체전연적류동화편이정황。
The migration phenomenon of the melt flow front of multi-cavity micro injection molding process within the cavity is observed and analyzed using temperature measuring system equipped of integration of thermocouple sensor and visualization holographic tracer technique. The experimental results show that in the injection rate of 140—220 mm·s?1, the plastic melt front in the main runner is “U flow state”, while it is upper offset within secondary runner;in the injection rate of 10—70 mm·s?1, the plastic melt front in the main runner is“fountain” flow state, while it is down offset within secondary runner; and in the injection rate of 80—120 mm·s?1, the plastic melt fronts within both main and secondary runners have no obvious offset. The results indicate that the injection speed is different during the micro injection molding, leading to various shear heat and also melt front offset. Therefore, a nonequilibrium flow coefficientλis introduced to determine the flow of the melt front and offset.