工程塑料应用
工程塑料應用
공정소료응용
ENGINEERING PLASTICS APPLICATION
2014年
2期
84-88
,共5页
裴士轻%曹阳根%李晋昇%殷志鹏%马宏学
裴士輕%曹暘根%李晉昇%慇誌鵬%馬宏學
배사경%조양근%리진승%은지붕%마굉학
注射成型%流变性能%时间差%压力差%测试方法
註射成型%流變性能%時間差%壓力差%測試方法
주사성형%류변성능%시간차%압력차%측시방법
injection molding%rheological property%time difference%pressure difference%test method
利用注塑机、模具调温机、阿基米德螺旋槽模具模拟实际注射过程,借助在模具内置两个压力传感器和数据采集系统,获得了塑料熔体填充过程中的时间压力曲线,从中提取了熔体流经两个传感器的时间差(Δt)及两个传感器压力峰值之差(ΔP)。基于Δt与ΔP计算了高密度聚乙烯熔体的表观剪切速率、表观黏度,在此基础上计算了非牛顿指数(n);基于ΔP与n计算了充填长度,并与充填长度实验值作对比。结果表明,表观剪切速率随着注塑压力的增加基本呈线性增加;表观黏度与表观剪切速率呈指数关系,基于获得的表观黏度与表观剪切速率计算的n与标准值相差不大,表明获得的表观黏度与表观剪切速率值较为可靠;基于压力差与n计算得到的充填长度在其小于1170 mm时与实际实验值匹配良好,表明获得的n在充填长度小于1170 mm时较为可靠。
利用註塑機、模具調溫機、阿基米德螺鏇槽模具模擬實際註射過程,藉助在模具內置兩箇壓力傳感器和數據採集繫統,穫得瞭塑料鎔體填充過程中的時間壓力麯線,從中提取瞭鎔體流經兩箇傳感器的時間差(Δt)及兩箇傳感器壓力峰值之差(ΔP)。基于Δt與ΔP計算瞭高密度聚乙烯鎔體的錶觀剪切速率、錶觀黏度,在此基礎上計算瞭非牛頓指數(n);基于ΔP與n計算瞭充填長度,併與充填長度實驗值作對比。結果錶明,錶觀剪切速率隨著註塑壓力的增加基本呈線性增加;錶觀黏度與錶觀剪切速率呈指數關繫,基于穫得的錶觀黏度與錶觀剪切速率計算的n與標準值相差不大,錶明穫得的錶觀黏度與錶觀剪切速率值較為可靠;基于壓力差與n計算得到的充填長度在其小于1170 mm時與實際實驗值匹配良好,錶明穫得的n在充填長度小于1170 mm時較為可靠。
이용주소궤、모구조온궤、아기미덕라선조모구모의실제주사과정,차조재모구내치량개압력전감기화수거채집계통,획득료소료용체전충과정중적시간압력곡선,종중제취료용체류경량개전감기적시간차(Δt)급량개전감기압력봉치지차(ΔP)。기우Δt여ΔP계산료고밀도취을희용체적표관전절속솔、표관점도,재차기출상계산료비우돈지수(n);기우ΔP여n계산료충전장도,병여충전장도실험치작대비。결과표명,표관전절속솔수착주소압력적증가기본정선성증가;표관점도여표관전절속솔정지수관계,기우획득적표관점도여표관전절속솔계산적n여표준치상차불대,표명획득적표관점도여표관전절속솔치교위가고;기우압력차여n계산득도적충전장도재기소우1170 mm시여실제실험치필배량호,표명획득적n재충전장도소우1170 mm시교위가고。
The practical injection process was simulated based on the injection machine,mold temperature controller and Archimedes spiral mold,the time-pressure curve in the process of melt filling was obtained by data acquisition system and two pressure sensors installed in the spiral mold,then the time difference (Δt) of melt flow through the two sensors and the peak pressure difference (ΔP) of the two sensors were extracted from the curve. The apparent shear rate and apparent viscosity of high density polyethylene were calculated by means ofΔt andΔP,and the non-newtonian index (n) was calculated based on the calculated apparent shear rate and apparent viscosity. Filling length based onΔP and n were also calculated,and compared with experimental data. The results show that apparent shear rate increases linearly with the increase of injection pressure. The apparent viscosity and shear rate turned out to be exponential relationship. The n values based on the apparent shear rate and apparent viscosity are similar with the standard values,which indicates that the calculated apparent shear rate and apparent viscosity are reliable. Based on differential pressure and flow index,the calculated filling length is matched well with the experimental results when the filling length was less than 1 170 mm,which indicates that the calculated n values are reliable.