一模多穴流動平衡之實驗探討
Date Issued
2004
Date
2004
Author(s)
柯岱佑
DOI
zh-TW
Abstract
The multi-cavity molding is desired since it is advantageous for low-cost mass production. The design of multi-cavity mold is usually symmetric; however; shear heating makes the flow in symmetrical runners imbalanced, resulting in different flow length and quality in different cavities. To solve this problem, the flow imbalance phenomenon in the standard symmetrical H-type mold with eight symmetrical runners is first observed. Then, four molds with variations of symmetrical runners are designed, constructed and tested: Converging H-type runners, Pinned H-type runners, Curved A runners, Curved B runners. The flow balance of each system is observed and compared. The effects of four molding parameters: injection speed, melt temperature, mold temperature, and backing-pressure of screw on flow imbalance are investigated.
Based on the observation of short-shots obtained from molding mold with eight symmetrical runner system, it is found that high melt and mold temperature can reduce the flow imbalance. High mold and melt temperature can reduce the shear heating effect.
The experimental results of four modified symmetrical runners shows that the Converging H-type, Curved A-type, and Curved B-type runners can improve melt flow imbalance of the inner runners. Melt and mold temperature can reduce the flow imbalance. within 230~237.5℃. Curved B-type shows the best improvement. Pinned H-type runners worsen the flow imbalance; the flow in the pinned runners increases the shear heating.
Subjects
流動不平衡
射出速度
模具溫度
螺桿背壓
融膠溫度
一模多穴
Multi-Cavity
flow imbalance
Injection Speed
Screw back-pressure
Melt Temperature
Mold Temperature
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91522714-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):c9d301e04d77fe476c65be4c7fd32657