Injection Molding
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Processing difficulties caused by melt flow rate mismatch of random copolymer polypropylene raw material
Problem Phenomenon
After using a certain batch of raw material, injection filling is difficult or flash increases, and process parameters need major adjustment.
MFR mismatch makes the original process parameters inapplicable, affecting production efficiency and product quality.
Cause Analysis
(1) Raw material MFR is on the low side; melt viscosity is high, and filling is difficult, requiring higher pressure
(2) Raw material MFR is on the high side; melt viscosity is low, and flash is easily produced
(3) Improper raw material grade selection; the MFR range does not match product requirements
(4) Mixing different grades results in inconsistent MFR
(5) Raw material is stored for too long and MFR changes
Solution
(1) Select grades with suitable MFR; '2079851475616104452 random copolymer polypropylene usually selects MFR 1-30g/10min
(2) Test MFR for each batch of raw material and use it after matching with process requirements
(3) Avoid mixing raw materials of different grades; test and verify first if mixing is necessary
(4) Appropriately increase barrel temperature and injection pressure when MFR is on the low side
(5) Appropriately decrease barrel temperature and injection pressure when MFR is on the high side
(6) Use raw materials within the shelf life to avoid excessive storage
Key Takeaway
MFR mismatch needs to be solved by selecting suitable grades and adjusting process parameters; the key is to establish an incoming material MFR testing system.
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