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