Please calculate the distance required for the reciprocating screw to retract in order to fill
the mold cavity during injection molding process using the information given below.
NOZZLE
ID = 28 mm
Figure: Schematic of a thermoplastic injection molding machine.*
Please refer to the Figure above.
Assume the cavity between the nozzle and the end of reciprocating screw is a
cylinder.
Calculate the volume of the mold cavity by neglecting the features machined on
the pocket.
Multiply the volume of the mold cavity by 1.25 in order to account for the
volume of the features machined on your mold cavity. This is your corrected
mold cavity volume
Calculate the distance required to retract by the reciprocating screw by equating
the corrected mold cavity volume to the volume of the cylindrical cavity formed
by retracting the reciprocating screw.
Bring the result to the lab and include this calculation to the results section of
your project report.
* http://www.idsa-mp.org/proc/plastic/injection/injection_process.htm