Apparatus and method for filling a mold with a liquid material

An apparatus for filling a mold with a compressible liquid material, comprising:

• a manifold;
• a plurality of runners connecting the manifold to the mold;
• at least one valve disposed in at least one of the plurality of runners;
• and
• a controller configured to modulate the at least one valve over a first plurality of pulse cycles during one filling cycle of the mold, wherein
• the at least one valve is in fluid communication with both the manifold and the mold,
• a first pulse cycle of the first plurality of pulse cycles includes
• moving a throttling member of the at least one valve from a first position to a second position, and
• moving the throttling member of the at least one valve from the second position to a third position,
• a flow aperture area of the at least one valve corresponding to the second position is larger than a flow aperture area of the at least one valve corresponding to the first position,
• the flow aperture area of the at least one valve corresponding to the third position is smaller than the flow aperture area of the at least one valve corresponding to the second position,
• the controller is configured to control the throttling member of the at least one valve to move from the first position to the second position when a measured dwell time in the first position is greater than or equal to a first target time, and when the measured dwell time in the first position is less than the first target time after a measured pressure of the compressible liquid material becomes greater than or equal to a first threshold pressure, and
• the controller is configured to control the throttling member of the at least one valve to move from the second position to the third position when a measured dwell time in the second position is greater than or equal to a second target time, and when the measured dwell time in the second position is less than the second target time after the measured pressure of the compressible liquid material becomes less than or equal to a second threshold pressure.

An article of manufacture, comprising a non-transitory machine-readable medium having instructions encoded thereon for enabling a processor to fill a mold with a compressible liquid material by executing the operations of:

• receiving at least one valve pulsing parameter defining a valve opening trigger,
• receiving at least one valve pulsing parameter defining a valve closing trigger,
• modulating at least one valve to perform a plurality of pulse cycles during one filling cycle of the mold, wherein
• a first pulse cycle of the plurality of pulse cycles includes
• moving a throttling member of the at least one valve from a first position to a second position, and
• moving a throttling member of the at least one valve from the second position to a third position,
• a flow aperture area of the at least one valve corresponding to the second position is larger than a flow aperture area of the at least one valve corresponding to the first position,
• a flow aperture area of the at least one valve corresponding to the third position is smaller than the flow aperture area of the at least one valve corresponding to the second position,
• the throttling member of the at least one valve is moved from the first position to the second position when a measured dwell time in the first position is greater than or equal to a first target time, and when the measured dwell time in the first position is less than the first target time after a measured pressure of the compressible liquid material becomes greater than or equal to a first threshold pressure, and
• the throttling member of the at least one valve is moved from the second position to the third position when a measured dwell time in the second position is greater than or equal to a second target time, and when the measured dwell time in the second position is less than the second target time after the measured pressure of the compressible liquid material becomes less than or equal to a second threshold pressure.