© MOOG 2019
This document is subject to MOOG INTELLECTUAL AND PROPRIETARY INFORMATION LEGEND . The details are on page II.
79
MRJ06301
2-7-3. PRELIMINARY SET UP
SHOT SIZE
Shot Size basically determines the amount of plastic to be extruded through the die gap to make the
container. In an accumulator machine it is the extrusion stroke of the accumulator, in a continuous machine
it is determined by the time required to extrude the plastic volume or weight required by the container and
tail, and also by the cooling capacity of the mold. This time or stroke was probably determined when the
particular blow molding machine was selected to produce the container.
DIE GAP
Die Gap will probably be set to 0% for an accumulator machine to eliminate drool. In a continuous extrusion
machine, the Die Gap must be used to set a minimum die gap opening (may also have mechanically set
minimum opening) to prevent damage to the extruder and/or tooling due to excessive pressure or to a
larger opening consistent with the parison tail requirements at the top of the container.
DELAY
Delay will initially be determined by the required tail length at the bottom of the container. Delay would be
equal to the tail length divided by the length of the mold.
AUTO SHOT
Auto Shot
does not apply to accumulator machines,.
Auto Shot
would be ON if the DigiPack
Ⅲ
is only controlling the parison wall thickness and its cycle time
is determined only by the interval between the machine controlled knife cuts.
Auto Shot
would be OFF if the machine timing is partially or totally controlled by the DigiPack
Ⅲ
. For
example, if the mold closure timing is controlled by a DigiPack
Ⅲ
marker pulse, then the time from the
knife cut to mold closure is set by the DigiPack
Ⅲ
’s Shot Size; the time from the marker pulse to the knife
cut is controlled by the machine’s controller.
WEIGHT, RANGE H and RANGE L
Weight, Range H and Range L
are set by default to zero at the beginning of setup.
DIE GAP OPENING
Die Gap Opening
is determined by the Die Gap Opening required to extrude the required parison weight
for the container and is part of the initial selection of extruder speed and the specific tooling used. This
average opening is set at program point 1 and program point 200 and the resulting die gap program will
be a constant die gap opening between points 1 and 200.
