 |
|
| |
|
|
|
|
| |
|
|
| |
| |
| |
|
Shuttle Machine Sequence of Operation, Shuttle Machine and Shuttle Machine Advantages and Disadvantages |
| |
|
 |
| |
|
|
| |
|
Shuttle machines are
either single-sided or dual-sided machines, and can be manufactured
to produce one- to six-layer containers - although the number
of suppliers who produce 4-6 layer machines is limited. In a
single sided machine, the mold "shuttles" under the
flowhead, closes to capture the parisons, then moves away from
the head. Blow pins are then forced downward into the molds,
helping to "calibrate" the necks while air is forced
into the cavity to blow the container. |
| |
|
|
| |
|
The shuttle motion
allows the bottles to be blown and cooled to the side, without
interfering with the parisons, which are continually extruding
from the flowhead. In a double sided shuttle machine, there
is a mold on each side of the flowhead, one shuttling to the
right, and one to the left, which generally doubles the output
of a single-sided machine. |
| |
|
|
| |
|
Shuttle machines may
extrude single or multiple parisons, and are characterized by
the number of parisons and the horizontal spacing between the
parisons. For example, a "4x100" shuttle extrudes
four parisons, spaced 100 mm between the centers. This would
require a platen (for attaching the molds) greater in size than
400 mm, to accommodate the required mold width. |
| |
|
|
| |
|
The horizontal or angled
shuttling distance is thus greater than 400 mm for a 4x100 shuttle
machine. In general, shuttle machines up to 2x100 mm spacing
are considered small machines; shuttles up to 6x100 mm spacing
are considered mid-sized machines; shuttles larger than this
are typically referred to as "long-stroke" machines. |
| |
|
|
| |
|
Shuttle machinery is used widely in the production of personal care bottles,
medical bottles, and some small industrial containers. |
| |
|
|
| |
|
Sequence
of Operation |
| |
|
The steps required
for a shuttle machine to blow mold a hollow plastic object
can be described by the following sequence of operations: |
| |
|
 |
As
the dropping parisons approach the length of the object
to be blown, the mold, in open position, shuttles sideways
to a point directly under the head of the machine. |
|
|
|
The molds close
to capture the parison. |
|
|
|
A knife cuts
the parisons directly above the molds. This may be either
a cold knife (cutting with a sharp edge) or a hot knife
(burning through the parison). |
|
|
|
The molds shuttle
away from the head until they are directly under the blow
pin stations. If the mold movement is horizontal, the
extruder head is made to bob up vertically, so that the
continuously extruding parisons do not drag against the
mold as it moves sideways. In some shuttle machinery,
the molds shuttle down at an angle, eliminating the need
for the head and extruders to bob upwards. |
|
|
|
The blow pins
are forced down into the still-open necks of the containers,
calibrating the necks of the containers. In most cases,
the blow pins punch down onto striker plates, which form
the top edge of the neck to a precise flat dimension. |
|
|
|
Air pressure
is applied to blow the containers. In many cases, the
blow air is turned on before the blow pins enter the open
neck of the parison, to force the plastic outward and
ensure a good neck formation. |
|
|
|
After the containers
have cooled, the molds open, and again shuttle under the
head of the machine. As the molds close on the molten
parisons, masking stations that are attached to the sides
of the mold close over the outside of the previously blown
containers, which are still held in place by the blow
pins. |
|
|
|
The blow pins
retract, leaving the containers held only by the masks. |
|
|
|
As the molds
again shuttle sideways, the masks transfer the formed
containers sideways to a punching station. Punches come
forward to remove the tails, top moil, and any handle
(grip) slugs away from the bottles. |
|
|
|
The bottles are
then conveyed out of the machine. This may be done by
transferring the bottles onto conveyor belts, by takeout
devices, or by simply dropping the bottles into a chute
or onto a takeaway conveyor. |
|
| |
|
 Top |
| |
|
|
|
|
|
|
| Copyright © 2007, N. A. GROUP OF COMPANIES. All rights reserved |
|
