3
M500 THEORY OF OPERATION
The Autocapsealer banding machine is designed to apply a heat shrinkable band to
containers. The containers are then transported through a heat source allowing the
banding material to shrink and conform to the surface of the container. This is
usually for the purpose of tamper-evidence. The material processed through the
machine is a tubular material, flattened and wound on a roll sometimes referred to
as a roll stock. The material, typically PVC, usually comes wound on a roll in
lengths of 500 meters. Because the material is flattened, the machine must open
the material to apply the bands over an object. For this task, we insert a cross-
folding device into the material. Then, we set the material with the device inside.
above a set of rollers, which are closer together than the device is wide. Feeding
the individual lengths of material plus the weight of the device and the friction of
pulling the material causes the device to interact with the roller removing the
original crease from the material. This process will cross fold the material. The
material is advanced by 2 opposed rollers, which are driven by either a servo or
stepper motor. The rollers create their grip on the material because of the pressure
against each other. The amount of rotation by the motor is set at the control panel
and will, in effect, cause a specific length of material to be advanced. The banding
material is then fed through the cutting mechanism to cut off the individual band
from the banding material. Directly below the cutting edge is a vacuum block
which will hold the band in the ready position until a container passes by. To
insure that the vacuum block gets a good grip on the band during the cutting
process, we use a band retention spring to hold the band against the vacuum block
until the band is completely cut. When the spring is removed the individual band
will bounce open to a round position. Because the band bounces open so fast a
band stabilizing finger opposite the vacuum block is used to prevent the band from
bouncing around. Above the band is a plunger, which will push the band down
when the container sensor detects passage of the container. The band is held at an
angle relative to that of the container’s path, such that the downstream portion is
lower than the upstream portion. By applying the bands at an angle, the band will
tend to align itself with the container during application. After the band is applied
to the container the process begins all over again until a new band is ready for the
next container. The container and band will now be transported through a heat
source, such as the Marburg CR6000 heat tunnel, which will shrink the bands to
complete the process.
