|
Dow Corning® GT-4201 and GT-6201 connector sealant pads are
designed to be applied directly into a connector housing using automated
equipment in either stamp-and-place or pick-and-place processes. Both
processes have similar steps and will be described below. Pick-and-place
would be used when the connector sealant pads are supplied as pre-stamped
shapes on a roll, custom cut and ready to insert in the connector. The pad
laminate can also be supplied in simpler, pre-slit rolls, not yet cut to
shape. This is done as part of the process in stamp-and-place operations.
Pre-stamped pads are more expensive to use than slit rolls, but
pick-and-place equipment is less expensive to purchase and is easier to
design. Both GT-4201 and GT-6201can be 10 - 25% less expensive when supplied
in simpler, slit rolls instead of pre-stamped pads. The amount of cost
savings will be dependent on the geometry.
We will discuss the pick-and place process first and then talk about what is
different for stamp-and-place below.
If you would like Dow Corning’s help in consulting on the specifics of your
process or even to process parts for you , click here to find out more or to request these services.
|
Step 1- Index connector and pad into position
The process automatically moves an empty connector housing into position for
sealing. At the same time, the next gel pad is indexed into place directly
above the connector cavity. With pre-stamped pads, there is no residual gel
on the edges of the Mylar ® carrier and nip rolls can be used to advance the
pads into place. Sensors are generally used to determine the presence of both
the empty connector housings and pre-stamped gel grommets.
|  | 
|
|
|
Step 2- Pad Pick-up
The equipment is outfitted with a pick-up head with a concave surface. The
face of the head has a grid pattern of holes to permit vacuum assist for
pick-up and air pressure for the subsequent release step. The concave shape
of the head will cause the grommet to “shorten in length” and ease insertion
by not contacting the side walls of the housing.
| | 
|
|
|
Step 3- Insertion of Pad
The head now lowers the pad into the connector cavity, releases it with the
assist of air pressure and returns to position for the next grommet.
Step 4- Insertion of Cap and Piercing
A cap, generally made from the same material as the connector body, is now
inserted into the connector cavity on top of the gel grommet. The cap will be
able to provide compression to the connector sealant pad to optimize sealing.
A piercing head with sharpened pins (one for each contact or wire location)
is now pushed through the cap and pad grommet. This piercing allows for lower
forces during subsequent connector pin insertion.
|
|
The process now loops back to Step 1 and repeats for the next connector.
It should also be mentioned that the equipment should accommodate splices
between rolls of sealant pads to allow for continuous processing. Sensors can
determine the presence of splices and move into position for the first grommet
on the new roll.
|
Change
