The use of male only formers for dip moulding tooling does not allow features such as holes and cut-outs etc' to be moulded into the finished item. Certainly the use of an air entrapment area on the tool can be used to form an opening but for small or more accurate openings the operation must be carried out post moulding.
The most common post operation is probably that of cable end opening where a moulded component is required to cover and protect a cable or shaft. Some cable entries are tapered or stepped so as the end user can cut at different points to accommodate different diameters.
The image on the extreme left below, shows a small gaiter for control joysticks as seen on some electrical wheelchairs. The simple opening to allow the shaft of the joystick to pass is easily cut on a suitable spinning mandrel. However, in use the moulding is held in place by a collar which has fixing screws pass through in each corner and so each corner of the moulding requires a hole
The simple approach would be to drill dot the position of the hole on each former to act as a guide for the operator to then hand punch each hole. For speed a system of punching all 4 holes in a single operation has been devised at CPL.
Sections of wall can be removed, see extreme right below, with specialist cold or heated blades set in a suitable press or, for small batch runs, trim guides can be scribed onto the tool to give a guide to trimming by hand.
Some applications such as Busbar wraps etc' may be required to completely enclose an area which needs to be insulated or protected from the elements. In such cases the moulding needs to be able to be fitted and removed easily and a method of fixing is required. The second image in on the left shows a flange with small diameter holes punched at regular intervals. The tool for this moulding has a centreline spine that follows the shape of the tool along one side. Other more complex shapes may require that the spine follow along an additional face of the former.
The spine also serves as a guide for slicing the moulding along its length on the tool for removal. To keep the moulding in place in use simple push through buttons are placed in the small diameter holes in the flange.
Most post moulding operations are variations of the above and CPL, with its long engineering partnership with sister company, Cove Industrial Enterprises Ltd, have developed a great many innovative and time saving tools to perform these operations. Each is designed for accuracy and time saving to compliment the fast production moulding cycles that CPL achieve and keep dip moulding costs extremely attractive to the designer/specifier