Plug in, turn on
There was plenty of room for the two Cannon projects that were under construction at the time of our visit. The first was an eight-station refrigerator production system, which was being built for a US appliance manufacturer. This was a repeat customer, whose operations have become more sophisticated with time. Initially, the customer ordered equipment suitable for HFC-245fa as the blowing agent, but moved to pentane-blown formulations. This led to design modifications.
Initially, the machine in Zelienople was designed with six RotoPlug fixtures, and two further fixtures were to be fitted later. In addition to the framework and mix-heads, Cannon will supply 16 tools, as two different models are to be made on the machine.
The moulds, which are for pentane-blown refrigerators, feature rear inlets, while the machinery system had a normal Cannon RotoPlug layout. The owner’s maintenance team will be able to swap the tools on from the top of the mould when necessary. Once they are removed, the tools will rest on a mezzanine floor until they are craned into or out of the machine.
Below the mezzanine, the fridge cores are placed into the machine using conveyors. The parts enter the rear of the foaming station, and leave via the front four minutes later.
The cabinets consist of a thermoformed liner, and the metal box as a hollow section. The cabinet components are indexed into position, and then pause before entering an IR oven, where the parts are warmed before the polyurethane is dispensed. While the parts are in the oven, they are centred so they are ready for the fixture.
When the parts reach the fixture, the bottom rises up, the side walls collapse together and the plug inserts. Each of the eight fixtures was equipped with Cannon FPL SR mix-heads, which engage with the cabinet. They move forward and pour polyurethane into the gap between the liner and the cabinet; it is dispensed from the bottom of the box and fills upwards avoiding voids. Each mix-head is held in place until the polyurethane has cured.
Cannon said these are self-cleaning mixing heads, and the internal design reduces friction compared to other models. This can give longer life and lower maintenance. The moulding fixture features water heating to warm the sidewalls of the refrigerator mould.
This is for dummies
While the refrigerator machine was the highlight of the visit , a smaller, turntable-based, machine for a very niche application also caught the eye. This featured a spray and a pour robot, built at the company’s nearby Cranberry, Pennsylvania site. This is Cannon USA’s main factory, and is home to lighter equipment assembly, R&D, spares, tech service and testing facilities.
The machine was for a customer in Wisconsin making CPR mannequins. These devices are integrally skinned, and contain sensors so that when CPR is being taught, the force students apply to the mannequin can be measured.
Mould release is first sprayed onto the inside of the mould and dried. A robot then pours urethane into the mould, which is cured. As it is curing, the turntable rotates about a central hub and, when it reaches the right part of the cycle, the pneumatically operated mould carriers open and the mannequin is extracted for further processing.