The domestic refrigerator/freezer doors can be foamed using different technologies:
- Different Blowing Agents including hydrocarbons
- Open Mould Pouring
- Closed Mould Injection
On top of this VAI – Vacuum Assisted Injection is applicable
These technologies can be combined together and used with different type of equipment/plants and chemicals depending on production needs:
- Stationary jigs with single model fixtures
These fixture holds a single plug, which can be foreseen for breakers down or breakers up injection. To change a model it is necessary to replace or adjust the plug, according to the design of the internal liner of the new cabinet to be foamed; it is also necessary to adjust the supporting side walls and top-bottom supporting walls according to the external dimensions of the new refrigerator.
- Stationary jigs with multiple model fixtures
This type of equipment is suitable for the injection of the cabinets in the “breakers up” position. It is equipped with the multiple plug system with 2, 3 or 4 plugs fixed to an upper rotating structure called Rotoplug® which, for a mould-change operation, easily and quick rotates around the long axis of the structure
With a Rotojig® system you have two fixtures in production: one on the lower side in operation and one in the upper side that is curing. The design of RotoJig allows for the rotation of the complete foaming fixture, including all the sidewalls, so that – after the injection and the initial expansion of the foam in the cabinet’s cavity – the entire polymerisation station is rotated by 180° and brought to a upper level, above the foaming station. This allows for a doubled foaming capacity per single production line: while the service operations are performed in the lower floor a cured fridge is demoulded from its fixture, a new empty shell is introduced, the fixture closes, the mixing head injects foam from the compressor area, the foam starts rising and fills the cabinet until it is mechanically stable) the polymerisation occurs in the upper floor.
- Carousels/turning tables with single model fixtures
Can be designed either with fully automatic operation or in a simpler and semi-automatic version for low production runs and more limited budgets. These plants are based on moving fixtures which can be operated at the service stations with fully automatic devices or with manual systems for the different required operations:
The domestic refrigerator/freezer cabinets can be foamed either with breakers up or breakers down.