Milan, Italy -- Cannon has released further information on its new vacuum-assisted injection (VAI) technology for refrigerator production, following a summit 9 Sept in Shanghai which bought together interested parties from government, industry and the media to discuss the development.
Using the VAI method provides a cost-effective eco-design and superior energy saving, according to Cannon, which announced at the Shanghai event, with Dow Chemical Co. and Chinese fridge maker Haier, the first mass production of domestic refrigerators using the new Pascal/VAI technology.
VAI has been around since 1998, and is used to apply a vacuum to the mould cavity for insulated sandwich panels made in a discontinuous process. Cannon has now extended this to the geometrically much more complex design of domestic refrigerators.
A controlled degree of vacuum is applied into the jig where an empty refrigerator cabinet is positioned, before foaming. This reduced pressure is applied to the cavity during injection, and during expansion of the foam, this helps efficient filling of the cabinet, providing substantial benefits:
• almost doubled productivity per foaming station, thanks to high reactivity formulations, providing faster demoulding.
• optimised distribution of foam density throughout the whole cabinet.
Close cooperation with Dow in the systems used resulted in the joint development of the whole Pascal solution. New polyurethane chemistry developed by Dow - which has not revealed further details -- reduces the foam's thermal conductivity to a new reference level, said Cannon, while maintaining foam density within industry-accepted levels and allowing a shorter polymerisation.
And Cannon said several patents have been applied for by the two companies.
The first industrial plant using with the Cannon VAI technology is in China, producing Class A++++ Haier refrigerators.
These domestic two-door fridges consume 0.19 kwh/24 h (the average is 0.30 - 0.40 kwh/24 h for comparable competitor's models).
Haier's fridges were launched in March 2011 at the World Appliance Expo in Shanghai.
Cannon has also developed a VAI polymerisation jig, in which the fridge cabinet is maintained under a controlled vacuum during all the foam injection time.
And finally Cannon's new RotoJig, a foaming fixture holding two polymerisation jigs mounted on the opposite sides of a rotating platform, allows floor space to be cut by 50 percent with a faster foaming cycle.
PIC: Piero Corradi of Cannon presenting the Pascal/VAI technology at the summit in Shanghai.