THE MAGAZINE DEVOTED TO NICKEL AND ITS APPLICATIONS
December 2007
Volume 23, Number 1
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This door, which appears to be made of mahogany, is actually formed from fibreglass in a
nickel shell mould.
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Moulds made from nickel vapour deposition prove durable enough to make thousands of fibreglass
doors
By Carrol McCormick
Nickel Magazine, December 2007 -- Natural wood doors are prized for their
warm colours and pleasing grain patterns. Fortunately for price-conscious consumers these attributes can be
precisely replicated in fibreglass on moulds created using a technology known as nickel vapour deposition
(NVD).
Weber Manufacturing Technologies Inc. of Midland, Ontario, Canada, has been making door moulds with its
NVD process for 12 years. This year, the company is introducing the technology to the global market.
Every year, some 15 million residential entryway doors are sold in the United States alone, of which 4.5
million are fibreglass, says Weber Manufacturing President Chris Edwards.
NVD shell moulds replicate wood’s grain pattern, individual fibres and pores. As a result, more homeowners
are turning to doors that closely approximate the real thing.
The NVD process is clean and self-contained, therefore costs associated with the disposal of by-products
do not apply. The only NVD by-product is a nickel oxide which is recycled.
In making the fibreglass outer door skins, Weber begins with a ‘master’ constructed from wood that
displays the most desirable grain features of a particular tree species (oak, cherry or mahogany, for
example). A silicone mould-making compound is poured over the ‘master’, creating a negative casting that
captures even the finest grain details. Weber then machines a steel mandrel that approximates the shape of
the master mould. The silicone negative casting is attached to a support frame and aligned 1.5 mm over the
mandrel face. The silicone mould-making compound is then injected into this 1.5-mm gap to create a positive
casting. Once it has been approved for aesthetic and technical correctness, the silicone-covered mandrel is
put into a NVD chamber and heated.
Nickel powder and carbon monoxide are combined to make nickel carbonyl, which is stored in a liquid state.
When required, it is converted into a vapour and introduced into the deposition chamber. When the vapour
comes into contact with the heated mandrel, nickel deposits form on the silicone-covered mandrel, atom by
atom, at the rate of 0.25 millimetres per hour until the nickel shell reaches the desired thickness. The
carbon monoxide is then removed from the chamber and reused to create more nickel carbonyl.
At the door manufacturing plant, positive fibreglass skins are compression-moulded on the nickel shells,
cured and removed. They are assembled with polyurethane or Styrofoam [TM] cores and other components to make
the finished doors, which are then painted or stained. The finished doors are more thermally stable than real
wood and more resistant to corrosion than steel residential doors.
The nickel mould shells are exceptionally durable, Edwards says. “We know of compression moulds (shells)
that have produced 250,000 door parts (in the compression moulds). We do not know of any moulds that have
worn out. It appears wear is not an issue.”
Carroll McCormick is a Montreal-based freelance writer.
Photos: Weber Manufacturing Technologies Inc.
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