What president Reinhart Weber jokingly refers to as his new chemistry set is an important link for Weber Manufacturing (Midland, Ont.) in its production of nickel shell molds. The Nickel Tooling Technology (NTT) division of Weber has produced nickel shells for plastic processes for eight years, but the deposition step was contracted out. The new nickel vapor deposition plant gives Weber Manufacturing control over quality and capacity, and puts the company in a position to offer nickel deposition services to other companies and establish licenses for mandrel manufacturing and other related technologies.
Unassuming from the outside, the nickel vapor deposition plant is a “very sophisticated chemical plant which required much custom-designed machinery,” Weber told the 200 guests assembled for the official opening in May.
Design, construction, testing and startup of the $12 million facility were completed in just 12 months. The plant will operate as NVD Nickel Products, a division of Weber Manufacturing.
The demand for high-precision nickel shells has grown rapidly, and prompted the decision to bring the nickel vapor deposition process in-house. The process converts nickel powder into solid nickel shapes, which can be used as the core and cavity of molds for various plastic forming processes.
Nickel versus steel molds
According to NTT, nickel shell molds can reduce mold weight by up to 75 percent, reduce cycle time due to better thermal efficiency and are harder than P-20 steel molds. NVD nickel shell molds can be used for spray and slush molds, extremely large injection molds, SMC compression molds, sink and bathtub molds for various processes, and for mold inserts for optical applications. But they cannot replace steel in every situation.
Nickel shells provide extremely fine reproduction of details, pattern and texture, and maintain a high degree of repeatability because multiple molds are made from the same master.
NTT has experience with nickel shell molds for automotive interior components and produced the 163,000 lb. mold for the body panels of the DaimlerChrysler CCV. More recently, NTT provided shells for most of the cockpit components in the new BMW S5 that will be produced in South Carolina, reports Rob Sheppard, general manager of NTT.
Solid to vapor to solid again
In very simple terms, Dr. George Tyroler explains the nickel vapor deposition process as follows: nickel powder is combined with carbon monoxide in a reactor to produce a gas, which is then cooled to -10 C. Once cooled, it becomes a liquid called nickel carbonyl, which is volatile and toxic. (The NVD Nickel Products plant uses state-of-the-art environmental controls.)
To produce a nickel shell, a mandrel machined to the reverse of the desired shape is placed in a deposition chamber. The nickel carbonyl is warmed and combined with carbon monoxide to return it to a vapor state. As soon as the vapors touch the mandrel they solidify; the carbon monoxide is released and is recycled back into the process.
NVD Nickel Products has four deposition chambers, measuring up to 80 in. by 120 in. Larger shells can be produced by welding several shells together.