BLACK AND DECKER CANADA WINS GOLD DESIGN AWARD FOR NEW CORDLESS, RECHARGEABLE POWER SPRAYER DEVELOPED WITH FEA SOFTWARE

Black and Decker used FEA software from ALGOR, Inc. to design the award-winning VP450 Power Sprayer's tank.

November 20, 1998, Pittsburgh, Pennsylvania -- Black and Decker has introduced a new cordless, rechargeable power sprayer that won Design Engineering magazine's 1997 Gold Design Award for its style and functionality. Black and Decker's Canadian design team in Brockville, Ontario, used finite element analysis (FEA) software from Pittsburgh-based ALGOR, Inc. to design the power sprayer's three-gallon tank and to discover and remove the cause of an air leak that was found in the sprayer's neck during physical prototype testing. By analyzing virtual prototypes on the computer, Black and Decker Canada was able to quickly and cost-efficiently design the power sprayer to meet consumer needs and the company's reliability and safety requirements.

Black and Decker Canada Receives Gold Award for Best Design

Many consumers complain that manual sprayers used to distribute insecticides, deck sealant, cleaners and other liquids are heavy, difficult to pump, often clog and cannot maintain consistent pressure. Black and Decker's VP450 Power Sprayer was designed to eliminate these problems. The VP450 is light, battery-operated, easy to clean and maintains a continuous pressure of approximately 20 psi. It earned the top award in the Consumer Product category at the 1997 Design Engineering Awards held in Toronto, Canada, which recognized Canadian designers and engineers for product innovation.

"The power sprayer tank balances aesthetics with functionality to meet consumer needs," said Black and Decker Canada's Project Leader Jake Prosper. "We designed the tank to have a slender, ridged shape that can also withstand expansion during pressurization."

FEA Software Used to Design Power Sprayer Tank

Black and Decker Canada used ALGOR's linear stress analysis software to design an attractive tank that experienced minimal stress and deflection during pressurization. High stress concentrations could cause the tank to rupture and deflection over 0.25 inch could be aesthetically unacceptable.

MASS, a consulting firm in Toronto, Canada, helped design the tank. MASS created a selection of 3-D polyethylene tank models using Pro/ENGINEER software. Black and Decker Canada Design Engineer Michael Milligan converted MASS' models to 3-D shell finite element models in ALGOR. He used ALGOR's Merlin Meshing Technology to refine the surface mesh created in Pro/ENGINEER in areas where he anticipated high stress and deflection and ALGOR's Houdini tool to create a solid FEA mesh.

Milligan then analyzed one-half of the symmetric tank models under pressure to reduce analysis time. Black and Decker chose the most attractive tank model with the least amount of stress and deflection. Milligan further reduced stress and deflection in the chosen model's midsection by rounding the tank's corners. He also decreased the tank wall's material thickness to reduce manufacturing costs.

Black and Decker Canada manufactured a prototype tank-molding tool and 20 tank prototypes that were tested in a laboratory with other power sprayer components under pressure and high temperature. Deflection in the tank prototypes correlated 90% with ALGOR software results.

The ALGOR computer model of the tank indicates reduced stress and deflection at the tank’s midsection as a result of rounded tank corners. The gray mesh at the forefront shows the model prior to pressurization. The scale of deflection was increased by 50 percent for better viewing.

Prototype Test Problem Quickly Resolved with ALGOR Software

During physical prototype testing, laboratory technicians discovered that the neck of the power sprayer, a narrow section connecting the tank and the air pump, deformed in warm temperatures. This caused air to leak where the neck attaches to the air pump.

Black and Decker Canada had not analyzed virtual prototypes of the sprayer's neck earlier because it had not foreseen a problem. Milligan turned to ALGOR linear stress analysis software to uncover the cause of the air leak.

Milligan applied forces in several directions until the ALGOR software analysis results were similar to those in the physical test. He determined that the threads in the sprayer's neck, which are intended to secure the air pump when it is screwed into place, were incorrectly angled, causing uneven pressure on the neck and forcing it to deform. He modified the angle of the threads in the ALGOR model, which eliminated the deformation. Laboratory test results of 20 new sprayer neck prototypes correlated closely with ALGOR software results.

"Some expensive design changes were suggested when the air leak was discovered, such as adding a plastic or metal part to strengthen the neck, but these were avoided because we used ALGOR software to uncover the root of the problem," said Prosper.

Black and Decker Canada Saves Money and Time Testing Virtual Prototypes

"Using ALGOR software, Black and Decker Canada avoided manufacturing two to three additional prototype tank-molding tools and as many as 60 additional tank prototypes, saving about $25,000 and months of time," said Prosper. "We also saved money and time using the software as a detective tool to uncover the problem with the sprayer's neck."