Tool program for Zoob takes coordination

Zoob. If you haven't heard of it yet, you probably will soon. It's the latest toy craze, one of the 10 best-selling toys for Christmas 1997 in the specialty-store market. Zoobs are brightly-colored linking pieces that when assembled look not unlike the molecular structure of a polymer chain.

Zoob's inventors aren't polymer scientists, but science is an interest of one of the toy's creators, Michael Grey. Zoob stands for zoology, ontology, ontogeny, and botany. Although Grey roamed through the worlds of math, physics, and genetics at the University of California in Berkeley, he ultimately ventured into molecular biology and also pursued a master's in fine arts at Yale University. Combining this love of science with his creative talents, Grey, along with partner Matthew Brown, formed Primordial LLC in San Francisco, to produce and market Zoob.

Zoob pieces come in five shapes with either a dimpled ball or a socket on each end. The pieces can be connected in more than 20 different ways, making their geometry complex and creating a challenge when it came to producing the prototype parts and production molds. Fortunately, one of Primordial's investors owns Rainin Instruments, a 55-press medical molding company in Emoryville, CA. The manager of tooling and molding at Rainin, Harry McRae, knows injection molding and moldmaking. With McRae's assistance, Grey and Brown were steered in the right direction in finding a capable moldmaker.

MGS Enterprises in Menomonee Falls, WI and its sister company, Moldmakers Inc., were chosen for the project. These companies specialize in engineering, designing, and building multicavity molds utilizing hot runner systems. They also provide prototype parts using stereolithography as well as preproduction tooling.

Starting with SLA

According to MGS vice president of engineering John Hahn, the first step in the process was creating a good, clean, usable Pro/E database from which the company produced the SLA parts. Once the SLA parts were approved and signed off on in April 1997, the company began building a single-cavity, preproduction tool and the 16-cavity production tooling concurrently, in order to save time and meet Primordial's August 1997 production date. But after the completion of the prototype tool, Grey didn't quite like the way the parts looked. The geometry wasn't exactly what he wanted, and he wanted to change the geometry of the socket's "jaws."

Hahn says one of the most difficult aspects of working with nonplastics people is communication and coming to a meeting of the minds: what the creators want the ultimate product to look like vs. what's possible and feasible for moldmaking and molding. "Trying to get people with different backgrounds to communicate on the same level and teach them all the processes and limitations of tooling and molding is also a challenge," says Hahn.

It took MGS six to eight weeks to get the complex geometry of the part like Grey wanted it. There was no single biggest challenge to the mold design, says Hahn. "There were a lot of challenges. The part has so much interaction with itself that the product design and the tooling had major hurdles to overcome."

While the molds were being built, Primordial was working closely with two resin companies to determine the best material for the Zoob toys. "We were concerned with flexural and tensile modulus. It was a function of resistance to fatigue and stiffness that we needed to create the intended result," explains Jim Stovell, operations manager at Primordial. "We tested 10 different grades of ABS, chosen for price and performance. Lustran 248 from Bayer was the material that did the job."

With the help of Mark Jacobson, district sales manager for M.A. Hanna Resin Distribution in Livermore, CA, Primordial selected Jatco Inc., a custom molder in Union City, CA, to mold Zoobs. In all, five 16-cavity, hot runner tools were built to accommodate anticipated production capacity. Jatco's experience in hot runner molding for medical instrumentation and electronics customers, as well as the toy industry, enabled it to take all the molds, drop them into five 200-ton Toyo presses and begin running.

"Our experience with hot manifold systems meant we brought them up online extremely quickly to meet a very narrow window for Christmas," says Paul Appelblom, president of Jatco. The company's successful startup on the project earned it a year's contract for production of the toys. Appelblom says that because the molds are extremely complex with expanding collets, slides that pull at an unconventional angle, and Mold-Masters' hot manifold systems, a high degree of preventive maintenance is required.

Engineering for Toys

Stovell explains that although Zoob is a toy and toys are typically thought of as low-precision molding, "Zoob's tight (.002-inch) tolerances are critical because every part must function in a variety of configurations, which means we produce these parts according to high-tech standards."

The pieces are molded in two halves and then sent to an assembly facility in Mexico for ultrasonic welding and packaging, then sent to specialty store retailers such as the Nature Co., FAO Schwarz, Learningsmith, and other independent toy shops, museum shops, and outlets.

Stovell says the company needed precision tools produced very quickly to meet a very narrow time-to-market window. "It happened and we were able to make our window," he says. The company got Zoob toys to market for the Christmas buying season.

Primordial expects to use 600,000 lb of resin this year to produce Zoob toys. Stovell adds that a second set of molds will be ready for production in the fall to accommodate increasing demand for the unusual toy. Stovell emphasizes that working with people such as McRae, Hahn, Appelblom, and Bayer's market development representative, Paul Rodriguez, facilitated the success of launching Zoob toys. "These people got us past the learning curve where many others flounder because they have great ideas but they just don't know the plastics business," he says.