Creating, designing and rotomolding a toy that will last

CLEVELAND — Tom Fish loves the rotational molding process, and the Little Tikes Co. creative director explained how the Hudson, Ohio, company uses CAD models and rapid prototyping to create new toys, in a presentation at TopCon 2014, the Society of Plastics Engineers' rotomolding conference.

“Rotomolding is the best process for a designer to work with. The fact that you make big sweeping curves, that's a plus, not a minus,” he said. “Little Tikes gets a lot of credit for making soft, rounded products. It wasn't that it was brilliant, you just have to make them soft and round to mold.”

Rotomolding also allows for easy color changes, something that is harder to do in injection and blow molding, he said.

Fish outlined a process he developed to design the layout of the spider — the framework molding a set of rotational molds — using three-dimensional CAD. The goal is to fit numerous parts onto one spider — such as all the parts in a playhouse. That makes efficient rotomolding, for the high-volume toys.

“The parts get thrown down a chute, trimmed and they're put into a box. And at our factory, they go on a conveyor that lifts them up, and out to the warehouse they go. Done!” he said.

Using CAD, during the design process, Fish can put in part parameters and adjust things like spacing between the parts and seeing comparative parting lines. If you make a change, the entire CAD drawing adjusts.

“As a designer, I change my design as I work through this, knowing what would or wouldn't fit,” he said.

Early on in the development process, Tikes' marketing department brings ideas for, say, a kitchen set, complete with the look, features and price of competitor's kitchens. Then the design team makes lots of sketches. A group comes together including marketing and consumer service people, who answer the 800 number for complaints.

Each component is costed-out, and they know beforehand the maximum size. “No matter how you do it, it has to fit in that box” on store shelves, Fish said.

The CAD drawings and spider layout also helps to figure machine usage, a key aspect of pricing. Tikes also uses a stereolithography machine to make small models.

The toy designers make models using foam, then colors them to look like the finished product. They bring moms in to get their opinions.

Fish said the Tikes design team works on 50 to 100 projects every year. A constant flow of new products is critical, since toys inherently have a short lifespan. “My average consumer starts at 26 inches tall and a few years later they're 40 inches tall,” Fish quipped. But sometimes you hit on a big winner for the ages — like the Little Tikes Cozy Coupe, turned out at a rate of 500,000 a year.

Fish said Tikes uses robotics to load and trim the Cozy Coupes. Resin is preheated in dedicated hoppers right at the machine, “so we're already putting resin into the molds at a raised temperature,” he said.

It's mass production makes it one of the best-selling cars in America.