Gemstar Mfg. LLC, known for its rotomolded protective cases and custom parts, finished an expansion this year to pursue one of its newer endeavors: single-layer fuel tanks made with acetal.
Last year, Cannon Falls, Minn.-based Gemstar used its trademark Robomold robotic rotational molding technology to expand its Stronghold line of double-walled hard cases, introducing more than 90 new sizes and configurations. The military-grade, reusable containers are used to protect high-value contents.
To help accommodate that product line expansion and the fuel tank work, the company earlier this year added 45,000 square feet of production space to the 40,000-square-foot Cannon Falls plant.
It also purchased some new equipment, said Kevin Lumberg, Gemstar's channel manager for custom parts.
"We now have two robots, one Rotoline 3.6. carousel and two Rotoline 2.6 carousel, independent three-arm machines that replaced two older Ferrys," he said Aug. 17 by phone.
Gemstar had a customer with a particularly tricky need: a fuel tank incorporating an interior funnel to prevent overfueling.
"Before, we could use nylon, but nylon is very difficult to work with, with tight windows. It forms completely differently and there's a lot of wastage," Lumberg said. Nylon also didn't produce the polished look the customer wanted, "and we couldn't get nylon to form that funnel feature."
Gemstar considered cross-linked polyethylene, which was easier to work with and looked great, but the tanks had to be sent out to be fluorinated, treated to decrease permeation.
"Shipping hollow tanks gets costly," he noted.
"There's been kind of a void in the market for something that could pass Environmental Protection Agency standards, was easy to work with and looks good. So to solve the customer's problem, we looked around and said, 'Can we get creative here?' "
