Rotational molding creates strong, hollow plastic parts in shapes that are impossible to produce with other methods. With its low tooling costs, this thermoplastic process is ideal for prototypes and lower-volume production runs for custom projects. (Rotational molding is well-suited for high-volume production runs, too.) Rotomolding or rotocasting, as rotational molding is sometimes called, also supports smooth, seamless surfaces in thermoplastics such as polypropylene. Importantly, custom rotomolded parts can include molded-in hardware and permanent branding, labeling, or markings that contain product or company identification.
Applications for rotational molding are numerous, and range from industrial products such as plastic mufflers and ventilation ducts to baby changing stations and shopping cart accessories. All rotational molders aren’t the same, however, and there’s no substitute for 70 years of experience and a strict commitment to detail. That’s why when Höweler + Yoon Architecture wanted to create an interactive playscape of illuminated ring-shaped swings, the Boston-based studio chose rotational molding services from Gregstrom Corporation.
“Swing Time” in Boston by Höweler + Yoon
Höweler + Yoon creates distinctive architectural designs for projects in the Boston area and around the world. When the Boston Convention Center wanted to brighten a patch of vacant cityscape known as the Lawn on D, the architectural firm was commissioned to create “Swing Time”. These 20 oversized polypropylene swings are equipped with solar-powered LED lights that change color based on the swing’s activity. An onboard accelerometer measures the acceleration forces of the swing and a custom micro-controller switches the light color from soft-white to purple as users interact with the playscape.
In addition to solar panels and steel beams, “Swing Time” incorporates sturdy metal rods that suspend the individual swings. In turn, each rod attaches to a metal plate atop the ring-shaped swing. Rotational molding supports molded-in hardware like this, but that’s not the only post-mold service that Gregstrom Corporation offers. The Woburn, Massachusetts plastic contract manufacturer can also mold-in graphics to replace stick-on labels that may have difficulty adhering to plastic surfaces. Gregstrom can also emboss information such as the company name or the words “patent pending” directly into the product.
Rotational Molding from Gregstrom
At its manufacturing center in Woburn, Gregstrom uses Ferry Rotospeed RS-220 and RS2-3300 machines to rotomold plastic parts that range in size from intricate spray manifolds to small plastic boats. Gregstrom’s auxiliary equipment includes a high-intensity mixer with an optimized vortex that “polishes” the plastic resin for more uniform colors, reduced porosity, and excellent physical properties overall. In addition to molded-in hardware and molded-in graphics, value-added services include optional polyurethane foam filling for additional rigidity and thermal insulation.
For more information about how Gregstrom’s rotational molding capabilities and how they can help you, please contact us on-line.