Rotomolded coolers are made using rotational molding, a plastics manufacturing process that creates strong, hollow plastic parts that can be filled with polyurethane foam insulation. Depending on the brand and model, rotomolded coolers may also feature built-in wheels and cup holders, integrated bottle openers, heavy-duty handles, molded tie-down slots, and an integrated locking system. Compared to soft-side coolers, rotationally molded coolers are more durable, have a larger capacity, and offer better ice retention. They’re becoming increasingly popular for keeping food and beverages cold.

Why are coolers made with rotational molding?

Unlike plastic injection molding, rotational molding has low tooling costs and supports quick tooling modifications. With rotomolding, the tools range from simple two-piece sheet metal molds to multi-piece aluminum molds with articulating features. Because there’s no pressure, hardware can be molded-in for strength and durability. Rotational molding also supports uniform walls without the thinning in the extremities that’s common to injection molding. From prototyping to production runs, rotomolding also confers advantages such as support for shapes that are unattainable via other production methods.

In addition, designers of food and beverage coolers like how rotational molding supports a wide variety of surface textures and colors. Rotomolded coolers can also feature Mold In Graphics, a permanent way to mark, decorate, brand, or label plastics parts. Commonly used rotomolding materials include LLDPE, HDPE, and PP. After coolers are rotationally molded, their hollow cavities can be filled with polyurethane foam to provide additional rigidity and thermal insulation. Additional components such as wheels or heavy-duty handles can then be installed.

Who makes rotomolded coolers in the United States?

Gregstrom Corporation of Woburn, Massachusetts (USA) makes rotomolded coolers and combines plastics manufacturing and polyurethane foam filling with value-added services such as component sourcing, product assembly, packaging and shipping. As this case study explains, Gregstrom produced a Heineken draught cooler that consisted of 40 off-the-shelf components, five custom-fabricated components, and five rotomolded plastic parts. Gregstrom also packaged and shipped these point-of-purchase (POP) displays directly to Heineken distributors.

Do you design coolers? Are you looking for an experienced rotational molder? Contact Gregstrom.