New developments let rotational molding compete with injection or blow molding. Computer-generated color renderings help rotational molders finalize designs. The use of 3D models boosts productivity and helps create drawing views and cross sections that simplify the job of building patterns. A premeasured amount of powdered or liquid plastic is placed in mold half. The mold is closed, transferred to the heating oven, and then on to the cooling station. During the entire heating and cooling process, the molds simultaneously rotate around two right-angle axes. Typical carousel rotationalmolding machine with three arms that rotate between loading/unloading stations, heating ovens, and cooling chambers. Kiss-offs increase part stiffness. They are used individually or in a series or pattern and will outperform ribs in many cases. The almost kiss-off gives nearly the same structural strength without adding a blemish on the outside wall. Rotationally molded newspaper boxes manufactured by Steel City, Youngstown, Ohio, unlike their metal counterparts retain their good looks (no chipped paint or scratches), remain rust free, and are nearly dingproof. Rotational molding gives a portable fuel tank a heavy-duty handle which provides good load control and a secure grip. Made by Tempo Products, Cleveland, the tanks have a 29-gallon capacity and are color coded for different fuel. Football enthusiasts now sit on rotationally molded bench seats. Designed by Dant Clayton Corp., Louisville, Ky., the plastic seats were installed in 1999 in the Citrus Bowl, Orlando, Fla. Normally with a volume requirement of 65,000 one would consider the blow-molding process. But the project required seven different sized seats each in three different colors. The blow-mold tooling would have been more expensive and the production runs for each size/color combination would have been small for the blow-molding process. Rotationally molded products are a good fit for a wide range of industries. Production runs
Products & Services
Plastic Mold Equipment Design and Fabrication
Plastic mold equipment design and plastic mold equipment fabrication services specialize in the design and fabrication of machinery used to create plastic molds, barrels or cylinders, liners, hot runner systems and component, and feeders.
Plastic Molding Services
Plastic molding services use a number of different molding techniques to produce components, including thermoplastic and thermoset injection molding, blow molding (includes injection blow molding), rotational molding, thermoforming, structural foam molding, compression molding, resin transfer molding (RTM), and others.
Molding machines form thermoplastic resin, thermoset polymers, or MIM compounds into finished shapes.
Topics of Interest
An advanced TekTuff SPA polyethylene (PE) lets Heritage Kayaks, Bristol, R.I., not only slim down its rotationally molded Featherlite kayaks without loss of structural toughness but also permits...
Rotational molding, also known as rotomolding, loads pre-measured plastic resin into molds that are moved to an oven where they are slowly rotated on both a vertical and horizontal axis. Hollow molds...
Chapter 6.1: Thermosetting-Plastic Parts
Chapter 6.2: Injection-Molded Thermoplastic Parts
Chapter 6.3: Structural-Foam-Molded Parts
Chapter 6.4: Rotationally Molded Plastic Parts
The manufacture of expanded polystyrene, polypropylene and similar molded parts (automotive bumpers, protective helmets, etc.) requires precise molding control for its vacuum, steaming and subsequent...
Blow molding is a well-established process that lets designers glean more design freedom and drop part cost by easing assembly via parts consolidation. Problem is, conventional low-durometer (<45...