Acrotech Plastics

Manufacturing Plant | Watertown, SD

When new environmental requirements were put in place for fuel tanks and other gasoline containers, AcroTech Plastics realized it was going to take a major capital upgrade and a plant expansion to build products to meet the new requirements. The plant management and ownership felt they needed to look at the options of either expanding the existing plant or building a new plant in another location. After much research, a decision was made to build a new facility and transfer manufacturing from Minnesota to Watertown, S.D.

West Plains Engineering is proud to be part of the design team that helped AcroTech make the move from Minnesota to South Dakota. At the Watertown Plant, AcroTech Plastics manufactures blowmolded plastic parts, some of which are fuel tanks for all terrain vehicles, snowmobiles, and motorcycles. On many of the parts, after the blow-molding is complete, AcroTech provides a secondary operations including robotic machining to provide added value to their customers.

A lot of heat is required in blow-molding to melt the plastic before the molding operation. Consequently, the manufacturing portion of the facility does not require additional heat, even in the winter. Ventilation fans are installed throughout the facility to provide outside air ventilation to help cool the plant. Some of the fans will be utilized year-round. Since the molds require cooling whenever manufacturing is taking place, a chilled water system is required year-round, even when the outdoor temperatures are so low that a traditional chiller cannot operate. The chilled water system design includes a traditional chiller to provide chilled water in the summer and a fluid cooler that can provide almost no cost chilled water during the colder months. In addition to the chilled water system, a second water cooling system is required to cool the hydraulics on all the presses. The hydraulic cooling loop is cooled using a closed loop cooling tower to reject the waste hydraulic heat.

The raw plastic is brought into the plant by rail car. The rail cars are emptied using a vacuum system, which moves the plastic pellets from the rail car to three storage silos. From the storage silos, the plastic is transferred into the building using another vacuum system and distributed to each of the 20 production presses utilizing a third set of vacuum pumps. The manufacturing process also uses a larger amount of compressed air to help cool the molds. Compressed air is piped from a pair of screw compressors out to all the presses and to several locations where secondary machining work is completed on the parts.

The electrical systems include the traditional systems of high bay lighting, fire alarm, and a data distribution system. Unique to this type of facility is the multiple electrical services required because of the high electrical usage by the blow-molding presses. The design for the original facility had four 2500 amp electrical services, four (4) 2000 KVA transformers, and two (2) utility loop switches. Additional services are installed as the new production equipment is arriving.