Economical vacuum formed pallet


At the 2008 SouthPack exposition, Morrison, TN-based ThermoFlex LLC, specialists in thermoforming, cast urethane and thermoset molding of material handling components, demonstrated its expanded capacity for vacuum forming high precision pallet-sized trays and platforms with accuracies suitable for robotic handling and automated part loading/unloading operations. This expertise results in solutions that integrate the economies of vacuum forming with the strength and precision normally associated with more expensive injection molding operations. ThermoFlex is able to produce containers and trays in sizes up to approximately 5 feet x 9 feet x 20-25 inches from high molecular weight polyethylene materials up to 1/2 inch thicknesses.

The design for the new tray concept includes targeted areas where pockets are precision routed in secondary operations to accommodate the robotic grippers for lifting the pallet to and from loading stations. In addition, reinforcement and stiffening points are integrated at strategic locations to assure the tray is strong and stable.

Some of the most critical details of producing the precision trays, according to Greg Hancock, vice-president and general manager for ThermoFlex, are in the vacuum forming process itself. “The process requires virtually continuous vigilance, monitoring and adjustments, if necessary,” remarks Hancock, “when trying to achieve tighter tolerances than conventional thermoforming projects require. The correct heating temperature and cycle time must be maintained…likewise the cooling cycle and removal temperature are vital, along with vacuum pressures. For the automated system or robot to do its job, the containers must be consistently sized, strong and rigid to eliminate deflection.”

“If the temperature is not accurately controlled and allowed to get too high, or if the cooling cycle is insufficient, the part will likely bend, bow, shrink or warp. If the heating cycle is too short, the temperature drops, or if the vacuum pressure is low, finer part details may be diminished or lost,” Hancock concludes.

With ThermoFlex engineering and design resources, precision trays and pallets can be configured to meet the demands of virtually all part configurations, process requirements, and robotic handlers. To assure results, the firm first produces a wood pattern of the tray concept from which samples are run… adjustments can be easily and economically made during this phase. Once sampling is complete and outcomes verified, aluminum tooling is fabricated to complete the production run.

ThermoFlex capabilities include cast urethane molding and thermofoam operations in addition to its vacuum forming operations. Products include urethane coated conveyor rollers, tool protection holders for the metalworking industry, assembly tools, bumpers, enclosures, grippers, covers, wipers, seals and custom dunnage components. Along with its sister facility, PolyFlex Products (Livonia, MI) providing custom injection molding services, ThermoFlex is a synergistic resource for the material handling industries.

Attention to process parameters such as temperatures and cycle times, plus incorporating effective design details are the critical elements to ThermoFlex’s precise and economical vacuum formed pallet trays, ideal for handling by robots and automation systems.