Originally Published MPMN June 2005
Drying Systems Improve Production of Hydrophilic Foams
Materials are heated and dried evenly and quickly
|Macrowave systems heat and dry hydrophilic foams evenly throughout their entire thicknesses.|
Foam-drying systems apply radio waves to foam webs or buns up to 4 ft thick at a frequency of 40.68 MHz. This process rapidly removes water without the quality control problems associated with conventional drying methods. Those problems include surface discoloration, cupping caused by nonuniform shrinkage, and surface hardening.
The Macrowave units from Radio Frequency Co. (Millis, MA) gently heat and uniformly dry hydrophilic foams evenly throughout their entire thickness. They can also dry water-based glues used in the construction of foam laminations up to several feet thick. Because the Macrowave energy will preferentially heat materials where the water content is the highest, the wet glues are heated and dried without directly heating the cured foams, thus avoiding overheating.
The company offers process development laboratory services to assist clients in developing the most efficient means to accomplish their foam-processing objectives. The laboratory is equipped with a simulator that can apply radio-frequency and conventional heat to simulate actual production conditions and provide a computerized record of all process parameters to facilitate scale-up.