Radio Frequency (RF) • Dielectric • Heating Systems • Sealing • Welding

Nemeth - Vanguard Manufacturer of Composite Preheaters

With U.S. fuel prices well over $2 a gallon, automobile manufacturers are acutely aware of the need for vehicles with greater fuel-efficiency. A lighter weight car or truck equates to more miles per gallon. Because of this, combined with cost savings, some automotive components formerly made of steel are replaced by lightweight composite materials.

Radio Frequency (RF) equipment is central in the manufacture of composite materials.

RF bonders are widely used to cure thermoset adhesives to assemble composite exterior panels such as vehicle hoods, doors, fenders and lamp assemblies.

RF preheaters are employed to heat various resin and composite materials with a suspended electrode prior to molding. Once the composite material is preheated, formed in a mold and cooled, it will never warp or disfigure, regardless of the heat applied to it. Most preheaters range in size from 4 kW up to 20 kW and utilize either a removable tray or a conveyor belt for the material.

Automotive manufacturers and suppliers presently employ numerous RF preheaters manufactured by Nemeth Engineering Associates, Inc. Nemeth preheaters come in a variety of shapes and sizes, ranging in power from 4 to 20 kW and offer a variety of options.

The 150SPH80 model can heat 24” x 24”stacks of SMC or similar composite materials up to 5” high at approx. 8 to 10 pounds per minute from ambient to 220 degrees Fahrenheit with 15 kW of RF power.

Other models are configured with rows of rotators for preform heating. Units can have two, three or more than four rows of rotators. These models come in standard sizes of 4, 7.5, 15 and 20 kW. A 4kW preheater, featuring an 8” x 8” top electrode with adjustable spacing from 1-1/2” to 6”, can heat up to two pounds of typical compounds in 60 seconds. A 20 kW unit, which has a 32” x 26” top electrode with adjustable spacing between 2” and 10”, can heat 15 pounds of typical compounds in 60 seconds.

Front- and top-loading preheaters are available, as well as top-loaders with manual and automatic (compressed air) operated hoods. For models used for preform heating, standard options include rotators, remote start, temperature sensor, positive exhaust system and PLC controller. All can be set to operate on 230 or 460 volts.

Nemeth Engineering Associates, Inc. also manufactures extremely reliable RF pultrusion preheaters. With up to 12 kW of power generated, pultrusion models can heat several parallel lines at once with 10” and 16” wide electrodes. These models feature a positive external clean air supply, spark detector and a closed-loop TC/auto power control.

Nemeth also carries a full line of preheater parts, including power tubes, rectifier modules and assemblies, capacitors, filters, rotators, blowers, contactor rings and shielding.