RF Preheater

RF Preheaters preheat molding materials uniformly, rapidly and with greater efficiency. Materials such asphenolic, melamine and urea compounds have a low heat transfer property and high moisture absorption. These materials are being processed either by compression molding or transfer molding. Therefore, molding these materials without preheating lengthens molding time, and increases tooling wear resulting in deterioration of product quality and increase of rejects.

In the past, electric or infrared heating was used to reduce these problems, but today high-frequency preheating is the method of choice. Unlike the conventional heating which transfers heat by conduction from the outside of the material to the inside – high-frequency heating generates heat inside the material. The alternative high frequency electric field generated inside the RF Preheater causes the polar molecules of the material to be heated to continuously align themselves with the field. The friction resulting from molecular movement causes the material to rapidly heat throughout its entire mass.

COMMON USES:

Preheating of thermosetting plastics (phenolic, melamine, polyester, and similar thermoset resins) for compression molding

APPLICATIONS:

Preheating and curing of polyester, urethane, epoxy, urea, silicone, synthetic rubber and phenolic resins • Adhesive curing • SMC (Sheet Molding Composite) Bonding • General drying • Testing/heating studies • Bulk or granular solids

Operation: Preforms are placed on the sliding tray provided with the Preheater. Optional rotators are available to enhance heating uniformity. An adjustable timer stops the preheat cycle; the operator then pulls the tray open and removes heated preforms.

Controls: Indicator Lamp features include: Power On, Ready, RF On and Fault. Power output is controlled by adjusting the electrode spacing.

Meters: All units include both plate and grid current meters.

Cycle Timer: Electronic cycle timer is provided to control the heat time; optional heat delay timer is also available.

Optional Equipment:

Perform Rotators for one (1) to four (4) rows of preforms

Heat Delay Timer

IR Temperature Sensor Integrated into the Heat Cycle

Remote Cycle Start/Stop Function