RF Preheater

RF Preheaters preheat molding materials uniformly, rapidly and with greater efficiency.  Materials such as phenolic, 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, to mold these materials without preheating lengthens molding time and increases tooling wear resulting in deterioration of product quality and increase of rejects.

Formerly, 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 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.

By using Radio Frequency it is therefore possible to preheat the molding material uniformly, rapidly and with greater efficiency.  This reduces the heating time by as much as one half.  It also increases the product quality by uniformly preheating the molding material, preventing blisters, blurs and flow marks subsequently reducing rejects, improving product appearance and quality.

Read more about our RF Conveyorized Drying System.