No.58

Microwave Heating
(Exerpt with minor changes from article in Machine Design, October, 1970)

By: George Badger

Photos

Plywood veneer is dried in the is oven with a combination of hot air and microwave energy. Column-like pipes carry hot air that impinges on the top and bottom of the plywood sheets ad they are carried along on the mesh conveyor. Rail across conveyor at right is the upper half of the slotted waveguide applicator.

Bottom half of folded waveguide is visible in this view of a machine for processing web (sheet) material by combination of microwave and hot air. Upper half of waveguide is hidden from view in the top part of the machine.

Microwave installation was designed specifically to produce tennis show soles. Ribbed arch at left is a flexible waveguide that carries energy from the power pack to the applicator on the right.

Bales of raw rubber are heated for subsequent processing in this pilot microwave installation. Only four minutes are required to bring bale to a uniform 80 degrees F, where many days of "thawing" are required with conventional heating.