Heat Processing of Lenses
Tempering is used both in plastics and the smelting of steel and iron ore. During the process of manufacturing optical lenses, heat is used to reduce the inner strain in the lens. To increase the lifetime of plastic products these stresses are removed by a tempering oven. The amount of stress is due to the shape, cooling time, and thickness of the material.
Stresses are created by the shrinking of material as is cools. When the plastic is poured into the shaping mold, it is hot. The material has lots of energy due to the heat. The molecules inside the liquid move around frequently and allow the material to be flexible. As soon as the material becomes cooler the energy lessens. The material shrinks to allow the access energy to dissipate. This then adds pressure to the material making it under stress.
From here the product can be tempered. Tempering is the process of slowly and moderately heating a material to increase the hardness and toughness of a material. The time and temperature of tempering varies upon the plastic being used. Usually tempering involves heating the plastic to just below its softening point. This allows the plastic to become flexible without being too viscous. Tempering is normally done by an enclosed oven. An operator will set the time and temperature of the oven and then mold the plastic when ready.
Whaley Products
 Packaged Chillers Non-expandable (integrated pump tank) 1.5Ton – 20Ton Single / Dual Circuits Single / Dual Pumps |
 SAE Series Modular Chillers Expandable (pump & tank on separate skid) 1.5Ton – 200Ton Single / Dual Circuits |
 SAR Series Split Chillers Expandable (Outdoor Condensing Unit) (pump, tank, evaporator on indoor skid) 1.5Ton – 200Ton Single / Dual Circuits |