Infrared oven

The mechanical foaming of PVC pastes has been carried out for some time on the basis of air or gas being whisked into specially formulated plastisols, which are cured using microwave or infrared ovens. The lightweight material is used for sound deadening or domestic applications. There has been a relationship established between the effects of residual emulsifier in the E-PVC resin grade and foaming behaviour (101). 

Infrared Oven - An oven equipped with infrared lamps where heat is generated by infrared rays. 

A combination of matched molding and thermoforming has been found successful with some high-performance parts. The material (fabric-reinforced PPS laminate) is heated to 316C (600P) in an infrared oven and then rapidly transferred to the mold. A seal is made... 

Squeezing/vacuum extraction/ steam cans Infrared oven... 

Phillips Petroleum has applied this technology to fabric reinforced Ryton (PPS) materials. A conveyorized infrared oven is used to rapidly preheat the lay-up to 600 °F in two to three minutes. The charge is quickly transferred to a preheated mold in a fast closing press for part forming. Total cycle times of one to three minutes are feasible with this automated approach. 

Infrared ovens with a more or less diffuse radiation pattern are also used to provide the needed energy. It must be kept in mind that the temperature achieved by a part exposed to infrared radiation is determined by the balance achieved between radiation received and radiation lost. This means that some parts will reach quite high temperatures if inadvertently exposed to the infrared source for too long a time. Sometimes, if parts of the assembly are of different materials or colors, temperature differences may result. Provisions for ventilation will probably also be required for infrared ovens. 

Key to type of equipment manufactured 1. air spray 2. airless spray 3. electrostatic liquid spray 4. electrostatic powder spray 5. pumps 6. fluid handling 7. multicomponent 8. automatic curve following 9. hot air ovens 10. infrared ovens 11. infrared sources 12. electrical induction generators 13. roll coaters 14. curtain coaters 15. dispensers for anaerobics 16. cleaning materials. 

If the thermal cure is to be accomplished with an infrared oven, the time will be much shorter but temperatures will be far greater than for a convection oven. Also, a number of recipes are usually needed to compensate for materials with different IR absorbance and panels with different thermal mass or thickness. 

The blanks are usually heated to about 150°-205° C (300°-400° F) from one side via high intensity pulsed infrared ovens. Generally a heating intensity of 6-7 W in."2 in 15-s on/off cycles is recommended. The blanks are then transferred manually or automatically via conveyors to the dies. 

Pulsed (on-off) heating cycles with infrared ovens normally are used to heat composite sheets prior to forming. A fast rise, fast decay heat source is desired to obtain a fast, uniformly... 

A combination hot air nfrared preheat process may be useful in a rapid commercial operation where space is at a premium. A large inventory of hot sheets is maintained in a compact circulating hot air oven. A short conveyorized infrared oven can be used for a brief final heating step close to the stamping press. 

There are several other methods that a flavor house may use to determine moisture content. They include microwave or infrared ovens (may be used in a spray drying operation for rapid analysis for process control) and refractive index (liquid... 

In addition to being used as processing aids, additional antioxidant is sometimes incorporated in the polymer after moulding. This applies to applications where relatively high temperatures are involved as in contact with hot foods, infrared ovens or in tropical areas where substantial exposure to ultraviolet radiation is likely to be encountered. 

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