... is needed: printing and dyeing, food, electronic, medicine, spin, timbering, paper industry, auto, plastic, fitment, shoemaking, metal, heat treatment, packing mechanism ... spectrum distributing, infrared radiation heating tubes are classified to: short wave (wave length: from 0.76 to 2.0 μm), middle ... wave (wave length: from 2.0 to 4.0 μm) and long wave (wave length: above 4.0μm ...