Hot melt adhesive prodn. - by pre-soaking polymers in melt in kettle, then pumping to second kettle while subject to high shear for very short periods

摘要

Process is for mfr. of hot melt adhesives. One or more polymers are dissolved in a melt consisting of dispensing materials which are solid and/or liq. at room temp. Mixing is realised with a shear energy input of at least 0.002, pref. 0.005 Kwh per kg of material and mixing time is a max. of 5s., pref. less than 1s. Shear speeds are 10000-500000, pref. 50000-200000 S(-1). Combined high shear rate and short shear times enable almost all hot melt adhesives to be produced without viscosity redn.. Materials forming a dispensing melt are introduced into a first kettle in which the polymers are warmed and presoaked. Heating and premixing of the product is achieved by pumping the mixt. via a shut-off valve, through a combined heat exchanger and static mixer, a further shut-off valve and back into the first kettle. USE/ADVANTAGE - To produce hot melt adhesives, has a shorter cycle time. Improves prod. quality.