Early electrical workers used it as a coating to insulate coils, and molded it into stand-alone insulators by pressing together layers of shellac-impreg-nated paper.
Kind of moisture expellable, smell preventive shoe is characterized by that the whole shoe liner is made into a form of gas pump which can expel the moist air out in the shoe.
88. Question: In PCBA, what is the function of a component's hold - down mechanism? Answer: It secures the component in place on the PCB, especially during the soldering process and under mechanical stress.