1858, an American named hamilton smith made the world's first washing machine in Pittsburgh. The main part of the washing machine is a bucket. There is a straight shaft in the bucket with blades. You can rotate the shaft by shaking the crank connected to it. In the same year, Smith obtained the patent right of this washing machine.
However, this kind of washing machine is laborious to use and harmful to clothes, so it is not widely used, but it marks the beginning of washing clothes with machines. The following year, a washing machine with a pestle as a stirrer appeared in Germany. When the pestle moves up and down, the wooden nail with spring constantly acts on the clothes.
Historical development:
Mechanical force, washing liquid and water are three elements in the washing process of washing machine. The mechanical force generated by the moving parts of the washing machine and the action of washing liquid separate dirt from clothing fibers. Heating the washing liquid can enhance the decontamination effect. Different fabrics have different suitable liquid temperatures, and the main indicators reflecting the washing performance of washing machines (that is, the ability to wash clothes) are washing rate (or washing ratio) and fabric wear rate.
Water washing rate is to measure the reflectivity of artificially polluted cloth and its original cloth before and after water washing with photoelectric reflectometer (or whiteness meter) under rated water washing state. Washing clothes has been an inevitable housework since ancient times, but before the appearance of washing machines, for many people.