As often as once a month.

Plastic extruders comprising at least one material feeding device, a pump unit and a nozzle arranged after the pump unit, the material feeding device being arranged to feed the material through the pump unit into the nozzle, the pump unit being a radial pump unit comprising conical screws arranged to be adjacently positioned and to rotate in the same direction, the radial pump unit being arranged to transfer an annular flow of the material into the extruder's nozzle.

 

Plastic crusher is used throughout industry to reduce materials such as coal, rock, salt, granite, etc. from a large size to a smaller size. Crushers designed for this purpose frequently include a pair of crushing rollers between which the material to be crushed is passed to accomplish the desired size reduction. The crushing rollers generally consist of an outer metal shell mounted on an inner hub. The outer shell will wear at different rates, depending on the type of metal and the material being crushed. As the outer shell wears it must be replaced, sometimes as often as once a month.

Plastic waste recycling, that is synthetic polymer-containing substances, pose an environmental issue because of the problems associated with disposal: a large volume of non-biodegradable material. Because of the limits on landfill capacity, future recycling or decomposition is a necessity. Direct recycling back to the manufacture is not always feasible because such waste plastic is often mixed with respect to polymer type and separation is uneconomical. Economical considerations for processing waste plastic often require the use of the unseparated mixed waste plastic. Plastic recycling originated with the manufacture of synthetic thermoplastics. Rejected parts, trim, and flash from operations represented valuable materials that were ground and recycled with virgin material. This process was potentially repeated a number of times provided the percentage of regrinds remained low.