Basic Knowledge Of Waste Plastics--cleaning And Drying Of Waste Plastics

There are two methods for cleaning and drying of waste plastics: manual cleaning and mechanical cleaning, some products are recycled, only manual cleaning can be used.

Waste plastics are usually stained with a variety of oil, dirt, sediment and garbage, and must be cleaned out of the external impurities attached to the plastic surface to improve the quality of recycled products. The cleaning method has two kinds of manual cleaning and mechanical cleaning.

The varieties of waste plastics are different from the degree of contamination, and the specific cleaning methods are different.

Manual cleaning and Drying

Manual cleaning should determine the specific cleaning method according to the product varieties and contamination degree.

General agricultural film and packaging materials cleaning and drying process as follows: Warm alkali water cleaning (remove oil) → scrub → cold water rinse → dry.

Packaging of toxic drugs film and containers of cleaning and drying: lime water cleaning (medium and disinfection) → scrub → cold water rinse → dry.

Mechanical cleaning and drying are divided into intermittent and continuous type two.

1. Intermittent cleaning first, put the waste plastics into a sink rinse, and the mechanical stirrer to remove the adhesive on the surface of the plastic loose dirt, such as sand, dirt and so on, to sink into the bottom of the trough; if wood chips and scraps of paper are many, can be further purified in the sedimentation tank with special pumps; for the attachment of solid dirt, such as printing inks, coated paper labels, can be artificial picking up the larger slice, soaking in the hot alkali water solution trough for a period of time after crushing, and then rubbing the collision with each other by mechanical stirring, Remove Dirt. Finally, after washing the crushing waste plastics into the centrifugal machine, and dry by two steps hot air to residual moisture ≤ 0.5%.

2. Continuous cleaning of waste plastics from the conveyor into the shredding machine, coarse crushing, and then sent to large pieces of separation, sand and gravel sink into the underwater, and regularly sent away. Floating materials through the conveyor roller into the wet grinding machine, then into the sedimentation tank, all the heavier than water is separated, even the smallest particles are no exception.

The material first enters the cyclone separator to carry on the mechanical drying, then passes through the tunnel type dryer, carries on the hot air drying. The dried material is recycled by the collector and prepares to granulation.