Plastic package recycling
Categories: Solid Waste Disposal
Plastic package recycling
Waste plastic package recycling will be developed as the second resource of regeneration and utilization
There are four ways of recycling plastic packag waste: first recycling; second regeneration; third research and developing of new products; the fourth is heat recovery and refining.
Plastic containers, especially a large plastic containers from the garbage sorting, after cleaning and disinfection can be recycling directly. Recycling of plastic packaging waste is mainly recycling and shape molten, etc. The process of recycling of plastic waste is: sorting, pre-science, melting, granulation (granulation without some direct molding), and molding.
Recycling equipment of plastic bottle crushing and washing
1. Pretreatment
Including pre-sorting, shredding, washing and drying.
1.1 Cleaning and drying
Plastic waste must be washed rough firstly, to eliminate the stones and metal or other solid waste, in order to prevent from damaging the crusher. Thick plastic waste washed by centrifugation dehydration, then sent to the crusher. After broken then wash carefully, inorder to remove the debris wrapped in it. Then need to be dried after washing to get ready for the next step of melting and granulation.
1.2 Shred
The commonly used plastic packaging waste crushing equipment are compression-type mill, impact crusher and shear crusher and shaft shredder so on. For the difficult crushing waste plastic products at the normal temperature , can use frozen crushing technology. Waste plastics are easy brittle at low temperatures, which makes it easy to shred. And a variety of different plastic brittle transition temperature, can use this to adjust the freezer temperature, to achieve selective separation.
2. Pre-processing of recycled materials
2.1 Ingredients
Recycling of waste plastics through a series of pretreatment and obtain dry powder, or directly plastics molding, or by molding after granulation. Prior to this, often require the ingredients, adding various ingredients such as stabilizers, coloring agents, lubricants, plasticizers, fillers and various modifier.
2.2 Kneading
Recycled materials kneading with all kinds of recycled additives is necessary, which can make the various components in the plastics prior to macro-mixing. After the kneading equipment and components selected, the kneading effect depends on the kneading process (such as temperature, time, feeding sequence, mixing speed) control. Kneading of recycled plastic is generally before granulation; if recycled material after crushing granulation and direct processing of shape without granulation, then kneading should be do before the shape is fixed.
2.3 Granulation
Regardless of the waste plastic products, the first pre-processing should be carried out before recycling of waste plastics in the preparation of recycled aggregates: identification, sorting, washing, crushing (hard goods) or chopped (soft goods), then through the hot sub-dry, the moisture content of not more than 5%. After this treatment the powder kneading with the other components of the co-ordination and then do the granulation immediately.
Some recycled materials (such as recycling of soft PVC products) can be plasticized by mill, released film, cut directly without shredding.
Preparation of PE, PP plastic pellets can be recycled by milling or mixing process, the process is basically the same, but after kneading then plasticized by mill, mixing, and pelletizing after put into pieces, may also be plasticized by mixer , mixing, then put into pieces before pelletizing.
Because of the high melt viscosity of recycled PVC material, should be use manual control on the mill, whether the recycled material is calcium plastic may also apply to the use of milling technology.
