Can be recycled into beverage bottles or other lids in daily life

Bottle recycling

Bottles include cool beverage bottles, mineral water bottles, liquid Food bottles, cosmetic bottles, etc., the materials used are polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (polyester) (PET), etc. Usually mineral water bottles are made of PVC or PET, carbonated drink bottles are made of PET, refreshing beverage bottles, liquid food bottles are made of PVC, PE, detergent bottles, cosmetic bottles, milk bottles, lactic acid bacteria drinks are mostly made of PE.

The various bottles that are recycled are generally sorted manually and then recycled according to different materials. At present, there are many technologies and equipment used for the recycling of various bottles

(1) Recycling of PET bottles. PET bottles are widely used in carbonated drinks such as Coca-Cola, Pepsi-Cola, and Sprite. Currently, most of them are composed of PET bottles and HDPE bottle bottoms. The bottle cap material is HDPE, and the trademark is biaxially oriented polyethylene. Propylene (BOPP) film is adhered to the bottle body using EVA adhesive. The way to reuse polyester bottles after recycling is through regeneration and granulation. Alcoholysis and other methods. No matter which method is used, the polyester bottle must first be separated from other bottles, and the polyester bottle body must be separated from the bottom of the bottle.

① Separation: The mixed addition bottles enter the crusher through the conveyor belt for crushing, and then undergo density separation.

② Regeneration and granulation: Extruder can be used for regeneration and granulation. The separated PET scraps are extruded and granulated by an extruder to form pellets. In order to avoid water absorption during extrusion and a decrease in physical viscosity, they should be dried before extrusion. The uses of PET pellets are as follows:

a. To re-manufacture PET bottles. Recycled pellets cannot be used in direct contact with food, but can be used in the middle layer of three-layer PET bottles to make carbonated beverage bottles. .

b. Spinning to make fiber, recycled PET material can be used to spin to make fiber, which can be used as pillow core, mattress, sleeping bag, felt, etc.

c. Glass fiber reinforced material. Glass fiber reinforced recycled PET has good heat resistance and mechanical strength and can be used to make automobile parts, such as heat-resistant automobile wheel covers. Its thermal distortion temperature Up to 240 degrees. The bending elastic modulus is 9500MPa, the bending strength is 214 MPa, and the impact strength is 15kf/m2.

d. After being mixed and modified, the recycled PET material can be mixed with other polymers to make Various modified materials, such as mixed with PE***, can obtain PET*** mixture with improved impact properties. PE:PET is (10~50): (90~50): If a small amount of polypropylene is added, ***The dimensional stability of the mixture can be significantly improved. Since the polarity of PE and PET is quite different, compatibility treatment is required when mixing. Generally, the compatibility is improved through graft modification of polyolefin.

③ Alcoholysis: PET waste is alcoholyzed in the presence of an alkaline catalyst, and then dibasic acid anhydride and other polycondensation are added to obtain a product with an acid value greater than 12. After dilution, filtering, and adding an appropriate amount of catalyst, it can be made Get alkyd resin paint. See the table below for the recipe. Reaction temperature 80~85 degrees, reaction 4~5h

PET waste alcoholysis coating formula

Material addition amount/% Material addition amount/%

PET Material 25 N-hydroxymethylacrylamide 2

Triethylene glycol 23 nonionic emulsifier 0.9

Dibutyl phthalate 18 anionic emulsification Agent 1.1

Vinyl acetate 24 persulfate initiator 1.4~1.6

a-methylstyrene 7 water 130

Methacrylic acid 1

Another example is to react PET waste with polyol at 220~250oc, and then solvate it to obtain an insulating paint with a three-dimensional network structure. The quality meets the requirements of GB6109 ③ Others, PET bottles are also Can be used to make plasticizer: 2-ethylhexyl terephthalate (DOTP), its plasticizing effect is similar to dioctyl phthalate (DOP), and is slightly better than DOP in terms of electrical properties and low-temperature flexibility. Waste PET bottles can also be made into adhesives and unsaturated polyester in a similar way to waste PET films

(2) Addition of PVC bottles, the PVC recycling process is as follows.

PVC bottles are cleaned, sorted, crushed and regenerated

The PVC bottles are first cleaned with steam and alkali solution to remove the trademarks, and then mechanically and manually sorted. The final PVC bottles are crushed twice, and finally a powdery regenerated product with a fineness of 500~1200μm is obtained, with a purity of up to 99.98%

(3) The addition of PE bottles, the PE used as bottle material is Mainly HDPE, including dairy product bottles, food bottles, cosmetic bottles, etc. After sorting and cleaning, the HDPE recycled bottles can be crushed and selected for the following uses:

① Use colored Coke bottle base< /p>

② Used to extrude the middle core layer of pipes

③ Fill with talcum powder or glass fiber to make flower tea cups or injection molded products.

④ Composite with this fiber and used as artificial wood. Because wood fiber has poor compatibility with HDPE, it is necessary to add appropriate coupling agent or use activated wood fiber.

⑤ To make artificial gravel, crush HDPE bottles into fine pieces or granules, and then stick the gravel shape made of yarn, metal, etc. on the surface, and then mix it with concrete or asphalt for civil engineering Building materials.

3. Recycling of polystyrene foam

Polystyrene foam can be effectively molded into polystyrene beads. Foam plastics used for packaging of household appliances or frozen food packaging; there are also a few instant noodle bowls made of expandable polystyrene beads. These plastic products are bulky and cost a lot of money, and their recycling has received special attention in China.

The main ways of recycling polystyrene foam include: granulation after volume reduction, crushing and use as various filling materials, cracking to produce oil or recycling styrene and others.

(1) After volume reduction and granulation, polystyrene foam can be melted, extruded and granulated to make recycled pellets. However, it is bulky and difficult to transport, so it usually needs volume reduction before recycling. Methods include mechanical method, solvent method and heating method.

(2) After crushing, it can be used as filler. Polystyrene foam products can be used as filler after being crushed to make various products. Such as ①Re-molding into foam plastic products

②Concrete composite panel products

③Gypsum sandwich bricks

④Used as asphalt reinforcing agent

⑤ Used as soil modifier

(3) Cracking to produce oil or recycling styrene, the device for cracking waste polystyrene foam plastic to produce oil is as follows

Waste Polystyrene foam pretreatment, heat treatment, volume reduction, catalytic cracking, distillation of styrene

(4) Others, waste polystyrene foam can be used to manufacture coatings and adhesives, etc.

① Coating, expandable polystyrene foam can be made into paint by crushing it and adding appropriate solvents. The process flow is as follows

Fillers, colorants

PS, ethyl acetate and grinding Over-grinding and processing

Ethanol, dibutyl ester, cyclic milling filter reaction kettle grinding filter product

Oxygen resin, nitrile rubber kettle

② Bonding Agent, a mixed solvent of esters and benzene, adding waste polystyrene foam, anti-sedimentant, plasticizer, phenolic resin and other additives, it can be made into coatings for cement, steel and wood.

③ Brominate to produce brominated polystyrene flame retardant, using aluminum dichloride as a catalyst to make electrophilic substitution reaction between waste polystyrene and bromine to produce brominated polystyrene, containing bromine The amount can reach 60% to 70% and is used as a flame retardant for thermoplastics such as PET, ABS, and nylon. Brominated polystyrene is cheap, has good flame retardant effect and thermal stability. A dosage of 5 parts (mass) can have obvious flame retardant effect. Used together with antimony trioxide, it has a good flame retardant synergistic effect.

Hope this helps