Styrofoam recycling route two

4. Addition of plastic footwear

Plastic footwear includes foam, non-foaming sandals and slippers, and various plastic soles. The main materials are PVC, PE, PE/EVA and so on. Before sorting and recycling, the sorting is first performed, and manual sorting is generally used. After sorting, various kinds of used footwear are regenerated according to material types and used.

(1) With regard to the addition of PVC plastic footwear, the addition of PVC plastic footwear mainly adopts the method of re-granulation. The waste PVC shoes material that has been sorted and washed is mixed on a double-roll mill. At this time, according to The specific source and quality of the waste, adding a variety of fine additives, after fully mixing out the film, pelletizing, filtering out, to obtain recycled pellets.

The addition of auxiliary additives is determined by the situation of waste PVC shoe materials. If it is the leftover material of the factory, there is no need to add additives, as long as it is mixed with a new material at a certain ratio, the ratio of the tangle material to the new material can reach 1:1 or even Higher, for the foaming of PVC waste, mixing temperature must be properly increased, mixing time also need to be extended to drive out bubbles.

For the poor quality of waste PVC shoe materials, it is necessary to add a variety of additives, and to remove various impurities, the method is through extrusion filter. The formula for determining the amount of plasticizer added is:

b C1K1 C2K2 b

X=A (A1 + A2 +...) × (1+)

100+b 100+ C1K1 100+ C2K2 100

A=A1+A2 + ...

In the formula: X - the mass of plasticizer to be added in the recycled ingredients, kg

A—The total mass of waste plastics in recycled ingredients, kg

A1 A2... - The mass of some waste plastics recycled and processed

b - The mass ratio of the plasticizer required in the recycled raw meal, %

C1 C2... - The mass ratio of plasticizer in the original formulation of a certain waste plastics reprocessed, %

K1 K2...—The retention factor of the plasticizer used for reprocessing a certain waste plastic is usually determined empirically.

Other additives, such as stabilizers, lubricants, etc. can also be determined in principle using the above formula and experience.

Used PVC agricultural film, plastic film commonly used to make shoes with PVC renewable materials, the general content of plasticizer in PVC film is about 42 parts, is introduced a few ingredients will be practical (using the ratio of factory PVC foam scrap).

Formula 1

Factory PVC Foam Footwear Scrap 10 kg Waste PVC Film 25 kg

New material powder 10 kg

The formula for new material powder is as follows:.

PVC (XO-4) 100 (mass fraction) Dibasic lead sulfate 5.0

DOP 35 Dibasic Lead Phosphite 2.0

DBP 60 medium yellow pulp 1.0

Mixed Ester 25 Iron Oxide Red Pulp 2.2

Barium Stearate 3.5 Carbon Black Pulp 0.14

Formula 2

Factory PVC foam scrap 30 kg New feed 10 kg

Waste PVC film 5 kg

The new ingredient formula is as follows.

PVC (XO-4) 100 (parts by mass) DOP 25

Tribasic lead sulfate (powder) 0.5 DBP 30

Strontium stearate 0.7

(2) Recovery of PE, PE/EVA shoes, PE, PE/EVA shoes are usually foamed products. The factory scrap is mainly crushed and granulated. Added to new materials, the waste collected by society can be mainly used for agricultural implements, fences and so on.

5. Polyurethane recycling

Polyurethanes are complex and their products include soft and hard foam plastics, thermoplastic elastomers, and industrial products. They are widely used in automobiles, home appliances, chemical industry, daily use and other fields. Recycling can be performed separately according to common types.

(1) Recovery of polyurethane flexible foams. Flexible polyurethane foams can be mechanically recycled. One is coated with adhesive, and the other is used for compression and recycling.

(2) Reaction Injection Molded Polyurethane Recovery 1 is used as a filler for glass fiber reinforced RIM-PUR. 2 Blended with polypropylene. The old RIM-PUR comminuted material and PP concrete together can produce a flexible PP elastomer. There are 1, activation treatment 2, the addition of compatibilizer 3, and the addition of inorganic fillers. 3 Direct Compression Recycling RIM-PUR Recycled Material The crushed and pulverized powder can be directly compressed to produce various products without the need of adding adhesives. 4 Part of the thermal degradation recovery, the RIM-PUR waste was heated to a certain degree in the kneader, and the PU molecular chain in the material was broken and degraded. The material changed from a hard to a soft plastic state, and then the isocyanate was added to make the material. The degraded PU molecular chains are cross-linked to produce hard materials, which are used in automotive tool kits and require high strength and hardness.