Review of recycling of plastic packaging material waste in various countries (10)

5.4.3 PET recovery and regeneration modifier

Japan implemented the container recycling method in April 2000. In 2001, PET bottles were recycled up to 170 kt, and the recycling rate was only 40%. In order to solve the technical problems of PET recycling and recycling, the Japanese company Sanghua Cheng successfully researched and developed two types of recycled PET modifiers, "AR-P-1000" and "AR-P-1100," which were introduced to the market.

The main characteristics of “AR-P” recovery and regeneration modifiers are: 1 It does not require drying when used; 2 It is very stable at room temperature; 3 It applies to all plastic molding processing equipment; 4 It can be arbitrarily colored; Blending Addition; 6 Improve the impact strength of PET recycled recycled materials. Since "AR-P" is dispersed in a fine state in the recycled PET molding material, the interfacial tension is small due to the shearing force of molding processing. The "AP-P" and recycled PET molding materials have a viscosity ratio of 1 and are dispersed well. This improves the impact strength of recycled PET molding materials. For example, when 5% AR-P is added, the notched impact strength increases from 2kJ/m2 to 5.5kJ. /m2. At -10°C, the impact strength at low temperature increased from 1.8kJ/m2 to 5kJ/m2. 7 Improves the viscosity of recycled PET molding materials, improves the flowability of PET melt molding materials, and is suitable for molding and processing into products with complex shapes and profiles.

5.4.4 Application of Characteristics of Crosslinked Polyolefins with Recoverable Properties

Japan Mitsubishi Chemical Corporation has successfully researched and developed cross-linked polyolefin plastics, called TRC plastics, in order to make effective use of resources.

TRC plastics mainly use polyolefin plastics in cross-linking, the temperature control at low temperature near the melting point of the crosslinking, and then by increasing the polyolefin plastic molding processing temperature to 190 ~ 250 °C, cross-linked polyolefins in the high-temperature state of the functional group dissociation, become Thermoplastic resin. For this reason, cross-linked polyolefin plastics can be recycled and reused.

The cross-linking dissociation performance of TRC plastics was tested and found that TRC plastics were melt extruded at a pressure of 0.23 MPa at 190-250°C for 6 min, and then extruded through a nose with an internal diameter of 2.1 mm and a length of 8 mm. The material has a smooth surface appearance. On the contrary, if the extrusion molding temperature is lower than 190°C, the appearance surface of the extruded material is uneven, indicating that the TRC plastic is not dissociated and is still in a crosslinked state. For this reason, the dissociation temperature of TRC plastic cross-linking must be controlled at 190 °C or more and remain for a certain period of time in order to cross-link and dissociate.

TRC plastics began to cross-link at 110°C, and the degree of cross-linking was determined to be 80% at this time and the flexural strength was 80 MPa, which was the same as that of general cross-linked polyolefins.

5.4.5 New Process for Conversion of Waste Plastics

The University of Pennsylvania recently developed and demonstrated a new Garthe method for converting plastic waste into plastic fuel blocks. Mixed waste plastics, including fouling materials, are usually treated by digging and burying. The new process involves shredding plastic waste and adding it to an electrically heated mold. Using milder temperatures, the heat is sufficient to melt the outer layer of the plastic, but it does not melt the rest of the material. The resulting serpentine compressed plastic is cut into small pieces and then mixed with the coal and placed in a burner, boiler or cement kiln to co-firing with the coal. This fuel can provide enough energy.

----China degradable plastic