Multi-material multilayer plastic packaging has a wide range of applications, such as food industry packaging, feed packaging bags, chemical industry, industrial materials and electronic parts packaging. The advantage of multi-layer composite packaging materials is that it can increase the storage period of products and increase the value. The selection of materials can meet the needs of water resistance, gas resistance, oil and gas prevention, rust prevention, radiation protection, and aseptic freshness preservation. Currently, there is no mainstream recycling solution for Multi-material multilayer plastic packaging materials on the market. Therefore, this project uses a microwave-assisted heating mechanism to develop a recycling process for soft multi-layer composite packaging and conduct a technical feasibility assessment. From the experimental results, it was found that tetrahydrofuran can be used as the inner plastic solvent. The heating temperature needs to be controlled at 50°C, and it can be heated quickly within 1 minute. The middle layer and outer layer plastic solution can use citric acid concentration of 35wt% or 5wt% and 10wt% sodium carbonate aqueous solution. Microwave heating for 2 minutes has the best effect. The structural assembly and testing of the microwave auxiliary system were successfully completed and met the design specifications. The system uses a 2.45GHz/3000W magnetron as the source of microwave energy and a WR340 square waveguide to transmit microwave energy. The system is designed to maximize energy efficiency according to the above microwave power and frequency. And a microwave reaction cavity that considers heating uniformity. In the future, a small-scale trial operation can be planned, and the feasibility of classified recycling and the commercial value of recycling can be confirmed with relevant manufacturers.

Multi-layer composite packaging, Microwave-assisted reaction, Recycling technology