1. Introduction

In recent years, with many foreign plastic sheet extrusion advanced equipment into China at the same time, domestic sheet packaging equipment manufacturers are also rapidly digging up, promoting the rapid development of the sheet packaging industry and equipment demand growth, and the continuous increase of domestic labor costs, people put forward higher requirements on the output, energy consumption, environmental protection and automation of equipment, Domestic sheet metal high-end equipment manufacturers (such as Hangzhou Kangfa Plastic Machinery Co., LTD.) according to the needs of sustainable development, concentrated superior resources, and many advanced suppliers and research institutes at home and abroad jointly research and development, make full use of the company's existing imported advanced equipment, improve the processing precision of parts, design and optimize the structure of various parts, processing technology, improve the overall performance of equipment, We successfully designed and manufactured the PET extrusion sheet equipment with a high output of 1200 kg per hour on the 95 model (the model is WSJP95-1200 twin screw extrusion sheet unit) and delivered it to the customer for verification and use, and the effect was very satisfactory, creating a high-end equipment of twin screw extrusion sheet in China. At present, it is the most advanced sheet metal production line equipment with mature technology and stable equipment. It has the characteristics of low energy consumption, simple process and convenient equipment use and maintenance.

The main characteristics of equipment green performance:

1. Compared with similar equipment in China, comprehensive energy saving can be improved by more than 30-40%. (Domestic similar equipment 95 models, the general output per hour 500 kg, and Kangfa development of new product output per hour 1200 kg);

2. Three-stage vacuum exhaust technology and oil-gas separation technology are adopted, leaving out the crystallization drying system. Not only reduce the footprint of the equipment, but also reduce energy consumption;

3, due to the use of twin screw optimization combination technology, greatly reduced PET viscosity reduction, to ensure product quality and stability;

2. Green production process of PET sheet extrusion equipment

PET sheet extrusion equipment is a new material developed in recent years, with its excellent toughness, high hardness, high transparency, non-toxic, tasteless, easy forming and recycling and other advantages, and combustion does not produce harmful gas excellent environmental performance, comply with the trend of environmental protection, gradually by consumers and producers of great green, Widely used in all walks of life product packaging, stationery, printing, gifts and technology.

Due to the high moisture content of common PET raw materials in the air, it will cause hydrolysis during melting and extrusion, so that the melt viscosity and molecular weight will decrease significantly, resulting in extrusion sheet foaming, brittle, yellow and other abnormal phenomena. At present, the main domestic equipment for the production of PET sheet material to solve the water content of raw materials is single screw extruder. Its processing route of "pre-crystallization, drying and melting extrusion" generally requires supporting crystallization drying system. The second is the planetary screw (multi-screw) free crystallization extruder, is free drying direct exhaust extrusion process, the third is the twin screw free crystallization drying extruder, also using the exhaust extruder direct extrusion molding.

3. Key technological innovation points of equipment

How to develop high efficiency PET extrusion sheet equipment, through multiple arguments, from the five links of technological innovation, structure optimization, precision manufacturing, to achieve high output and low energy consumption of equipment, to create high efficiency twin-screw extrusion sheet equipment in China.

1) Twin screw combination technology

Years of accumulation of twin screw configuration research and design experience and advanced software technology to optimize the combination of special double threaded components and unique screw combination, to achieve conveying plasticization, mixing and mixing, shear dispersion, homogenization and homogenization, exhaust dewave, extrusion and other functions. In particular, it has high efficiency in the removal of crystallizing water inside PET material. The specially designed exhaust port is free and unobtrusive, realizing low temperature extrusion and avoiding thermal degradation of PET.

2) Vacuum exhaust technology

Multi-stage forced exhaust is efficient and safe to ensure that PET materials are melted and plasticized without hydrolysis or crystal point. Special three-stage vacuum exhaust technology and oil and gas separation technology, super large gas extraction, ultra-high vacuum degree, greatly reduce the viscosity of PET.

3) High strength roller internal spiral runner technology

High strength roller internal spiral runner structure design, supporting water temperature control system, so that the roller has accurate temperature control and efficient heat transfer effect;

4) Intelligent remote control technology

Through the company's server IDC center industrial data center and industrial data acquisition and analysis software, remote monitoring network equipment, standard motor health detection and analysis system, equipment energy management and optimization system, remote monitoring of the health equipment in the customer's factory and various process data collection and storage, process data analysis, optimize the production process formula.

5) Equipment manufacturing process craftsman spirit

Parts selection, manufacturing process, processing precision, heat treatment and surface treatment, appearance design and other industrial design for comprehensive research, to ensure the stability and reliability of equipment, improve the stop.

4. Equipment performance is as follows:

1, multi-component feeding device technology, suitable for new material, return material, color master ratio control;

2, raw materials free crystallization drying technology, low comprehensive energy consumption, cost saving;

3, high torque extruder unit, supporting torque protector;

4, equipped with large filter area melt filter, save a lot of time and labor consumption of net changing operation;

5, three roller calendering roller pressing adopts hydraulic device, compact structure, convenient auxiliary facilities layout, simple operation; The water temperature system adopts the temperature dual PID control technology of heating and cooling.

6, online cutting, crushing, conveying recovery system, special winding structure design, realize online non-stop coil change, unwinding device, save a lot of working time and labor consumption;

7, online silicon coating system, improve sheet adaptability and protection, improve competitiveness;

8, high precision twin screw extrusion system adopts pressure closed-loop feedback control technology, heating and cooling temperature double PID control technology;

9, the machine adopts PLC control, to achieve automatic control of parameter setting, data calculation and feedback, alarm and other functions;

10, advanced double PID control algorithm technology, real-time statistical analysis of technical data, real-time improvement measures to ensure that the production process is always in a statistical control state, in order to improve the quality of products, precision, energy consumption and other performance indicators.

5. Market application prospect and development direction

Domestic demand for various packaging equipment is increasing day by day. Enterprises in the field of sheet thermoforming packaging usually purchase multiple sets of equipment to meet the production demand, which is because domestic equipment is still in low output and a large number of labor force to complete, indicating that our equipment suppliers need to improve the automation and intelligence of equipment, to improve the production speed and efficiency. At present, domestic and foreign twin-screw extruder industry development trend is to high output, low energy consumption, environmental protection, automation, intelligent direction.