As we all know, the future direction of the manufacturing industry - green, low-carbon, intelligent production of cast film equipment is also the direction of development.Chinese CPP film production line is also becoming more and more obvious, 2014 China's widest 5.3 m cast CPP film production line Put into production, is designed and installed by Shaoxing Borui Extrusion Equipment Co., Ltd., put into use this device also marks the domestic equipment in the green, low carbon, intelligent design and improvement of some adapt to the needs of the market.
First, save energy
For cast film equipment, green, low carbon is to reduce energy consumption per unit of production, improve resource utilization efficiency and reduce carbon emissions throughout the design process has been around the subject of energy conservation.
1. Extruder design improvements and energy savings:
The higher the screw extrusion speed, the lower the energy consumption of the extrusion unit.In the high-speed extrusion of the plastic above, Borui shielding section designed by the single-level to multi-level design, and design separation groove and slot pitch Design, to ensure high speed extrusion plasticization completely.
2. Heating energy saving design, in the cast film equipment, heating energy consumption is always accounted for not very large proportion of normal production accounts for only about 13-17% of the total energy consumption.
Reduce the cooling area, improve the efficiency of heating energy consumption
In reducing the heat dissipation area Borui company uses ultra-small aspect ratio (L / D = 22-25) extruder, compared with the L / D = 32 extruder, the need to heat the area and the cooling area simultaneously reduced 21.87% -31.25%, this saving is double for us;
For the screen changer, we also reduced the loss of heating energy consumption based on the reduction of the heat dissipation area. After comparing the heating and power loss of the double cylinder screen changers, plate changers and other screen changers, we decided not to Change the filter area under the premise of the use of the smallest heat dissipation area of the filter, in order to achieve lower heat loss.
Insulation measures the implementation
In the area of the connecting tube that needs to be heated, it is clear that the connecting tube only serves as a segment for connecting the screen changer and distributor pipeline The connecting pipe does not have any plasticizing function, so in the connecting pipe part we use flexible pipe connection, the use of ultra-low power heating tape wound heating, jacket insulation sleeve, both to play an energy saving effect and has a safety effect, will not produce Danger of scalding.
3. Drive energy consumption in the cast film equipment accounted for a smaller proportion, but the subtleties of the design is still able to ensure low drive power consumption.
One of the design advantages: researching the cooling and crystallization of the film on the cooling roll, we found that the area where the film can be rapidly cooled is actually very short, so we do not need a large diameter cooling roll as long as it meets the needs of high-speed film cooling and crystallization So that we can calculate the drive roller configuration and drive power required;
Design the second of the advantages: After studying the film cooling and crystallization process, we decided to increase the cooling bellows and remove the back-chill roll (commonly known as: the second chill roll), so after the chill roll drive along with the water cycle pump to save drive consumption;
Design advantages of the three: edge material recovery system breaker bypass ventilation opening, is able to give full play to the efficiency of the recovery fan to improve the suction efficiency of the edge of the outlet, reducing the recovery fan configuration power and power consumption, together with the recycling side of the hopper Through the feed, making the entire recovery system energy consumption decreased 37% relative to peers;
4. Auxiliary power consumption is in two aspects: refrigeration unit and circulating pump
After fully studying the crystallization of polyolefins, it is found that the crystalline region of the polyolefin is in a wide temperature range between the melting point and the glass transition temperature, but the crystallization temperature (Tmax) at which the crystalline polymer is most rapidly crystallized is: Tmax = ( 0.80-0.85) Tm, Tm - melting point.
Analysis of a variety of polyolefin materials is not difficult to come to the crystallization temperature of the fastest temperature range between 120 ℃ -80 ℃, the original we do not need lower and lower temperature of chilled water, we want a fast heat exchange roller, let The material temperature is rapidly lowered from above 120 ° C to below 80 ° C, the transparency of the film is guaranteed. We need a rapid heat exchange of the chill rolls to remove the chillers. The superior design consists in removing the circulation of the after chill roll and the post chill roll Pumps, together with the drive system and frequency converter, are out of point for us.
Second, safe, stable, efficient, intelligent design
1. To prevent hidden dangers of equipment: heating, electrical safety, electrical short circuit, electrical operation, insulation failure;
2. personal accident safety: mechanical damage, burns, noise pollution, radiation, static electricity;
3. Prevention of mechanical accidents should focus on the structural design of equipment and equipment installation quality.
For example: The design speed of the production line of Borui CPP film equipment mold width ≤4000mm has been raised to 300m / min, to ensure the start-up 20um × 260m / min, 25um × 240m / min production Speed of operation
5 intelligent design: PLC central control unit and man-machine interface; servo or frequency converter;
6. Bus control; more user-friendly program operation, the entire line of higher intelligence, more convenient operation.
Third, save investment costs
Introducing the operating energy consumption to say that the cost of investment, lower investment costs is not only the investment side of the fixed asset investment savings, the same for the social significance of the equipment in the process to give priority to meet the needs of the film production process, concise and economical is also a green , Low-carbon ecological surplus.
1. High-speed extruders are no longer required to be too large in diameter for the same production capacity; ultra-small length-to-diameter ratio (L / D = 22-25) Barrel screw processing difficulty, saving material costs.
2. After the cooling roller (commonly known as: the second cold roll) removed, saving a lot of energy consumption, of course, saving on investment costs: After the purchase of cold roll; Drive motor; Drive inverter; Circulating cooling water pump.
Production line design process to minimize the use of aluminum guide roller, both to avoid the film during the operation of the scratch, but also reduces the investment cost of equipment.