Extruder energy saving solutions bloom

The rising cost of raw materials and the pressure on energy costs have made energy-saving and material-saving the focus of the extrusion and processing industry. At the same time, extrusion technology suppliers have demonstrated their ability to develop a variety of energy-saving solutions from various perspectives to best meet the energy-saving needs of users.

On the market of materials and energy consumption that control production switching, the demand for small batches and short lead times has been rising, and frequent switching of product specifications and types has become an important factor that manufacturers have to consider. The shutdown, reinstallation and commissioning of the specification switching process often mean a large amount of raw materials, labor, and energy loss. The higher the equipment's production efficiency, the greater the losses. For the needs of the market, rapid change of specifications and rapid replacement of varieties have become important technologies for processors to increase their competitiveness.

In this environment, many European large pipe manufacturers began to install Krauss Maffei Berstorff's Quick Switch system, which has significant flexibility and material savings.

Two Belgian customers recently ordered the company's two complete production lines, a 25-63mm production line and a 70-160mm production line. The main machine is Krauss Maffei Berstorff's proven 36D single-screw extruder, spiral tube die and Quick Switch switching technology. A 160-250mm production line was newly installed at one of the world's largest pipe manufacturer plants in Germany. The production line is also equipped with the company's inner pipe cooling system (IPC), which can increase production without increasing cooling costs. An Italian customer will soon install a new Quick Switch system to produce polyolefin pipes up to 160mm in diameter.

The QuickSwitch system significantly increases the flexibility of the production line, allowing manufacturers to complete the entire production line diameter change in just a few minutes with a single button press. All wasted material is just a short truncated cone. In fact, the time saved by the rapid replacement process actually means a significant reduction in energy consumption. The material waste caused by the traditional switching process and the energy consumption during the commissioning phase cannot be ignored.

In the processing of pipes, films, etc., rapid switching technology can be used. For compounding manufacturers, easy cleaning of equipment is the key to rapid product change. North American masterbatch maker Comai recently ordered a Coperion new ZSK Mc18 twin-screw extruder. There are two factors influencing this decision. Antonio Sedan, managing director of Comai, explained that on the one hand, the company had been using three ZSK compounding extruders in 1999 and it has been used very well, with high reliability of the equipment. The wear resistance of all components is very much recognized. On the other hand, using the ZSK70M18 can achieve higher yields and product switching can be achieved very quickly, cleaning time significantly shorter than previous models.

According to reports, the key factor of this new compounding system that can rapidly increase production volume and improve masterbatch quality is that the processing area is optimized. The optimized cooling system and improved temperature control can not only significantly reduce energy consumption, but also improve the overall thermodynamic performance of the temperature control and compounding process in the entire processing zone.

The system's cleaning performance has also been improved, enabling faster and easier cleaning. The system's quick-release structure reduces installation and reassembly time. This has special advantages for masterbatch production because masterbatch production often requires the replacement of pigments, additives, and sometimes the need to replace the base resin. Moreover, any urgent, unplanned, masterbatch orders may result in a temporary interruption of a long-term stable production line.

The use of a new extruder screw, barrel structure, and supporting system to equip the extruder with a new screw, barrel structure, and exhaust system is also an effective means of increasing efficiency and reducing energy consumption.

For example, the use of a higher aspect ratio low shear screw, the use of a slotted barrel, the use of a more efficient exhaust system, and the like are all effective means.

Battenfeld Cincinnati's new twinEX twin-screw extruder fully embodies energy-efficient features. twinEX offers four extruder models from 78mm to 135mm. Compared to other counter-rotating twin-screw extruders, the specific energy input of twinEX is approximately 15% lower, while at the same time the output is increased. This is achieved by lengthening the processing unit to 34L/D and incorporating a reduction in heat loss. The main design features include a fully insulated barrel, intelligent APC cylinder air-cooled (strong air-cooled system), Intracool screw core temperature regulation system and optimized screw design.

In addition to extruders, the continuous development of downstream equipment is equally important for the improvement of profile extrusion performance. Battenfeld Cincinnati not only designs and manufactures downstream equipment, but also cooperates exclusively with Gruber Extrusion Technology on engineering projects. The two professional extrusion technology companies jointly provide high-productivity, energy-efficient complete window profile extrusion lines. Gruber Extrusion Technology has recently developed an energy-saving vacuum system featuring a more efficient dry vacuum setting and a vacuum box with a variable vacuum control system. Compared with the traditional system, the setting table with energy-saving vacuum system can reduce energy consumption by up to 50%.

In recent years, Bruckner's double-pull film production line has become one of the best-selling technologies in the market. While Brückner's production line meets higher width and higher efficiency, energy saving is also an important feature of its production line. E.g:

The "thermal regeneration system" can regenerate the energy wasted by the transverse directionr. The system can also be used for the upgrading of existing production lines, including non-Bruckner production lines. For example, Bruckner installed this system for Turkey's Polinas Plastics company from the installation. So far it has saved energy consumption by 300,000 Euros.

Specially designed "energy monitoring tools", according to energy monitoring, can provide semi-automatic and fully automated control so that the production line can take into account and save energy and resources in the production mode of operation.

The direct Casting PET production line, from polyester production directly to the production line die, enables both raw material and film production to save energy.

The optimized temperature control of the film cast can realize the cooling of the entire thickness of the film cast to a minimum, and from this temperature to the temperature required for the MDO stretching, the energy consumption of the heating can be effectively reduced.

Direct drive of all components reduces energy consumption between the motor and the belt and improves process control.

The use of a twin-screw extruder with exhaust can reduce the energy consumption required for the PET process, eliminating the need to consume pre-drying energy.

The use of adjustable drives for auxiliary motors, such as pumps, fans, etc., can optimize the operating point and, in turn, save energy.

EXTRUDEX Plastics Machinery Co., Ltd. developed a new single-screw extruder and named it HELIBAR. After several improvements, the equipment has been fully optimized in terms of energy efficiency, economy, reliability, continuous power and service life.

With the same production volume, HELIBAR can reduce energy consumption by 10% to 60% by reducing the cooling requirement and reducing the size of the structure. The specific data is as follows: compared with the new type of extruder, the energy consumption is reduced by 10%; compared with the old type of equipment, the original motor and gear box are retained, the screw and barrel are modified, the energy consumption is reduced by 20%, and the complete machine is replaced with 60 Series HELIBAR devices replace the 90 Series extruders and reduce energy consumption by 60%.

According to Helmut Wahl, General Manager of EXTRUDEX, the main reason why these advantages can be achieved is that there is no wear and tear, even when dealing with additives with a strong wear effect (for example, pigments).

The extremely low pressure in the feeding area of ​​the extruder is the source of no wear. "The energy consumption is extremely low due to low frictional heat, reduced cooling requirements, and completely insulated barrels," Wahl added.

Depending on the type of mold and the type of material being processed, in 90% of cases, HELIBAR equipment does not require an expensive cooling water system for the cooling unit, and a lower-cost air-cooling unit can be used.

Energy-efficient direct-drive system Davis-Standard has conducted energy efficiency and noise tests on three types of single-screw extruders. The two types of extruders are the traditional forms of using DC motors and AC motors to drive the reduction gearbox respectively. Compared with PMSM or torque motors, the direct drive system of the gearbox is not applicable. Both extruders use a thrust bearing system to withstand high axial forces during extrusion. For accuracy, each comparative extruder has the same processing area including the feed zone, barrel, screw, and control system. High load studies with HDPE and low load studies with PP.

Monitoring of drive and motor performance uses a Power Quality Analyzer to record power consumption. The recording parameters include three-phase voltage, current, and power. All extruder operating conditions include throughput, melt temperature and head pressure to ensure consistency of the experimental process. The experiment used a fully equipped Davis-Standard 2.5 inch extruder with an aspect ratio of 30, equipped with five electrically heated, water cooled barrel sections.

Studies have shown that direct drive systems have many advantages over traditional extrusion systems. For low torque materials (PP), the direct drive system consumes 15-20% less energy than the AC system and 20-50% less than the DC system. Correspondingly, for high torque resin (HDPE), the direct drive system saves 10-15% over the AC system and 17-40% over the DC system. With a typical operating condition with a basic speed of 100 rpm, DC motors require 10-15% less power than AC systems and 20-25% less than DC systems.

The noise of the direct drive system is also significantly reduced. The noise of the conventional system mainly comes from gear rotation and cooling fans used to cool the stator and rotor of the motor. In the two traditional systems studied, the DC system has a separate fan, which is independent of the extruder speed and operates at the same speed and wind speed. The AC system has a built-in fan that runs with the motor. Sound level tests show that the direct drive system is significantly quieter.

To realize the energy saving of the extruder, there are many factors that can be considered. Careful study of each manufacturer's different energy saving systems will have special benefits, such as new heating devices, optimization of the cooling system for extruders and dies. Wait.