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Precise feeding and dosing
Source：International Plastics News for Asia
Date Published：11/28/2018 10:11:26 PM
Recent developments in the auxiliary equipment sector point towards forwad-looking mixing, dosing and feeding systems that cater to the requirements of manufacturers wanting to improve their efficiency through integrated systems.
ELMET, which supplies operating systems for the entire field of injection moulding of two-component liquid silicone rubbers (LSR), is the first producer in this segment to offer the option to connect its multi-component dosing system TOP 5000 P to the injection moulding machine using an OPC-UA protocol. This “open platform communication” enables communication and automated information exchange from machine to machine (M2M) in real time. Consequently, ELMET has made it possible for its customers – without the need for a license – to integrate the dosing system into the production control system, plus much simplified operation of the dosing system from the injection moulding machine. The technology is currently fully operational with Engel machines, while others are at the preparation stage.
According to Mark Ostermann, Sales Manager at ELMET: “With the new OPC-UA connection, processors have the possibility to store recipes and parameters together with the machine data, and they can enter parameters for the dosing system directly into the control unit of the injection moulding machine and call them up from there. The data of the dosing system can be implemented easily into the production control system. No additional expensive license is needed because the injection moulding machine is established anyway in the control system. ELMET is thus making a valuable contribution to improving user friendliness even further and to minimising the risk of error in the day-to-day business.”
The TOP 5000 P is designed for large-series production of high-quality parts. It is suitable for shot weights in a range of less than 0.1 g to several kg, and can manage containers with a capacity of between 20 and 200 litres and material viscosities from 9,000 mPas to 3 million mPas, even with large viscosity differences between the components. Only recently, the SHORE-MIX extension stage came onto the market, in which three dosing systems comprising two A and two B components produce a mix with exactly reproducible Shore hardness.
TOP 5000 P is equipped with two separately functioning control circuits, one of which ensures over 99% emptying of the containers, while the other makes sure that the volumes fed into the process correspond exactly to the target figure. Consequently, this system is especially valuable when the process window is tight and the start-up conditions are difficult. And, with an additional additives control solution, we achieve constant, highly accurate dosage, irrespective of sediments, wear and tear and viscosity differences.
Advancing the compounding process
Coperion and Coperion K-Tron released Coperion ZS-B side feeder which is used to feed raw materials into numerous extrusion processes. The side feeder is equipped with the patented Feed Enhancement Technology (FET) that increases the material intake capacity in the processing of feed limited products by up to three times. For the improved feeding accuracy of loss-in-weight feeders, Coperion K-Tron offers the unique EPC electronic pressure compensation system.
Coperion ZS-B twin screw side feeder enables the reliable side feeding of fillers and additives.
The Coperion ZS-B twin screw side feeder enables the reliable side feeding of fillers and additives in powder or pellet form or cut glass fibres into the process section of the twin screw extruder. The ZS-B features a self-cleaning profile of the twin screws and product feeding into the screw flights of the extruder without stagnant zones. It requires very little space due to its compact design. The side feeder is equipped with the patented FET Feed Enhancement Technology developed by Coperion, which applies a vacuum to the feed zone by means of a porous, gas-permeable wall. The resulting gas extraction increases the material intake capacity in the processing of feed limited products by up to three times. Throughput rates will considerably
increase and the use of finer non-compacted fillers is possible.
Coperion K-Tron offers the electronic pressure compensation system (EPC) for its high-accuracy loss-in-weight feeders. The main advantages of the new system include improved accuracy and reliability as well as lower initial cost and easier installation compared to traditional mechanical pressure compensation systems. The company has designed a clever but simple electronic solution for accurate and steady pressure compensation in feeder hoppers and outlets. The modular design incorporates pressure sensors and electronics tailored to interact smoothly with Coperion K-Tron’s KCM feeder control system. Retrofitting options for existing feeders are available. EPC can be installed on a majority of Coperion K-Tron gravimetric feeders in almost any application and all industries.
Moretto’s concept of “Efficiency 4.0” was recently launched as an advanced machinery and solutions for plastic processors. For Moretto, “Efficiency 4.0” means a plant made up of high technological machinery, connected and integrated with each other by a supervision system that guarantees total control of the process, the possibility to reduce energy consumption and to increase the final quality.
DPK from Moretto is a compact loss-in-weight dosing unit.
Nowadays injection, extrusion and PET processing are characterised by specific complexities and high levels of performance, in which production and energy efficiency play key roles. Moretto aims to support customers by providing low energy consumption machines, conceived with the criteria of Industry 4.0 and based on the respect for environmental needs. Moretto’s goal, also declared by the new pay off Empowering Plastics (that means “infuse more power to plastic”), is to help the industry through know-how, service, innovation and highprecision machines.
In particular, its DPK is a new compact loss-in-weight dosing unit, suitable for intermittent or continuous dosing of small quantities of colour or additives into a flow base material.
In operation additive, that is visible to the user in a rugged acrylic hopper, is metered into a free flow of base resin based on processing consumption and using the changing weight of the additive hopper (loss-in-weight) as a guide to the metering rate.
Load cell technology and control algorithm make the DPK ignore vibrations and provide stable metering and dosing precision to ± 0.03%. Gravimetric precision is assured even at very low dosing rates. It is obtained by loss-in-weight selfcalibration and fine-tuning of metering stepper-motor speed. The icon-navigated, colour touchscreen control provides easy, intuitive operation. USB and serial RS485 connectivity. DPK solves the problem of overdosing with an extremely precise control.
Maintenance hoppers are placed on the processing machine to provide a reserve and assure process continuity. There are six types of hopper, each responding to specific requirements. The TMM mini series is compact in size and suitable to accept receivers and containers in conveying systems. The TMX Pyrex series is suitable for containing dried granule. Its Pyrex body offers optimal visibility and excellent thermal protection. Version with infra-red sensor available. The HM - HMX stainless steel series (with mixer) is ideal hoppers for the processing of poorly flowing regrind and for recovery of the latter in a closed circuit without any risks of stratification. The DHM - DHMX insulated stainless steel series (with mixer) is ideal for the processing of hot dried materials. These guarantee constant process variables and significant energy savings thanks to incorporated insulation in ceramic fibre.