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| Issue date:01/08/2011 |
| China Plastic & Rubber Journal (CPRJ) - Aug 2011 Issue |
| Source:China Plastic & Rubber Journal |
| Jin Gang, South China University of Technology |
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| Aiming for the high hygienic requirement of the medical and pharmaceutical industry, KraussMaffei has introduced the CleanForm injection technology. |
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High efficiency, energy conservation and precision are the top three priorities related to injection technologies. Leading suppliers have put efforts on developing equipment, mold and die and applications. It proved that high quality and efficiency could coexist with low energy consumption. Based on the new injection exhibits at CHINAPLAS 2011, this article serves as a testament to the breakthrough of injection technologies and rapid development of applications market.
With 180,000 sqm of exhibition area, CHINAPLAS 2011 has created a new record. The plastic processing technologies and machines exhibited show a tendency towards high productivity, energy conservation, low consumption and low labor costs. For example, most of the injection machine manufacturers displayed products that are equipped with hybric system, which might soon be a standard of injection machines.
Some exhibiters showcased all-electric injection machines, and NC machine manufacturers have joined the race of injection technologies. New products keep being launched in the field of auxiliary equipment, automation and control, visual identification and image diagnosis system for mold and die. Hot runner systems continued to be a hot topic in injection molds. These trends are not to be repeatedly discussed, instead some unique technologies will be the focus of this article.
Clean production equipment
Equipment used for manufacturing medical and pharmaceutical instruments need to comply with strict hygienic standards. Various injection machine manufacturers have expressed their views on the topic.
Undoubtedly, the concept of cleanroom from KraussMaffei is one of the solutions. This technology is to treat the mold-locking unit as a clean unit to minimize the chance of contamination. This mold-locking unit has the hydraulic pressure direct-locking two-board structure. Its opening and closing mold and mold-locking hydraulic system are devised at one side of the injection system - besides the hydraulic pressure cylinder for ejection device - so that the possibility of contamination by hydraulic oil is minimized.
The mold-locking structure looks like a bolt, because it is a cantilever without base. In normal production, the whole mold-locking unit is pushed into an empty clean room with high cleanliness. If injection mold replacement or maintenance is needed, the whole machine will be moved backward. It is then conveyed into general rooms which could greatly reduce the costs of sterilizing contaminated clean rooms.
There is a sealing board at both sides of the mold-locking unit, while the control panel can be pulled out and installed on the side wall of the clean room, preventing pollutants from entering the clean room during the replacement process. With a series of prevention systems, the injection machines of KraussMaffei minimize the chance of contamination and reach ISO5 (100) supreme clean room level.
Another injection machine manufacturer Engel has its own solution for clean room production. Utilizing the advantage of structure without a pull rod, it can avoid pollution from hinge lubrication and can easily install mold replacing guide roller under the two moldboards. As it does not need hoist equipments to replace molds, the chance of contamination is small. The height of clean room can be lowered and costs are saved.
Besides, the structure consumes less space during the take out process, allowing for a smaller clean room. In addition, many details reflect the deep understanding of Engel on clean room production, such as the system for collecting and discharging the hot air generated while heating the material cylinder, sealed motor without cooling fan, flexible sealing device at the oil tank vent, dust sealing measures at the outlet port and more.
Wittmann-Battenfeld showcased its full electric micro-injection molding machine for the production of ultra small stents used in medical industry. |
Micro-injection molding equipment
The MicroPower 5-15t full electric micro-injection molding machine exhibited by Wittmann-Battenfeld was manufacturing very small stents at CHINAPLAS 2011. Each stent weights only 0.00108 gram, and the corresponding runner is 0.16 grams (one mold four cavities). The biodegraded material is plasticized in the plasticization system with a screw of 14mm diameter and then sent into the 5mm-diameter plunger cavity. Injection and molding is done by the screw after measurement, which hardly needs any cooling time.
The manipulator directly collect the finished pieces from the mold and send them to the image identification system for size measurement. It will move the qualified products to the next working space and blows small finished pieces into the glass bottle for packaging. All functions are integrated in a machine, and all parameters, curves and measurement images are shown on the operation screen. The advantage of combining Wittmann and Battenfeld is fully represented on this machine.
Full electric injection machines
More and more Chinese machines manufacturers launched full electric injection machines, but most of them carry the structural characteristics of traditional hydraulic press. Haitian Zhafir Mercury Series injection molding machines are one of the special one.
Zhafir Mercury injection machines use plasticization and injection separation methods to ensure accuracy of injection volume. |
Mercury injection molding machines use plasticization and injection separation methods to ensure accuracy of injection volume. Plasticization and injection are powered by directly connected moment motor. Though with a larger size, it has better response speed and control accuracy than the synchronous or gearbox driven mechanisms.
The mold-locking system may be the most innovative, using motor oscillating type wrist pin for opening and closing mold and mold-locking, thus the nodes of wrist pin are reduced and the mechanism is relatively simplified. Less rotation of the counterparts reduces size error arising from wear and tear, and improves accuracy of products and durability of equipment. Pull rods are replaced by the side boards, so the space for loading mold is expanded. The top board, side boards and two clevis pins at the rear establish a stable and closed structure. The moving mold board moves along the linear guide installed on the side board, thus the whole mold-locking system forms an independent module.
Such module design can build different systems upon requirements. In a highly homogenous injection machines market of China, the Mercury series is a shining star.
Four-color in-mold assembly technologies
The visitor is very glad to have a picture with a four-color RP100 turntable model and the injection molding production cell. |
Various production components in recent years have formed an important trend of injection technology, which was often seen only in European leading suppliers. The major concept is to integrate the processes that need subsequent treatment or secondary machining into the injection molding process. Now domestic suppliers in China are showcasing their ability in this field by cooperation with upper reach and lower reach of industrial chain.
The four-component innovative production combination exhibited at CHINAPLAS 2011 by Guangzhou Borch is an attractive production unit. The unit comprises a set of BM260-4C four-color injection machine equipped with four-color in-mold assembly mold, forming a four-color RP100 turntable model with disc and gear which can be rotated smoothly. The whole set of machine realizes one-time injection and molding of seven pieces and four-color plastic workpiece, which is the final finished product after leaving the mold.
The partners of the whole system consist of Brother Mold Plant, Hong Kong Redco Company, Taiwan Edenmold Hot Runner Company, Hong Kong Standard Company and etc.
Bottle preform injection machine
PET preform injection technology is another highlight of injection machine manufacturers. Performers of different quality meet the requirement of a diversified market demand. Good bottle preform molding machine reflects good integration of injection machine, mold, automatic equipment, molding and other aspects. Mold cavity quantity and production cycle are the core performance indicators of the machine.
The U-PET360-5000 preform injection machine of Guangzhou Yidao was highlighted at CHINAPLAS 2011, demonstrating the production of 22.28 gram large carbonic acid beverage preforms. With mold cavity quantity of 96 and molding cycle of 11.8 seconds, the machine is close to the world's best. According to the introduction, in order to ensure injection and mold-locking precision, there are 13 sensors in the hydraulic press system for measurement, and close-loop control is performed on pressure and speed. The palm system for taking out products and cooling was also developed solely by Yidao Company, which uses double-servo motor driven gantry structure with high and stable operation speed.
Application of information technology
The concept of "the internet of things" is becoming popular in manufacturing industry in recent years, but it remains a nonsense in injection machine industry. Besides applications and technology development, the information system management has seen more and more attention by injection machine suppliers.
Cosmos i-Tech Solutions Ltd., a subsidiary of Cosmos Machinery Ltd., has developed the ISee injection manufacture management system, which extends information technology to management of manufacturing injection machine. It successfully enhances business development of the company.
ISee utilizes the data gathering system on injection machine and wireless network communication interface to automatically upload the real-time operation data of injection machines in workshops to the servers, and generate various statements after calculation and treatment. The gathered data can be as specific as pressure and position of each operation in each process from each machine. The data can be summarized as total products, rate of finished products, activation of machine, power consumption of the whole factory in consideration of quality control and other management data.
Employer or product manager can turn to Ipad to see the desired production information at any place from any time. The development of ISee system is obviously a milestone of China's plastic machinery entering the era of "Internet of things".
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| Copyright © Adsale Publishing Limited. Any party needs to reprint any part of the content should get the written approval from Adsale Publishing Ltd and quote the source "China Plastic & Rubber Journal (CPRJ)", Adsale Plastics Website - www.AdsaleCPRJ.com. We reserve the right to take legal action against any party who reprints any part of this article without acknowledgement. For enquiry, please contact Editorial Department. |
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| Copyright © Adsale Publishing Limited. Any party needs to reprint any part of the content should get the written approval from Adsale Publishing Ltd and quote the source "China Plastic & Rubber Journal (CPRJ)", Adsale Plastics Website - www.AdsaleCPRJ.com. We reserve the right to take legal action against any party who reprints any part of this article without acknowledgement. For enquiry, please contact Editorial Department. |
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