The hottest quality begins with material handling

Quality begins with how good the quality of the materials formed by material handling

is, and how good the quality of the final product can be. The world's highest level of injection molding plants is now used for medical purposes. This can be mainly attributed to the FDA standard, which regulates access to the world's largest internal market - the U.S. market, but also attributed to the enterprise standard formulated by global manufacturers such as B. Braun Melsungen

Figure 1: the conveyor produced in the purification room

meets these standards, which ensures these enterprises a unique position among their competitors and forms the key of these technologies. Within the supply chain, the necessary measures and their technical implementation put forward special requirements for auxiliary equipment manufacturers. They can only be provided by fully qualified suppliers to equip and integrate all components in a complex factory

when B. Braun Melsungen planned to modernize the auxiliary equipment of the production line last year, the factory specifications were correspondingly rich and strict

the production of the factory is carried out on three shifts every day, six days a week. When the machine operates in the purification room, it must pass through the appropriate air lock to enter the purification room. The materials to be processed are stored in indoor hoppers and interchangeable containers and must be dried in some cases. The material reserve for interchangeable containers is designed as a darkroom

German colortronic is authorized to develop and implement modern concepts. The fully automatic material handling system consists of pneumatic conveyors, more than 50 granular separators, two computer monitored material exchange desks, several sets of additive feeding systems, and a drying system with 8 drying hoppers. Although each component can be operated locally, the system is controlled and monitored from the central visual system

Figure 2: stainless steel and glass tube system

ensures almost non adhesive material delivery

medical technical requirements 2 The reduction mechanism composed of synchronous toothed belt and precision ball screw pair is rigorous

medical technology is one of the most demanding industrial production fields. Because of health requirements and standards, a wide range of special solutions are often essential. Here, manufacturers have an important competitive advantage. They can meet most of these requirements, and they just have to make modifications to them

the most important and indispensable condition for making defect free products is the production in the purification room. When producing articles for medical applications, it is particularly important to eliminate organic or inorganic particles. Because the main problem is airborne dust particles or pollen, things like solenoid valves must not be used in purification rooms

the vacuum conveyor on the injection molding machine is therefore equipped with a turbine guide disc valve (Figure 1). These valves operate without compressed gas, which will introduce pollutants into the purification room. When conveying, the vacuum conveyor is under low pressure through a vacuum line, so it can be regarded as safe. When idling or waste discharge, the situation is different. In this case, dust-free equipment with anti fouling surface must be used. In addition to pollutants from the environment, the risk of being contaminated by colloidal particles themselves must be eliminated. However, problems often occur only when changing batches or refueling. Therefore, from the perspective of machines, the seamless funnel loader composed of stainless steel polished by electrolysis has become a standard, and the cleaning of the loader will not leave residues (Fig. 2). Compared with aluminum, this stainless steel has good adhesion resistance

Figure 3: material drying is an important prerequisite for product quality

in terms of materials, in order to ensure the manufacturing quality, it is important to observe the drying parameters and material quality when using dry colloidal particles. In addition to optimizing the conveyor specification according to the expected transmission cycle and considering the residence time in the processing machine, the drying system must also be considered as an important factor when any one parameter exceeds the preset value (Fig. 3). The material shall be conveyed in the smallest possible proportion to prevent dehumidification caused by colloidal particles. This is possible by using the feed valve. These pneumatically operated valves can provide the machine with an accuracy of almost grams (Figure 4)

however, the drying quality must be ensured first. This can be achieved by monitoring the residence time through the aforementioned valve. When the machine starts, the valve only releases the material after a certain drying time, and the length of time depends on the torque. In other words, it changes the required torque specific material. During operation, the conveyor system controller monitors the drying time required for observation, and if it is not observed, an alarm will be heard

however, with modern high-performance thermoplastics, it is not only that the drying time is not enough, but also fatal. Excessive drying will also have harmful effects on material properties and final products. Therefore, excessive drying of colloidal particles must be avoided as much as possible. For this reason, the automatic cover controlled by fuzzy logic is installed in the air supply. They control the supply of drying gas according to the drying state of the material. When it has reached the preset value, the cover will reduce the gas supply to each drying hopper. In order to prevent the blower of the drying device from continuing to operate at full power when the demand is reduced, it is adjusted by the frequency converter. The energy saved for blowing and heating is a welcome bonus that quickly becomes significant in three shifts

however, the most important factor in the quality assurance of material supply is, of course, the use of correct materials. This obviously old-fashioned requirement also hides measures to prevent inadvertent mixing of materials. To this end, two kinds of factory components have been substantively assembled to prevent errors. First, the positioning system with the source as the target is stored in the transmission controller by engaging each controlled air extraction valve in the device. Therefore, no material will be transported to the machine through improperly connected pipelines. An error message warns the operator. On the other hand, in-depth investigation and Research on the traditional key raw material industry, the new interchangeable containers are recorded by the barcode scanner every time the batch is changed (Fig. 5). Because this scanner can be easily integrated into a control system containing a type database, material levels and batches are matched and recorded

Figure 4: the feeding valve with an accuracy of grams

factory monitoring and visual

control system constitutes the core of the factory. All functions focus on this point. B. Braun chose to use a control system consisting of three connected computers in a building, two of which are used as clients to serve two production areas in separate locations, and one as a server

all computer workstations have the same user interface (Figure 6), which can remotely control and monitor all factory components. This means that the dryer controller, three sets of conveying systems with all separators, all color masterbatch metering systems, pump conversion and material management can be operated centrally. In such a system, the basic elements of quality assurance are also particularly easy to configure for a complex factory. Some factors will be highlighted below

Figure 5: use a barcode scanner to record interchangeable containers every time you change batches

first, 100% reproducibility is important for high-quality products. If they are mixed with masterbatch on the machine, it is indispensable to have a formula storage for all equipment. However, the main focus is on plant reliability, which is subject to many factors. For example, not all production employees have the same authorization. At this point, phases and authorization levels with multiple passwords are considered. Of course, these passwords must meet the company's security regulations and be changed regularly by customers. In order for all settings to be tracked and recorded, they are stored in a record file. This document shows when and what settings are made up of what terminals. It must be able to operate different systems at the same time, and it must have full multi-user functionality. In the current situation, more than 100 operators are registered in this system

one of the most effective methods of quality assurance is, of course, to simplify the process and workflow. This also includes the simplest possible operation of such a complex factory. Graphical user interfaces have proven to be intuitive tools for this purpose. The clear presentation of the most important parameters makes it easy to manipulate factory components and reduces employee taboos. The fully written error information provides in-depth help and eliminates the need to search for ambiguous codes. Therefore, B. Braun also provided its employees with factory flow charts and operation instructions

Figure 6: user interface for factory monitoring

minimize maintenance

only when there is a certain concept of maintenance and repair can the maximum factory effectiveness be achieved. This maintenance should only minimally affect the ongoing production process. For plant visibility, this is accomplished by remote maintenance through the modem. The application of this external modem also ensures the maximum security against misuse, because entering the factory from the outside is of course a nightmare for every safety manager. In the factory situation described above, users have also invested in preventive maintenance and installed spare blowers for the three transmission systems. One of the three blowers can be replaced by an automatic pump conversion accessory. The latest generation of claw type drying vacuum pump has been installed here. Because of its function, it can be regarded as maintenance free, unlike the paddle type blower, which runs without oil. The recorded production data also contributes to the ease of factory maintenance. Using high-performance server hard disk can ensure the safety of data. As part of factory supervision and maintenance, various parameters can also be checked in detail. Temperature and dew point curves are evaluated in multiple charts to help operators identify trends and assess continuity. The display of maintenance intervals greatly simplifies the maintenance plan. The experience of operating the plant shows that comprehensive consideration of production is the key to achieving high reliability and production goals. In particular, medical technology needs to integrate the production area upstream of the injection molding machine into the concept of quality assurance. This auxiliary area plays an important role in the overall success of the factory

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