Quality control analysis of film production line I

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The third option is to put the detection system in the cutting position, such as in the slitting coiler. The main advantage of this is 100% final quality control, which avoids complaints and enhances customer loyalty. However, in this case, only limited process control is possible, such as the analysis of all drums from raw material batches by combining gel frequency and standards. In this way, a connection can also be established between raw material batches and different extruders

therefore, the question about the best position of the detection system can not be answered in general. Instead, the film maker will have to weigh his main objectives in each case. For example, if he wants to ensure the best extrusion, the system should be placed in the extrusion position. On the other hand, if he wants to ensure 100% final quality control for customers, it may be best to put it in the cutting part

cost factor

the cost of installing the detection system consists of direct and indirect costs. The direct cost is the price of the system, including transportation, installation, startup and training. Indirect costs are first and foremost the labor and time required to care for the system

training concept for system managers is a one-day or two-day training course, which is about 14 days before startup, as well as a training meeting during startup and a one-day follow-up training 4 to 10 weeks after startup. System managers are responsible for the task of managing the system, such as determining methods for various products with certain customer specifications. On the other hand, operating system employees only need to know how to deal with various alarms

the time and labor cost of the care system will depend on the degree of integration. For example, if the development department takes measures to evaluate new methods and materials, the cost will naturally be higher than if only testing is used to monitor the extrusion process

practical examples

measure with a dial gauge based on two force columns. Finally, let's take a look at some practical examples from different fields to illustrate the different possibilities of joining the detection system

the cost is getting lower and lower. The first example is related to the extrusion of film blowing. Here, the detection system is installed in front of the winding device, which can monitor the overall width of the tubular clamping film. Transparent and white opaque films are detected by emitting light. The most commonly used resolution of the system is mm. The inspection system controls the extrusion device (for example, it identifies when cleaning is necessary or when the mold needs to be cleaned). At the same time, it detects the critical gel size beyond the specification of the coating film

on the other hand, because of the rotation of the bubble, it is often sufficient to statistically evaluate only part of the film roll in film blowing extrusion. For cost reasons, this structure is certainly worth considering

this statistical control is useless in casting film extrusion without rotation, but the material properties remain unchanged or even higher. Full detection provides the advantage that defects in the drum can be accurately located. In the cut clamp pipe led out by the film blowing device, it is no longer possible to make 100% detection because of the rotation of the material bubble

the flat film used to detect thermoforming is often combined with the reflected light and emitted light used for transparent and opaque films. Here, in addition to monitoring the extrusion process, it also detects important defects (gel and black spots with a diameter of more than 500mm), shortening the cycle time in the hot forming process

various concepts can be imagined for the extrusion of stretched film. From an economic point of view, a good solution is to use the server system and two camera beams to fully detect the extrusion process and partially detect the stretching process. Of course, the tensile drum can be fully tested where necessary, although it may be expensive for a drum with a width of 10 meters. If the time delay between extrusion/drawing process and cutting on the slitting coiler is relatively short, a practical method will complete quality control on the slitting coiler to ensure 100% final quality control

Fig. 2: open inspection rack for inspecting PC board in this example involving an extrusion line for manufacturing optical PC board, the inspection system is placed directly behind the calender (Fig. 2). Here, as long as there are problems such as bubbles, gel or black spots, it will remind the operator so that he can immediately interrupt the extrusion process. In a separate room about 30 meters away, there is a saw, which cuts the plate covered with protective film into 3M long. There, a warning light is connected after a certain time delay, and an alarm will be sent to the stacker if the plate is out of specification. Moreover, the quality report of the plate is automatically printed on the label. The detection system is connected to the production manager's office and the development department through the enterprise's computer system, so the data can be effectively managed and analyzed

the last example comes from extrusion coating and viscosity control. The detection system used for the coating device must monitor the coating process. The combination of prefabricated product control and process with 100% final quality control is usually the best solution. Because transparent and non transparent reels are made on the coating production line, the combination of reflected light and emitted light is an advantage


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