The color chromaticity change of a plastic product can reflect changes in the parameters of the production process or reflect changes in the raw material or intermediate feeding process. The in-line color measuring instrument that can work continuously can be directly applied to the color measurement of the finished product of the extruder, so that the whole process of production can be systematically controlled. Using this method, measures can be taken in real time during the production process, which provides a good technical means to avoid quality deviation accidents in production. It is well known that color measurement analysis can be used as a means of defining product quality characteristics. This type of analysis is often used in the quality inspection of the ultimate product. The usual product color measurement analysis is done by manual direct sampling from the product line or by automatic sampling. There is a big difference between the different methods of color measurement analysis: in the common off-line color measurement analysis method, the color measurement analysis result cannot be obtained immediately, so this is also an offline method. Used in real-time processes to achieve real-time process control reasons. The on-line color measurement analysis method can obtain the analysis results only a few seconds after the detection of the final product is completed, but since this ordinary color measurement sensor cannot be used in the harsh working environment of the production process, An insurmountable disadvantage of this method, that is, it can only be used at a very late stage in the process of production, which results in a very long time lag with the early stage of the process, so it is only suitable for a limited range. Real-time process control. In contrast to the above two methods of color measurement analysis, an in-line color measurement analysis method can provide analysis results in a very short time, and since this measurement method can be used to measure the sensor Directly in contact with the high temperature and high pressure molten fluid, the measurement signal is taken directly from the extruder exit product itself, so this analytical method is especially suitable for those production processes that require rapid adjustment and correction of the production process. Measuring probe is equipped with a sapphire lens Comparison between different color measurement methods Off-line color measurement analysis methods are the most common in production and have a wide range of applications. This method of analysis generally involves the following steps: Collect samples from the product line Transport samples to the analytical laboratory Adjust and convert the sample material into forms and specifications that can be analyzed (eg color patches, color grids, etc.) Cooling the temperature of the sample material to room temperature Samples are measured with a dedicated color measuring instrument Send the analysis results to the product quality management section Through manual analysis, certain adjustments and corrections are made to the process. Repeat this process again Obviously, it takes a long time from the start of sampling from the production line to the final record analysis and the transfer to the product quality control part through the above series of steps. Another big problem is that only one sample point can be analyzed during this period of time. Since it is impossible to control the current process based on past data results, how to control the actual production process through color detection Still unclear. Another topic is: for sudden color shift situations (which are also common in actual conditions), off-line color measurement analysis is impossible to measure, so it is impossible Such production status is determined in real time and corresponding measures are taken. The online measurement analysis system makes color quality control of semi-finished or intermediate processes possible. For example, at the intermediate stage of the production process, quality can be controlled by color quality analysis of the semi-finished product. These measurement analyses are generally used to record the actual state parameters of the finished product, and all factors that cause color deviation during the production process are simply recorded and documented. However, due to the long overall response time of the on-line online measurement system, if the automatic control loop is formed, there will be a large system lag, which seriously affects the stability of the production system. Therefore, this analysis method is not suitable for negative feedback control. The classic process control system. In an in-line color measurement system, the measuring sensor can be directly in contact with the molten medium at the exit of the extruder, which not only achieves continuous measurement, but also provides the producer with the sensor directly involved in the measured medium. When measuring the color shift of the medium, the opportunity of the process is directly observed. The in-line color measurement analysis mode eliminates the first six steps in the offline analysis process and does not produce time lags that cannot be overcome when compared to online color measurements. The application of in-line color measurement analysis technology in the extruder production process can provide real-time and correct color change information in a very short time, so it can be supplied to the production control part in the correct process in the early stage of the product chain. Quality information to facilitate decision making and real-time control of the production process. Embedded color measurement analysis technology In order to detect and record the change of the color value of the extruder outlet product, it is necessary to install the color measuring sensor on a mounting hole at the exit of the extruder through a screw connection. The color measuring sensor is installed at the extruder outlet by screw connection. On one of the mounting holes. The part of the "special extruder color measurement sensor" that is in contact with the medium being measured is designed with a protective sleeve that is strong enough to protect the sensitive components inside it. A lens made of sapphire material is placed on the top of the sensor. Due to its high hardness, sapphire is the world's second-hardest diamond material, so sapphire is particularly suitable for use in extruder applications. We know that the temperature and pressure at the exit of the extruder are very high, and the friction generated by the action of the extruded material on the sensor is also very large here, and the lens using other materials cannot work normally. The main points of the in-line color measuring sensor set in the extruder unit are as follows: When installing the color measuring sensor, first, care must be taken to prevent the sensor from touching those mechanical moving parts, such as rotating parts. Second, it is necessary to ensure that the measured medium must be in full contact and cover the sapphire lens during the active process, and cannot be separated from the lens. Since there is always contact with the active medium to be tested, we do not have to worry about the lens contamination problem. This is because the sapphire lens has a self-cleaning function to ensure that it is not contaminated or the medium to be tested. When the measured medium flows through the lens, the strong flash from the xenon flash illuminates the measured medium in front of the sapphire lens. In order to be able to do this, the flash is transmitted to the sapphire lens through six sets of composite glass conducting fiber bundles. The reflected beam of the measured medium is fed back to a dedicated image analysis processor through a fiber at the center of the composite glass conducting fiber bundle. The system repeats the measurement analysis every 10 seconds. So in this way we can get continuous color measurement signals. Calibration and system structure The special design of this special extruder color measuring sensor means that the measuring instrument can be easily calibrated without interrupting the work. To do this, it must be ensured that the optical grade of the optical fiber is not rotatable, twisted in the sensor case, and calibrated on a standard black and white reference. The use of green color control standards is a standard method of inspection. It can also be calibrated using ambient environmental conditions. The system can save its static zero for three months and recalibrate after three months. The core color measurement component in the system is CCD (CCD is the abbreviation of ChargeCoupledDevice, which is a semiconductor imaging device), and the system also uses a dedicated photometer (image analysis processor) technology. The dedicated image processor measures wavelengths between 360 and 780 nm, which covers the spectrum of visible light. By using CCD technology combined with a monochromatic lens, it is possible to achieve a better analytical measurement than a standard color measuring device. The in-line color measurement system includes a dedicated image processor, Xenon flash, signal processing unit, a mainstream configuration computer using Windows XP operating system, and a touch screen for operation installed in the on-site protection box. For NEMa4. The touch screen protection box is made of stainless steel. This protection box is dust-proof and waterproof, and can be used in harsh industrial environment. Even in a very high temperature environment in an industrial production site, since the built-in air conditioner is designed in the entire system, it can work stably for a long time. Functional combination People can analyze the color measurement results in the form of historical trend records. The measured color measurement data of the measured medium can be displayed simultaneously on a computer control interface. The data is compared with the upper and lower limit set values ​​at any time, and the operator is prompted to pay attention to the red and green indicator lights. The measured value of the measured medium is displayed independently on the other side of the trend screen. The measured value within the range of the process limit value is displayed in the green color font. When the control limit value is within the tolerance range, the measured value is displayed in yellow color, and if the limit value is exceeded, the data will immediately change from yellow to red. And flash alarm. At the same time, these color switching signals are not only displayed on the screen, but also the current signal status is indicated and alarmed in the field with red and green signals of the same color. The touch screen installed at the production site can display the computer's control screen, and the operator can select from the four trend dialogue pages (ie dL*, da*, db*, dE*). The system also provides all standard spectral reference frames, including conventional white and yellow combined spectral formats. Real-time process control The extruder production process is a highly complex maneuvering process that contains many influencing factors, each of which may have an impact on the quality of the ultimate product. Moreover, the extruder itself has a large and decisive influence on the ultimate product due to its unique structural factors relative to process influencing factors such as temperature, pressure and passage speed. In addition, the extrusion process will also affect the ultimate quality of the product due to differences in the materials being processed (such as raw materials produced by different processing processes or raw materials of different mixing ratios). These influencing factors, whether individually or in combination, directly result in a change in the color of the extruded product. It is thus, by using the in-line color measurement analysis method to measure the color change of the product in real time, the machine system characteristics or the control and optimization of the process parameters can be defined in time. Through practical application, people can more and more clearly get the correlation between the color measurement value and the product quality defect. This correlation is exact and is particularly evident in some processes, for example, there is a very large correlation between the change in the percentage of titanium dioxide (TiO2) in the extruded product and its color brightness analysis value. The change in the titanium dioxide content causes a significant change in the color brightness of the product. The cause of fluctuations in the color and chromaticity of the product can be attributed to the pulsating impact due to the transfer pump or the sedimentation of a liquid pigment medium. It can be further pointed out that the color measurement can also find, analyze and diagnose the comprehensive problems of the extruder, such as those caused by homogenization and certain measurement methods, as well as other fluctuations affecting the stability of the production process. And so on the comprehensive problems in the production system. in conclusion Of course, product color chromaticity analysis is not a necessary part of the end product quality inspection, but the use of real-time color measurement technology is a very good way to achieve a stable production process. Customized Handle,Minimalist Walnut Door Handle,Aluminum Alloy Door Handle,Stainless Steel Door Handle Guangzhou Junpai Hardware Co., Ltd , https://www.gdjhfurniture.com