On-line spc analysis system and method for measuring process capability of weighing filling equipment

Abstract

The invention provides an online SPC (Statistical Process Control) analysis system for metering process capability of gravimetric filling equipment. The system comprises a data acquisition card for real-time online acquisition of data, including the tare weight of products and the net weight of the products, of the gravimetric filling equipment, a database for storing the data, and a data analysis unit for reading the data to be analyzed from the database and analyzing the tare weight of products, the net weight of the products, the average tare weight of the products, the average net weight of the products or the capability index of a metering system. The online SPC analysis system for the metering process capability of the gravimetric filling equipment is capable of outputting the results of analysis in real time so that the operating personnel can take intervention measures according to the results, and therefore, stable control of the production process and reduction of risks in the metering process are realized. The invention also provides an online SPC (Statistical Process Control) analysis method for the metering process capability of the gravimetric filling equipment.

Description

technical field [0001] The invention relates to the technical field of automatic collection and analysis, and more particularly relates to an online SPC (statistical process control) analysis system for measuring process capability of weighing filling equipment. Background technique [0002] Weighing filling equipment is widely used in petrochemical, food and beverage, medicine and other technical fields, and is closely related to our life. As a commodity, its net weight is closely related to the interests of our consumers. [0003] figure 1 It is a structural schematic diagram of a metering system for a weighing filling machine in the prior art. The metering system includes: a load cell 1, a filling head assembly 2, a photoelectric cell 3, a weighing instrument 4, a packaging container 5, and a process control PLC6 (PLC). A corresponding packaging container 5 is placed on the upper platform of the bracket assembly of the load cell 1, and the filling head assembly 2 quanti...

AI Technical Summary

Problems solved by technology

In the metering system of the above-mentioned prior art, when determining the weight of the quantitatively packaged product, because the process control PLC6 can only detect the signal that the weight of the product currently being filled reaches the set value, the actual product weight value cannot be recorded, and cannot Realize closed-loop control

[0008] Therefore, the analysis of the measurement process capability of the filling equipment can only obtain the weight of some products by sampling offline according to certain rules, and then calculate and analyze the sampling data to determine that the net weight of the quantitative packaging product meets the target time-consuming and labor-intensive, and the information obtained is relatively limited

For abnormal products, it cannot be discovered in time, let alone take measures in time. If measurement risks are found, the products may have already flowed into the market. Large sampling frequency will undoubtedly greatly increase labor costs, and there is a large lag in the analysis process

[0009] In addition, the sampling method adopted in the prior art calculates the average tare weight by sampling the tare weight of a certain number of packages before filling, extracts and weighs the gross weight of the product, calculates and obtains the actual net weight of the product, and then controls the net weight of the quantitatively packaged product. Due to the limitations of the sampling inspection method, it is impossible to guarantee that the actual net weight of each product can meet the requirements, and there is a greater risk, especially when the production speed is high, the control is more difficult. Will lead to data distortion, so there is a greater risk of measurement

[0010] Moreover, for multi-head packaging equipment, it is difficult to distinguish the metering situation of each filling head, so as to analyze and adjust separately, which increases the difficulty of controlling the overall state of the system and also makes it difficult to improve the metering accuracy.

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