How to control the error of the small-range quantitative packaging scale?

With the development of economy and technology, people put forward higher requirements for electronic packaging scale. Weighing and packing machines are also rapidly developing in the direction of intelligence, advanced automation, high performance and economy.

Based on modern electronic weighing technology and PLC programmable control technology, on the basis of absorbing domestic and foreign advanced experience and sufficient market research, a series of small-range weighing packing machines have been developed. It adopts two-stage feeding method of coarse and fine. The types are divided into single-head, double-head, four-head, etc. The weighing range ranges from 15g to 2000g, and the measurement accuracy can reach ±0. 20% to ± 1%. It is suitable for medium bag packaging of grains, seeds and other granular materials, puffed foods such as shrimp crackers, corn and other powders and granules such as feed and fertilizer.

How to control the error of the small-range quantitative packaging scale?

The small-range electronic packing scale is an automatic measurement and control system integrating electronic weighing and control. Its system error is composed of the following aspects.

Control error

The control system controls the weight of the material entering the weighing hopper by controlling the feeder. The error of the weight of the material relative to the weight set by the user is called the control error. In order to be efficient and accurate, weight packing machines generally use multiple groups of feeding. The coarse feed has a large flow rate, which is mainly used to shorten the feed time and ensure the weighing speed. The fine feeding takes 1/2 to 1/3 of the entire cycle, and only 5% to 10% of the rated weight is added to ensure the accuracy of the weighing.

The control error is mainly composed of the output error of L/C, the dynamic detection error of the instrument and the action error of the control mechanism. The above-mentioned three kinds of errors are also caused by the change of the response time of the control element and the change of the travel time of the actuator. That is to say, these three error factors affect the accuracy of the automatic weight packing machine by changing the actual feeding time, so that the actual feeding time of each speed of the packing weight machine produces random errors during each feeding process of the automatic weighing packing machine.

Improvements

The error of the system cannot be completely eliminated, but the following measures can be taken to reduce the adverse effect of the error.

(1) Due to the complex structure, CAD is used for precise design during the design process. At the same time, the machining accuracy and assembly accuracy of mechanical processing are strictly controlled during the production process to avoid errors caused by problems such as inflexible rotation and tight fit caused by poor manufacturability.

(2) In the measurement process, the vibration and stabilization time of the measurement bucket have a great influence. Adjust the stopper brush to make the feeding stable and even, avoiding the situation of fluctuations. At the same time, a layer of rubber plate is added to the contact part of the material door and the measuring hopper to avoid the rigid collision between the material door and the hopper, reduce vibration and shorten the stabilization time.

There are many measures to reduce the error, and in the application process, it should be determined according to the specific situation. If you are looking for the good quality small scale packaging machine and weigh filler packaging machine, please kindly contact us to get latest quotation.