The Difference between a Combination Weigher and a Traditional Quantitative Automatic Packaging Weigher

With the rapid development of modern industry, the packaging industry has higher requirements in terms of packaging accuracy, packaging speed, and packaging range. Traditional quantitative automatic packaging scales have been difficult to meet these requirements. The computer combination weigher was developed under this requirement. The difference between it and the traditional quantitative automatic packaging weigher:

1. Different Weighing Principles

The quantitative automatic packaging scale is weighing while feeding, and continues to feed until the target weight data is reached. When there is a slight difference between the target weight and the target weight, a weighing object must be added, that is, after rough measurement, fine measurement is performed. If the weighing object is larger or heavier, there will be a larger error, which affects the accuracy of the weighing. The computer combination weigher is composed of multiple weighing units with independent feeding and discharging structures. Generally, the computer combination weigher is composed of 8 to 32 weighing units. The computer uses the principle of permutation and combination to automatically optimize and calculate the load of each weighing unit, and obtain the best and closest combination for packaging. For example, a computerized combination weigher with ten weighing units. When weighing, each weighing unit is weighed, and the weight data of each weighing bucket is read into the computer, and then the computer makes an optimal combination. According to combinatorial mathematics, ten weighing units can achieve 1023 combinations. The computer selects the combination that is closest to the target weight value from these 1023 combinations. In this way, the single weight of the weighed object is relatively large in the above-mentioned precise measurement and weighing, and it is difficult to solve the work of the quantitative value. The computer combination weigher takes the combination closest to the target weight as the final result.

2. The Reliability of the Test Data Is Different

Since the traditional quantitative automatic packaging scale is weighing while adding materials, the sensor is weighing under dynamic conditions. If the object to be weighed is impacted or bounced, it will cause the sensor to sense unstable weight data and cause errors. The vibration feed of the computerized combination weighers is for the buffer hopper. The weighing of the weighing hopper is carried out under stable conditions, so the obtained weight data has a higher accuracy.

3. Drop Error

This error is a very significant error for quantitative automatic packaging scales. When the weight value in the weighing hopper reaches the set value, although the electromagnetic vibrating feeder has stopped, the moment it stops, the existence of a section of the weighing object from the weighing hopper to the vibrator will eventually fall into the hopper to cause a so-called drop error. Although some quantitative automatic packaging scales reduce the drop error by shortening the feeding time, due to the influence of system uncertain factors such as flow rate and feeding uniformity, there are still different degrees of error. The computer combination weigher feeds from the buffer hopper to the weighing hopper. After the weighing hopper is completely stabilized, it sends an instruction for weighing, so there is no drop error.

4. The Difference in Weighing Speed

Traditional quantitative automatic packaging scales generally have to go through the weighing process of coarse measurement and fine measurement, especially the process of fine measurement needs to be added bit by bit, which takes a long time and affects the weighing speed. For example, the weighing speed of a quantitative automatic packaging scale below 1 kg is generally 20 to 30 bags/min. However, in the computer's rapid optimization and combination calculation, the computer combination weigher can generally reach 100 to 120 packs/minute with a scale of 14 weighing units, which is 4 to 6 times faster than the weighing speed of the quantitative automatic packaging scale. Moreover, it is easy to cooperate with various packaging machines. It greatly improves the packaging efficiency, and it is more suitable for the needs of modern production management.

5. The Difference in Weighing Range

With the same accuracy, the weighing range of the computerized combination weigher is larger than that of the quantitative automatic packaging weigher. Under normal circumstances, the weighing range of the quantitative automatic packaging scale under the same accuracy is controlled within 4 times, while the weighing range of the computer combination weigher in the small weighing section can reach more than ten times. It can also be seen from a large number of test results that there is a difference in the weighing range between the two. For example, in the weighing range of more than ten grams to 1 kg, the computerized combination weigher can reach the accuracy level of X (1), especially in the small weighing section. If you want to keep the accuracy level unchanged, the quantitative automatic packaging scale can only reduce the weighing range and form a multi-segment weighing. Only by producing multiple series of products can a certain aspect of the manufacturer's requirements be met. General manufacturers will hardly accept this phenomenon. This brings limitations to its practical application, and it cannot meet the requirements of different packaging specifications (10-1000g) in some production fields but with similar accuracy.