How detergent powder packaging machine detects and rejects bags with incorrect weight or contaminants?

Detergent powder packaging machines often use the following methods to detect and reject incorrectly filled or contaminated bags:

1. Weight check: The machine measures the weight of each filled bag using load cells or scale systems. If the weight is outside the acceptable tolerance range, the bag is rejected. This ensures all bags have the proper amount of detergent powder.

2. Metal detection: Metal detectors can detect the presence of metal contaminants like nuts, bolts, or machine parts in the powder. If metal is detected, the machine rejects the bag. This prevents foreign contaminants from entering the product.

3. Vision inspection: Some machines use vision systems to inspect the powder flow into the bag or to check the bag sealing after filling. If the powder flow is disrupted or the seal is not intact, the bag is rejected. This helps ensure powder is properly filled into securely sealed bags.

4. Vacuum seal check: For machines that vacuum seal bags, a vacuum sensor detects if the proper amount of air is removed from the bag before sealing. If too little or too much air is detected, the bag is rejected to prevent vacuum seal quality issues. 

5. Leak detection: A few machines pass filled bags through a leak detection system, which applies pressure to check for any leaks or imperfections in the seals or bag. Leaky or punctured bags are rejected. This verifies bag integrity before the product reaches customers.

6. In addition to the above automated checks, some machines also have manual inspection points where operators can visually inspect bags and manually reject those with issues. Automated systems are preferred as they are more efficient, consistent, and help minimize human error.

So in summary, detergent powder packaging machines use a combination of weight measurement, contaminant detection, vision inspection, vacuum and leak checks as well as manual inspection to effectively detect and reject incorrectly filled or contaminated bags.