High-loft bedding products such as quilts, pillows and down-filled items are thick and resilient, so metal contaminants can shift between fiber layers and be hard to detect. Buyers and quality inspectors should focus on tunnel height, conveyor throughput and magnetic field penetration, and choose the opening based on the compressed thickness of the product, avoiding both reduced sensitivity from an oversized tunnel and deformation from an undersized one.
For detection methods, electromagnetic needle detectors suit online screening for broken needles and ferrous contaminants, while metal detectors complement this for stainless steel, copper and aluminum. For down or synthetic fiber filling, place the inspection station after filling and before sealing so contaminants sit in a thinner layer, and set up a sensitivity check routine using standard test pieces to verify equipment status at intervals.
When selecting equipment, evaluate line speed, product size and workshop conditions together. The machine should offer interference-resistant design and stable conveying to reduce false alarms from drifting or stacked bulky materials. Companies serving export or demanding customers may add X-ray inspection as a complementary method for imaging metal, glass and stone contaminants. Before rollout, test with actual products over several rounds, record sensitivity and false-alarm rates, then fix the process parameters.