High-Speed Inspection of Soft Personal Hygiene Products
Use line scanning and deep learning to detect defects in soft products on fast-moving production lines
Overhead line scan camera detecting defects on continuously flowing roll of disposable diaper material before individual sheets are cut.
Individual personal hygiene products, such as disposable diapers and feminine care items, need to be inspected for defects at extremely high speeds of up to 1,300 units a minute. These products consist of multiple layers of natural and synthetic fabric. The inner (absorbent) layer is usually white, and the outer layers are often printed with various patterns and brand differentiation. They can also be embossed with various surface textures. A single machine often handles the manufacturing process by combining the multiple layers together with inspection points along the way.
Soft personal hygiene products are multilayered manufactured items, which means they can suffer from a wide range of defects, including:
- Surface damage or contamination
- Damaged parts, including side tabs, frontal tape, elastic waistbands, and leg cuffs
- Misalignments between layers
- Excessive wrinkles and folds
Traditional 2D vison systems cannot perform the image processing required fast enough to keep up with the high-speed continuous feed of material. The inspection process is even more complex for product parts that have printed or embossed backgrounds and textures, as they can come down the line misaligned, making it difficult to distinguish a misprinted product from a correctly printed one that is misaligned. For a consumer product, particularly such an intimate one, standards for cosmetic defects are high.
Depending on the complexity of the disposable product in terms of color, pattern, and branding, there are two solutions for automated inspection during the manufacturing process.
White soft personal hygiene materials:
For either all white disposable products, or the white core layer, the Cognex line scan vision system is the best choice for continuous inspection applications. It acquires 67,000 lines per second at 2,000 pixels per line, to build up high- resolution detailed images. This is the only embedded industrial line scan system that processes images directly on the camera, so it does not require a PC for additional processing and is plug-and-play with industrial protocols.
Disposable soft personal hygiene products with colored print designs, brand patterns or embossed surface textures:
Cognex AI-powered technology is ideal for the high-speed inspection of disposable soft personal hygiene materials, such as the outer layer, that are patterned with colored designs or branding. The defect detection tool is trained using a set of images of a range of error-free products. The tool identifies products that deviate from the acceptable, trained model, capturing both functional and cosmetic defects. To minimize inspection changeover and machine downtime due to changes in print design or branding, the defect detection tool can be quickly retrained with a new image set, which increases overall equipment effectiveness (OEE).
- Detect a wide range of surface and structural defects regardless of background
- Reduce customer complaints
- Maintain brand quality