Method for detecting colored foreign particles in light-colored powder and system therefor
US4976540A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1989 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | May 25, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8592
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An efficient and reliable method and a system are proposed for detecting colored foreign particles in a white or light-colored powdery product such as a polyvinyl chloride resin with an object of product inspection and quality control. The method comprises the steps of eliminating static electricity from the powder, e.g., by spraying ethyl alcohol, continuously feeding the powder at a controlled rate on to a belt conveyor to form a uniform powder layer having a flat and even surface thereon, bringing the powder layer below a reflection-type laser-beam scanning detector projecting a laser beam with scanning and receiving the reflected beam and monitoring the output signals coming out of the detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.