Pulp dirt count measurement using on-line automated inspection technology

摘要

Pulp quality demands have been steadily increasing over the last ten years with the increasing demands of pulp end users, particularly when producing various consumer products such as tissue, diapers, etc. Traditionally pulp dirt count quality control has been accomplished by manual off-line visual laboratory methods with a pulp sample analyzed every 30 minutes against the Tappi, or ISO, dirt size standard. Now with a new product called the PULP-Inspector™, pulp dirt can be accurately and continuously measured on-line using high speed, and high resolution, digital camera technology. The inspection is designed to exceed the smallest 0.04mm2 dirt count size, classify dirt into user selectable size categories, and provide a running average parts-per-million (PPM) trend value. If the pulp dirt count maximum value is exceeded the operators are immediately alarmed to allow for corrective action to be taken allowing the pulp to be automatically rejected. In addition to dirt inspection, the system can also detect shives and various other contaminants such as metal, oil, insects, etc. Today's latest digital cameras, combined with LED lights, are very reliable, easy-to-use and require no periodic maintenance. Manual off-line dirt counting is eliminated freeing lab personnel to focus on other tasks. Furthermore, the system can be set-up to automatically reject bales when the dirt count is exceeded, and critical defects detected. There are now many on-line pulp dirt count systems in operation demonstrating the benefits it offers in ensuring the desired pulp quality is 100% achieved. On-line dirt count inspection is often combined with runnability control web monitoring cameras placed in the pulp dryer wet-end to eliminate breaks. These camera solutions have proven to offer a rapid return-on-investment.