Pixargus is now offering its PC7 also for laboratory use as PCR7 R (Roughness). By objectively inspecting the compounding quality ahead of the extrusion process, the new system ensures that only high-quality compounds will be processed.
The new PC7 R system automatically and objectively measures in real time the size of particles in the surface of extruded test strips processed by lab-scale extruders in the compound mixing shop.
The system enhances process reliability as it allows to determine – ahead of production – whether a compound will be suitable for production and whether the final product will comply with the specified quality requirements. Especially in the rubber industry, this analysis is indispensible as the input material is a natural product and its properties may vary within a broad range. During vulcanization, even just a very few minor impurities in the compound may already lead to large increases in volume and hence to a significant deterioration of quality.
At the same time, PC7 R cuts the time-consuming effort involved in the visual checks of the test strips by means of microscopes. This accelerates the overall compound testing and approval procedures prior to production. And it substitutes subjective evaluations by objectively measured data.
The fact that the results from the measurements in the compounding lab can be linked with the inspections made as part of final quality control provides a very high potential for quality improvement. Thus, Pixargus is taking quality assurance to a new level. By relating the analysis data from the compounding process to the data acquired by the Pixargus inspection systems installed at the end of the process chain, it is possible to objectively determine which compounds will lead to products of optimum quality and which ones will result in rejects.
Also for the incoming control of materials, the system offers great benefits. Should a delivered compound not comply with the specified quality requirements, the laboratory may provide testing logs containing objectively determined, substantial data.
By adding the new system to its range of quality control systems for the complete extrusion process from compounding down to quality control of the final product, Pixargus has further strengthened its position as a provider of systems for comprehensive quality control.
Christian Struck, Process Developer Continuous Vulcanization at Toyoda Gosei Meteor GmbH, where the new system is employed, confirms its great value: “With the new system in place, we have been able to analyze the compound quality much faster, much more efficiently and above all based on objective data, before the production process actually starts. This has reduced the costs of the analysis process by approximately 30 percent – while achieving an improvement in quality. The system has paid back within a period of six months.”
Background: The technology in detail
Thanks to the PC7 R system, it is now possible to assess the quality of a compound swiftly and based on objective data, allowing a quick decision as to the suitability of a compound for production.
A novelty of the system is that by measuring the particle size in the test strips the compound quality can be reliably assessed well in advance of the production process. It is no longer necessary to wait until the final product is available. This also provides the advantage that the process can be optimized at a very early stage. In the past, the compounds had to be visually checked by means of microscopes, which was a personnel-intensive activity.
The usually about 1-meter-long test strips produced by a lab-scale extruder are placed on the conveyor belt of the PC7 R system. The conveyor transports the strips through the measuring head fitted with a special illumination unit and a high-resolution camera, which scans the surface as the strip passes through the measuring unit. PC7 R captures particles from 20 µm upwards and evaluates their size distribution. Should the distribution not be as specified, PC7 R will trigger an alarm and send out digital and analog I/O signals for a machine stop.The system can be used both for testing new compounding recipes and for monitoring the quality of compounds over longer periods of time.
Pixargus has derived PC7 R from its proven ProfilControl series of surface inspection devices for rubber profiles. These devices are equipped with a special LED segment which makes the individual particles of the surface clearly visible. A high-resolution line scan camera captures images of the complete surface. The images produced by the camera are evaluated at a rate of approximately 100,000 particles per minute by a software specifically developed for this application.