Sappi installs web inspection system on PM 2

The web inspection system is based on camera inspection in transmission and reflection of the web. The first of the three measuring beams on PM 2 is installed in front of the speed coater and checks the raw paper. It detects the web using seven transmission cameras. The second beam has been integrated after the last blade coater station and uses 12 illumination cameras to detect coating errors in the oblique light by measuring reflection. In this process the camera bar supports are mechanically adjusted and the camera and light angles are aligned with the web in multiple stages. The third measuring beam is located in front of the pope reel and uses seven transmission cameras to detect errors in the finished paper.

Of the three measuring beams that Sappi has installed on PM 2, the illumination measuring beam is particularly significant. It has an optimized camera angle to detect even the smallest coating errors such as blade marks, coater smudges, scratches or streaks on the functional side of the special paper with a hitherto unknown degree of precision.

The new investment, a six-figure EUR sum, means even the tiniest of production errors can be detected at machine speeds of up to 1,200m/min across the 4,700mm working width.

Each type of error is detected with excellent quality standards and accurately documented via the web inspection system. A high resolution camera delivers photos of the damaged areas and the specific error location is pinpointed. The live error map is updated on the inspection screen every five seconds. In subsequent production stages, the faulty paper location can then be cut out to ensure that customers only receive the highest quality.

Sappi said this investment sees it raise the quality standard and quality assurance levels in the production of special papers on PM 2, which is used to manufacture special paper types such as Algro Sol, Algro Finess, Algro Vitess, Parade Prima and many other kraft papers.

The latest investment represents a further step in the expansion of the specialty paper sector at Sappi and follows the multi-million EUR conversion of PM 2, and the commissioning of the new Paper Lab. Read more about Sappi’s work to develop and enhance its operations at Alfeld in Labels & Labeling, issue 2, 2015, which you can read online here.

Klaudia Vandieken, the project manager responsible for implementing the new web inspection system on PM 2 at Sappi Alfeld, said: ‘With the illumination measuring beam for the reflectance test we are offering a world first.

‘Thanks to the new technology we can intervene in ongoing production early on and significantly reduce even the smallest production errors and eliminate defects. This in turn raises our high quality levels even further. Our customers profit from improved processing features of our special papers.’