Paper and Pulp Analysis

Pulp & Paper Analysis

Paper Applications

The large amount of different and highly specialized products in the paper and paper processing industry need tools to ensure a constant product quality.

From teabags, tissue paper, beyond photo-copying paper to heavy cardboards, there is a huge variety. One thing in common is the need for a quick analysis technique in order to determine the physical parameters like thickness, grammage, wet extension and moisture content.

Determination of Absolute Moisture in Paper

Each porous material contains water in the form of vapor in larger pores and in the form of liquid in the narrow capillaries of the structure. The typical reference analysis for moisture content is a Karl-Fisher titration, where the sample is heated up and the use of special reagents is required. The preparation of this titration plus the measurement time takes about 30 minutes and exceeds the measurement time of approximately 20 to 30 seconds by FT-NIR spectroscopy by far. 

Determination of Paper Grammage and Thickness

The thickness of paper or cardboard is decisive for the further conditioning, especially the choice of coating and furthermore printing method. It is a typical number to specify the paper type. Conventionally the thickness can be determined by a special testing procedure with a precision micrometer. Alternatively, the grammage and thickness values can be analyzed with an MPA FT-NIR spectrometer using the integrating sphere.

Determination of Ash in Paper

The ash content is a conventional expression for the residue on ignition from a solid sample according to certain testing procedures. As a result an empirical number will give an indication for the quantity of mineral salts and other inorganic substances in the sample. FT-NIR spectroscopy has proven to be a good method for the analysis of ash content in various types of paper.

On-line Monitoring of the Silicone Coating Process

The FT-NIR spectrometer MATRIX-F duplex, developed for contactless measurements, can be used for monitoring the grammage of silicone coatings directly at high-speed coating machines. The results are transferred to the control system to adjust the e.g. silicone addition.