Newsletter #4 | A peek behind the scenes: How to make a beverage coaster

Station 4: Pulpers

This series of articles, titled “How to make a beverage coaster,” sees us answer the following question: How are beverage coasters actually made? After grinding come pulpers, where all the “ingredients” for making wood pulp board are mixed together before the resulting mixture goes through the board machine screen.

The recipe for our wood pulp board

KATZ has two pulpers at our Weisenbach site (so what is a pulper, you say? Well, you can think of a pulper as a giant blender). One of these pulpers (with a capacity of 12 m³) is used to produce the suspension for the wood pulp board’s top layer, while the other (with a capacity of 17 m³) is used to make the suspension for the wood pulp board itself. Chemical pulp, mechanical pulp, and offcuts are broken down in the pulpers by quickly spinning blades, resulting in the corresponding fibers being suspended in water and the materials being mixed into a fiber suspension. This production step takes an average of twelve minutes and is carried out 24 to 48 times a day depending on the capacity available.

Measuring instruments ensure consistent quality

In order to be able to ensure consistent suspension quality, removing impurities while uniformly breaking down the various individual materials is essential. This requires the corresponding pH value, temperature, and impurity rate to be monitored continuously.

Fluctuations in the composition of raw materials, such as those resulting from the use of various wastepaper grades or varying offcut quantities, can affect the quality of the resulting board, including the corresponding strength, thickness, and smoothness.

If you missed station 3 of the article series “How to make a beverage coaster”, click here