Production process at the new particle board plant "Helena"
04.07.2019 | Actualité | SWISS KRONO GROUP
Menznau. Raw panel technologist Christian Heinemann invited us to visit him in the inner sanctum – in the control room of the particle board plant, he offers insights into the production process.
All roads lead to the control room. It is from here that all production processes are controlled, checked and, if necessary, corrected by way of cameras and sensors. This is the workplace of raw panel technologist Christian Heinemann, who knows every step of the particle board production process inside and out. In order to manufacture market-ready particle boards out of the initial components of glue and chips, the first step is to carry out a predefined process. But what does that process look like?
First comes the chip preparation, which includes three work steps: the wood is processed into chips that are then dried and screened. After the preparation comes the resination of the particles. In separate particle mixers, fine and coarse particles are mixed with glue and various additives. The mixture consists mainly of a paraffin emulsion that ensures enhanced swelling characteristics as well as hardeners for the later solidification of the resin and water. For special products such as moisture-resistant or fire-resistant panels, colors are added for identification purposes.
The coarse particles for the middle layer are fed through a chute in which the dried particles, formed into a curtain, are sprayed with resin on both sides. The method of chute resination offers the advantage of optimal glue distribution on the particle surface while simultaneously conserving resources. Afterwards, the glued particles also go through a conventional glue blender. The fine particles for the cover layer are glued in a conventional process. In a glue blender, tools arranged in a central, rotating shaft spread the glue over the particles.
The glued particles are then fed into the forming station that features four forming heads. For the surface of the continuous board, two forming heads for the face layers apply fine particles by throwing, while two further forming heads scatter the coarse particles for the proportionally larger core layer by dropping. From the forming station, the particle mat proceeds down the forming belt to the press. Shortly after the particle mat goes through the pre-press, it enters the hot press. At press temperatures of 230-240 degrees Celsius, the particle mat is pressed to the desired thickness. In the hot press, two process steps are executed simultaneously: the particle mat is compressed by a factor of 2-3 times and the glue sets.
After the press procedure, the still endless board is cut to size. The particle boards can be cut to final formats of 2.80 m to 5.60 m in length. As the boards are still very hot due to the hot press, they are now cooled down to a temperature of 70-80 degrees Celsius in four cooling stars. In a final step, the boards are stacked in the stacking station and transported to the intermediate storage warehouse where they remain until they are sanded in the first finishing step.