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Bad Fredeburg sawmill: roller doors in action

Height: XS, width: XL: The particular working conditions of the sawmill led to unusual door sizes with a height of 1.50 metres and a width of up to 11.43 metres.

The roller doors through which the sawn goods are taken outside at the Bad Fredeburg sawmill are only 1.50 metres high but up to 11.43 metres wide. This height is fully adequate to ensure a friction-free flow of goods where persons do not need to pass. Although the two entrance doors are not in such an unusual aspect ratio, at 45 square metres they are substantially larger. "These dimensions are indeed unusual, but do not pose a technical problem for the ThermoTeck doors", says Thomas Bräutigam. The door expert from Teckentrup was present during installation of the doors.
Wood has been gaining in popularity for many years, the demand for the natural construction material is continuously rising.  So it is no surprise that the wood-processing industry is also continuously increasing its capacity. An example of this is the tradition-steeped "Dickel Holz" company from Schmallenberg in the Hochsauerland region. Founded in 1948 as a carpentry business and active with a sawmill since 1959, recent years have beem particularly marked by growth: in 2010, sawn timber sorting was switched over to mass production, in 2013 a structural timber works was added and kiln drying capacity was increased. New construction of the biomass warehouse took place in 2014. Within the framework of this conversion and expansion work, a hall that had previously been used as a warehouse was turned into a production area. The new equipment, an integrally-controlled reducer band saw, now takes up more than half of this hall.

Goods can be easily transported into the hall via the conveyor. The door closes the entrance properly, with a robust rubber seal at the bottom end. The door reinforcement is protected from wind and weather by a cover.

With the new utilisation, the delivery and collection process is also changing. Here, the transfer stations for the sawn wood serve for goods exchange – persons or vehicles co not use these hall doorways. Hence the openings could be made very small. The doors (ThermoTeck roller door, Teckentrup) make do with a size of 1.50 metres. The sawn timber is conveyed automatically to the transfer station, forklift trucks pick up the goods from the outside. "The widest door is 11.45 metres wide – we were able to manage that using the usual manufacturing process", reports Thomas Bräutigam. The order dimensions extend from 11.50 metres in width and 12 metres in height. These can even be considerably extended upon request: 18 metres (wind load class 1) can be technically realised.

Another unusual solution is installation of the doors as "external rollers". This means that the hall space is completely available for use by the sawing and working processes. Because the transfer station is roofed – primarily to protect the wood – these doors did not also need additional covering.

45 square metre door
The largest door in the sawmill has a size of more than 45 square metres. Thermoteck doors can even be considerably larger: The thresholds for standard models are 11.50 metres wide and 18 metres high. But even this door is pretty impressive.

The two roller doors for entry and exit are substantially larger: 7.44 x 6.13 and 6.165 x 6.00 metres. "That is really impressive – although our standard door of up to 12 metres in height can be used", states Bräutigam. ThermoTeck roller doors are distinguished by their cost-effectiveness, robustness and simple construction. Due to the space-saving roller technology and the durable roller door reinforcement, they are especially suited to high, and above all wide, hall entrances such as in Schmallenberg. The doors fulfil EN 13241-1 and hence all European requirements with respect to mechanical loading, safety of use, tightness and wind loading. "Especially in industry, the micro-profiling of the door reinforcement is an advantage: the door absorbs smaller impacts or collisions, such as could happen when using a fork lift truck", says Bräutigam.

Optical sensors in the base seal ensure safety. They prevent the door from closing if an obstruction is in the way.

 

Special designs did not need to be found for drives, safety components, etc., solutions were used here from the wide range on offer. All doors are motor-driven, and closure-edge safety systems with optical sensors ensure safety. In keeping with robust factory application, the doors are double-skinned. With about 20 opening cycles each day the load on the drive is not unusually high – even when operating six days per week, the system thus remains well under the load for which the motors are designed. The entrances are currently being used even less regularly, they are managing with two to three openings per day. However, whether it will remain this way is debatable: if growth at Dickel continues in this way, perhaps the doors will have to be moved more often. "Since doors are designed for 30,000 opening cycles per year, the Schmallenberg company has no impediment to growth in this respect", says Bräutigam.