Neue Nachsortierung EN New re-sorting system

The Pfeifer sawmill in Uelzen processes raw timber from 2.5 to 4 m in length using its Kallfass restacking unit…

The Pfeifer sawmill in Uelzen has been in business for almost 30 years and, while timber production was originally around 200,000 cubic metres p.a., the anticipated volume this year is 500,000 m³. This enormous increase over the years means that bottlenecks are experienced at a variety of production stages. One of these was remedied around the turn of the year 2018/19.

The Pfeifer Group sawmill in Uelzen/DE is primarily involved in the production of packaging material and timber. “We’re a completely integrated location, utilising every product created at the site”, stresses site manager Marco De Gennaro in reference to the associated block production and CHP plant. Timber production has more than doubled since the mill was commissioned in 1991. The target volume for 2019 is 500,000 m³. The Pfeifer Group invests constantly to maintain its state-of-the-art technological capability and continuously enhance performance. A further step in this direction was taken in the autumn of 2018 when Kallfass (Baiersbronn/DE), specialists for mechanisation, installed a new sorting system for dry material. A re-sorting plant was already in operation Uelzen, but this had reached the limits of its performance. “We liked the Kallfass concept very much, and the company had proven to be a good partner”, explained De Gennaro. The new system is designed for a volume of 90,000 m³/p.a. “All our dry timber will run through this line in future”, says the site manager. He is particularly satisfied with the millimetre precision with which boards from 600 mm in length are cut, a point he emphasised in our discussion.

Sophisticated solution

The new dry sorting system enables Pfeifer to process raw material from 2.5 to 4 m in length. Karsten Gottschalk, project manager at Pfeifer in Uelzen, quantifies board cross sections at a thickness of 12 to 100 mm and a width of 70 to 250 mm. The generously dimensioned sawn timber discharge is suitable for either double packets with a width of 1.2 m or 2 m wide large packets. A tilt destacker separates the timbers in layers, whereby the stack battens fall automatically onto a conveyor belt. Kallfass installed an additional automatic batten collector for this purpose which, in effect, is a miniature sorting system. “As packets are often stacked in double layers, we separate the boards using a separation stage. In the case of single-layered packets, this can be passed over for a higher output”, explains Kallfass Managing Director Hans Haist during the tour. The boards pass by the operator in a transverse run-through, with the operator assessing them and ejecting substandard examples. This is followed by the tong loader that separates the board film. Kallfass guarantees a performance of 120 cycles per minute. A moisture meter measures the wood moisture. Material that is too moist is separated and dried again. The downstream Kallfass CNC crosscutting saw in Uelzen has four chop saws. This means that cutting with millimetre accuracy is possible as of a capping length of 600 mm. The stacking unit is equipped with magazines for automatic batten positioning. The finished packets are lowered using a hoisting unit where they are strapped and coated in film by an existing plant. The clean packets then stand on a roller conveyor ready for removal. Kallfass project manager Enrico Goldhahn summarises the advantages of the system: “No time is lost during destacking by the buffer, and just as little during packet assembly, thanks to continuous stacking with the auxiliary hoisting unit”. The new Kallfass re-sorting plant currently operates in two shifts. “But we can add another shift if necessary”, says De Gennaro.

Discharge: Kallfass installed a cross conveyor that provides space for several packets – then the process continues to the tilt destacker

During separating in layers, the stack battens fall automatically downwards to the automatic batten collector.

The boards run in the transverse transport past the worker who assesses them and, where necessary, ejects substandard examples.

Packet assembly and removal: Batten magazine with automatic stick placement.

Individual cycling with tong loader: This has a capacity of up to 140 pieces a minute.

The Kallfass CNC cross-cutting system enables cross-cutting of boards to the desired length.

Holzkurier 42/2019, pictures and text Martina Nöstler