Kallfass Sonderlösungen für Deckenelement-Werk

Leimholzwerk spielt alle Stücke EN Glued timber plant has it all

Multi-storey production for multi-storey timber construction

Step-by-step, Best Wood Schneider has filled its new ceiling element plant with more and more processing steps over the last few years. On three floors it now has a BSH line (glued-laminated timber) and a BSP line (cross-laminated timber) line, from which trimmed and glazed rib elements can be produced downstream. The bulk of the highly complex production was planned and realised in close cooperation with Kallfass.

With the “best wood CLT Box Ceiling”, Best Wood Schneider from Eberhardzell in Germany, has successfully combined the positive properties of BSP and BSH. The combination of glued-laminated timber and ribbed beams results in a structurally effective and at the same time space-creating timber element which is comparatively low in weight. Finish-trimmed and glazed, the result is a high degree of prefabrication with quick installation times on site.
Explained in a few short sentences here, these wooden box elements are the result of many years of development work, which also posed major challenges in terms of machine and plant engineering too. “We produce exclusively to order and offer our customers a wide range of products and finishing steps,” explains Schneider Project Manager Andreas Schilling and adds: “In addition, there is the complex arrangement of the production lines over a number of levels.” Schneider realised the plant over three storeys with numerous interim levels – the timbers are transported back and forth for the individual processing steps between the levels at 0 m, 6.5 m and 12.5 m by two lifts, before the automatic transfer of the finished elements to a high-bay warehouse. “This arrangement saves building land and above all means shorter distances within production,” says Managing Director Ferdinand Schneider, explaining the advantages of this arrangement.

Vollautomatisches Regalbediengerät

A fully automated storage and retrieval system links the individual processing steps with each other.

New production process

As one of the main suppliers, the tradition-steeped Swabian company Kallfass was commissioned for much of the planning work and also supplied large system components for all three levels of the production system. The Kallfass installation begins on the top floor where the single-layer boards are taken in. Elements which are later used for the transverse layers of the BSP, which is up to 1.25 m in width, are cut to length by a chop saw. The transverse layers are then lowered by a lift table and rotated through 90°. The downstream lay-up station uses longitudinal and transverse layers as well as a glue application station to produce the 16 m long layer package, which is transferred to the CLT press of another manufacturer.

“For the production of the ribbed ceilings we developed and realised a process with Schneider which had not previously existed in this form before.”

Hans Haist, Managing Director at Kallfass

After the press the boards seem to be spoilt for choice – but they always end up exactly where they are supposed to be, in dependency on each order. “A roller conveyor on rails installed by us picks up the boards and, in accordance with the instructions from the master computer, brings them to the glazing line, planer, trimming centre or to the storage and retrieval system realised by us,” says Kallfass Managing Director Hans Haist, explaining the options. The latter is fully automated, places the components in interim storage and links the individual processing steps with each other. For example, the storage and retrieval system also charges the rib element production system, whereby Haist does not wish to provide further details about this part of the installation, with the following reasoning: “For the production of the ribbed ceilings we developed and realised a process with Schneider which had not previously existed in this form before.” The rib elements can be finish-trimmed and/or sanded and glazed after production – just like the BSP elements.

Ready-made laminated beam ceilings

On the middle floor, 6.5 m above ground level, Schneider produces the laminated beam elements. This is dealt with by Kallfass and it transfers them on – depending on the order – for further processing or stretch foil wrapping, after which the elements are moved on to the high-bay warehouse immediately downstream.
In the same way as for the box elements, Schneider also offers its customers glazing for the laminated beam ceilings. If this is required, an inclined lift, also from Kallfass, brings the parts to the ground floor. Here, Schneider employees rectify any surface damage before the elements run through a two-stage sanding and glazing process. On this level Kallfass is responsible for the complete mechanised solution between the machines.

The glazed elements are transferred back to the middle floor again by the same inclined lift, where they are also packetised, packaged and placed in storage. From the high-bay warehouse the packages are transferred via a conveyor system to a central truck loading station, which was realised by Kallfass some years ago.

Erfolgreiches Projekt von Kallfass und best wood Schneider

Following the successful project at the headquarters, talks get straight under way about the next major project together in Meßkirch.

Maximum flexibility

In the event of a fault – for example, the failure of one of the two glazing lines – Schneider can reschedule the elements along the running line at any time. “This maximum flexibility in terms of production, namely that every element can run through all possible production stages and can be fed in and out at any point was demanded by Schneider and was one of the biggest challenges of this project,” stressed Haist. That this worked out successfully and all other promises made by Kallfass were fulfilled to the satisfaction of Schneider is perhaps best confirmed by the follow-up order: In Meßkirch, Best Wood Schneider is currently realising a production line which is envisaged to set new standards, especially in terms of logistics – from log deliveries to the finished BSP, the aim is to completely dispense with stackers. The systems from Kallfass will once again play a central role here too.

Kallfass Wender zur Positionsausrichtung

A turning device moves the element into the correct position. Since many of the timbers are produced in exposed quality, this is particularly gentle on the material.

Zwei Kallfass-Aufzüge verbinden drei Produktionsebenen

Two lifts from Kallfass connect the three levels for the timbers.

BSP-Platten lasiert und abgebunden

Depending on the order, the BSP boards are glazed, trimmed and/or processed further into rib elements.

Kallfass Sonderlösungen für Deckenelement-Werk

Kallfass is one of the main suppliers at the Schneider ceiling element plant and supplied numerous special solutions.

Erfolgreiches Projekt von Kallfass und best wood Schneider

Following the successful project at the headquarters, talks get straight under way about the next major project together in Meßkirch: Max (left) and Ferdinand (third from left) Schneider and Andreas Schilling (right) from Best Wood Schneider together with the Kallfass managing directors.

Images and text: Günther Jauk, Holzkurier
Holzkurier BSP-Special 2021

VerleimenVerpressen_Erzeugen_Querlagen

Alles aus einer Hand EN Everything from a single source

Kallfass, located in Baiersbronn/Germany, is well known as a mechanisation specialist. The same applies to the fact that the mechanical engineering company equips cross laminated timber systems. With this in mind, we can refer to some well-known projects. Recently Kallfass has added a CLT press (Cross Laminated Timber) and a CLT turning device.

The mechanical engineering company Kallfass from the Black Forest has already been involved as a supplier in several cross laminated timber projects in Austria and Germany. The most recent work completed was that of Stora Enso in Gruvön/Sweden. Construction work on this site began in 2018 and the system has been running in automatic mode since the beginning of 2019.

To date, this is the largest project for Kallfass in the area of cross laminated timber applications. The company not only supplied the entire mechanical equipment—from the feeding of packages to the acceptance of the finished pressed elements—but was also responsible for the overall layout and the complete safety control system. The fact that Stora Enso has selected Kallfass as its supplier is probably also due to the fact that Kallfass has already been involved in the Austrian CLT plants in Ybbs and Bad St. Leonhard, Austria. The total capacity in Sweden totals 100,000 m3/year.

Large packages also possible

Stora Enso also operates a sawmill in Gruvön, Sweden which supplies the raw materials for the laminated timber elements. The sawn timber (dried and battened or pre-planed) is transported by truck to the Kallfass feeding station. This feeding station is also designed for large packages up to 5.8 m long, 2 m wide, and 3 m high. A vacuum-operated de-stacking device separates the packets layer-by-layer. If stacking strips are available, a brush automatically scrapes them off and collects them. The Kallfass mechanism separates the layers and feeds the boards piece by piece to Finscan's quality scanner. In this area, the strength and the moisture of the timber is also measured. Any unsuitable workpieces are ejected from the process.

Two paths for the boards

“The scanner provides us with the information whether there are cracks on the front sides or knots in the base of the finger joints. If this is the case, we trim the front sides," says Kallfass Managing Director Hans Haist. The boards pass through a front end cross-cut with adjustable servo stop. Subsequently, the zero line is changed and the same process takes place on the other side of the board. If the scanner also finds undesirable wood features in the centre of the board, these pieces are ejected to an upper level where a cross-cut system made by PAUL Maschinenfabrik GmbH cuts out these areas. “However, this concerns only about 5% of the total quantity. Most of it goes straight on to the Grecon finger-jointing system”, describes Kallfass Project Manager Helge Widmann.

The Kallfass mechanisation cycles both the long workpieces and the cross-cut lengths from 800 mm upwards at a rate of up to 50 boards per minute. They travel in the direction of the finger-jointing system with the continuous press. Subsequently, the mechanisation takes over the finger-jointed lamellas again downstream of the moving cross-cut saw. These lamellas are between 8 and 16 m long. The applied adhesive can now cure on a 25 m long buffer section before Kallfass feeds the lamellas into the Rex planing machine. After the lamellas are pre-planed, they are cycled in the direction of the board press: First, a system provided by OEST Mineralölwerk GmbH, applies a layer of adhesive to the the lamellas. Subsequently, these lamellas are fed into the glueing press made by DIMTER GmbH. The single-layer boards produced in this way are then taken over again by a Kallfass system.

This is where the paths split: A VOITH crane picks up the longitudinal layers and transfers them to the intermediate storage. Previously, a chop saw, installed downstream of the glueing press, has already cut the longitudinal layers to the width required by the order. In order to make the best possible use of the DIMTER press, the longitudinal layers are always produced in 16 m lengths wherever possible. If shorter boards are required, Kallfass has developed a special system to recycle the remnants of the longitudinal layer.

Transverse layers measuring up to 1.5 m are stacked by Kallfass to a height of 2 m and are also transported by a VOITH crane to a second storage area. These processes are fully automated. A controller determines the suitable storage location.

Vereinzelung der Pakete

Sawed with millimetre precision

Now, the longitudinal and transverse layers are combined to form a layer package. The longitudinal layer already has the right format. The transverse layers, measuring up to a maximum of 1.5 m long, come from five buffer locations and are transferred to a 16 m long conveyor. Several boards are placed one after the other on this conveyor until the required board length is reached. If the length is exceeded, a saw cuts the transverse layer accordingly. The timber offcut then becomes the beginning of the next layer. Subsequently, vacuum systems alternately lift the single-layer boards onto a conveyor belt upstream of the press until the layer package is completely assembled. “Several CTL boards can also be laid on top of each other using a dry joint”, explains Widmann.

Downstream of the MINDA CLT press, Kallfass again takes over the multiple press layer package, separates the elements by means of a push-off process, and transports the elements to the grinding machine. Downstream, they are supplied to a VOITH crane, temporarily stored or transported to one of the three Hundegger machining centres.

In the interview Widmann mentions two more figures regarding the safety concept: “At the Stora Enso factory in Gruvön, 1.2 km of fencing and 82 safety doors were installed”.

Full-service provider

However, Kallfass cannot “only” supply the mechanisation for a cross laminated timber factory. Since last year the company also has a CLT press in its product range. “We have developed this CLT press in response to numerous customer requests”, explains Haist. Thanks to it modular and stand-alone segmental design, it makes no difference whether the layer package is built up of boards or pre-glued panels. The customer also has flexibility when it comes to the design of the workpiece. The board dimensions range from 7 to 20 m long, 2.2 to 3.6 m wide, and 6 to 60 cm high. The hydraulic system forms the core of the system. It enables an almost isobaric (without pressure difference) pressing process. In addition to vertical pressure, Kallfass also equips the cycle press with cross pressure units on request. The area-dependent pressure control enables a pressure in excess of 1 N/mm2 even at maximum plate width.

Kallfass will complete its CLT product range with a further innovation in the future: “We have developed a board turning device for cross laminated timber, which can turn the elements very easily and quickly”, explains Widmann. The turning device handles CLT up to 16 m long, 3.6 m wide and 300 mm thick. It is designed for a weight of more than 10 t. “With this device, CLT can be turned over without any risks and without hurting anyone. For example, in joinery centres, one area of application is for two-sided processing", concludes Haist.

Kallfass presented its new CLT press for the first time last year at the LIGNA Expo in Hanover, Germany.

Vereinzelung der Pakete

Kallfass supplied Stora Enso with the entire mechanisation in the cross laminated timber system – the picture shows the separation of the packages in layers.

The scanner (A) detects cracks and knots, the Kallfass saws (B) cut off the front sides accordingly.

Pressen Taktpresse

Modular design: Kallfass manufactures the CLT press in segments so that it can be adapted exactly to customer requirements

Mechanisation of the longitudinal (left) and cross layers (right) before they are assembled into the layer package.

Verleimen, Verpressen, Wenden

Turn once, please: To bring the longitudinal layers to the correct side, Kallfass installed a board turning device.

Text Martina Nöstler, Pictures Kallfass, Holzkurier BSP-Special 2020