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