Author: kallfass

The latest and, simultaneously, largest sawmill in the Juodeliai Group is currently operating in Marijampole/LT. The largest sawmill group in the country encompasses four locations and is responsible for cutting over 1.3 million solid cubic metres of logs per annum. Juodeliai aims to produce around 650,000 m³ of pallet timber in 2022, generating over € 200 million in turnover as a result. With customers in over 40 countries, the company is highly export oriented, although, according to CEO Andrius Zimnickas, no business relations are cultivated with Russia or Belarus, despite their geographic proximity. The company mainly obtains its spruce and pine logs and, also, hardwoods from Lithuania, a fact that also makes Juodeliai the largest consumer of timber in the country.

The company commissioned a fourth sawmill in 2020 in Marijampole, about a two-hour drive west of the capital Vilnius. Designed for an annual capacity of 250,000 m³, Juodeliai also produces pallet timber there for the global market. When it came to machine suppliers, the company opted for proven plant solutions from companies such as Linck, Holtec, Microtec and Kallfass. The latter is responsible for the mechanisation, sorting and stacking of main products and side boards.

„A practical, solution-oriented approach is the main reason we are cooperating again with Kallfass.“

Andrius Zimnickas, Juodeliai Group CEO

A challenging project

Kallfass takes charge of the main product upstream of the two multi-blade saws. A vertical system transports the separated logs as a whole to a peel-off system. Aided by gravity, these form a veritable carpet of boards. After passing a visual inspection station, layers are formed and the boards are cut at both ends before being fed layer by layer to a stacker.

Adequate capacity

Kallfass collects the side boards in buffer levels. “As we had little experience with these short dimensions, the design was partially based on assumptions that, ultimately, worked out very well indeed”, reported Kallfass Project Manager Matthias Link.

Solution-oriented approach

This was neither the first nor the last joint project for Kallfass and Juodeliai. The German plant engineers had already been involved in a greenfield project for the Lithuanian timber industry in 2014. “We’re delighted to have opted again for Kallfass. They never try to offer us prefabricated solutions, but rather concentrate on our ideas and implement these. This practical approach is the main reason we decided to work with Kallfass again”, emphasised Andrius Zimnickas, adding that the next project, a second main product stacking system for Marijampole, has already been commissioned. This will be commissioned in the 1st quarter of 2024 at the latest.

Holzwerke van Roje GmbH & Co. KG operates a sawmill at its Oberhonnefeld-Gierend location (Rhineland-Palatinate) with an annual timber output of around 450,000 solid cubic metres. 90 % spruce and 10 % Douglas fir are currently processed, but Managing Director Gerhard Hauschulte estimates that pine will be added to this again to ensure the availability of timber logs in future. A planing mill and pellet production facility producing 80 000 t per annum are attached to the saw mill, and a cross-laminated timber production facility is currently under construction. Holzwerke van Roje currently has a workforce numbering 160 employees.

The planing mill was completed last year as a completely new installation at the plant and adapted to meet the special needs of sawmill production. The objective is to clearly strengthen processing of sawn timber. Up to 70,000 m³ of planed workpieces will be produced per annum from the main product, which is equivalent to about 50 % of the main product produced in the sawmill.

Kallfass GmbH in Baiersbronn delivered the complete fully automated mechanisation technology for the new Rex “Big Master” planing machine from Georg Schwarzbeck GmbH & Co KG in Pinneberg, including a wrapping station. A cupping and moisture meter, a “Golden Eye” quality scanner from Microtec, a marking station from REA JET and the strapping unit from Fromm are integrated in this facility.

During conversion planning in April 2020, the two existing planing lines were dismantled in June of last year. Kallfass began at this time to install parts of the mechanisation technology in cleared areas of the facility while production was still underway. Commissioning of the complete plant then followed at the beginning of September. The plant was producing around 400 m³ of planed workpieces a day in 2 shifts by the end of the year.

Production at the van Roje sawmill is very customer-oriented, serving buyers all over Europe. There is a focus on markets in the Netherlands and United Kingdom with the majority of orders for lengths exceeding 6 m. Van Roje has also concentrated on the European market in recent years, exploiting domestic sales opportunities freed through the booming US sawn timber market. Stock dimensions up to 620 mm and log lengths of 3 to 14 m are cut. The maximum length in the timber sorting system is 8 m. Frequent product changes of up to four times an hour are part of everyday production at van Roje. This means that, when it comes to the cross section and length, a broad variety of dimensions is encountered in the planing mill, and it is necessary to work with relatively small batches. The smallest batches frequently involve only two packages per dimension. The planing mill therefore needs to be very flexible and produce everything from roofing battens with numerous special dimensions to raw solid structural timber. The maximum dimensions of completely planed products at van Roje are 150 x 320 mm. In particular, the maximum possible length of up to 8 m means the plant differs from the majority of industrial planing mills.

Minimum adjustment times and “profile management” on the planing machine

The flexibility required at van Roje is reflected in the configuration of the Rex “Big Master” planing machine: With ten planing cutterheads (four horizontal and two vertical tools and four individual chamfering tools for an all-round workpiece chamfer) finished product widths of 60 to 400 mm and heights of 15 to 200 mm can be created with continuously adjustable feeds of 30 to 150 m/min. In addition to planing and profiling, single and multiple cutting to length of the workpiece is also possible, and van Roje uses up to five saws.

Different board widths can be processed in layers simultaneously on the machine with only narrow gaps between them. Width adjustment is servo controlled at an adjusting speed of 20 mm/s. The Rex profile management control system enables storing of working shaft positions which have been configured. If a particular profile needs to be repeated, the operator, after deploying the required tools, can select the profile using the assigned workpiece name. The machine then automatically moves each spindle into the correct position. Shafts not required for a procedure go into idle mode, leading to a palpable reduction in the electric power input.

Compact mechanisation for workpiece lengths up to 8 m

Kallfass installed a fully automated mechanisation solution here with an interface connection to the van Roje ERP system (Timbertec). With regard to operation of the planing mill, aside from the plant operator and a stand-in, only two other employees are required for wrapping.

Following tilt destacking of the raw material packages (presorted in the sawmill in the case of freshly cut material) and separating, unsuitable material can still be ejected from the sorting conveyor prior to planing machine charging. The plant can therefore also be used for stacking of drying packages. A growth ring detector (cupping detector) integrated on the unscrambler and a moisture meter from Microtec combined with a board turner contribute to the improvement of planing quality. Timber that is too moist can be ejected and raw material turned, depending on the growth ring position.

A freely positionable triple cross-cut saw is installed upstream of the planing feeder and frequently used at van Roje. Cutting upstream of the planing machine achieves absolutely fringe-free cuttings. The feeding of the planing machine achieves 50 cycles/min. Directly downstream of the planing machine, the workpieces pass through a “Golden Eye” scanner from Microtec that organises the product into strength classes C16 and C24. They can then be separated from each other in the passage and either sent directly to one of the two stackers or, previously, to a bundling unit. Adaptation of CE certification for mechanical sorting is currently underway at van Roje. The customer can therefore be offered a combination of mechanically and visually sorted planed workpieces.

Four strapping stations are available at the bundling unit. Up to ten stick bundles can be created there every minute. Packages can be produced on stackers equipped with stick magazines at a rate of 10 layers/min.

Flexibility and rapid dimension changes are core requirements of mechanisation at van Roje, given the frequent product changes involved. A dimension change upstream of the planing machine takes around 1 minute under practical conditions and 20 seconds downstream of the planing machine, meaning each dimension change takes a total of 1 to 2 minutes. The entire mechanisation is designed to provide a feed of 200 m/min. The compact mechanisation layout can accommodate timber lengths of 8 m with ease, while the minimum length for raw material is 2.00 m and 1.80 m for planed products. Package lengths up to 8 m can also be wrapped on the package wrapping unit.

CLT marketing from May

The planing mill is not only designed for finishing the main product, but also represents an important downstream production section for the cross-laminated timber production facility under construction. B sorters for lamellas originally created in the sawmill for other products are calibrated and quality sorted here for use as top layer lamellas in cross-laminated timber (CLT). Lamellas cut especially for the top layer in the sawmill are planed directly in the cross-laminated timber plant. Raw lamellas created from side products are planed and quality sorted for use as (non-dovetailed) transverse layers in the CLT. The option to create different board widths in a layer on the planing machine really pays off here. Exploitation of side products can therefore be considerably increased.

When compared to the usual contemporary production process in CLT manufacturing, the entire production process is to be optimised for resource efficiency, from production of raw lamellas in the sawmill to the completed CLT construction element. Particular attention is also paid to the conservation of raw materials in the cross-laminated timber plant (which bears the project name “Cross Works”). Window and door cutouts are returned to the raw materials cycle again through a treatment process. The cutouts created are separated and recycled in the cross layer. These efforts to achieve resource efficiency have also encouraged support of the overall project through funding of EUR 5,993,815 from the environmental innovation programme of the German Federal Ministry of the Environment. 75,000 m³ CLT should be manufactured annually as of April in 2-shift operation. van Roje wants to begin marketing its cross-laminated timber in May.

The best concept

The choice of a supplier for the new plant fell on Kallfass, the mechanisation specialist from Baiersbronn-Klosterreichenbach/ DE. “Naturally enough, we took a look at different suppliers, but Kallfass offered us the best concept”, related Wolfgang Kolb, justifying the decision he reached together with his son, Fabian Kolb. One aspect appealed in particular to the pair. “Kallfass was the only supplier to develop a combined solution for the main product and side product, being in fact the only one to come up with the idea. Together with the close proximity to Baiersbronn and the excellent reputation Kallfass enjoys, the latter was the decisive factor”, explained Kolb.

„Kallfass was the only supplier to offer us a combined solution for the main product and side product.“

Wolfgang Kolb, owner of Sägewerk Kolb

No worker needed for the side products

Kallfass delivered a complete sorting system to Kolb, with 75 boxes, a stacking system and a connection to the sawmill. During a tour of the facility, Kallfass Managing Director Hans Haist pointed out the separating unit behind the board edger. “Depending on the sawing pattern, up to five boards positioned closely next to each other can be delivered to the existing cross conveyor. We integrated a further separating unit in this area by installing a single feed unit in the sawmill, ensuring continuous and uninterrupted transport down the line”. The side products from the board edger are conveyed to the upper deck of the sorting system via a conveyor belt. They continue their journey from a curved conveyor to a cross conveyor towards the boxes. Feeding on a carrier chain continues in this area, and the length, width and thickness is measured. This data is used for box classification. The boards then continue their journey into one of the 75 boxes. “What’s special here is that, in principle, the side boards are sorted without worker intervention. A worker assessing the product and, in effect, standing one floor lower can intervene in the process if necessary”, explained Kallfass Project Manager Dominik Hauser. This means that the entire plant can be operated with just one worker.

Kallfass installed its reliable inclined boxes at Kolb. “The advantage of this is that – due to a filling level control – the boards only have a minimum drop height and, as a consequence, fewer breakages occur”, explained Haist. “Also, a box can now hold almost twice the previous volume”, added Fabian Kolb. A box that has been suitably filled is then discharged downwards. The journey to the assessment station continues via a longitudinal conveyor and unscrambler. Where necessary, the worker can eject boards with waney edges or of unsuitable quality downwards though a flap. The layers of boards then pass through the tried and trusted multiple cross-cut saw from Kallfass. This is equipped with a zero line and three variable saw aggregates. Finally, the layers are transferred to the stacking systems through automated stick placement, with the completed packages travelling downwards and being strapped manually by the forklift operator. The installation of an automated strapping system is planned in this area.

Stacking of the main product is also automated

As mentioned at the outset, Kolb can also move main products of up to 6 m in length on the new Kallfass plant. These travel from the circular re-saw on a conveyor belt to the sorting system on the lower floor. They move from here through a separating unit to the worker and complete the same journey as the side products through the multiple cross-cut saw and layer formation to the stacker. “Moving the side boards and part of the main product over the same system gives us enormous flexibility”, emphasised Wolfgang Kolb.

The new Kallfass plant is designed for lengths of 2.5 to 6 m and side products with a thickness of 18 to 100 mm. When stacking the main product, Haist estimates the thickness to be 120 mm. The sorting system is designed for an output of up to 50 cycles per minute, while the stacker can complete up to ten layers each minute. Kallfass installed the control cabinets and electronics in a container which was delivered to Kolb as a turnkey unit. The supplier also delivered the entire control system. The layout of the sawmill, with the plant on two sides of a stream, led Kallfass to construct the new sorting and stacking system 0.5 m higher. The walls of the sawmill, constructed with cross-laminated timber (CLT), are also at the same distance from the floor. “There are also no motors in this area, so the plant can begin operating quickly again following any flooding”, explains Haist.

Rapid output achievement

Those responsible primarily focused on flexibility and, simultaneously, a high level of availability with regard to the new planing line. For this reason, mechanisation was entrusted to Kallfass in Baiersbronn-Klosterreichenbach, Germany. “We knew Kallfass would supply the solution we wanted”, Lang emphasised. The mechanisation specialist had already converted an existing planing line in Ramstein, and this worked out perfectly. In retrospect, Lang is more than satisfied with handling of the project. “I’ve rarely experienced such a perfect commissioning. We achieved almost 100 % output after four weeks, and 6000 m³ of battens had already been bundled in this period. If we had to, we’d construct the plant in the same manner again”.
Kallfass adapted the new planing line to fit an existing facility exactly. The plant can process lengths ranging from 2 to 5 m, widths of 60 to 300 mm and thicknesses of 14 to 120 mm. Issues relating to available space mean the vacuum lifting device destacks the dried timber packages in layers. A stick stripper brushes the stacking strips down and conveyor systems collect these. An operator initially assesses the workpieces visually in the transverse transport. Following this, they are checked with a Brookhuis moisture measuring. “Unsuitable timbers can still be ejected here”, explained Kallfass Managing Director Hans Haist. Kallfass subsequently installed the longitudinal feed in the direction of the WJS planing machine. Depending on the timber length, this can achieve up to a maximum of 80 cycles a minute.

„Kallfass handled the entire project impeccably. We achieved almost 100 % output within four weeks.“

Dr. Stephan Lang, CEO of Rettenmeier Holzindustrie

Resorting for higher quality

There are two options downstream of the planing unit. Timbers that can be classified as a higher quality through cutting are sorted out to the left onto a conveyor in film layers. These can be fed into the process again if, for example, a dimension change occurs in the planing machine. “This resorting dispenses with the need for a further stacking system and complex trimmer station”, said Haist. The majority of planed workpieces are pulled onto a cross conveyor behind the conveyor with the temporarily stored film layers. An operator examines the workpieces here, ejects timber pieces of unsuitable quality and, by drawing on the timbers, can determine the chop cuts. In addition, Rettenmeier opted for a bundling system. In the case of single pieces, this simply involves “running over” these with transport chains. Kallfass also integrated a labelling system in this section. Kallfass was already involved in the development of this solution at Cordes, and it is also employed in Ramstein. “Both the bundles and wooden strips can be labelled”, explained Haist.

Following this, the timbers pass through the tried and trusted multiple cross-cut saw from Kallfass. The saw is equipped with four variable saw aggregates. The layers are then transferred to the stacking system which is equipped with magazines with automated stick placement. The stacker is also suitable for DIY packages (i.e. quarter packages). Finally, the finished packages are foil-wrapped and prepared for shipping. When it comes to foil wrapping, Kallfass provided yet another machine that mills the grooves in squared timbers. “This has proven its worth on numerous occasions”, said Haist.
“The new planing line allows us to achieve classic four-sided planing and, also, separation, or simply tongue and groove sections. That makes us extremely versatile. Kallfass provided us with a simple, but extremely efficient solution that allowed us to cover all requirements”, Lang confirmed.