The constricted design of the sawmill necessitated very specific planning. The plant runs alongside a stream and is bordered on the opposite side by railway tracks.

A waste wood content of 35% that wants to be processed efficiently. A narrow sawmill with a limited amount of space. Challenged by these conditions, the Austrian company Schaffer Holz GmbH recently integrating a new, customised system from the mechanical engineering company, Vecoplan AG, for reliable, economical and sustainable waste wood processing.

When a sawmill starts cutting timber, it doesn’t only produce valuable sawn wood; a lot of waste wood is also left over after the cutting process has ended. This by-product can quickly become a major problem if it is not disposed of efficiently.

If chips, bark and wood chips are allowed to accumulate, production downtime looms large. That’s why Schaffer Holz integrated a customised solution right from the start when building its new sawmill.

The company specialises in the processing of thick timber, mainly processing large logs measuring 45 cm in diameter. The window and furniture industries are among its customers, as well as manufacturers of soundboards and tone woods for pianos.

A large proportion of the production is exported abroad. To avoid jeopardising this value chain, the new sawmill had to be designed in such a way that the by-products could be reliably processed from the start.

35% waste wood

The challenge involved several aspects: the high proportion of waste wood (around 35%) which is produced from an annual cutting volume of 1,50,000 solid cubic metres, had to be considered, as did the narrow and confined layout of the plant on site.

The sawmill stretches along a stream and is bordered by railroad tracks on the opposite side, which extends the length of the facility. The entire disposal technology had to fit into the special architecture without compromising on performance and reliability.

Schaffer Holz opted for a complete solution from Vecoplan, consisting of conveying, shredding and screening technology optimally adapted to the complex system.

The exact separation of wood chips and sawdust is particularly important to the company, as the quality of the end product influences the sales price. The quality of the wood chips has a direct influence on the price in the Austrian region. If it exceeds the minimum requirements, it has a positive effect on revenue.

Maximum utilisation

Vecoplan has developed a customised system for Schaffer to match the company’s requirements perfectly. The solution for waste wood disposal includes conveyor technology, a powerful drum chipper and an intelligent screening system with a vibrating separator.

The wood residues are first transported via vibrating screens and conveyor systems to a powerful drum chipper, which produces high-quality wood chips. These chips are recycled in the paper industry.

Using a drag chain conveyor, the wood chips and sawdust are fed to a vibro screen to separate excess lengths which then are fed back to the chipper via a conveyor belt. The sawdust and wood chips, now freed of excess lengths, are then transferred to a VRF 500-P pipe belt conveyor by another drag chain conveyor.

The drag chain conveyors form a closed system and ensure a continuous material flow. They’re combined with the VVR vibrating conveyor, which regulates the material feed by means of a uniform conveying flow.

The VRF pipe belt conveyor system then transfers the fine wood chips to the VSS 6000 vibrating separator above the sawdust boxes. The VRF was specially developed for the clean and quiet transport of bulk goods over long distances and Schaffer uses it for an 80-metre-long route across the entire factory yard.

The closed system ensures that the material is conveyed very cleanly and safely. Another special feature of the system is the subsequent material separation by the vibrating separator directly above the storage box. The two-line separation takes place just before discharge, so wood chips and sawdust can be precisely separated and optimally utilised.

The Vecoplan system processes up to 18 cubic metres of waste wood per hour, a level of performance that is crucial for smooth sawmill operation.

Tailor-made tech

The implementation of this demanding project was an exciting challenge for both Schaffer and Vecoplan. One of the biggest hurdles was the integration of the waste wood disposal into the existing production processes and the cooperation with several suppliers.

Following a 1-year planning phase, the installation was started in March 2024. The system was finally commissioned in July and has been producing impressive results ever since.

The effects on the company’s operations are clearly noticeable. The entire disposal process runs smoothly, and the quality of the wood chips meets the highest standards. This has a direct economic significance, as better sorting increases the market value of the by-products. Wood chips are sold to the paper and pulp industry, while sawdust is mainly used by pellet producers.

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