Processing techniques which can utilise low quality and/or small dimension timber

1. Processing techniques which can utilise low quality and/or small dimension timber EURIS– Europeans Using Roundwood Innovatively & Sustainably

2. Lecture Objectives • Student should gain: • Basic understanding of principal wood processing techniques • Basic modalities of wood sorting according to the chosen processing technique • How to put value into a low quality/low dimension log of wood. EURIS– Europeans Using Roundwood Innovatively & Sustainably

3. Introduction Wood can be utilised as it is (roundwood), just through crosscutting, for many purposes such as agricultural poles, fences,… Anyway in most cases it must be processed to be decomposed and recomposed to make the final product EURIS– Europeans Using Roundwood Innovatively & Sustainably

4. Introduction The decomposition of roundwood to produce semi-finite needs specific mechanical techniques The recomposition of semi-finite to final products needs assembling techniques, mostly glues. The complete process aims at adding value into the final product EURIS– Europeans Using Roundwood Innovatively & Sustainably

5. First wood processing techniques 1 2 • Sawing • Rotary cutting • Slicing • Clefting • Chipping 3 4 5 EURIS– Europeans Using Roundwood Innovatively & Sustainably

6. Sawing The more utilised way to produce or edge boards, or, from low diameter wood, very thin elements for ski production or decoration layer for laminate parquet flooring. The wastes are chips and slabs

7. Rotary cutting The way to produce 1 – 2 mm thick veneers mostly for plywood production, generally after steaming. Veneers can be glued together also to produce microlam or LVL.

8. Slicing The way to produce very thin (some mm/10) veneers mostly for decoration of different kind of panels. This process too is made generally after steaming Veneers can be glued together also to produce microlam.

9. Clefting Radial-longitudinal cutting of wood, without producing chips as wastes. To produce fuel wood or elements for non-permeable uses, such as elements (staves) for barrels or wooden shingles.

10. Chipping From low quality/low dimension material, to obtain wooden chips. Wooden chips can be then processed to produce panels or energy as they are.

11. Solid Wood Panels Raw material: Low quality/dimension hardwoods from coppices. Low quality/dimension softwoods from thinnings. Black locust and Sweet chestnut Austrian pine (Pinus nigra L.) From Tuscany EURIS– Europeans Using Roundwood Innovatively & Sustainably

12. Production system

13. Production system

14. Production system

15. Production system

16. Product characterisation Dimensional stability Mechanical tests Bending Shear

17. Application examples From the panel to the furniture

18. Open-air furniture Raw material: Low quality Umbrella pine from winter storms.

19. Production system Semi-finished: Sawing Finished glulam Ripping Rotary cutting Plywood Veneers sorting

20. Production system Final products: open-air furniture for the regional park from where pines were from. Assembling plywood and glulam

21. Wood-plastic composites From very low quality roundwood. In the example from southern Italy plantation Eucalyptus. The utilised Eucalyptus clones are characterised by a dense wood, having conspicuous shrinkages. Moreover stems present high growth stresses which lead to the opening of cracks at felling

22. Production system Low quality logs are chipped; chips are refined in order to obtain wood flour (b). Wood flour is mixed at high temperature (200 °C) with thermoplastic resins like polypropylene and extruded (c). The obtained product is a composite thermoplastic panel where wood flour act as filler.

23. Product characterisation The product characterisation pass through mechanical tests (-e- is a tension specimen). The increment in mechanical performances from the original propylene is low. The thermoplastic panel allows its transformation by means of hot moulding into final products such as boxes (f) or roof tile (g)

24. Product characterisation A complete roof made with wood-plastic composite. The obtained product is less polluting and more recyclable than the simple plastic. Physical and mechanical improvement from the plastic of origin are very low.

25. Low technology/high design Merry-go-round made with chestnut roundwood Chestnut roundwood: Basement made of chestnut roundwood; horizontal helix made of crossed chestnut slabs. The project allows utilising low cost and low value material.

26. Low technology/high design Seesaw made with chestnut wood Chestnut sawn wood: Vertical element made of two chestnut coupled boards. The horizontal balancing element is a chestnut board; the rotation is ensured by metal elements.

27. Low technology/high design Bicycle parking system with chestnut slabs Chestnut slabs: Waste elements can be worked with simple tools (even chainsaw). The utilisation of very durable wood, like chestnut, is essential to ensure a long life of the artefacts.

28. Conclusions • Wood processing aims putting value into wood products • The choice of the processing techniques is strictly linked to the characteristics of the raw material. • Raw material must be sorted before processing according to dimension/quality. • Generally semi-finite must be recomposed to obtain final product.