Materials

The material use of the resource ‘wood’ is at the focus of the ‘Materials’ area. Wood-based materials are investigated, developed and manufactured with the latest laboratory and technical equipment. Thereby, the principle of ‘cradle-to-cradle’ is pursued in order to promote and intensify the sustainable use of one of the world’s oldest raw materials in a social, ecological, and economic way.

The main activities of the ‘Materials’ department are centred on the laboratory manufacture and analysis of wood particles and of any kind of wood-based materials. In addition, perpetual research is carried out with a view to newly or further develop wood-based materials. This also includes the investigation of alternative or novel bonding agents for low-emission and high-performance materials and special products. A state-of-the-art technical facility where the entire value creation chain from round wood to finished panels can be reproduced enables us to permanently work on optimising the technology.

Detlef Krug

Dr. rer. nat.

Detlef Krug

Head of Departement · MDF · OSB · PB · SWP · Adhesives · Alternate feedstocks · Monitoring

+49 351 4662 342

+49 162 2696 333

send E-Mail

Particle Manufacture and Analysis

The conversion of solid wood into wood particles is at the central focus of ‘Wood based Material Production’. Only by preparing special lignocellulose structural elements wood based materials intended for use in defined applications can be manufactured.

The technical equipment of the ‘Materials’ area enables the manufacture of wood particles of various sizes and qualities:

  • Wood flakes
  • Shavings
  • Strands/wafers
  • Fibres
Pulp
Pulp

The ´Material´ area is equipped with numerous laboratory devices for the desintegration of raw timber, recyced products, annual plants and other agricultural products:

  • Drum chipper
  • Knife ring chipper, disk chipper, whole-log chipper
  • Hammer mill, cross beater mill and whirlwind mill
  • Laboratory defibration unit
  • Atmospheric refiner

The impact of the geometry and composition of particles or particle blends onto the manufacturing process and the properties of the product can be evaluated by applying special analytical methods. By identifying these correlations, the technology of chipping and defibration processes can be optimised and further developed continuously.

Manufacture and monitoring of wood-based materials

Wood is a very versatile material. Shaping and moulding enables the composition and manufacture of widely varying wood-based materials for use in load-bearing and non-load-bearing applications. On the one hand, products are manufactured in the ‘Materials’ department that are very similar to solid wood, such as solid wood panels and plywood (laminated woods), and particle-based materials (made of chips or fibres), on the other, that can hardly be identified as wood.

Wood based panels
Wood based panels

The technical equipment permits industrial-scale transition of the various processes of the manufacture of the organically and inorganically bonded wood-based materials, from drying via gluing to pressing the finished materials on a laboratory scale in analogy to industry. Several technical solutions are available for transforming layers or particles:

  • A solid-wood panel press
  • A short-cycle press
  • Hot presses with re-cooling
  • A high-frequency heating press

 

As to what extent materials are fit for certain applications or meet the desired requirements are investigated on laboratory and industrial panels with the help of various short-term or long-term tests (e.g., of the raw density profile, dimensional stability, creep behaviour).

The scope of analyses also includes, apart from those mentioned above, the testing of biological, physical and mechanical and surface properties and of the emission behaviour of wood-based materials

Development and analysis of woodbased materials

The constant change of the social, ecological and economic environment inevitably requires to steadily improve the classical materials and development of innovations. Hence the ‘Materials’ department continually works on solutions of current issues around the material of wood.

Along with the ever recurring themes of sustainability, conservation of resources, climatic change and energy consumption, the following issues are among those of current topicality:

Model of a HF press
Model of a HF press
  • Variation of raw material application (e.g., alternative wood species, annual plants)
  • Pulping of lignocellulose raw materials (chip and fibre manufacture)
  • Application of traditional organic and inorganic bonding agents as well as of alternative bonding agents/bonding agent combinations (e.g., proteins, powder lacquer residues)
  • Composite panels with alternative and functional core layers
  • WPC (Wood-plastic/polymer composites)
  • Powder-lacquer-based wood particle materials
  • Thermally or chemically modified wood-based materials
  • Insulation materials from organic raw materials (e.g., leather)

Moreover, the department’s staff performs monitoring tasks in companies manufacturing particle-like wood-based materials (chipboard, OSB, fibreboards), laminated work materials (solid wood panels, plywood) and WPC.

Testing of glues and additives

Adhesives
Adhesives

The development of wood-based materials is closely linked to the development of suitable adhesive systems. Without any bonding agents, most lignocellulose-based materials can hardly be imagined. High speed of reaction, low emissions, low cost and high cross-linking capability with the structural elements, for example, are of decisive importance to a successful adhesive. How good the new or further developed adhesive system is shows in most cases only during or after the manufacture of panels.

On the one hand, the ‘Materials’ department tests the technological implementation of the gluing of particles (blender, blowline) or of layers (pouring, brushing) with various adhesives and additives as well as their impact on the pressing process (pressing time, pressure, temperature). On the other hand, it determines the parameters of the acquired bonding quality (e.g., gel time, resin dispersion, density profile or internal bond). Apart from the classical adhesives based on formaldehyde or isocyanates, alternative bonding systems are the subject of investigations, such as thermoplastics (PVAc, EPI), natural polymers (proteins, lignin), inorganic bonding agents (cement, gypsum, soluble glass) as well as wood-inherent bonding forces. In addition to that, several additives are applied to purposefully improve the materials (e.g., regarding hydrophobing, fire protection, emissions reduction).

Technology optimisation and consultancy

The manufacturing technology for wood-based materials comprises a series of procedural steps, from the manufacture of particles to hot pressing. The marketing potential of a material largely depends on its price that is based on the economic design of the various processes.

In the manufacture of wood-based materials, the optimisation of technology generally aims at energy savings, increased service life, quick changeover, increased flexibility and material savings. The ‘Materials’ department deals with the following topics in particular for developing existing technologies further:

  • Adhesive savings by improving adhesive application onto fibres in the blowline and by applying technologies like the combination gluing and blender gluing
  • Generation of well-defined chip and strand geometries by varying the cutting edge geometry and angles in various chipping units
  • Determination of optimal pulping conditions in the refiner (retention time, pressure, temperature, disc gap) to achieve the desired fibre sizes and qualities
Refiner tests
Refiner tests
  • Reducing the pressing time by pre-heating applying the HF technology
  • Investigation of the impact of the particle geometry onto the compression process
  • Effects of various raw materials on energy consumption during the pulping process
  • Optimised design of the pressing process to achieve an adjusted raw density profile of particle-based materials

Services Materials

  • Manufacture of defined wood particles like strands, flakes, chips and fibres
  • Morphological analysis of particles by screening (vibrating sieve for flakes, chips and strands , air jet sieve fibres and fines) and digital image analysis (Camsizer)
  • Evaluation of bonding systems by ABES
  • Manufacture of wood-based composites applying various adhesives and additives
  • Process analysis via PressMAN®
  • Optimisation of production technology for e.g. combination gluing, raw material use, fibre pulping grade, chip and strand geometry, press conditions
  • Evaluation of duration of load and creep behaviour of wood based materials
  • Evaluation of dimensional stability of wood based materials in different climatic conditions
  • Determination of density profile
  • Determination of characteristics values

Technical equipment

Log processing:

  • rotor debarker
  • wood splitter
  • drum chipper
  • vibrating sieve

Chipping:

  • knife ring flaker
  • disc chipper
  • cross beater mill (knife ring mountable)
  • drum dryer for strands
  • flash tube dryer for chips
  • tumbler screening sieve

Pulping:

  • Defibrator (pre-steaming, multiple screwing device, retention vessel, pressurized refiner)
  • blowline gluing
  • flash tube dryer

Hydrothermal pre-treatment of lignocellulose biomass for the extraction of sugars:

  • retention vessel
  • discharge by steam explosion and at atmospheric conditions

Blending:

  • various blenders for fibre-like materials
  • various blenders for chip-like materials
  • blender for strands
  • blending in blowline

Pre-pressing and pressing:

  • HF-pre-press (high frequency preheating)
  • downstroke presses (cooling system, moulding possible)
  • upstroke high-speed-press
  • upstroke press for layer based composites

Insulation materials manufacturing:

  • Steam flow wood insulation press

Particle analyses:

  • by image analyses (Camsizer)
  • by screening (air jet sieve, vibrating screening machine)

Special testing’s:

  • Density profile analysis acc. to IHD standard
  • Creep properties/duration of load acc. to EN 1156
  • Dimensional stability acc. to IHD standard in differential air
  • Automated bonding evaluation system (ABES)