“

the thermovacuum treated wood ”

32

Thermovacuum for a new kind of wood

Why is the development of such solution interesting?

The project objective is to test the innovative process of 7 wood species widespread in EuropeFir, Spruce, Maritime Pine, Ash, Beech, Poplar, Oak. These woods are today considered economically unattractive; the process gets wood with the durability and aesthetic characteristics of resistance similar to those of tropical woods.

Tv4newood project, financed by European Commission with Eco Innovation programme 2012, has the aim to create and disseminate in European market a new process for generate thermally modified wood that has special properties of strength and durability. The timber produced is created without adding chemicals and with a considerable saving in energy, this is possible with a technology that operates “under vacuum”,

The positive effects are:

99Raising the value of the European wood today underexploited

99Use of European wood from certified forests for production in different market sectors

99Decrease of tropical wood of dubious origin demand

99Decreased production of CO2 due to the transport of large quantities of wood from great distances

99Rising employment in the wood industry

99Dissemination of wood products completely biodegradable

Main project results:

99Vacwood® registration trademark and certificated product

995 production plants world wild

99Decrease of tropical wood of dubious origin demand for about 120.000 m3 in 5 years

99Decrease of water 980.000 mc and 620.000 KWh with Thermovacuum process

99 Innovative Vacwood® available for Indoor parquets / Naval furnishing and cladding / house restructuring /external joinery

Co-funded by the Eco-innovationInitiative of the European Union

54

Who are the partners involved?

Coordinator of project WDE-MASPELL SRLOwner of innovative solution patent and Vacwood® Trademark. Wde-Maspell designs and manufactures plants for the heat treatment of wood.

CNR IVALSAThe Trees and Timber Institute of the National Research Council (CNR)Technical responsible of project perform the laboratory tests regarding the product certification of treated wood, the standard-setting process and implementation of the LCA

CONLEGNOItalian national wood and cork services consortium (CSLS)CSLS is responsible for dissemination towards end users and final consumers. Will spread to other European associations theproject results.

SWEDISH UNIVERSITY OF AGRICULTURAL SCIENCES (SLU)Department of Forest Product.SLU perform laboratory tests for the certification of the finished TVW product

ECOLWOOD (ECW)French Sme for wood treatment under vacuum. ECW is the first industrial Vacwood® manufacturer in Europe. ECW produced the Vacwood® for laboratory tests and the TVW samples.

MEDITERRANEAN REFITTING GROUPItalian SME for the interior and exterior of the luxury boats, the first user of vacuum heat-treated wood for the furniture of a prestigious yacht.

Where are the process and wood tested?

CNR IVALSA San Michele all’Adige (Trento)

Test for: treatment process and Vacwood® mechanical properties

Ecolwood a Monistrol sur Loire (Francia)Production capacity 8 m3/cycle

Fir, Spruce, Maritime Pine, Ash, Beech, Poplar, Oak

Swedish University of Agricultural Science (SLU)

Department of Forest Product. SLU perform durability laboratory tests for the

certification of Vacwood®

76

The manufacturing of VacWood® relies on the use of high temperatures in a under vacuum environment, without any chemical additives. This process improves many wood features:

99Resistance to biological agents,

99The resistance to atmospheric agents,

99The dimensional stability

99The ‘thermal insulation

99A pleasant odour of the product

99The mechanical strength, very close to that of a natural wood

99The reduced moisture content and wettability

99The uniform colour for the entire thickness of the wood

99The compatibility with the environment of a 100% natural product and free of pollutants

The Thermovacuum process has other positives features:

99Very low energy consumption

99Emission of VOC - volatile organic compound – very close to that of natural wood

99No leakage into the surrounding environment

The wood treatment process, patented by WDE Maspell, take place in a single machine for all process stages. The three stages are:

DRYING:The wood is properly dried until it contains an extremely low moisture content, close to 0%, using a vacuum drying process within a superheated steam atmosphere in order to guarantee the quickest and most effective drying, without stressing the woody matter.

HIGH TEMPERATURE:During the thermal vacuum treatment stage, the temperature is raised up between 170°C and 210°C, depending on wood type and expected result; wood stays in this condition for between two to four hours. Thanks to the continuous extraction of the internal atmosphere by an innovative vacuum pump system, the emissions of the gases produced by the wood are condensed, diluted and stored without any risk to the environment. The cooling period follows, whereby an air-air heat exchanger is used, down to a temperature of 90°C, without the addition of coolants or direct contact with the atmosphere.

CONDITIONINGStarting from the pre-existing under-vacuum values, the conditioning stage consists of increasing the pressure within the cell using the steam produced by atmospheric pressure. This process allows the wood, which is practically anhydrous, to regain an equilibrium moisture content of approximately 4%, thereby avoiding the stress of atmospheric contact.

WP N° 1 Project Management

WP N° 2 Manufacturing process definition and data collection

WP N° 3 LCA (Life Cycle Assessment)

WP N° 4 Process and product certification

WP N° 5 Market Replication

WP N° 6 Business Plan

WP N° 7 Dissemination Activities

Project started 1st September 2013

Project end 31st August 2016

European Countries involved 3: Italy, Sweden, France

Partners Involved: 6

Project budget: 1.771.928

European fund (50%): 885.964

For more information please write to tv4newood@wde-maspell.it

Project work packages VacWood® wood innovation

98

Loss of massLoss of mass is the best indicator and guarantee of treatment intensity and is closely linked to thermal degradation, which indicates the way in which the wood is changing its chemical structure via the partial evaporation of certain components.

Equilibrium moisture content and dimensional stabilityThe variation in the equilibrium moisture content of VacWood® correlates to the exposure temperature. Its value decreases, while maintaining this feature over time, in a range between 4% and 8%.

ColourThe colour of VacWood® changes throughout the three treatment categories described previously. The higher the exposure temperature, the darker the wood becomes. The colour acquired by wood is uniform throughout its surface, inside and outside.

Currently the VacWood® brand applies to 7 wood species: Silver Fir, Spruce, Maritime Pine, Ash, Beech, Poplar and OakThere are three treatment categories, which have been designed to guarantee the performance of the wood in line with the chemical and physical changes achieved due to the rising temperature that is applied. Each category foreseen a different treatment for various wood thickness, up to 22 mm and 33 mm.

VacWood® – C (COLOUR)The maximum treatment temperature is 170°C, which guarantees that the wood becomes a darker colour compared to untreated wood, giving it a more attractive appearance and evening out the colouration in raw material which features differences between sapwood and heartwood.

VacWood® – S (STABILITY)The maximum treatment temperature is 190°C in order to achieve an even darker colour and greater dimensional stability. Ideal for uses that require the wood to be immobile (ex. flooring, internal doors and windows).

VacWood® – D (DURABILITY)The maximum treatment temperature is 210°C in order to achieve an even darker colour and an improvement in durability class, which is defined as the resistance capacity of the woody matter against biodegradation (fungus, mould) and is linked to classes of risk that determine the particular exposure conditions (outdoors, in contact with ground, etc.) in which we can use the wood. This, therefore, opens up the option of using species that undergo rapid biodegradation in environments that were previously risky for them, thereby allowing less valuable forest resources to be used, yet ones which grow quicker, in an exponential way.

Treatment categories and wood species

The physical properties of VacWood® include

4

step

HT CONDITIONINGDRYING

-DT+DT

t

Tpr

TfTi

Ucr Ueq

765432 t

u

T

p

1

Ui

GLOSSARYUi Initial MC (Moisture Content)Ucr Critical MC: the MC that the wood must contain at the end of the drying stage and at the beginning of the thermal treatment.Tcr Critical T: the T at which the modification reaction starts.+DT Heating rate during the warm up.Tpr Maximum constant T during the thermal treatment.t Duration of treatment (hours) at Tpr.p Vacuum pressure (mbar) during the thermal treatment.-DT Cooling rate from Tpr to Tcr.Ueq MC of wood after the treatment, ready to be used in operative conditionsT Temperatureu Humidity

170°VacWood® – C

190°VacWood® – S

210°VacWood® – D

NTNot treated

1110

The VacWood® brand is constantly evolving, the aim is to expand it to many more local wood species interesting for market penetration. WDE MASPELL team puts them through a long and proven testing phase, which guarantees compliance with trademark and target performance levels.

This task will be the results of knowledge and experience sharing of our technical and scientific partners, wood producers, wood users and custoers, that will take part to this ambitious project.

Mission

WDE MASPELL SRL Strada di Sabbione 65/A 05100 Terni (TR) ITALIATel: +39 0744 800672

Fax: + 39 0744 807056

www.wde-maspell.itwww.tv4newood.it

e-mail: tv4newood@wde-maspell.it

Official partners

co-financied project

Co-funded by the Eco-innovationInitiative of the European Union