Microwave Wood Processing

Grigory Torgovnikov

Commercial applications of MW wood modification

1. Timber Impregnation with Preservatives or Resins

                                                                                   Uptake after pressure impregnation (l/m³)

  Control After MW cond.
 Douglas Fir heartwood
 60 - 90
 375 - 426
 Radiata pine heartwood
 120 - 140
 361 - 516
 Messmate 18 192 - 255
 Yellow Stringybark posts
 46 340 - 400

Control                                MW treated                               Control                                     MW treated

2. MW Hardwood Timber Pre-Treatment for Fast Drying

MW energy consumption 80 - 100 kW-h/m³

Drying time reduction 2 - 10 times

                                                                                        Drying Kiln

 

3. Growth and Drying Stress Relief in Timber

Microwave irradiation of eucalyptus timber can provide the relief of growth and drying stresses
 
                 MW treated                                     Control                                                                          Control
                 
                    MW treated                                   Control                                                                       MW treated
                      

4. Microwave Modified Timber "Torgvin"

"Torgvin" has the following altered properties compared to unmodified wood:

  • improved permeability
  • reduced density
  • reduced heat conductivity (better heat insulation)
  • reduced shrinkage and swelling
  • improved acoustic properties (better sound insulation)
  • high flexibility

5. New Wood Material "Vintorg"

Vintorg is manufactured from modified wood "Torgvin" by impregnating with resin and curing in a press.       

Vintorg has the following advantages:

  1. High strength properties
  2. Natural appearance and structure
  3. Good dimensional stability
  4. The use of low grade material
  5. Can be fungi proof
  6. Can be fireproof
  7. Can have high electric conductivity
  8. Low cost production

6. Microwaving Timber and Wood Chips for Pulping

 

 

 Advantages:

 

Improved yield                      7 - 40 %

Reduced chemical use          22 - 31 %

Throughput increase            20 - 40 %

Energy savings                     25 - 39 %

Reduction of wood losses

Possibility to use diverse chip size or wood pieces