WOOD MODIFICATION TO ENHANCE FIRE RETARDANCY

• US 20170226424A1
• Filed: 08/07/2015
• Published: 08/10/2017
• Est. Priority Date: 08/07/2014
• Status: Abandoned Application

• Current Assignee: Wood Modification Technologies Ltd.
• Original Assignee: Chemenz Limited
• Inventors: Moon, Ronald Philip
• Application Number:
  US15/502,064
• Publication Number:
  US 20170226424A1
• Time in Patent Office: Days
• CPC Class Codes: B27K 2240/30 Fireproofing
• CPC Class Codes: B27K 3/02 Processes; Apparatus
• CPC Class Codes: B27K 3/0292 for improving fixation B27K3/0285 takes precedence
• CPC Class Codes: B27K 3/08 Impregnating by pressure , e.g. vacuum impregnation
• CPC Class Codes: B27K 3/153 Without in-situ polymerisation, condensation, or cross-linking reactions
• CPC Class Codes: B27K 3/22 Compounds of zinc or copper
• CPC Class Codes: B27K 5/001 Heating
• CPC Class Codes: B27K 5/0085 Thermal treatments, i.e. involving chemical modification of wood at temperatures well over 100°C
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: C09K 21/02 Inorganic materials

Abstract

The co-formulation of a wood preservative (‘treated’) with an inorganic (alkali metal silicates) based flame retardant which undergoes chemical impregnation. Once the ‘treated flame retardant” working solution has fully penetrated (sapwood) into the wood, it then undergoes a heat (fixation) process using various heating schedules to achieve chemical fixation. The treated flame retardant Modified Wood [tfrMW] products are then tested for their enhanced fire performance properties. When heated, wood undergoes thermal degradation and combustion producing gases, vapours, tars & chars. Using the ‘cone calorimeter’ test method, the [tfrMW] products showed a significant reduction in the following parameters: heat release rate (HRR), mass loss rate (MLR) & smoke generated (SEA) values compared to untreated radiata pine.

Claims

1. A process of imparting enhanced fire retardant properties to lignocellulosic material comprising of a wood preservative chemical(s) (referred to as ‘

treated’

) in combination with &

without an alkali metal silicate (referred to ‘

flame retardant’

) that via a impregnation treatment process is infused into the cellular internal voids &

then is polymerised via a heat process to produce an insoluble fixed ‘

treated flame retardant Modified Wood’

[tfrMW] product.

2. The product produced (′

treated flame retardant Modified Wood) by the process of claim 1, wherein the product(s) possess the property of increased fire retardancy

3. The product produced by the process of claim 1, wherein the ‘

treated flame retardant Modified Wood, [tfrMW], generates an incremental increase in durability

4. The wood impregnation treatment process of claim 1, wherein the pressure ranges from 50 to 3,000 kpa &

vacuum 0 to −

90 kpa.

5. The wood impregnation treatment process of claim 1, wherein the chemical absorption (uptake) ranges from 15 to 1,000 Litres/m3 (loading)

6. The process claim 1, wherein allows for wood preservative chemical &

flame retardant in the combined ‘

working solution’

to co-penetrate during the wood impregnation treatment process

7. The process claim 1, wherein that the ‘

treated flame retardant’

working solution during the heat process, converts from its oligomeric state (SiO2/Si) into longer chain polymeric silicon species rendering it (fixed) insoluble.

8. The process of claim 1 includes wood preservatives types;

Copper Chrome Arsenate (CCA), dissolved Copper Azoles (dCA), micronized Copper Azoles (mCA), Alkaline Copper Quaternary (ACQ), micronized Copper Quaternary (mCQ) &

water based Azoles.

9. The process of claim 1, includes the soluble alkali metal silicates (′

flame retardant′

);

sodium silicate (ortho, meta, di &

trisilicates), potassium silicate &

lithium silicate.

10. The process claim 1, wherein allows for wood preservative chemical retentions to range from 0.1 kg/m3 copper (Cu) to 20 kg/m3 copper (Cu) for the copper based wood preservatives.

11. The process claim 1, wherein allows for the alkali metal silicates (flame retardants) chemical retentions to range from 0.2 kg/m3 Si (for Sodium, Potassium &

Lithium) to 35 kg/m3 Si (for Sodium, Potassium &

Lithium).

12. The process of claim 1, includes a chemical penetrant (oxygenate type) that assists in the chemical impregnation (penetration) of the alkali metal silicates.

13. The process of claim 1, wherein said other additives (i.e. water repellents, and colourants) included in the chemical formulation (working solution) &

impregnation treatment process to produce other value added properties of wood such as increased dimensional stability &

colour.

14. The process of claim 1, wherein allows the heat (fixation) process temperature for the ‘

treated flame retardant’

to be within the range 50 C to 150 C (centigrade)

15. The process of claim 1, wherein allows the heat (fixation) process temperature for ‘

treated flame retardant’

Thermally Modified Timber (TMT) in the range 150 C to 250 C

16. The process of claim 1, wherein allows the heat (fixation) process temperature for ‘

flame retardant’

Thermally Modified Timber TMT) in the range 150 C to 250 C.

17. The product produced by claim 15, 16, wherein the Thermally Modified Timber (TMT) product possess the property of increased fire retardancy

18. The process of claim 1, wherein the ‘

treated flame retardant Modified Wood [tfrMW] will meet the Australian Bushfire Standard (AS3959 BAL29) &

the USA Forest fire Standard (ASTM E

     84).

19. The process of claim 1, wherein include wood species;

radiata pine (pinus radiata), western red cedar &

other cedars, douglas fir, southern yellow pine, scots pine, hoop pine, slash pine &

all the other soft &

hard type pines.