Wood Characteristics, Machining Wood Characteristics, Machining & Coating Properties& Coating Properties

of Rubberwood Plantation of Rubberwood Plantation in Chinain China

Haikou 2008-12-08

International Workshop on Rubberwood Processing International Workshop on Rubberwood Processing Technology and Promotion of Sustainable Technology and Promotion of Sustainable DevelopmentDevelopment

Youke ZHAO Xiaomei JIANG Jianxiong LU

（ Research Institute of Wood IndustryChinese Academy of Forestry ）

Main Contents

1. Rubberwood Characteristics

2. Rubberwood Machining Properties 3. Rubberwood Coating Properties

4. Comparison of Machining & Coating Properties between Rubberwood and Others

1. 1 Anatomical properties 1.2 Chemical properties 1.3 Physical & mechanical properties 1.4 Tension wood 1.5 Natural durability

1. 1. Rubberwood CharacteristicsRubberwood Characteristics

Macroscopic features ：

Wood whitish yellow or pale cream, then turn light brown

Texture moderate coarse to even

Grain straight to slightly interlocked

1. 1 A1. 1 Anatomical propertiesnatomical properties

Microscopical photos of rubberwood for transverse, radial & tangential sections

Proportion of wood tissue: Fiber: 61.5% ， Vessel: 9.5% ， Rays+Parenchyma: 29%

1.2 1.2 Chemical propertiesChemical properties

Tab.1 Chemical composition of rubberwood（%）

LigninHolocellu

lose-Cellul

ose Hemicellu

lose 1% NaOH extractives

Benzene-alcohol

extractives Ash

20.29 70 40 20 16.21 6-10 0.8-2.3

1.3 Physical & mechanical properties1.3 Physical & mechanical properties

Test material : dried center lumbers (2 m (l) x 45mm(thickness)) from 27 rubber trees grown in Hainan Provided by Lezhoug Timber Plant of Hainan Nongken Timber Industry Co.

Tab.2 Physical & mechanical properties of rubberwood

Density and Density and strength strength ：： MiddleMiddle

Species number

Air dried density g/cm3

Compression strength

parallel to the grain MPa

Bending strength

MPa

Modulus of elasticity

GPa

Toughness kJ/m2

Average 0.653 43.4 87.9 8.807 25.8

Standard deviation

0.036 4.833 11.351 1.343 9.065

1.4 1.4 Tension woodTension wood

Tension wood is common in rubberwood

impact of typhoon, existing in the tilt trunk and branch

distinctly different from the normal wood in anatomical, physical & mechanical and chemical properties

An important defect, should be paid more attention

Fibers with a gelatinous layer (G-layer)

• Differs in color and texture from the normal wood

• Fibers with a gelatinous layer (G-layer)

•Rough surface is readily occured when sawing, affecting the quality of lumbers

1.4 1.4 Tension woodTension wood

1.5 Natural durability1.5 Natural durability

• Only sapwood (no heartwood), non-durabl, easy decay,

•fresh sawn timber should be rapidly treated and dried

2. 2. Rubberwood Machining PropertiesRubberwood Machining Properties

-- Planing

-- Sanding

-- Boring

-- Shaping

Testing Method: ASTM D-1666 Grade I: Excellent (no defects) 5 pts. Grade II: Good (light defects which can be eliminated

by light sanding) 4pts Grade III: Fair (some obvious defects which can be

eliminated by sanding) 3 pts

Grade IV: Poor (deep and big defects which is hard to eliminate) 2 pts

Grade V: Very poor (prohibited to use) 1point

OVERALL POINT: 5*GradeI%+4*GradeII%+3*GradeIII%+2*GradeIV%+1*GradeV%

QUALITY LEVEL: excellent (4-5 points), good (3-4 points), fair (2-3 points), poor

(1-2 points), and very poor (<1point)

Tab. 3 The number of specimen and the size for testing machining properties

Testing materialsTesting materials

Machining itemsThickness ×width × length

（mm）Specimen amount（ piec

es）

planning 19×102×910 27

sanding 11×110×400 27

boring 19×76×510 27

shaping 19×76×510 27

KUW-500F1 automatic feed 2 faces plannerKUW-500F1 automatic feed 2 faces planner

2.1 Planing properties 2.1 Planing properties

Testing results of planing

No defects sample

Torn Grain

Planing testing resultsPlaning testing results ：：

All belong to Grade I (Excellent Level)Excellent Level)

Torn grain is main defects

Tab 4. Planing results of different planing thickness

Planing thickness

Grade I proportion（ %）

Grade II proportion（%）

Grade III proportion （ %）

Quality points

1.6mm40.74 3.70 4.52

0.8mm 81.48 18.52 0.00 4.82

2.2 Sanding 2.2 Sanding propertiesproperties

WS-65 Wide Belt Sander

Feed speed ： 5.8m/min5.8m/min

Sand paper ： 120#120#

Sanding thickness:0.3mm0.3mm

Grade I sample

Sanding TestingSanding Testing

Sanding defect － light fuzzy grain

Excellent (Grade 1) and Good (Grade 2 ) specimens : 59.26% & 40.74% ， quality points: 4.59 ， belong to ExcellentExcellent

Main defect: fuzzy grain

Sanding testing resultsSanding testing results ：：

B13S Bench B13S Bench BorerBorer

2.3 Boring properties2.3 Boring properties

Boring Testing resultsBoring Testing results

钻孔试样（孔上周缘）

Grade I sample

Boring Testing resultsBoring Testing results

Bottom edge tear outing and fuzzy grain

Grade I and Grade II ： 59.2659.26 % % and 40.40.74%74% ； quality points: 4.594.59, meaning exceexcellentllent

Main defects tear outing and fuzzy grain

along the edge of hole

Boring testing resultsBoring testing results

Forming ToolForming Tool

MX519 Single Spindle Moulder

2.4 Shaping properties2.4 Shaping properties

Shaping testing resultsShaping testing results

Without defects, fuzzy grain & burning samples

Grade I and Grade II ： 66.67%66.67% and 33.33%33.33% ； quality point: 4.674.67 Quality level: excellentexcellent

Main defects ： fuzzy grain & burning

Shaping testing resultsShaping testing results

3. Rubberwood Coating Properties3. Rubberwood Coating Properties

An important process for high added-

value wood products

Protected and decorated

Coating adhesionCoating adhesion ：： Based on ASTM D3359-93,

a cutter is used to cut on the coating surface

Wearability of coatingWearability of coating: based on GB/T17657-199

9 ， equipment is Taber Abrasion Resistance typ

e instrument

3. Rubberwood Coating Properties3. Rubberwood Coating Properties

Three coating processes ： 1 ) brush the water-soluble painting 3 times 2) brush polyester paintings 3 times 3) brush the water-soluble painting twice and then to

brush polyester painting once

3.1 Test methods of adhesion and wearability 3.1 Test methods of adhesion and wearability of coatingof coating

A cutterA cutter Taber Taber Abrasion Resistance InstrumentAbrasion Resistance Instrument

3.1 Coating adhesion classification3.1 Coating adhesion classificationTab. 5 Classification of adhesion results

Grade ASTM Classification

Description

I

5B The edges of the cuts are completely smooth; none of the squares of the lattice is detached.

4B Small flakes of the coating are detached at intersections; less than 5 % of the area is affected.

II 3B Small flakes of the coating are detached along edges and at intersections

III 2B The coating has flaked along the edges and on parts of the squares.The area affected is 15 to 35 % of the lattice.

IV 1B The coating has flaked along the edges of cuts in large ribbons and whole squares have detached. The area affected is 35 to 65 % of the lattice.

V 0B Flaking and detachment worse than Grade 1.

Test results of coating adhesion Test results of coating adhesion

Tab. 6 The adhesion properties of 3 coating processes

Coating Processes

Grade I(%)

Grade II(%)

Grade III(%)

Quality points

The first 44.44 44.44 11.11 4.33

The second 0.00 44.44 55.56 3.44

The third 77.78 22.22 0.00 4.78

3.2 Wearability of coating3.2 Wearability of coating

Wearability of coating: the anti-abrasion capa

city of solid wood, which is very import for flo

oring

According to the weight loss per 100 rotates abrasion:

Grade I≤0.08g/100r 5pts

0.08g <Grade II ≤0.10g/100r 4pts

0.10g/100g <Grade III(Qualified)≤0.15g/100r 3pts

Grade IV: >0.15g/100r 2pts

Similar equation was used to calculate the OVERALL

Quality points

3.2 Wearability of coating3.2 Wearability of coating

Testing results of wearability of coatingTesting results of wearability of coating

Tab. 7 Wearability of coating of 3 different coating process

Coating Process Grade I（%）

Grade II

（%）Grade III（%）

Grade 4（%）

Quality Points

The first 100.00 5.00

The second 22.22 77.78 0.67

The third 33.33 66.67 4.33

4. Comparison of Machining & 4. Comparison of Machining & Coating Properties between Coating Properties between Rubberwood and OthersRubberwood and Others

Quality level of machining & coating properties of rubber wood are

excellentexcellent

Very poor Poor Fair Good Excellent

0 1 2 3 4 5

wearability of coatingcoating adhesion

shaping

boring

sanding

planing

ItemsRubber wood

Oak Walnut Birch

Planning

Proportion of Grade 1 and 2

100 100 93.3 100

Quality level excellentexcellent excellent excellent excellent

Sanding

Proportion of Grade 1 and 2

100 100 100 96.88

Quality level excellentexcellent excellent excellent excellent

Boring

Proportion of Grade 1 and 2

100 100 100 100

Quality level excellentexcellent excellent excellent excellent

Shaping

Proportion of Grade 1 and 2

100 82.8 90 96.7

Quality level excellentexcellent good excellent excellent

Coating adhesion

Proportion of Grade 1 and 2

100 100 -- 100

Quality level excellentexcellent excellent -- excellent

Wearability of coating

Proportion of Grade 1 and 2

100 100 -- 100

Quality level excellentexcellent good -- good

The machining and coating properties are all excellent and wit

hin the Grade I range, which is better than that of furniture common used species such as oak, walnut and birch. Therefore, from the aspect of machining & coating properties, the rubberwood is good for solid wood products such as furniture and flooring

5. Conclusion5. Conclusion

Furniture are made of rubberwood

Kitchen board, knife rest and boxes are made of rubberwood

For your attentionFor your attention

谢谢谢谢