Table 1. Broadleaf Timber Plywood Gradation

Categories of defects

Inspection Item

Face

Back

Grade Of Plywood

AA Grade

A Grade

B Grade

C Grade

(1)Pin knots

””

Allowed

(2)Inter grown knots

maximal single diameter (mm)

10

20

Not Restricted

(3)partially inter grown knots, dead knots, inbark

the entries on one  side per square meter

Not allowed

3

4

6

Not Restricted

””

partially inter grown knots

maximal single diameter (mm)

Not allowed

10 25
(not counted up to 5)

Not Restricted

Dead knots

maximal single diameter (mm)

Not allowed

4
(not counted up to 2)

6
(not counted up to 4)

15

50

Inbark

maximal single length (mm)

Not allowed

15
(not counted up to 5)

30
(not counted up to 10)

Not Restricted

(4)Abnormal structure

””

Allowed

(5)Split

maximal single width (mm)

Not allowed

1
Basswood:0.5
Southern Timber:1.5

1.5
Basswood:1
Southern Timber:2

3
Basswood:1.5
Southern Timber:4

6

maximal single length (mm)

200
Southern Timber:250

300
Southern Timber:350

400
Southern Timber:450

Not Restricted

(6)Worm holes,dog holes,holes

maximal single diameter (mm)

Not allowed

2

4

8

15

the entries on one side per square meter

4

4(not counted up to 2mm)

Not Sifter Shape Appearence£¬Not Restricted

(7)Discoloration

Not exceed the area of side(%)

Not Allowed

5

25

Not Restricted

Note: ¢ŁTint fleck streaks is counted as discoloration£»
¢ŚA grade: fuscous fleck streaks not exceed 20mm in length and 2mm in width;
¢ŪB grade: fuscous fleck streaks not exceed 150mm in length and not exceed 3 spots per m2
¢ÜBasswood Board(except AA grade),false heartwood is allowed ,but the color and luster of the A grade should be attempered
¢ŻBasswood board (A gradee),brown or black pith flecks are not allowed;
¢Ž(AA grade) limbic heartwood of different color are counted as discoloration

(8)Rot

””

Not allowed

Symbols of incipient decay are allowed if not affect  strength ,yet the area not exceed 1% of the side area

incipient decay is allowed but the veneer of this part will not flake off,also can't be twisted into powder

(9) outer ply open joint

Max. single width(mm)

Not allowed

0.5

1

2

Max. single length account for the length of the panel (%)

10

30

50

Bar /metre in width

1

2

Not restricted

(10) outer ply overlap

Max single width(mm)

Unallowed

8

Not restricted

Max. single length account for the length of the panel (%)

20

(11)Core gap

The core gap appressed to outer ply

Max single width(mm)

Not allowed

2

4

8

10

Bar /metre in width

2

3
(not counted up to 2mm)

Not restricted

The max gap width of other ply(mm)

10

(12)centers gap

Max single width (mm)

Not allowed

10

(13) blister,

delamination

””

Not allowed

(14)Hollow,

imprint,bump

Max. single area(mm2)

Not allowed

50

400

3000

Not restricted

the entries on one side per square meter

1

4

Not restricted

(15) torn grain

Not exceed side area(%)

Not allowed

1

3

25

Not restricted

The depth not exceed(mm)

0.4

Not penetrate through, allowed

(16)outer ply sanding through

Area on side per mm2

Not allowed

1000

Not restricted

(17)glue penetration & any other manmade stain

Not exceed side area(%)

Not allowed

0.5

3

30

Not restricted

(18)patchӢshim

Allowed(If made in proper way and fill up durably),the entries on side per m2

Not allowed

3

Not restricted

Not restricted

add up to not exceed side area(%)

0.5

3

Gap not exceed(mm)

0.5

1

2

(19)aluminous inclusions

””

Not allowed

allowed

(20)defects at the edges of the panel

Not exceed  mm(within the nominal breadth)

Not allowed

5

10

(21)other defects

””

Not allowed

Regarded as the most similar defects

Table 2. conifer timber plywood gradation

Categories of defects

Inspection Item

Face

Back

Grade Of Plywood

AA Grade

A Grade

B Grade

C Grade

(1) Pin knots

””

allowed

(2)intergrown knots,partially intergrown knots,dead knots

the entries on one  side per square meter

Not allowed

5

8

10

Not restricted

””

Intergrown knots

Max. single diameter (mm)

Not allowed

(not counted up to 10)

Not restricted

partially inter grown knots,dead knots

Max. single diameter (mm)

Not allowed

5

15
(not counted up to 5)

30
(not counted up to 10)

Not restricted

(3)Abnormal structure

””

allow

(4)inbarkӢresin pocket

the entries on one  side per square meter

Not allowed

3 4
(not counted up to 10)

10
(not counted up to 15)

Not restricted

””

inbark

Max. single length (mm)

Not allowed

15

60

Not restricted

resin pocket

Max. single length (mm)

Not allowed

15

30

Not restricted

(5)split

maximal single width (mm)

Not allowed

1

1.5

3

6

maximal single length (mm)

200

400

800

Not restricted

(6)Worm holes, dog holes, holes

maximal single diameter (mm)

Not allowed

2

5

8

15

the entries on one side per square meter

4

5
(not counted up to 2mm)

10
(not counted up to 5mm)

If not Sifter Shape Appearance then not Restricted

(7)Discoloration

Not exceed the area of side(%)

Not allowed

tint 10

30

Not restricted

(8)Rot

 

Not allowed

Symbols of incipient decay are allowed if not affect  strength ,yet the area not exceed 1% of the side area

incipient decay is allowed but the veneer of this part will not flake off, also can't be twisted into powder

(9)Resin streak

Max single length(mm)

Not allowed

150

Not restricted

Max. single length account for the length of the panel (%)

10

the entries on one  side per square meter

4

(10) outer ply open joint

Max. single width(mm)

Not allowed

0.5

1

2

Max. single length account for the length of the panel (%)

10

30

50

Bar /metre in width

1

2

Not restricted

(11)outer ply overlap

Max single width(mm)

Not allowed

8

Not restricted

Max. single length account for the length of the panel (%)

20

(12)core gap

The core gap appressed to outerply

Max single width(mm)

Not allowed

2

4

8

10

Bar /metre in width

2

3
(not counted up to 2mm)

Not restricted

The max gap width of other ply(mm)

10

(13)centers gap

Max single width (mm)

Not allowed

10

(14)blister,

delamination

””

Not restricted

(15)hollow, imprint,

bump

Max. single area(mm2)

Not allowed

50

400

3000

Not restricted

the entries on one side per square meter

2

4

Not restricted

(16)torn grain

Not exceed side area(%)

Not allowed

5

20

60

Not restricted

The depth not exceed(mm)

0.5

Not penetrate through, allowed

(17)outer ply sanding

   through

Area on side per mm2

Unallowed

1000

Not restricted

(18) glue penetration

 & any other manmade

stain

Not exceed side area(%)

Not allowed

1

10

Not restricted

(19)patchӢshim

Allowed(If made in proper way and fill up durably),the entries on side per m2

Not allowed

6

Not restricted

add up to not exceed side area(%)

1

5

Not restricted

Gap not exceed(mm)

0.5

1

2

(20)aluminous inclusions

””

Not allowed

allow

(21) defects at the edges of the panel

Not exceed (mm)  (within the nominal breadth)

Not allowed

5

10

(22) other defects

””

Not allowed

Regarded as the most similar defects