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A review of British Standards for composites Part 1 Glass fibre for reinforcement
A rew'ew of British Standards for composites Part I Glass fibre for reinforcement The rapid growth and diversification of composite materials has outrun the specification writer. There are, however, certain isolated areas where British Standards exist and these standards will be reviewed in this and following issues
INTRODUCTION
Desized fabrics
Part one of this article is devoted to the most well established reinforcement for plastics- glass fibre. There are, in fact, three British Standard devoted specifically to this subject. 1'2'3 They cover (in order of publication) woven glass fibre fabrics, 1 chopped strand mat, 2 and glass fibre rovings. 3
This second part of the standard lays down requirements for glass fibre fabrics which comply with the first part of the standard, but which have been desized. A method for determining the residual size content is described in the appendix and the standard stipulates the percentage residual size content. The standard lays down the minimum breaking strengths and uniformity. The test samples shall be taken from each quantity of fibre desized in the desizing operation.
WO VEN GLASS FIBRE FABRICS This standard consists of three parts. The third part, on finished fabrics was published in 1961. The other parts, desized fabrics and loom state fabrics were published at the same time, but were revised in 1966.
Loom-state fabrics The standard describes requirements for loom-state glass fibre fabrics, intended after further treatment, for plastics reinforcement, woven from continuous filament yams in a range of thicknesses and weaves. The fabrics are made from E glass. They should comply with requirements given in Table 1. Methods of determining weight and breaking strengths are given in the appendices. When asking for the material the purchaser should remember (if he wants a standard material) to give the manufacturer the following information
a The number of warp ends required b The number of weft picks required c The count of the warp yarn and the number of filaments per strand d The count of the weft yarn and the number of filaments per strand e The weave of the fabric required
Finished fabrics The third part of this standard lays down requirements for fabrics complying with parts 1 and 2 which have been finished to make them suitable for use with polyester resin systems. The breaking strengths are specified, but the most important sections, in the author's opinion, are specifications of laminating properties and the electrical conductivity of an aqueous extract. The finished fabric when made into a laminate should wet out readily, (test laminates are described in an appendix). The test laminate must also comply to limits given in the standard for flexural strengths. Electrical conductivity of aqueous extracts must also conform to specified limits. The sample should be selected from each 2000yd of finished fabric.
CHOPPED STRAND MAT This standard, published in 1962, covers a specification for glass fibre chopped strand mat for the reinforcement of polyester resin systems. It defines the material as strands being laid at random and held together with a chemical binder for the reinforcement of polyester resin systems.
General purpose mat At least one sample shall be taken and tested from either the fabric produced from each beam or from 1830m intervals from a creel of yarn packages
Part one discusses the manufacturing specifications for general purpose mat. It should comply with Table 2. The strand shall be composed of filaments with an average fibre diameter of 8-13/am and a strand length of 25.4-50.8mm
COMPOSITES September 1970
303
Table 1
Constructional details the manufacturer should provide the purchaser with (BS 3396) Average Warp weft ends picks per 10 cm -+ 2½%
Approximate thickness
Average weight -+ 10%
Weave
P1/11 P2/11 P4/11 P5/33 P6/22 P6/33 P8/33 P14/33 P31/5.5 P32/11
mm 0.08 0.08 0.13 0.18 0.15 0-15 0.23 0.56 0.03 0.05
g/m 2 81.9 99.4 136 177 188 188 243 547 36-4 50.6
Plain Plain Plain Plain Plain Plain Plain Plain Plain Plain
177 252 252 59 142 142 142 67 213 252
173 173 165 67 126 126 102 63 197 181
tex 11-1/2 11-1/2 11-1/2 33-2/2 22-1/3 33-1/2 33-1/2 33-3/4 5.5-1/2 11-1/0
P33/5-5 P34/33 P35/33 P36/33 P37/11
0.05 0.13 0.10 0.10 0.13
55.2 51.1 77.3 82.8 125
Plain Plain Plain Plain Plain
252 75 59 126 252
220 71 51 110 158
5-5-1/2 5.5-1/2 33-1/0 33-1/0 33-1/2 33-1/2 33-1/0 33-1/0 11-1/3 11-1/2
P38/33 P40/33/5.5 T2/22 T3/22 T3/33
0.13 0.25 0.15 0.28 0.28
127 421 188 331 331
Plain
181 299 142 118 118
181 24 126 118 118
33-1/0 33-2/2 22-1/3 22-2/3 33-2/2
33-1/0 5.5-1/0 22-1/3 22-2/3 33-2/2
17.2 114.0 30.8 51-4 45-0
$2/22
0.20
306
224
213
22-1/3
22-1/3
48.8
46.3
S2/33
0.20
306
224
213
33-1/2
33 - 1/2
42.8
40.5
$11/22/11
0.20
294
189
126
22-2/3
11-1/2
82.3
$12/33
0.38
442
189
126
33-2/2
33-2/2
72.0
48.0
0S11/33
0.46
353
150
102
33-2/2
33-2/2
57.0
39.0
P41166
0.18
204
165
126
66-1/0
66-1/0
30.0
22.9
Designation
Plain 2/2 Twill 2/2 Twill 2/2 Twill 8 Shaft satin 8 Shaft satin 4 Shaft satin 4 Shaft satin Mock leno Plain
Nominal count of yarn* warp weft tex 11-1/2 11-1/2 11-1/2 33-2/2 22-1/3 33-1/2 33-1/2 33-3/4 5-5-1/0 11-1/0
Minimum average breaking strength* warp weft kgf/cm kgf/em 13-7 13.4 19.4 13.4 19.4 25.5 22.5 25.5 30.8 27.4 27.0 24-0 27.0 39.0 76.5 72.0 8-20 3-79 9.71 6.98 9.71 7.12 11.2 12.0 29.1
8.50 6-75 9-75 10.5 12.1 17.2 0-455 27.4 51.4 45.0
9.71
* No minus tolerance on the average value, but a tolerance of - 20% is permitted on individual values
(1-2in). A keying agent (methacrylatochronic or silane) shall be incorporated in the size. The cross breaking strength of a laminate is specified. Test samples shall be selected by the purchaser from each 45-000kg (100 0001b) of mat.
E glass. The filament diameters are specified and the rovings should comply with the properties shown in Table 3. A coupling agent should be incorporated in the size applied to the strand.
CONCL USION Special purpose m a t This mat must meet extra specifications in addition to those of part 1 of the standard. Samples shall be selected from each 3200kg (70001b) or 5300m (17 500ft), which ever is the greater, for determination of the cross breaking strength and the conductivity of the water extract.
GLASS F I B R E RO VlNGS This standard on rovings for the reinforcement of polyester and expoxide resin systems is the most recent (1969). It specifies requirements for glass fibre rovings made from 304
COMPOSITESSeptember 1970
This review only covers the salient points of each standard. Purchasers of these materials should be aware of the existing standards and what they can request from the manufacturer. The standards are available from The British Standards Institution, Maylands Avenue, Hemel Hempstead, Hertfordshire, England.
REFERENCES 1 BS 3532, Parts 1,2,3, HMSO, London (1961, 1966) 2 BS 3496, HMSO, London (1962) 3 BS 3691,HMS0, London (1969)
Table
2
Requirements for manufacture of general purpose mat (BS 3496) Frequency of testing
Properties
Nominal value
Tolerances
Length
As agreed between supplier and purchaser or as stated by supplier
-+ 12in (304mm) to nearest 6in (152mm) or -+ 1 per cent which ever is greater
Each roll
Width
36in ( 0 . 9 m ) 45in (1.3m) 72in (1"9m) or as agreed between supplier and purchaser
+ 1in -
0in (+ 25.4 - 0mm) at any point, to nearest 1/2in 12-7mm)
Each roll
Loss on ignition
Percentage as agreed between supplier and purchaser
-+ 2*
At least once per 5 000ft (1 500m)
Average weight (/f2)
l oz (305g/m 2 ) 1V2oz (458g/m 2 ) 2oz (610g/m 2 ) or as agreed between supplier and purchaser
-+ 8%
Each roll
Strand weight distribution
As agreed between supplier and purchaser
The weight of any specimen not to vary from the nominal by more than 17% and the range baded on nominal not to exceed the following values 3 specimens-20% 4 specimens-21% 5 specimens-22% 6 specimens-23%
At least once per 1 000ft (300m)
* eg nominal loss on ignition = 6%, actual loss on ignition may be between 4 and 8%
Table
3
Test requirements for glass fibre rovings as laid down in (BS 3692) Minimum frequency of testing
Property
Specified limit shall be
Roving count -+10% from Tex the nominal value stated by the supplier
Moisture content
Loss on ignition
Normal grade Selected grade each 500kg
each 250kg
0"3% maximum
each 20 000kgeach 5000kg
+20% from the nominal value stated by the supplier or -+0.2 from the nominal value whichever is the greater tolerance
each 20 000kg each 5000kg
Minimum frequency of testing Property
Specified limit shall be
Minimum crossbreaking strength 1 Reinforced polyester rod dry 58.8hbar (6000kgf/cm; ) wet 49-0hbar (5000kgf/cm 2 ) 2 Reinforced epoxide rod dry 58.8hbar (6000kgf/cm 2 ) wet 36-3hbar (3700 kgf/cm 2 ) Conductivity max 1.25/zS/m of water extract
Normal grade Selected grade
each 50 000kg each 5000kg
each 50 000kg each 5000kg
each 50 000kg each 5000kg
COMPOSITESSeptember 1970 305
INTRODUCTION
Desized fabrics
Part one of this article is devoted to the most well established reinforcement for plastics- glass fibre. There are, in fact, three British Standard devoted specifically to this subject. 1'2'3 They cover (in order of publication) woven glass fibre fabrics, 1 chopped strand mat, 2 and glass fibre rovings. 3
This second part of the standard lays down requirements for glass fibre fabrics which comply with the first part of the standard, but which have been desized. A method for determining the residual size content is described in the appendix and the standard stipulates the percentage residual size content. The standard lays down the minimum breaking strengths and uniformity. The test samples shall be taken from each quantity of fibre desized in the desizing operation.
WO VEN GLASS FIBRE FABRICS This standard consists of three parts. The third part, on finished fabrics was published in 1961. The other parts, desized fabrics and loom state fabrics were published at the same time, but were revised in 1966.
Loom-state fabrics The standard describes requirements for loom-state glass fibre fabrics, intended after further treatment, for plastics reinforcement, woven from continuous filament yams in a range of thicknesses and weaves. The fabrics are made from E glass. They should comply with requirements given in Table 1. Methods of determining weight and breaking strengths are given in the appendices. When asking for the material the purchaser should remember (if he wants a standard material) to give the manufacturer the following information
a The number of warp ends required b The number of weft picks required c The count of the warp yarn and the number of filaments per strand d The count of the weft yarn and the number of filaments per strand e The weave of the fabric required
Finished fabrics The third part of this standard lays down requirements for fabrics complying with parts 1 and 2 which have been finished to make them suitable for use with polyester resin systems. The breaking strengths are specified, but the most important sections, in the author's opinion, are specifications of laminating properties and the electrical conductivity of an aqueous extract. The finished fabric when made into a laminate should wet out readily, (test laminates are described in an appendix). The test laminate must also comply to limits given in the standard for flexural strengths. Electrical conductivity of aqueous extracts must also conform to specified limits. The sample should be selected from each 2000yd of finished fabric.
CHOPPED STRAND MAT This standard, published in 1962, covers a specification for glass fibre chopped strand mat for the reinforcement of polyester resin systems. It defines the material as strands being laid at random and held together with a chemical binder for the reinforcement of polyester resin systems.
General purpose mat At least one sample shall be taken and tested from either the fabric produced from each beam or from 1830m intervals from a creel of yarn packages
Part one discusses the manufacturing specifications for general purpose mat. It should comply with Table 2. The strand shall be composed of filaments with an average fibre diameter of 8-13/am and a strand length of 25.4-50.8mm
COMPOSITES September 1970
303
Table 1
Constructional details the manufacturer should provide the purchaser with (BS 3396) Average Warp weft ends picks per 10 cm -+ 2½%
Approximate thickness
Average weight -+ 10%
Weave
P1/11 P2/11 P4/11 P5/33 P6/22 P6/33 P8/33 P14/33 P31/5.5 P32/11
mm 0.08 0.08 0.13 0.18 0.15 0-15 0.23 0.56 0.03 0.05
g/m 2 81.9 99.4 136 177 188 188 243 547 36-4 50.6
Plain Plain Plain Plain Plain Plain Plain Plain Plain Plain
177 252 252 59 142 142 142 67 213 252
173 173 165 67 126 126 102 63 197 181
tex 11-1/2 11-1/2 11-1/2 33-2/2 22-1/3 33-1/2 33-1/2 33-3/4 5.5-1/2 11-1/0
P33/5-5 P34/33 P35/33 P36/33 P37/11
0.05 0.13 0.10 0.10 0.13
55.2 51.1 77.3 82.8 125
Plain Plain Plain Plain Plain
252 75 59 126 252
220 71 51 110 158
5-5-1/2 5.5-1/2 33-1/0 33-1/0 33-1/2 33-1/2 33-1/0 33-1/0 11-1/3 11-1/2
P38/33 P40/33/5.5 T2/22 T3/22 T3/33
0.13 0.25 0.15 0.28 0.28
127 421 188 331 331
Plain
181 299 142 118 118
181 24 126 118 118
33-1/0 33-2/2 22-1/3 22-2/3 33-2/2
33-1/0 5.5-1/0 22-1/3 22-2/3 33-2/2
17.2 114.0 30.8 51-4 45-0
$2/22
0.20
306
224
213
22-1/3
22-1/3
48.8
46.3
S2/33
0.20
306
224
213
33-1/2
33 - 1/2
42.8
40.5
$11/22/11
0.20
294
189
126
22-2/3
11-1/2
82.3
$12/33
0.38
442
189
126
33-2/2
33-2/2
72.0
48.0
0S11/33
0.46
353
150
102
33-2/2
33-2/2
57.0
39.0
P41166
0.18
204
165
126
66-1/0
66-1/0
30.0
22.9
Designation
Plain 2/2 Twill 2/2 Twill 2/2 Twill 8 Shaft satin 8 Shaft satin 4 Shaft satin 4 Shaft satin Mock leno Plain
Nominal count of yarn* warp weft tex 11-1/2 11-1/2 11-1/2 33-2/2 22-1/3 33-1/2 33-1/2 33-3/4 5-5-1/0 11-1/0
Minimum average breaking strength* warp weft kgf/cm kgf/em 13-7 13.4 19.4 13.4 19.4 25.5 22.5 25.5 30.8 27.4 27.0 24-0 27.0 39.0 76.5 72.0 8-20 3-79 9.71 6.98 9.71 7.12 11.2 12.0 29.1
8.50 6-75 9-75 10.5 12.1 17.2 0-455 27.4 51.4 45.0
9.71
* No minus tolerance on the average value, but a tolerance of - 20% is permitted on individual values
(1-2in). A keying agent (methacrylatochronic or silane) shall be incorporated in the size. The cross breaking strength of a laminate is specified. Test samples shall be selected by the purchaser from each 45-000kg (100 0001b) of mat.
E glass. The filament diameters are specified and the rovings should comply with the properties shown in Table 3. A coupling agent should be incorporated in the size applied to the strand.
CONCL USION Special purpose m a t This mat must meet extra specifications in addition to those of part 1 of the standard. Samples shall be selected from each 3200kg (70001b) or 5300m (17 500ft), which ever is the greater, for determination of the cross breaking strength and the conductivity of the water extract.
GLASS F I B R E RO VlNGS This standard on rovings for the reinforcement of polyester and expoxide resin systems is the most recent (1969). It specifies requirements for glass fibre rovings made from 304
COMPOSITESSeptember 1970
This review only covers the salient points of each standard. Purchasers of these materials should be aware of the existing standards and what they can request from the manufacturer. The standards are available from The British Standards Institution, Maylands Avenue, Hemel Hempstead, Hertfordshire, England.
REFERENCES 1 BS 3532, Parts 1,2,3, HMSO, London (1961, 1966) 2 BS 3496, HMSO, London (1962) 3 BS 3691,HMS0, London (1969)
Table
2
Requirements for manufacture of general purpose mat (BS 3496) Frequency of testing
Properties
Nominal value
Tolerances
Length
As agreed between supplier and purchaser or as stated by supplier
-+ 12in (304mm) to nearest 6in (152mm) or -+ 1 per cent which ever is greater
Each roll
Width
36in ( 0 . 9 m ) 45in (1.3m) 72in (1"9m) or as agreed between supplier and purchaser
+ 1in -
0in (+ 25.4 - 0mm) at any point, to nearest 1/2in 12-7mm)
Each roll
Loss on ignition
Percentage as agreed between supplier and purchaser
-+ 2*
At least once per 5 000ft (1 500m)
Average weight (/f2)
l oz (305g/m 2 ) 1V2oz (458g/m 2 ) 2oz (610g/m 2 ) or as agreed between supplier and purchaser
-+ 8%
Each roll
Strand weight distribution
As agreed between supplier and purchaser
The weight of any specimen not to vary from the nominal by more than 17% and the range baded on nominal not to exceed the following values 3 specimens-20% 4 specimens-21% 5 specimens-22% 6 specimens-23%
At least once per 1 000ft (300m)
* eg nominal loss on ignition = 6%, actual loss on ignition may be between 4 and 8%
Table
3
Test requirements for glass fibre rovings as laid down in (BS 3692) Minimum frequency of testing
Property
Specified limit shall be
Roving count -+10% from Tex the nominal value stated by the supplier
Moisture content
Loss on ignition
Normal grade Selected grade each 500kg
each 250kg
0"3% maximum
each 20 000kgeach 5000kg
+20% from the nominal value stated by the supplier or -+0.2 from the nominal value whichever is the greater tolerance
each 20 000kg each 5000kg
Minimum frequency of testing Property
Specified limit shall be
Minimum crossbreaking strength 1 Reinforced polyester rod dry 58.8hbar (6000kgf/cm; ) wet 49-0hbar (5000kgf/cm 2 ) 2 Reinforced epoxide rod dry 58.8hbar (6000kgf/cm 2 ) wet 36-3hbar (3700 kgf/cm 2 ) Conductivity max 1.25/zS/m of water extract
Normal grade Selected grade
each 50 000kg each 5000kg
each 50 000kg each 5000kg
each 50 000kg each 5000kg
COMPOSITESSeptember 1970 305