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Specification for high silica glass fabric
1 Scope
1.1 Subject content
This specification specifies the technical requirements and quality assurance regulations of high silica glass fabric (referred to as the "high silica fabric").
1.2 Application scope
This specification is applicable to borosilicate glass fabric, and the high silica fabric made by acid leaching, thermal sintering, and other methods.
2 Normative references
GB 191-85 Packaging - Pictorial marking for handling of goods
GB 3691-83 Terms and definitions for fibre reinforced plastics
GB 5434-85 Terms and definitions for textile glass
GB 7689.2-87 Textile glass - Woven fabrics - Determination of number of yarns per unit length of warp and weft
GB 7689.3-88 Textile glass - Woven fabrics - Determination of mass per unit area
GB 7689.4-89 Textile glass - Woven fabrics - Determination of width and length
GB/T 7689.6-89 Textile glass - Woven fabrics - Determination of tensile breaking force and breaking elongation (strip method)
GJB 179-86 Sampling procedures and tables for inspection by attributes
3 Requirements
3.1 Qualification
The products delivered according to this specification shall be products that have been identified as qualified or approved.
3.2 Base fabric
3.2.1 High silica base fabric is made of borosilicate glass fiber.
3.2.2 The specification of the base fabric shall meet those specified in Table 1.
3.3 Products
3.3.1 Specifications and physical and chemical properties
3.3.1.1 Specifications and physical and chemical property indexes of high silica fabric shall meet the requirements of Table 2.
Table 1
Nominal thickness mm 0.250
Nominal fiber diameter μm Warp 7
Weft 7
Nominal linear density tex Warp 112
Weft 96
Nominal twist T/m Warp 120
Weft 120
Table 2
Product code BWT260—82
Loss on heating % ≤ 3.0
Content of SiO2 % ≥ 96.0
Thickness mm 0.260 ± 0.026
Fabric density pcs/cm Warp 14 ± 1.0
Weft 14 ± 1.0
Mass per unit area g/m2 240 ± 20
Tensile breaking force N Method A Warp direction ≥ 440
Weft direction ≥ 290
Method B Warp direction ≥ 290
Weft direction ≥ 190
3.3.1.2 Unless otherwise specified, the width of the high silica fabric shall be 82 ± 2.0 cm.
3.3.1.3 Unless otherwise specified, the piece length of high silica fabric shall be 85 ± 8.5 m, and splicing is not allowed. For short fabric rolls that do not meet the requirements of piece length, but the length is not less than 30 m, it is allowed to leave the factory in the proportion of not more than 10%.
3.3.1.4 Unless otherwise specified, the weave of high silica fabric shall be plain weave.
3.3.2 Appearance quality
3.3.2.1 The color of high silica fabric is white or light brown.
3.3.2.2 High silica fabric shall not have crease, damage, pollution, pilling and other defects that affect the use.
3.3.2.3 The cloth surface of high silica fabric shall be kept flat, and free from loose on one side but tight on the other, or loose on both sides but tight in the middle.
3.3.2.4 According to Table 3, the appearance defect degree and deduction points of high silica fabric shall not be more than 60 points per 100 meters of fabric on average.
3.3.2.5 Each piece of fabric is allowed 4 false cuts.
Table 3
No. Defect name Defect degree Deduction
1 Broken warp Single broken warp, every 10 cm long
Double broken warp, every 3 cm long 1
1
2 Elastic warp Every 1 m long for each elastic warp 1
3 Coarse and fine warp Twice as coarse or fine as the original warp, every 1 m long 1
4 Weft crackiness More or less 2 weft yarns within 1 cm warp direction 1
More or less 3 (or above) weft yarns within 1 cm warp direction 5
5 Sloughed-off weft More than 2 per shuttle 5
6 Gout With width of 1 ~ 3 mm, each piece
With width of 3 mm and above, each 1
5
7 Joint trace Over 90 mm in length, each 1
8 Throwing of weft Throwing of weft over 1 cm on the fabric surface, each 1
9 Defective selvedge Looped pile with raw edge, rotten edge, and protruding edge of more than 5 mm, every 10 cm long in the warp direction 1
10 Crease Less than 5 cm
5 cm to 10 cm
Above 10cm 1
5
Cut
11 Broken hole 2 warp and weft yarns or less are broken at the same time or in total, at each place 1
Three warp and weft yarns are broken at the same time or in total, at each place 5
Three warp and weft yarns or more are broken at the same time or in total, at each place False cut
4 Quality assurance requirements
4.1 Responsibility for inspection
Unless otherwise specified in the contract or order, the manufacturing party shall be responsible for completing all inspections specified in this specification. If necessary, the ordering party or superior appraisal organization has the right to inspect any of the inspection items described in the specification.
4.1.1 Acceptable responsibility
All products must meet all requirements given in clauses 3 and 5 of the specification. The inspections specified in this specification shall be an integral part of the entire inspection system or quality program of the contractor. If the contract includes inspection requirements not specified in this specification, the contractor shall also ensure that the products submitted for acceptance meet the contract requirements. It is neither allowed to submit products that are known to be defective in quality consistency sampling nor require the ordering party to receive defective products.
4.2 Inspection classification
The inspection specified in this specification is divided into:
a. appraisal inspection;
b. quality conformance inspection.
4.3 Inspection conditions
Unless otherwise specified, the inspection environment conditions shall be: a temperature of 20 ± 3 °C, and the relative temperature of 65 ± 3%.
4.4 Appraisal inspection
In case of any of the following conditions, appraisal inspection shall generally be carried out:
a. restoration of production after halting for one year;
b. significant changes in materials, process, or equipment after formal production;
c. transfer-plant production;
d. during regular production, periodic inspection shall be carried out after certain output has been accumulated;
4.4.1 Inspection items
The inspection items include all the items required in 3.3.
4.4.2 Sampling scheme
4.4.2.1 Batch: take the same batch of raw materials and high silica fabric produced in the same process as one batch.
4.4.2.2 Sample: the fabric rolls randomly selected from the submitted inspection batches are samples according to regulations.
4.4.2.3 Sampling: according to the general inspection level I and secondary sampling scheme stipulated in GJB 179, the acceptable quality level AQL is determined by mutual consultation between the manufacturer and the ordering party.
1 Scope
2 Normative references
3 Requirements
4 Quality assurance requirements
5 Delivery preparation
6 Instructions
Annex A Method for determination of loss on heating and silicon dioxide content of high silica glass fabric (yarn) (Supplement)
Annex B Determination of thickness of high silica glass fabric (Supplement)
Annex C Determination of tensile breaking force of high silica glass fabric (method B) (Supplement)
