New European Quality Draft Standards for silk fabrics(1)
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2007-05-11 11:27:00
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TO ESF MEMBERS
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May 2007
Dear Sirs,
Some months ago the European Silk Forum has decided to promote the Europeanization of standards for the quality of silk fabrics on the basis of rules already existing in France and Italy.
The technicians have met and have prepared a common draft of standards for:
- Silk woven fabrics for women’s wear;
- Silk foulards and scarves;
- Silk woven fabrics for ties.
We invite you to check the parameters and to eventually send your remarks to silkforum@unindustria.co.it, within July 15.
European Silk Forum
The Secretariat
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Draft standard
Textiles – Silk woven fabrics for women’s wear – Requirements and test methods
1 Scope
This standard specifies the requirements for some basic technical and performance properties of silk woven fabrics for women’s wear along with the test methods for their evaluation.
This standard applies to all types of woven fabrics and includes requirements for ecological parameters, product care and general recommendations for textile labeling concerning fiber content.
This standard can be used:
- to agree fabric specifications between supplier and customer;
- as a reference for a company’s quality system;
- for the fabric supplier’s declaration of conformity;
- for product certification purposes by certification bodies.
Any properties not considered in this standard are to be specified by contract agreement.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 139 Textile – Standard atmospheres for conditioning and testing
ISO 7211-1 Textiles – Woven fabrics – Construction – Methods of analysis – Part 1: Methods for the presentation of a weave diagram and plans for drafting, denting and lifting
ISO 7211-5 Textiles – Woven fabrics – Construction – Methods of analysis – Part 5: Determination of linear density of yarn removed from fabric
ISO 7211-4 Textiles – Woven fabrics – Construction – Methods of analysis – Part 4: Determination of twist in yarn removed from fabric
EN ISO 13937-1 Textiles – Tear properties of fabrics – Part 1: Determination of tear force using ballistic pendulum method (Elmendorf)
EN ISO 13936-1 Textiles – Determination of the slippage resistance of yarns at a seam in woven fabrics
EN 1049-2 Textiles – Woven fabrics – Construction – Methods of analysis – Determination of number of threads per unit length
EN ISO 3071 Textiles – Determination of pH of aqueous extract
EN 1773 Textiles – Fabrics – Determination of width and length
EN 12127 Textiles – Fabrics – Determination of mass per unit area using small samples
EN 25077 Textiles – Determination of dimensional change in washing and drying
EN ISO 6330 Textiles – Domestic washing and drying procedures for textile testing
EN ISO 105-C06 Textiles – Tests for colour fastness – Colour fastness to domestic and commercial laundering
EN ISO 105-D01 Textiles – Tests for colour fastness – Colour fastness to dry cleaning
EN ISO 105-E04 Textiles – Tests for colour fastness – Colour fastness to perspiration
EN ISO 105-X11 Textiles – Tests for colour fastness – Colour fastness to hot pressing
EN ISO 105-X12 Textiles – Tests for colour fastness – Colour fastness to rubbing
EN ISO 3175-1 Textiles – Dry cleaning and finishing – Method for assessing the cleanability of textiles and garments
EN ISO 3175-2 Textiles – Dry cleaning and finishing – Procedures for tetrachloroethene
EN ISO 3759 Textiles – Preparation, marking and measuring of fabric specimens and garments in tests for determination of dimensional change
EN ISO 13934-1 Textiles – Tensile properties of fabrics – Determination of maximum force and elongation at maximum force using the strip method
EN ISO 14184-1 Textiles – Determination of formaldehyde – Free and hydrolyzed formaldehyde (water extraction method)
EN ISO 105-B02 Textiles – Tests for colour fastness – Colour fastness to artificial light: Xenon arc fading lamp test
BS 2819 Methods for determination of bow, skew and lengthway distortion in woven and knitted fabrics
DIN 53894-2 Testing of textiles – Determination of dimensional change of textile fabrics – Steaming on ironing machines
UNI 11057 Textiles – Chemical tests – Determination of pentachlorophenol - tetrachlorophenol and their salts and esters in the textiles
3 Sampling
From each commercial or production lot, take three pieces of fabric in a random manner; from each of them take laboratory specimens of a size suitable for the tests to be done.
If the lot consists of less than three pieces, samples will be taken from each piece of fabric.
Samples must not present any alterations or visible defects, such as holes, tears, stains, differences in colour, etc. Moreover, samples must be representative of all colours/patterns in case of colour fastness tests.
4 Requirements and test methods
The requirements specified in this standard concern properties that can be evaluated by laboratory tests or sensorial (visual) assessment of the fabric or are defined by tolerances allowed.
The properties and relevant test methods considered are as follows:
- structural characteristics (4.1);
- physico-mechanical characteristics (4.2);
- colour fastness (4.3);
- colour conformity (4.4)
- ecological characteristics (4.5);
- fibre content labelling (4.6);
- care information(4.7).
4.1 Structural characteristics
4.1.1 Fabric construction (ISO 7211-1)
The fabric construction must correspond to that specified in the contract.
4.1.2 Mass per unit area (EN 12127)
The articles falling within the scope of this standard can be classified into four categories:
category A : £ 40 g/m2;
category B : from 41 g/m2 to 80 g/m2;
category C : from 81 g/m2 to 160 g/m2;
category D : > 160 g/m2.
In any case, the tolerance allowed on the value declared by the supplier is ±5%.
4.1.3 Width (EN 1773)
Total fabric width is meant as the distance from the outermost yarn of the piece on one edge to the outermost yarn on the other edge, measured perpendicular to the warp direction.
Usable fabric width can be meant as:
- the distance from the outermost yarn of the piece on one edge to the outermost yarn on the other edge excluding the selvages;
- the print width;
- the dimension included within marks left by any finishing apparatuses;
The tolerance is calculated on the most restrictive conditions among those mentioned above.
The tolerance allowed on the total or the usable fabric width declared by the supplier is -1%. There are no limits in case of a width exceeding the nominal value.
4.1.4 Threads (picks) per unit length (EN 1049-2)
The tolerance allowed on the value declared by the supplier, expressed as threads/cm or picks/cm, is ± ±2% with a minimum of one thread/cm
4.1.5 Linear density (size) and twist of yarn removed from fabric (ISO 7211-4 and ISO 7211-5)
The results of the measurement of size and twist must be related to the corresponding values for the same fabric in the raw state.
The tolerance allowed on the nominal yarn size (related to the raw fabric) declared by the supplier on an average basis is ±7% for a yarn size between 22.2 and 24.4 dtex (20-22 deniers).
The tolerances allowed on twist values are shown below:
Table 1
Twist(turns/min) Tolerance allowed(%)
150 3 t/min 15
300 3 t/min 3 151 10
700 3 t/min 3 301 7
t/min 3 701 5
4.2 Physico-mechanical characteristics
4.2.1 Tensile properties – Maximum force (Strip method) (EN ISO 13934-1)
Depending on the mass per unit area of the fabric, the minimum acceptable values are as follows:
Category A : 150 N;
Category B : 250 N;
category C: 300 N;
category D: 450 N.
4.2.2 Tear properties of textiles – Tear force (Ballistic pendulum method) (EN ISO 13937-1)
The test consists in measuring the tear force required to propagate a single-rip tear of a defined length from a cut in a fabric when a sudden force is applied. This force is dependent on the mass per unit area of the fabric, as shown below:
Category A: 0.5 daN;
Category B 0.7 daN;
Category C 0.8 daN;
Category D: 1 daN.
4.2.3 Slippage resistance of yarns at a seam (EN ISO 13936-1)
The result is expressed as the force (N) required to produce a 6 mm yarn slippage at a standard seam. Depending on the mass per unit area of the fabric, the minimum acceptable values are as follows:
Category A: 60 N;
Category B : 80 N;
Category C: 110 N;
Category D: 130 N.
4.2.4 Skew distortion (Angular displacement of weft yarns) (BS 2819)
The skew distortion must not exceed:
- 2.5% for Category D
- 4% for Category A & B & C
- 1.5% for printed fabrics & geometric pattern (weft/pattern displacement).
4.2.5 Dimensional change following steaming on ironing machines (DIN 53894-2)
The maximum dimensional change allowed for fabrics subjected to steaming on ironing machines is as follows:
- fabric yarn twist £ 700 turns/min: ±3%;
- fabric yarn twist 3 701 turns/min: ±4%.
4.2.6 Dimensional change in laundering treatments
The test conditions must be chosen and applied according to the method of maintenance prescribed for the fabric (4.7).
The test methods used are as follows:
- EN ISO 3175 Parts 1-2-3-4 (Sensible procedure with finishing treatment according to Method A);
- EN 25077;
- EN ISO 6330 (Washing cycle: simulated hand washing and drying method C: flat drying).
The maximum tolerances allowed for the dimensional change in laundering treatments are:
- washing: ±3%;
- professional cleaning: ±2%.
4.3 Color fastness
The color fastness properties required for fabrics falling within the scope of this standard are as follows:
- color fastness to artificial light;
- color fastness to rubbing (dry and wet);
- color fastness to perspiration (acid and alkali);
- color fastness to dry cleaning;
- color fastness to domestic and commercial laundering;
- color fastness to hot pressing.
The minimum foreseen requirements are reported in Table 2.
Table 2 – Minimum requirements
Type of fabricFibre content: 100% silk Dyeing/printing technologyYarn and piece dyeing + printing
Property Minimum requirements
Colour fastness Test method Cange in colour Staining
Artificial light EN ISO 105-B02 3 -
Dry rubbing EN ISO 105-X12 - 3
Wet rubbing EN ISO 105-X12 - 3
Acid perspiration EN ISO 105-E04 3 3
Alkali perspiration EN ISO 105-E04 3 3
Dry cleaning* EN ISO 105-D01 4 4
Domestic and commercial laundering* EN ISO 105-C06 4 3
Hot pressing EN ISO 105-X11 4 -
*These requirements are dependent on the care instructions reported in 4.7.
4.4 Color conformity
4.4.1 Color reproducibility
It is not possible to guarantee a perfect color reproducibility in an industrial process. This is true particularly in the case of the correspondence between the colors of the sample piece and those of the following production lots.
Color conformity must be tested under standard conditions. The difference between production lots and sample piece as well as among different production lots must never be lower than level 4 (tolerance - 0.5) of the gray scale (EN ISO 20105-A02). In case of instrumental test according to CMC (2:1)-D65 Specifications, the difference must not exceed DE 1.0.
The dyeing lot identification code must be indicated by the supplier on the label of each piece of fabric.
4.4.2 Color uniformity
Color conformity must be tested under standard conditions. The tolerated difference between the middle area and the selvedges of the fabric or between the first and the last portion of the piece must never be lower than level 4/5 (tolerance - 0.5) of the gray scale (EN ISO 20105-A02) in visual assessment. In case of instrumental test according to CMC (2:1)-D65 Specifications, the difference must not exceed DE 0.6.
4.5 Ecological characteristics
The ecological properties of textiles are of great importance today, even for marketing reasons. This is confirmed by the EU legislation in force at the time of publication of this standard.
A selection of the most significant toxicological parameters has therefore been made:
Note 1: EEC Council Regulation No. 880/92 of 23rd March 1992 on a Community eco-label award scheme.
Note 2: European Commission Decision of 17th February 1999 (OJEC L57/21 of 5th March 1999) establishing the ecological criteria for the award of the Community eco-label to textile products.
4.5.1 pH of aqueous extract (EN ISO 3071)
The pH of the aqueous extract of the finished fabric, determined by cold extraction in distilled or deionized water or in a 0.1 M potassium chloride solution, must be in the range 5-7.5 pH units.
4.5.2 Free and hydrolyzed formaldehyde (EN ISO 14184-1)
The amount of free and hydrolyzed formaldehyde in the dyed fabric must not exceed 75 ppm.
4.5.3 Pentachlorophenol and tetrachlorophenol (UNI 11057)
Use of pentachlorophenol, tetrachlorophenol and their salts and esters is not allowed. The amount detected must not exceed 0.05 ppm.
4.5.4 Azo dyes (EN ISO 14362-1-2)
The legislation in force at the time of publication of this standard applies.
Note: European Parliament and Council Directive 2002/61/EC of 19th July 2002 on azo dyes.
4.6 Fibre content labelling
The legislation in force must be applied.
At the date of the writing of this standard :
Note 1: European Parliament and Council Directive 96/74/EC of 16th December 1996 on textile names.
Note 2: European Parliament and Council Directive 96/73/EC of 16th December 1996 on certain methods for the quantitative analysis of binary textile fibre mixtures.
Note 3: European Parliament and Council Directive 73/44/EC of 26th February 1973 on certain methods for the quantitative analysis of ternary textile fibre mixtures.
Note 4: European Parliament and Council Directive 97/37/EC of 19th June 1997 adapting to technical progress Annexes I and II to European Parliament and Council Directive 96/74/EC on textile names.
4.7 Care Information
Care labeling is the means of communication used by the producer to provide the consumer with information about the methods for an adequate maintenance of the garment.
To select the right conditions, it is necessary to objectively evaluate the durability, color fastness and dimensional stability properties of the fabric used.
Annexes Informatives
Table 1- Fabrics denominations
Category A very light/transparent fabrics
Category B light fabrics
Category C middle-weight fabrics
Category D heavy fabrics
Table 2
Yarns denominations
Type of yarn Twist (turns/min)
Trame < 300
Organzine, first twist 750/800
Organzine, second twist 650/700
Grenadine, first twist 1500/1600
Grenadine, second twist 1400/1500
Crêpe, 4 or more ends 2200/2400
Crêpe, 3 ends 1600/2700
Crêpe, 2 ends 2800/3000
Highly twisted single end 2700/3100
Source:Industry Website