New European Quality Draft Standards for silk fabrics(2)
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2007-05-11 11:33:00
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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
Silk foulards and scarves
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Draft standard
Textiles – Silk foulards and scarves – Requirements and test methods
1 Scope
This standard specifies the requirements for some basic technical and performance properties of foulards and scarves made of pure silk woven fabrics along with the test methods for their evaluation.
This standard applies to all types of woven fabrics and includes requirements for ecological parameters, care information, and general recommendations for textile labeling concerning fiber content.
This standard can be used:
- to agree product 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 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 color fastness – Color fastness to domestic and commercial laundering
EN ISO 105-D01 Textiles – Tests for color fastness – Color fastness to dry cleaning
EN ISO 105-E04 Textiles – Tests for color fastness – Color fastness to perspiration
EN ISO 105-X11 Textiles – Tests for color fastness – Color fastness to hot pressing
EN ISO 105-X12 Textiles – Tests for color fastness – Color 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 color fastness – Color fastness to artificial light: Xenon arc fading lamp test
BS 2819 Methods for determination of bow, skew and lengthways distortion in woven and knitted fabrics
UNI 11057 Textiles – Chemical tests – Determination of pentachlorophenol - tetrachlorophenol and their salts and esters in the textiles
3 Sampling
From each lot take three boxes in a random manner; from each of them take a number of foulards/scarves suitable for the tests to be done.
If the lot consists of less than three boxes, samples will be taken from each box.
Samples must not present any alterations or visible defects, such as holes, tears, stains, differences in color, etc. Moreover, samples must be representative of all colors/patterns in case of color 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);
- color fastness (4.3);
- edging (4.4);
- ecological characteristics (4.5);
- fiber content labeling (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 two categories:
- Category A £ 40 g/m2;
- Category B > 40 g/m2.
The tolerance allowed on the mass per unit area value is + 5%
4.1.3 Measures of made-up article (EN ISO 1773)
According to trade customs, the size specifications must refer to the measures specified in the contract. So, measurements must be made on the fabric or on the finished article after conditioning according to ISO 139 Standard. In the case of unedged products, the difference between the values determined before and after edging must not exceed 0.7 cm for each side of the article
The tolerances allowed on the measures are as follows:
Foulards
- for fabrics made with plain or twisted (max. 800 turns/m) yarns: ± 2% for both directions;
- for fabrics made with twisted (above 800 turns/m) yarns: ± 4% for both directions.
Scarves
- ± 2 % for the short side of the article;
- ± 1 % for the long side of the article.
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 tests for determining size and twist require the removal of yarns from the made-up article. The results of measurements must be related to the corresponding values for the 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 : 100 N;
category B : 200 N.
4.2.2 Skew distortion (Angular displacement of weft yarns) (BS 2819)
The skew distortion must in any case not exceed 1.5%.
4.2.3 Dimensional change in laundering treatments
The test conditions must be chosen and applied according to the instructions 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 ISO 3759
- 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%;
- dry cleaning: ±2%.
4.3 Color fastness
The color fastness properties required for woven fabrics for foulards and scarves are as follows:
- color fastness to artificial light;
- color fastness to rubbing (dry and wet);
- 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 technology Yarn and piece dyeing + printing
Property Minimum requirements
Colour fastness Test method Change in colour Staining
Artificial light EN ISO 105-B02 3 -
Dry rubbing EN ISO 105-X12 - 4
Wet rubbing EN ISO 105-X12 - 3
Dry cleaning* EN ISO 105-D01 4 4
Domestic and commercial laundering* EN ISO 105-C06 4 4
Hot pressing EN ISO 105-X11 4 -
*These requirements are dependent on the care instructions reported in 4.7.
4.4 Edging
Edging of foulards and scarves must comply with following requirements:
- edging stitches: 3 4 per cm;
- composition of sewing thread: 100% silk; 100% cotton, polyester/cotton blend; 100% polyester.
The color fastness properties of sewing threads must at least equal those of the made-up article.
These prescriptions do not apply to hand edging.
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 Fiber content labeling
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
light/transparent fabrics in case of values A £ 40 g/m2;
middle-weight fabrics in case of values B > 40 g/m2.
Table 2 - Yarns denominations
Type of silk 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