Test standards │ Test report │ Explanation of washing

General

Many of AIKE Techniche's fabric products have been independently tested to European (EN) and or International Standard Organisation standards (ISO) to demonstrate that they are flame retardant or slash resistant and these tests are used to obtain CE certification for our garments.

Details of standards and test methods involved in testing for the relevant properties, and the interpretation of their results, are described below along with illustrations of how tested garments are labelled. The company operates a full quality system conforming to ISO9001.

For all garments where a claim for some form of personal protection is made must be submitted for independent testing firstly to verify if the fabric being used and garment construction conform to the property(s) claimed and are fit for purpose. If the fabric/article passes the required test(s) it is awarded a CE certification details of which must be shown, along with the makers details by using pictograms, such as those illustrated below, representing the hazard against which protection is being claimed Since 2003 all items that are submitted for CE marking as personal protection equipment must also be examined in accordance with EN340, a general assessment standard described below, as well as the specific standard relating to the property being claimed for that garment.

EN340

EN340 covers dimensional stability of the fabric and the suitability of the garment design for the purpose intended. This standard also the defines toxic, carcinogenic and other materials prohibited from use, or which are allowed to be present only below set levels, in products sold in the European Union. T his standard specifies tests that must be carried out on different categories of material. The two main tests applicable to textile fabrics, in addition to dimensional stability, are for the pH value (highly acid or alkaline) and the presence of banned Azo dyes.

Tests for flame spread, heat transfer through a fabric or garment resistance to molten metal splash and build up of static electricity.

EN531, EN533 EN470 and EN1149.

General

The first three of the above standards are means of assessing the degree of resistance to burning of a fabric and/or heat transfer through fabrics from a heat source or molten metals and other similar products. EN1149 assesses the potential for an electrostatic charge to build up on a fabric which could discharge to earth in a possibly hazardous environment.

They are usually referred to in the description and labelling of garments claiming some degree of protection against  accidental contact with heat and/or flame and other heat hazards. Such garment labels should contain the letters CE and the pictogram for protection against heat and fire.

The test number of the standard to which the fabric has been tested has to  be shown above the pictogram, and the level of performance within the test standard that the fabric achieves has to be shown below the pictogram. Typical labelling is illustrated below .

	EN533		EN531
	INDEX3 5X40		A B1 C1 D2 E1

CE certification of a flame retardant garment includes, in addition to the verification that the fabric in the garment meets the standard to which it  is certified, an assessment of that garments dimensional stability and; its fitness for the purpose intended under EN4340.

EN533:1995 Protective clothing; Protection against heat and flame. Limited flame spread materials and material assemblies.

This standard only covers resistance of a material or assemblies of materials to flame spread, no other properties are considered. It is a basic standard which demonstrates that the fabric tested has flame resistant properties and gives an indication as to the degree of resistance.

The actual method of testing for flame spread is described in standard EN532. This test consists of the application for a fixed time (10 seconds) of a specific propane gas flame, placed horizontally at a fixed distance from the bottom of a vertically suspended strip of the fabric of fixed width (50mm). Once the fabric has been exposed to the flame it is observed for holes in the fabric, the formation of flaming debris and the spread of afterglow (continued burning without flame). The test specimen is then awarded an index level according to its performance with regard to the three properties mentioned above.

Index 1; After testing any remaining flame or any hole in the fabric formed by the flame during testing must not reach the edge of the fabric. There must be no flaming debris. Any afterglow (residual burning) must not spread beyond the area affected by the flame during the test.

Index 2; As index 1 but there most not be any holes in the fabric.

Index 3; As Index 2 but any flaming of the fabric after the flame source has been removed must cease within 2 seconds of the sources removal

EN532; will shortly be replaced by the very similar test ISO15025, which is already the standard test for things such as racing drivers clothing, as the main test for flame retardant properties.

For a fabric to be tested to EN533 it is tested both as received and then also after washing a number of times using the method laid down in standard ISO10528:1995 and dried according to standard ISO 6330:1984. The number of times the fabric has been washed and the temperature of washing is also included in any description of the results. The index level reached and the number of washes and temperature (C) at which the fabric has been washed are also shown below the heat and flame pictogram as no washes x temp used. 5x40 after the index therefore means that the sample tested after washing was washed 5 times at 40C.

Manufacturers will sometimes quote results as tested to EN532, quoting an index level only. This means that the fabric has been put through the flame test without washing and not through the full test method required by EN533.

EN 531:1995 Protective clothing; Protection against heat and flame.

This standard is a more comprehensive standard which includes tests for other properties In addition to testing for limited flame spread. The standard requires, in addition to testing for limited flame spread using EN532, that the fabric must also be tested for one or more of the following additional properties before it can be claimed to meet EN531:

The rate at which convective heat passes through the fabric. The rate at which radiant heat passes through the fabric. How it reacts to having molten aluminium metal poured on it. How it reacts to having molten iron metal poured on it. The labelling of a garment meeting this standard is shown in the general section above.

When testing the fabric for limited flame spread  under this standard using test method EN532 the washing requirements of the sample prior to testing are different from those stipulated for EN531. Here the fabric has to be washed only 5 times and dried according to ISO6330:1984. The fabric does not have to be washed prior to testing for other properties.

All performance levels claimed under this standard must include results of tests to EN532, this result must meet Index 3 as described for EN531above and is denoted as A in the list of results below the pictogram. As mentioned above, any product certified to EN531 standard must also have been tested for least one other of the properties listed. These properties are given the letters B, C, D, and E, each letter is followed by a number which indicates the level of performance that the fabric has achieved in the relevant test. Details of the tests used to measure these other properties are described below. If the relevant letter does not appear in the list under the pictogram on a garments label then no claim is made as to the fabric/garments ability to protect against that particular hazard. For example a fabric shown as achieving levels A B1 C1 h as only been tested for limited flame spread and items B and C below.

B Convective heat transfer as tested by method EN367. This involves placing a standard heat source (a flame) a fixed distance in front of the fabric and measuring the time it takes for the temperature on the other side of the fabric to go up by 24C. The equipment is designed to expose the sample to a heat rate of 81 KW per square metre. The temperature rise mentioned is effectively how long it would take before burns would be seen on any skin on the other side of the fabric. Levels ranging from 1 to 5 are awarded in accordance with the time it takes the temperature to rise the required amount, this level is represented as a number after the letter B below the pictogram

C Radiant heat transfer as tested by method EN366. This method is the same as EN367 except that the heat source is radiant (an electric fire bar) which exposes the sample to radiant heat at a rate of 20 KW per square metre. The results graded by levels ranging from 1 to 4. Both tests EN366 and EN367 have a minimum result below which a level cannot be awarded.

D and E; Resistance to molten aluminium and iron splash as tested by method EN373 and EN348. Theses tests involves placing a sample of the fabric to be tested at a steep angle to the horizontal with a sheet of simulated skin (P VC) underneath and pouring a known weight of molten metal over the fabric sample from a fixed height. The test is repeated with increasing weights of metal until the simulated skin shows distortion and/or metal adheres to the fabric. A test level is awarded according to the weight of metal poured when distortion occurs. Again, the level achieved is shown as a number after the letter D (for aluminium) or E (for Iron) below the pictogram.

EN470-1: 1995 Protective clothing for use in welding and allied processes.

This standard involves testing for limited flame spread using EN532 as in the tests above, the fabric must meet index 3 to pass.

Resistance to welding splash is measured using a test method which described as part of EN348 and is a variant of the methods used for EN531 parts D and E. This test involves placing a test specimen of fabric at a specified angle and then heating a specified type of welding rod at a specified distance above the fabric. A thermocouple is placed on the lower side of the fabric under the point where the drops of molten welding rod land on it. The thermocouple measures the increase in temperature of the underside of the fabric as the drops land on the upper surface. The pass level for the test is determined by the number of drops required to increase the temperature on the underside of the fabric by 40C.

This standard also requires the fabric to be tested for tear strength, tensile strength and dimensional stability. Typical work wear fabrics comfortably achieve the pass levels set for these properties

EN1149:1995 Protective clothing; Electrostatic properties. Surface sensitivity (test methods and requirements).

This standard includes the methods to test for a fabrics susceptibility to build up an electrostatic charge on its surface and the speed at which a charge when built up will decay. It is a way of assessing the potential for a spark of static electricity to be discharged from the fabric to earth so causing an explosion or fire. The standard consists of three tests that are referred to as EN1149-1, EN1149-2 and EN1149-3. EN1149-1 and EN1149-3 are the ones most often used.

Before testing the sample is washed 5 times according to BS EN ISO 26330:1994 Procedure 4A using ECE reference detergent and tumble dried using procedure E in a machine with an exhaust temperature less than 50C.

EN1149-1; Horizontal resistance test. The resistance of a fabric is measured across its surface by a modified Ohm meter as illustrated above. The test is a simple pass or fail, the pass is achieved if the resistance measured is less than 510 ohms.

EN1149-2 Vertical resistance test. The resistance of the fabric is measured from one surface to another by a modified Ohm meter similar to that used in part 1 above.

The test is again a simple pass or fail, the pass is achieved if the resistance measured is less than 510 ohms.

EN1149-3; Charge decay test.

A standard static electric charge is developed on the surface of the fabric and the time measured for the charge to decay to half its strength. A fabric passes the test if the time is less than 4 seconds. The pictogram used in labelling for this standard is shown below.

	EN1149 1

EN1149- Standards for cut resistant fabrics and garments.

EN388 is the main European standard designed to assess the performance of a fabric or layers of fabric for their ability to resist heavy rubbing, cutting by a blade or sharp object, tearing, and puncture by a pointed object. The test procedure involves carrying out a specific test for each of these properties. A performance level is awarded according to each test result, for example a material with an abrasion resistance of between 100 and 500 cycles would be awarded level 1.

The pictogram for mechanical hazards is used in combination with the test information to show the performance of the fabric or garment.

	EN388
	2344

On labels showing that when a garment has been approved for CE marking to EN388 standard these test levels are quoted as four numbers below the EN388 pictogram, the numbers are always shown in the order in which the tests are described below. The minimum test results required to achieve the various performance levels shown by the numbers below the pictogram are listed in the table below.

Please note the geometric progression between the minimum results required to meet the increasing performance levels. This means, for example, that the increase in test performance required to improve from blade cut index level 4 to index level 5 is eight times that needed to improve from level 1 to level 2. Please also note that where multiple layer materials are involved the abrasion and tear resistance levels are derived form the most resistant of the individual layers, not the combined assembly. Blade cut resistance is the only parameter where a performance level 5 is awarded.

EN388,6.1 - Abraision resistance.

This test is carried out using an instrument known as a Martindale tester in which the material to be tested is placed on a bed and a rubbing head of fixed size and weight, covered with a standard abrasive material, is moved in a circular motion over the test specimen.

Four samples of the material are tested and the test result is the number of cycles required to rub through the material. The standard abrasive material used in this test = is severe in action, it is unusual for textile materials to withstand the 2000 cycles required to meet performance level 3.

The performance level of a single material is decided by the lowest result of the four tests in accordance with the table above.  For multiple layer materials each layer is tested separately, the performance level is based on the lowest individual result of the most resistant material.

EN388,6.2 Blade cut resistance.

The instrument used for this test consists of a circular, free rotating blade, under pressure from a standard weight, which is moved backwards and forwards over the surface of the test material over a fixed stroke length. The test result is the number of cycles taken for the blade to cut through the material. To take the sharpness of the blade into account the test is performed using a standard material before and after testing the sample, the mean of these two tests on the standard material is defined as blade cut index 1. The test result is the ratio of the number of cycles required to cut through the sample to the number of cycles required to give blade cut index 1.

Where multiple layer materials are involved the layers are assembled and tested as they would be in the garment. Two test samples are selected, each sample is tested five times and a mean blade cut index calculated from the five tests. The performance level is awarded in accordance with the lower mean blade cut index of the two samples.

EN388,6.3 - Tear resistance.

In this test a sample of material to be tested is prepared in a standard way and clamped in the jaws of a strength testing machine. The jaws are moved apart at constant speed and the force needed to tear the material measured. For single materials the performance level is given by the lowest result of four tests. For multiple layer items each layer is = tested separately, four tests carried out on each material. The performance level = is based on the lowest individual result of the most tear resistant material.

EN388,6.4- Puncture resistance.

This test uses a standard, rounded point which is pushed through the material a fixed speed and the force required for the point to penetrate through the material is measured. Where multiple layer materials are involved the layers are assembled and tested as they would be in the garment. Performance levels are awarded in accordance with the lowest of four test results.