At Fabrics Galore many of our furnishing fabrics come with a Martindale rating, which informs customers on the fabric’s suitability for upholstery use. Although we have previously touched on this in our blog “A Guide to Choosing Upholstery Fabric” we wanted to explore the Martindale ratings in greater detail as well as offer guidance on the need for fire retardant fabric.
What are Martindale Ratings?
History and explanation of Martindale Ratings:The Martindale rub test is a measurement to determine the durability of a fabric over time. The test and instrument were invented by Dr James Graham Martindale during World War 2 when the Wool Industries Research Association (WIRA) asked him to design a machine able to test carbon coated wool fabrics for protection against gas attacks.
How they are determined:
The Martindale test measures the number of times discs can vibrate sandpaper or wool across a fabric before it shows wear. The fabric is placed on a special machine and the wool or sandpaper covered discs move across the fabric in a uniform, repetitive way at high speed, designed to imitate someone sitting on a fabric covered seat over a period of time. The number of oscillations is calculated at exactly the moment when the fabric starts to show degradation when compared with the original fabric, and this provides the Martindale rating.
Significance of the rating scale:The Martindale test is viewed universally as the definitive way of assessing the strength and quality of an upholstery fabric. The testing process is in accordance with International standard ISO 12947-2:2000.
Decorative - Less than 10,000 Rubs indicates suitability for use as cushions.
Light Domestic - 10,000 to 15,000 Rubs indicates suitability for occasional domestic use on items of furniture such as a bedroom chair.
General Domestic - 15,000 to 25,000 Rubs indicates suitability for everyday domestic furniture use such as a family sofa.
Heavy Duty - 25,000 to 30,000 suitability for domestic use with higher-than-average wear such as a sofa used by a large family with pets.
General Commercial Use - 30,000 to 40,000 is suitable for use in the hospitality industry such as hotels and restaurants.
- Commercial Grade - 40,000 plus for the very highest commercial use such as transport and public areas with high traffic such as a theatre or auditorium.
Linen blend furnishing and upholstery fabric
with Martindale 15,000 suitable for light domestic use
Grey Velvet and Grey Polyester Upholstery Fabric
with Martindale over 100,000 suitable for heavy domestic and commercial use
Why are Martindale Ratings Important for Fabrics?
Understanding durability of fabrics:The result of the Martindale test is an indication of the quality and durability of the fabric under examination; the higher the rating the more durable the fabric. The Martindale test cycle may continue for several hours or days, depending on the type and quality of the fabric.
Assessing suitability for various usage applicationsIt is important to assess the intended use of the item of furniture before selecting a fabric. How much use the chair or sofa will incur determines which fabrics are available for your project.
Comparing fabrics for specific projectsMany furnishing fabrics are suitable only for use as soft furnishing fabrics by which we mean a cushion, curtain or blind. If no Martindale rating is shown, that is a good indication that the fabric is not suitable for use in upholstery, although some fabrics such as bouclé may be used for light domestic upholstery – a good example is an occasional chair. Wool, polyester blends, some velvets and heavier weight cottons may all have a Martindale rating satisfactory for upholstery use.
Bouclé upholstery fabrics with Martindale 100,000
suitable for domestic and commercial use
Requirements for Fire Retardant Fabrics
Understanding safety requirements for public spacesTheatres, hotels, public auditoriums are all examples of public spaces where the use of fire-retardant fabrics is a legal requirement. The term fire-retardant as applied to natural materials, refers to a material’s ability to reduce fire hazard, as most natural textiles will burn under certain circumstances. However, fire retardant fabrics burn without generating a flame, preventing the rapid spread of fire.
All fabrics for use in public or commercial environments in the UK must meet the British standards outlined below.
Differences between the various British standardsBS 5852:2006 specifies the testing methods used to assess the ignitability of single material combinations, such as covers and fillings used in upholstered seating, or finished items of seating. It tests the effects of a burning cigarette, or other fire sources such as burning matches or a newspaper.
BS 5867 is the British standard for flame retardant fabrics. It applies to curtains and blind fabrics for windows – in this test the fabric is placed on a metal frame and a flame is applied to the surface for 15 seconds both before and after cleaning.
The Crib 5 test for upholstery and furniture coverings uses a small 5-tiered structure made from wooden sticks that are glued together. A lint pad is attached at the bottom and propane-diol is added to test upholstery. The 5-tier crib is lit with a match. The fabric cover or filling upholstery is tested for flames or smouldering . Assuming it does not ignite or smoulder, the upholstery arrangement will pass the test as "non-ignition".
Combining Martindale Ratings & Fire Retardant Requirements
How to choose the right fabric for specific needsHeavier fabrics with a tight weave such as 100% wool and polyester and those that are treated with flame-retardant substances burn more slowly than loose weave, lighter weight fabrics. Look for fabrics which meet the standards required for public, commercial or private domestic use and ask for certification proof if in doubt.
Examples of applications that require fabrics with both high Martindale Ratings and fire retardant propertiesAny applications of fabrics in public places such as hotels, restaurants, nursing homes, where safety is paramount and the fabric will be exposed to high levels of repeated use, will require a fabric with both a high Martindale rating and the fire-retardant properties outlined earlier.
While the Martindale ratings are important to understand as an indication of how long the item of furniture will retain its original properties without visible wear and tear, fire safety requirements are essential to understand particularly if you are purchasing fabrics for use in a commercial setting.
We hope the information provided in our guide to Martindale ratings and fire retardant standards will help you to choose appropriately from our furnishing and upholstery collections. As always, please do not hesitate to call our friendly team for advice on any of your home furnishing projects.
Photo credit Sven Brandsma