Wool mattresses & upholstery fibres explained
Updated 2020: Wool conjures up many familiar connotations, whether it be that warm winter jumper, smart business suit, favourite childhood scarf or your Grans questionable knitting gifts at Christmas!
Believe it or not, it is also used in some items you wouldn’t potentially associate with, such as high wicking sports equipment or even as a blend in shirts. The reason for that is it’s an incredibly resilient and versatile material.
Wool Mattresses Explained
There are a number of benefits with wool which is why high-end mattress manufacturers use it so frequently. We will cover primarily Sheep wool but also link into other wools, such as Cashmere and even Camel wool. There are some grey areas to watch out for to make sure when you’re looking for wool upholstery, you’re not getting the ‘wool pulled over’ your eyes.
What exactly is wool?
Wool is an animal hair that is actually a protein called keratin. It is found on animals that require both insulation and protection from the outside elements such as variable weather and extremes in temperature. The easiest way to think of this is having to have a coat that is both suitable for the warmest, driest of summer days and the wettest torrent of winter. Not exactly the easiest of tasks! Having been around commercially for hundreds of years, it is fair to say it is probably the most successful natural fibre. In fact, the oldest wool textile, found in Denmark, dated back to 1500BC.
Wool fibres can come from many animals, but in sheep, the fibres are made up of three components.
- Cuticle – the outer layer of each individual strand. These have scale-like cells on them meaning when they rub they can stick together, some wool fibres under microscopes look like tiny hooks. This means they can be spun together.
- Cortex – the centre of each strand which contains tiny elliptical cells that contain melanin, similar to skin pigment if you like.
- Medulla – honeycomb cells of each strand that provides many air spaces that give wool its thermal value.
Wool is hydrophilic; it takes on water freely. Meaning it can also be dyed easily, hence all those fantastic colours of wool you see in knitting shops and jumpers.
Wool as a breathable fibre
Wools main benefit is that it is incredibly breathable allowing it to wick away both moisture and increases in temperature when it is placed against say a warmer sleeper. It has the opposite effect when it is cold, of helping to trap warm air and release heat against a colder body. Given this ability to absorb and then disperse moisture it means that, unlike synthetic fibres which tend to trap moisture and heat, wool can help regulate your temperature. This makes wool an excellent mattress component as it keeps a mattress cool in the summer and warmer in the winter.
Wool as a mattress upholstery layer
Wool is frequently used in high-end mattresses as it has excellent heat regulation properties and loft, meaning that it’s frequently used in the top comfort layers of a mattress. It can give that softer top feel that allows that slight sink into a mattress. As wool is a durable material it also lasts for years compared to synthetic fibres which can break down relatively quickly and flatten. It doesn’t trap heat like memory foam so allows a sleeper to regulate their body temperature easier. If you’re a warm sleeper this is a godsend.
Wool is a brilliant comfort layer and acts as a highly resilient and breathable wadding in mattress layers. When coupled with the spring and rebound of horsetail and horsehair wool provides both durability and comfort.
Wool can be blended with other fibres to help keep its loft high
The loft is basically the height and form of the fabric/fibre, how tall it sits once it has been woven or processed.
Pure wool on its own has a habit of compressing so you need to take further steps to avoid this when hand making a mattress. It is often blended to keep its bounce or height. We only blend our wool with natural cotton.
When wool isn’t really wool in a mattress
Some manufacturers will claim their mattress features ‘natural wool fillings’. Upon further inspection, you find out its a 4% wool 96% polyester/white fibre blend, which isn’t wool at all. Secondly, if it is wool it turns out to be a 50gsm sheet, again pointless unless we are talking 200gsm sheets or above there’s no point as it would be paper-thin.
Wool is usually used in the top comfort layers of the mattress where the benefits are most readily experienced by the sleeper. Wool should never be mixed with synthetic foams, which are heat retentive as it will completely negate the beneficial properties of wool unless only being used as a fire retardant wrap.
How is wool harvested?
Sheep’s wool is an incredibly durable fibre as it is considered a sustainable fibre taken from sheep without necessarily the need to harm the animal. It is also a byproduct of the farming industry.
Sheep are usually sheared once a year, though some breeds may require two shearings. Usually, this is before the heat of summer as it keeps the sheep cleaner and less prone to disease that if they have a thick coat of wool hanging off them all year which could allow any injury, cuts to be hidden from the farmers looking after them.
The shearing is a painless experience for the sheep and the pelts that are sheared off are they taken for processing.
The wool is then sorted and graded into different qualities and purposes. Usually, the best quality of wool comes from the sides and shoulders of the sheep. The lower quality comes from the lower legs. All of this wool is then sorted and sold based on its grade and end-use, whether it be high-quality jumpers or more durable coarser woollen rugs.
The wool is then processed in a variety of baths t remove dirt and grime, see the above image for an example of the well-weathered sheep! This involves a series of alkaline baths where the wool is washed. It is never allowed to dry out fully during this process to keep it more manageable.
This is where the clean fibres are then passed through a machine with a set of teeth and are teased into a uniform layer of wool. This gives it consistency allowing it to be manipulated into sheets rather than just bunches of wool. The image below shows pre-carded wool, fluffy and light in a bundle.
Usually, this is the end of the wool processing technique when used as a mattress filling. However, if the wool was the then to be processed further to make fabric for a headboard or mattress base, in super high-end mattresses, then it would follow the additional steps.
The fibres are then spun, usually on a mule spinning machine, into long lengths of fibres. As wool has a natural tendency to stick together given the shape of the fibres it is relatively easy to spin these fibres together. These yarns are then transferred onto bobbins to create huge lengths of spun fibre. If you think of a big cotton reel it’s not too dissimilar, albeit 1000 times bigger!
Lastly the spun fibre is then woven into an array of fabrics or material which is then used in a multitude of upholstery, clothing or textile uses. You could write a whole article just on the weaving process which is a skill within itself.
Unfortunately for the UK, a number of these skills are being taken over by mass-produced textile factories in developing countries such as India using cheaper blends and less stringent manufacture methods. However, there are still some UK based textile mills in Yorkshire and Huddersfield. They even manufacture the elusive UK sourced, sheared and woven wool, like the three swatches shown below, which is like gold dust and the creme de la creme of wool textiles. We are looking to introduce a range of mattress bases and headboards in this superlative fabric soon.
Wool as a natural fire retardant
Wool has another incredible benefit in that it’s a natural fire retardant. Upon coming into contact with fire wool just singes and doesn’t propagate naked flames. It can act as a barrier to keep flames away from other layers beneath it. It has been used for years to wrap non-fire retardant materials such as coir or synthetic latex materials.
Cashmere wool is renowned as one of the most luxurious wools on the planet. It’s synonymous with expensive super soft cashmere jumpers and scarves. Cashmere wool is sheared from the Kashmir goat who is used to extremes of both cold and hot temperatures. Kashmir goats can be found originally in Asia, specifically Kashmir and Mongolia. More recently Kashmir goats are being bred and sheared in Australia, America and even the UK.
Kashmir goats have two coats:
- Outer coarse protective coat to survive the elements and damage
- Undercoat which is a soft fine fibre to provide warmth, wicking and comfort for the goat. It is the undercoat that is used to make Cashmere wool, due to the limited supply when compared to shearing a sheep, Cashmere is a premium and expensive product.
The soft fibres of this undercoat provide a super lightweight breathable microclimate which is brilliant at transferring heat and wicking. We tend to use Cashmere as a spring insulator, as its super soft and flexible whilst allowing air to move between our Calico encased vanadium springs and the upper upholstery comfort layers. Think of it as a super breathable semipermeable layer. Cashmere is also super lightweight meaning it’s very flexible and you don’t need as much of it to get the same benefits you may get from other wools, by our very ethic we always put a super high GSM layer in our mattresses and why not, it’s fabulous!
Again be aware of ‘containing Cashmere’ on mattress descriptions, more often than not this is a few rogue hairs thrown in with some low-grade wool, or worse ‘white fibre’ which is a trade name for a mix of recycled synthetic fibre bits and bobs. Find out the GSM of the Cashmere in any mattress, and if the retailer can’t tell you exactly and with confidence, find another supplier.
Anyone who remembers the 1970’s, no need to all put your hands up to show your age, will remember the luxury must-have clothing item. The Camel coat. We remember them well, people would save up months to have one and not just because they were the must-have fashion accessory. Far from it, they were one of the most hard-wearing, breathable, warm and resilient coats available. The most startling benefit was that it didn’t shrink, like some wool jackets if it got soaking wet and then dried out too quickly. It was the perfect stylish winter and summer jacket!
Today Camels have received something of a snub by the public, often thought of as maybe not as luxurious or stylish as Cashmere or Mohair. Which is really unfair given that Camel as a fibre, especially for a mattress is brilliant. Camel wool is obtained from the two-humped Bactrian Camel often found in Eastern Europe and Asia. The lack of interest in Camel wool has seen a reduction in its price, so it wouldn’t surprise me if manufactures here in the UK start to use it as an alternative to Cashmere.
The fibre is collected from the soft underbelly of the Camel, who will regularly be subjected to the sub-zero freezing desert at night and then 40 degrees plus of the scorching desert midday heat. It has outstanding insulation properties and is very soft to the skin, probably far softer than lamb or merino wool!
Is wool anti-allergen?
This is a really interesting point as many people suffer from allergies, whether its dust, animal proteins or natural products irritating them. However, wool absorbs moisture from its surroundings and dissipates the moisture amongst the wool until it’s evaporated quickly, which some fabric experts argue reduces fungal growth, which requires moisture being left stagnant. This removal of moisture, in turn, breaks the food chain, fungus being a tasty part of the dust mites diet, that house mites rely on. Each person will have the best understanding of their allergies, but it is worth bearing in mind when making your mind up. Especially as synthetic fibres such as polyester which struggles to wick away moisture. We welcome debate on our ‘Ask us’ forum from any allergy specialists on this quite under-studied subject matter.
Wool Mattresses By John Ryan
We have a number of our hand-crafted mattresses that contain British wool which can be followed by the links below.
Artisan Naturals 1200GSM Blended British fleece wool and cotton.
Artisan Bespoke 004 1200GSM Blended British fleece wool and cotton + 1000GSM Bonded fleece wool and cotton.
Artisan Luxury (Our softest wool filled model) 1200GSM Blended British fleece wool and cotton + 1000GSM Pure British wool.
Artisan Bespoke (Our firmest upholstery feel) 500GSM Pure British wool + 1200GSM Blended British fleece wool and cotton.
Artisan Bespoke 002 1200GSM Blended British fleece wool and cotton + 1000GSM Bonded fleece wool and cotton.
Wool is an incredibly versatile and multifunctional natural fibre. In mattresses, it provides not only comfort but the ability to regulate a sleepers temperature far more effectively than synthetic man-made fibres. Wool can be used as a top comfort layer, or further down the mattress layers for a softer support layer. Naturally fire retardant and long-lasting, it’s a fantastic natural fibre to use within any top-end mattress.
As detailed above you need to know the exact GSM and quantities to know if the retailer is using the wool correctly or just putting a few odd fibres in there for a selling tool! Using British wool not only supports the UK farming and textile industry but also means that the distance it’s travelled is reduced, meaning its better for the environment.
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