For many years anyone cleaning a car has used soft cotton cloth for polishing, be it ‘cotton stockinette (mutton cloth) or maybe even old cotton towelling. Whilst a deep shine is easily achievable the main downside to these types of products is they tend to shed bits of fluff called lint over the polished surface. This can be eliminated using a lint free cotton cloth. Problem solved…not quite.
Don’t get me wrong, soft cotton cloths are available in many great products and are generally good value for money but microfibre* is in a different performance league while remaining great value for money.
How Microfibre cloth is made
Microfibre cloth is made from microfibre yarn. Microfibre yarn is made from two types of oil based hydrocarbon derivatives, that’s plastic to you and me, polyester and polyamide (nylon). Most automotive microfibre cloths will be an 80:20, 70:30 mix of these two materials. To produce yarn, granules of the two materials are mixed together with a colour pigment added and then heated until they melt and are then pressure sprayed through tiny nozzles. This produces a yarn made up of numerous strands of micro fibres – you wondered where the name came from. This process is similar to a spider using its spinaret to produce spider’s web and is of a similar thickness, between 3 and 5 microns, about half the thickness of a human hair. This yarn is then woven or knitted into cloth.
We use different cloths for different jobs – big soft moppy microfibres for final buffing, flat twill type microfibres for glass and noodle looped microfibre mitts for washing to name but a few applications. They all start as the same yarn but are woven or knitted on different machines to produce very different final cloths with special characteristics for particular applications.
So, why is Microfibre so special?
Well, it’s all down to the science.
There are two ways of cleaning a surface, chemical action and mechanical action.
Firstly, chemical cleaning requires some kind of solvent to loosen dirt’s grip on a surface so it can be removed by wiping with a cloth or jet washed away. We usually use the most common and cheapest solvent around, water. Water on its own is not great at releasing grease and dirt from a surface so we generally add some kind of detergent like car shampoo or TFR (traffic film remover) to the water. Detergents are what are known as adjuvants, they make the water wetter! This simply means they weaken the surface tension of water molecules allowing the water to more easily encapsulate the dirt particles so they can be removed without scratching the surface being cleaned. So once the chemical action has happened it’s time for the mechanical phase.
Going over your car with a soapy sponge or cotton cloth will remove most of the dirt. For the most part you are simply mechanically pushing the dirt off the surface.
There is a second mechanical process at work too. This is down to the physical attraction of molecules to each other explained by Van der Waals force where tiny charged particles in molecules stick together like tiny magnets. Remember the microfibre strands are 3 to 5 microns thick. The very finest of cotton yarns are at least 10 microns across. This means that microfibre cloth can collect many more particles of dirt and of a much smaller size, even as small as bacteria. So, this explains in part why the ‘ dirt grabbing’ surface of a sponge or cloth is not as effective as the ‘dirt grabbing’ ability of a microbre mitt.
The second, and possibly more important, reason why microfibre is more effective for removing dirt, water or polish residue than other cloths, sponges or wash leathers is due to the material it is made from – plastic- plastic’s physical and chemical properties means it attracts more particles by van der Waals force than natural products like cotton cloth, sponge or chamois leather, so more dirt is removed with each pass. Not only this, a microfibre cloth will hold the gritty particles inside the cloth until you wash it in hot water when the fibres uncurl slightly releasing the dirt.
Once you have washed your car you put your microfibre mitt to one side and rinse with clean water in order to remove the remainder of soapy water molecules holding dirt particles. If you have ever used a chamois leather to dry your car you will have found that several passes are needed to collect all the water into the wash leather. Again, the ‘water grabbing’ ability of the fibres in the leather are not as effective as the ‘water grabbing’ ability of microfibre drying towels.
To protect the paint surface of a car we tend to use a wax based polish. Once a layer of polish has been applied it needs to be buffed to a deep shine, again the special characteristics of microfibre cloth allow a quicker removal of polish residue from the surface than other cloths.
*Microfibre is spelt microfiber by some people, especially Americans and ‘USA-o-philes’.