Fleece jacket material is a synthetic fabric that is made from polyester. If the polyester isn’t broken down to make fabric then it is used to make plastic bottles. Fleece jacket material can also be known as polar fleece or polartec.
The process for making fleece fabric is quite complex and detailed. There are several stages that have to be achieved and carried out to specific requirements and this involves several heating stages.
Producing polyester
Polyester in its early stages is produced by heating terephthalic acid with
ethylene glycol. These chemicals are then pumped into a huge container
which is then heated to 150 – 210 degrees Celsius (302-410 degrees
Fahrenheit). This first heating process creates dihydroxydiethyl
terephthalate which is then pumped into another container where it is heated
again to make PET, and as the liquid cools it is broken down into chips.
Drawing and crimping
The tow is then passed through heated rollers of a drawing machine increases
the strength of the fibre and help the crystalline PET set into smooth
string. The tow is then passes through a crimping machine which also
add strength. The crimped tow is put into a dryer and then cut into
lengths a couple of inches long. Once the tow has dried it will start to
look fluffy and like wool.
Spinning
The hardened tow fibres are tested for strength and thickness before being
passed through a carding machine. This machine aligns the fibres
before they are fed into a spinning machine that twists the strand into
a fine yarn which is wound onto spools.
Knitting
The yarn spools are then fed into a specialist industrial knitting machine
which is called a circular knitting machine. The knitting machine
then binds the yarn into a continuous cloth which can be several yards
long.
Napping and shearing
The cloth is next fed into another machine called a napper. The napper runs bristles along the cloth which raise its surface. The cloth is then sent through a shearing machine which will cut the fibres that were raised by the napper machine. The napping and shearing process used for making fleece is similar to the procedure that is used for making velvet and corduroy.© Fleeces.org 2009