Recycled yarns from textile waste and the manufacturing process therefor

The subject invention provides a new method for manufacturing yarns using recycled cotton waste and a new type of recycled cotton yarn. Various types of cotton waste materials such as manufacturing by-products and post-consumer material are used in conjunction with virgin yarns to produce recycled yarns of sufficient quality to be used for garment manufacture.

FIELD OF THE INVENTION 
The present invention relates to the textile industry and the manufacture 
of yarns, and in particular relates to the utilization of inexpensive 
cotton waste materials as the source material in a process for making 
recycled cotton yarn. 
BACKGROUND OF THE INVENTION 
In the cotton textile industry, using the current processes of producing 
finished apparel and related goods from raw virgin cotton, 20-49% of the 
original fibre in the raw material is typically separated as waste in the 
various processes. Once produced the finished goods have a limited life; 
when they have ended their useful life they are possibly used as rags for 
a brief period and then typically discarded to end-up in a landfill or 
waste incineration facility. 
This manufacturing and post consumer waste generated in this way is 
extensive. According to The Byproducts Association of America, in 1990, 
approximately 7.7 billion pounds of new and used fabric and clothing and 
related textile products were discarded. 
Cotton agriculture also has a significant impact on the environment and is 
the highest or second highest agricultural user of pesticides, herbicides 
and fungicides. 
Our society is becoming increasingly aware of the severity of our 
environmental problems and in particular the scarcity of appropriate 
landfill sites, and the deleterious impact of waste incineration, 
industrial discharges, and the use of pesticides and other chemicals in 
agriculture. As a result of this increasing awareness it is becoming 
increasingly important to reduce the amount of waste we generate, recycle 
more of the waste that is generated, and reduce or eliminate as much toxic 
chemical use as possible. Governments often regulate these matters making 
such efforts not only environmentally responsible but often necessary to 
comply with the law. 
The chart below sets out some of various types of manufacturing and post 
consumer textile wastes along with some current or potential uses of these 
materials. 
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MANUFACTURING WASTES 
Current or 
Waste type % of crop Potential uses 
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gin motes 5% Coarse count yarns 
carding waste (such as for mop heads, 
drafting waste some upholstery yarns, 
5% industrial belting, 
rope and twine). 
comber noils 
5-7% Paper making. 
drawing wastes Health and beauty aids. 
fly waste Upholstery stuffing and 
bedding. 
yarn & thread ends 
2-3% Stuffing 
fabric & fabric 
8-34% Stuffing 
trimmings* 
Total 20-49% of cotton harvested 
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POST CONSUMER TEXTILE WASTE 
Waste Type Uses 
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synthetic producer's 
Stuffing, felts, 
waste industrial belting, rope, 
twine. 
used clothing Rags. 
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Only a portion (in some cases very small) of each waste type is being 
recycled or reused. Much of the cotton waste goes directly to landfills 
and a large proportion of the gin motes are being ploughed under in 
farmers fields to eliminate the increasing tipping fees associated with 
commercial waste disposal. 
While there are potential uses for these wastes, unfortunately not all of 
these wastes are being reused or recycled. Even when these materials are 
recycled or reused, most of the uses for these wastes are for relatively 
low value goods which often have a very short useful life. If a higher 
value and more durable use is found for these wastes, then much more of 
these wastes will be used--which will reduce the waste stream into 
landfills and waste incineration facilities, and reduce the amount of 
pesticides, herbicides, fungicides, and other chemicals used in growing 
and processing cotton by decreasing the amount of virgin cotton needed for 
the apparel and related industries. 
This invention is the use of any and all of these wastes for the 
manufacture of yarns of high enough quality, and thus higher value, for 
use in the garment and related industries. Specifically, this invention 
involves the use of pre-consumer and post-consumer fabric/apparel waste in 
the manufacture of high quality yarns using a process that is economically 
feasible on a commercial scale. 
While most of the types of waste materials that are recycled to make these 
high quality have already been reused or recycled to some extent in other 
products, most of the uses for these wastes are for very low value goods 
and only a portion of the wastes are being reused or recycled. While some 
of these wastes are also being recycled into new yarns, as shown in chart 
above, these yarns are typically coarse count yarns not suitable for use 
in the apparel industry, except possibly for use in heavy woven outerwear 
or sweaters. These conventional uses are definitely lower value uses than 
the products of this invention. 
The process of the subject invention involves making finer count--being 8 
count and above--cotton yarns either completely from 100% recycled cotton 
textile waste, or using a combination of virgin and recycled cotton, 
together with post-consumer shoddy to fabricate yarns of quality suitable 
for the apparel and related textile industries. 
The principle of this invention is that through processing the waste fibres 
differently, and by twisting the yarn made from these fibres differently, 
finer count yarns can be made from 100% cotton textile waste and from 
blends of 100% cotton and synthetic wastes; and by processing used 
clothing differently to open the fabric up with less breakage and better 
parallel alignment of fibres, post-consumer shoddy can also be used when 
blended with other textile fibre wastes or virgin cotton to make yarns 
suitable to the apparel industry.

DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATIVE EMBODIMENTS 
Referring to the diagram, the gin mote wastes must first be cleaned. This 
process is accomplished by passing the motes through one or more 
conventional cotton cleaning and/or opening machines. This process is a 
relatively standard operation. The gin motes are the only waste type used 
that require a pre-cleaning process. 
Gin motes are the wastes created when mechanically harvested cotton is 
cleaned. The gin motes consist of long or spinnable cotton fibres, short 
unspinnable fibres, and unwanted debris, consisting of leaves, twigs, 
bolls, seeds, sand and dirt. The cotton gin opens the gin motes by pulling 
it apart and allowing the heavier debris like seeds, twigs, and sand to 
fall out with some of the lighter debris. 
After the gin motes have been cleaned and opened, the motes, carding waste, 
drafting waste, comber noils, drawing wastes, and fly are then blended 
before carding begins. All of the types of waste mentioned here need not 
be used for a particular yarn. The exact combination of raw materials used 
for any particular batch will depend on the availability of raw materials 
at the time of processing. 
In some cases the carding and all the processes through spinning will be 
done at another mill, in which case the cleaned or reclaimed gin motes and 
other wastes will probably be baled before being sent to the spinner for 
blending and/or carding and must be processed through opening equipment 
before being processed through conventional cotton carding machines. 
The next step in the process if blending. Blending is usually used to meet 
the cost and property designs of a specific fabric and is also a 
relatively standard process. If bales were sent to another mill, tufts of 
the different fibres would be cut off different bales in the desired 
blending proportion, and sucked into a large mixing box which has air 
blown around to mix the different fibres and then the fibres would be sent 
into the carding equipment. 
Blending can take place at different points along the entire process of 
making yarns from textile waste as shown in diagram. Exactly when the 
blending takes place depends on the source of fibres being blended and the 
capabilities of each mill involved. 
Carding is used to separate (or open), align and deliver fibres in a sliver 
form, which is described as a continuous strand of loose fibres about as 
thick as man's thumb with no twist. Carding is also used to further remove 
any impurities still present in the material. 
The carding equipment consists primarily of cylinders with teeth. When 
processing gin motes, the carding equipment should also have crush rolls 
to break down remaining debris (leaves, bolls) and suction cleaning. This 
type of equipment is more appropriate because of the high proportion of 
debris in gin mote waste. 
Next, in the drafting process, the fibres are brought into parallel 
alignment in preparation for spinning. The sliver is passed through a 
series of one or more pairs of rollers with each successive pair of 
rollers rotating faster than the previous pair. In this manner the sliver 
is drawn into a thinner strand of fibres and the alignment of fibres 
becomes more parallel. At this time twist is also added to the strand of 
fibres to preserve the strength of the sliver and prevent breakage. 
At this point any other fibres going into the yarn such as those from 
thread & yarn waste, fabric trimmings, or used fabric/clothing are blended 
in the drafting process. 
When processing virgin cotton fibres into yarn, the fibres would normally 
go through a combing process at this point to remove the shorter fibres as 
the shorter fibres make it difficult or even impossible to spin a strong 
enough yarn using standard spinning processes. In the present process the 
fibres are not subjected to a combing operation. Instead the yarn is 
twisted approximately 10-15% more than is standard with virgin cotton. 
This results in decreased waste, which would have to be disposed of, and 
to keep more of the original fibre in the finished products. Thus, 
operational costs are reduced by excluding the combing process and also 
reduce loss of source material. 
Before going on to the spinning process the processing of the other types 
of wastes will be described up to the drafting step. 
The fabric trimmings and used clothing may be blended before garnetting if 
there are different coloured pieces of the same type or similar types of 
fabric. However, if the fabric types are of significantly different 
physical properties (for example a very loose poly/cotton sweater knit and 
tight woven cotton) they should be garnetted separately and then blended 
afterwards, see diagram. 
Before garnetting, all garments and/or fabric trimmings must be sorted by 
hand into similar types of fabric unless they were collected from one 
source and are already separated by fabric type. Also, the following need 
to be removed from clothing: 1) all buttons 2) all zippers 3) all heavy 
seams, such as taped seams or seams where fabric has been folded and 
double stitched 4) any other hard fasteners, etc. which the garnetting 
equipment either could not pull apart or which could not be used in making 
a yarn. 
The goal to achieve in the garnetting process is to grind and pull the 
fabrics apart into a fibrous state as quickly as possible while preventing 
the breakage of too many of the individual fibres. If too many of the 
fibres break then the resulting yarn will be too weak. The faster the 
garnetting equipment runs, the lower the cost of the operation, and the 
more breakage of fibres. 
When clothing and fabric trimmings are garnetted into fibres for use in 
making felts or maybe very coarse yarns, the equipment processes fabric at 
the rate of 2,000 to 5,000 pounds per hour or higher. In the present 
invention, the equipment processes 1,000 to 2,500 pounds of fabric and/or 
clothing per hour. The variation that permits use of garnetted fabric 
trimmings and clothing to make finer yarns than previously done on a 
commercial scale, and make them out of 100% waste, is that the equipment 
is run slower and spinning the yarn is done differently; this is explained 
later. 
Next the garnetted waste must be carded. This waste is carded much more 
than virgin cotton or even previously described wastes. This should also 
be carded with the flat set about 50% closer than would be used for more 
typical types of waste such as gin motes. 
As mentioned before any remaining blending of fibres is done in the 
drafting process(es). Typically at least two processes of drafting should 
be used, particularly if there is used clothing or shoddy in the fibre 
mix. 
During the spinning process the equipment is slowed down and the yarn is 
given more twist; this gives the yarn greater strength and allows the use 
of fibres which are shorter than virgin cotton fibres. In spinning the 
yarns, it has been found that 10-20% more twists then normal when using 
virgin cotton will probably be needed for enough strength in the finished 
yarn. For example: the 10 count, 100% recycled cotton yarns produced by 
this process has 14 twists per inch instead of the 11-12 twists per inch 
of a cotton yarn made from virgin cotton fibres. 
When speaking about the twists in a yarn there are two measures which are 
used, twists per inch and twist multiple. The equation which relates these 
two measures follows: 
.sqroot.10.times.twist multiple=twists per inch 
In open end spinning, the standard twist multiple for 10 count 100% cotton 
yarn to be used in knitting is 3.50, our 100% recycled 10 count cotton 
yarn for knitting has a twist multiple of 3.90 to 4.10. 
See the chart on the following page for twist multiples for open-end yarns 
created using this process: 
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TWIST MULTIPLES FOR 
RECYCLED YARNS vs STANDARD YARNS 
Standard yarns 
Recycled Minimum Recycled 
Size (virgin) yarns content 
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KNITTING YARNS 
8 count 
3.20-3.30 3.60-3.90 100% 
10 count 
3.50 3.90-4.10 75% 
12 count 50% 
14 count 30% 
16 count 
4.00 20% 
18 count 10% 
WARP YARNS FOR KNITTING 
8 count 
3.50-3.60 4.75 100% 
10 count 
4.00-4.20 5.25 75% 
12 count 
4.60-4.80 50% 
14 count 
4.85-5.10 30% 
16 count 
4.85-5.25 20% 
18 count 10% 
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While the preferred forms of the invention have been set forth and 
described in detail, it will be understood that this invention is not 
restricted to the particular details of construction and arrangements set 
forth and illustrated in the accompanying drawings, and it will be 
understood that changes may be made within the scope of what is 
hereinafter claimed.