What are the faults of yarn?
From all the above yarn faults, some important yarn faults have discussed in the following:
- Slubs: Slubs are fish-shaped thick places from 1-4cm long and about 5-8 times longer than the average yarn diameter at the thickest portion.
- Cracker: …
- Spinners Doubles: …
- Bad Piecing and Double Gaiting: …
- Slough Off: …
What is yarn Classimat fault?
Classimat faults are the one of the important yarn characteristics which affects the quality of the yarn, efficiency of the further process and quality of the fabrics.
How do you control yarn imperfections?
Yarn imperfections have increasing trend with an increase in the feed amount. 10. A higher noil% always improves the imperfections in the final yarn.
In which process objectionable faults of yarn are removed?
Tandem or double carding at low production rates and combing are the surest ways of reducing the incidence of yarn faults. The use of overhead cleaners during spinning reduced the fault level appreciably.
What is CV in yarn?
The variation of the yarn count (CV count) is the variation from one bobbin to the other. If this variation is more than 2% the difference in the fabric is visible with bare eyes. … In general the lower the C.V.% the better is the measured value of the yarn.
How is yarn IPI calculated?
The imperfection index (IPI) is the sum of yarn thin places/ km (-50%), thick places/km (+50%) and neps/km (+200%) per kilometer of tested yarn for ring spun yarn [2, 59] .
What is yarn imperfection?
Imperfections can be defined as the total number of neps, thick and thin places in a given length of yarn. … A yarn with more imperfections will exhibit poor appearance grade, lower strength and poor performance in weaving is likely to produce fabric with low quality.
Is a type of yarn fault?
Yarn faults The defects of yarn is called Yarn faults. When an uneven place or impurities or any other lack of minimum quality is found in a yarn is called yarn defects or faults. 5. An abnormally thick place or lump in yarn showing less twist at that place.
What is Traverse ratio?
Traverse ratio (also known as winding ratio/crossing ratio) is an important parameter associated with cross wound packages that is defined as number of coils laid on the package in a double traverse. … Such ribbon forming number shall be termed as “nominal traverse ratio”.
How do you improve the quality of yarn?
The proposed method of yarn condensing has great potentiality to be used as an alternative method of compact spinning as it is capable of producing optimum quality yarns at lower cost. compact spinning as it is capable of producing optimum quality yarns at lower cost.
What is periodic fault?
Periodic faults and spectrogram
Periodic faults do not arise only drawing stage as mentioned before. This type of faults may also arise in blow room, carding, roving and spinning process due to some machinery and drafting causes. The lengths of periods can be determined on the spectrogram.
How do you increase yarn strength?
Factors that affect yarn strength are as follows –
- Staple length. Longer staple cotton gives higher strength and this is true even in the case of synthetic staple fibre such as nylon and terylene. …
- Fibre fineness. …
- Fibre strength. …
- Twist. …
- Evenness. …
- Fibre length variation and distribution. …
- Fibre finish. …
- General factors.
What process is used after simplex?
The drawn sliver is used as a feeding material in a simplex machine. After completion of this process, the resulting material is called roving. We can say that “a simplex is a machine which converts the drawn sliver into a thin strand of fibres having some amount of twist”.
Which process is used to remove thick and thin places from the yarn?
A yarn clearer is a device to remove faults (thick places, thin places, foreign matter) from the yarn. Yarn clearing improves the quality of the spun yarn and hence of the cloth made of it.
How do you reduce thin spots in yarn?
are a few points to be looked into in ring frames for the control of long thin places. Optimum back-zone settings with a reduced break drafts helps to produce yarns with less number of thick/thin places and slubs.