In the yarn spinning department heads must alert all the staff members to locate exactly the sources and causes of origin of such waste and plan out ways and means (by installing waste containers, by proper house keeping, by modifying undesirable worker practices and by improving handling and transport methods) to keep the wastes under control. Suitable display boards in bold writing at different places may also be put up to draw attention of everyone constantly.
In the following table we will show norm for waste in different label of yarn processing.
Types of waste
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Norms
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Remarks
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Blow room waste
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1.25 times the trash in mixing
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For a cleaning efficiency of 75 to 80 per cent,lint in waste should not exceed 33 to 40 per cent.
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Card waste
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4 to 5 per cent for foreign cotton and 5 to 6 per cent for Indiancottons
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Flat speed 50mm.Use of continuous strippers,or metallic clothing results in 1 per cent to 1.5 percent reduction in waste.
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Comber waste
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10 to 12 percent
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Depends on yarn strength,type of cotton used method of lap preparation and fractioning efficiency of comber.
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Hard waste in ring spinning ,reeling and winding
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0.5 percent
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Spoiled doffs soft. Bobbin s,bad bottoms etc. should be controlled.
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Sweeping and clearer waste
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1.5 percent
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(1) Pick waste before sweeping instead of sorting afterwards (2) provide operatives with bags and discourage them throwing waste in floor.
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Card web and lap
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0.7 percent
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An allowance of 12 cm. per lap and 8 metres of sliver per card per strip.
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Sliver in combers and lap former
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1.0 percent
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Stoppages of combers due to roller lapping and sliver breaks assumbed to be 2 per comber hour.
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Drawing sliver
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0.5 percent
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Two passage breaks per 100 delivery hours assumed to be 8 in first head and 4 in finished head.
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Speedframe sliver and roving ends
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1.0 percent
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Two process. Breaks per 100 spindle hours assumed to be 4 in inter and 3 in roving. Creel only when at least one half of the bare bobbin in visible.
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Ring frame , bondas and pnuemafil
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2.5 percent
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Depends on end breakage rate and work assignment and supervision.
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