1. Pre Spinning Processes
(YM-2012)
M Irfan
Department of Textile Engineering
National Textile University Faisalabad
Reference:
The Rieter Manual of Spinning

2. Waste management in BR
• Raw material contributes more than
50% to the total cost of yarn
• It is also known that more than 50%
of the waste extracted in blowroom
(droppings of blowroom as well as
card) can be useful fibers which can
not be avoided
• These fibers can be recovered
and result in saving
• 6-8 % is primary waste that
contains 50% fiber which can be
recovered
• Still contains 6% trash
• 2.5% or up to 5% maximum can
be fed back
M Irfan, PhD

3. Waste management in BR
• In modern blowroom, waste is collected and transported
pneumatically
• In spinning mills, following wastes
1. Directly reusable waste:
• Can be fed back to the blowroom after collection
2. Dirty waste: used after recycling
3. Dust and fly: not used
• Managing dirty waste and dust and fly is difficult
• Non useable waste
• Coarse dust left after recycling (secondary waste)
• Fly from preliminary filters
• Dust from fine filters
M Irfan, PhD
Particle Size (µm)
Trash Above 500
Dust 50-500
Micro dust 15-50
Breathable dust Below 15

4. Dirty waste recycling
• Dirty waste can be reused but it has to pass through a waste recycling unit before
being mixed with the virgin raw material
• 30-40% fibers in the dirty waste can be reused
• Can be fed back in the same mill or used in rotor spinning
• The recyclable waste both from blowroom and card can be sucked directly to a
pre cleaner
• Recovered fibers can be fed directly to the blowroom or can be pressed in bales
for off-line uses
• Waste recycling unit can contain
• A pre cleaner
• A mixer
• A fine cleaner if needed
• A bale press if recycled fibers are not used immediately
M Irfan, PhD

5. Dirty waste recycling
M Irfan, PhD

6. M Irfan, PhD
• Online recycling
• Recycled raw material is used
immediately after recovery and can be
mixed with the same raw material
• Recycling machines are part of
blowroom
• Offline or batch recycling
• Waste or secondary raw material is first
pressed in bales

7. M Irfan, PhD
• Waste chambers of blowroom, card and
comber are connected by suction duct to
central suction that leads to bales
presses
• Separate bale press is required for
each waste type
• One bale press can also serve
(intermittent and alternate working)
• Intermittent operation can separate
different wastes
• Otherwise separate duct is required
for each type of waste

8. Dust handling
• Dust is removed almost at every machine in spinning mills
• The liberated dust should not be allowed to bind with fibers again and should be
removed immediately
• Machines up to draw frame are fully enclosed and connected to dust extraction
lines
• Released dust passes immediately into these ducts and separated
M Irfan, PhD

9. Dust handling
• Dust laden air is usually passed through
two filters to remove dust
• New installations have mostly a central
filter, older ones mostly have individual
filters
• Filtration can be done in two stages
• Primary/preliminary filter
• Slow rotating drum
• Fine filter
• Filter drum
• Dirty waste is then packed
M Irfan, PhD

10. M Irfan, PhD

11. Waste cleaning concept by Trutzschler
M Irfan, PhD

12. Waste cleaner CL-R by Trutzschler
• Waste recycling unit by Trutzschler has
following feature
• Integrated pre-cleaning stage
• Four rolls with five cleaning elements
• Tray feed for short fibers
• Availability of special clothing
• Adapted roll speed
M Irfan, PhD