Index
- General - Technology of Short-staple Spinning
- Raw Material as a Factor Influencing Spinning
- Opening
- The need for opening
- Type and degree of opening
- The intensity of opening
- General considerations regarding opening and cleaning
- Carding
- The purpose of carding
- Clothing arrangements
- Forces acting on the fibers
- Fiber transfer factor
- The most important working regions in carding
- Straightening-out of fiber hooks
- Cleaning
- Blending
- Reducing the Unevenness of Yarn Mass
- Unevenness of yarn mass
- Basic possibilities for equalizing
- Doubling
- Leveling
- Drafting with simultaneous twisting
- Attenuation (draft)
- The draft of the drafting arrangement
- The drafting operation in the drafting arrangement
- Behavior of fibers in the drafting zone
- Friction fields
- Distribution of draft
- Other drafting possibilities
- Additional effects of draft
- Yarn Formation
- Assembly of fibers to make up a yarn
- Arrangement of the fibers
- Number of fibers in the yarn cross-section
- Fiber disposition
- The order of fibers within the yarn
- The positions of the fibers in the yarn structure
- Yarn structure
- Fiber migration
- Imparting strength
- Possibilities for imparting strength
- True twist (with reference to ring-spun yarn)
- False twist
- Self-twist
- Assembly of fibers to make up a yarn
- Handling Material
- Carriers for material
- Material carriers and transport
- Package forms
- Classification
- The most widely used package forms with internal formers
- Laying down in cans
- Winding by rolling and lap forming
- Winding on flyer bobbins
- Winding of cops
- Build of cops
- The winding process
- Force and tension relationships during winding by using travelers
- Effects on the traveler
- Carriers for material
- Quality Assurance
- References
- The Blowroom
- Introduction
- Summary of the process
- The components of blowroom machines
- Feeding apparatus
- Opening devices
- Classification
- Endless path devices (spiked lattices)
- Gripping elements (plucking springs)
- Rotating devices
- The grid
- Interaction of feed assembly, opening element and grid
- Alternative cleaning possibilities
- General factors influencing opening and cleaning
- High-performance machines ought to be easy to handle
- Transport of material
- Control of material flow
- Damage prevention and fire protection
- Waste management
- Economy of raw material utilization
- Quantity of waste material
- Classification of spinning mill waste
- Recycling of waste
- Handling dust and fly
- Final disposal of waste
- The Card
- Summary
- The operating zones of the card
- Material feed
- Feed device to the licker-in
- The licker-in zone
- Auxiliary carding devices (carding aids)
- Main cylinder
- Flats
- Doffing
- Detaching
- The machine drive
- Card clothing
- Autoleveling equipment
- Basics
- Classification
- The principle of short-term autoleveling
- The principle of medium-term autoleveling
- The principle of long-term leveling
- Measuring devices
- Maintenance
- Stripping the clothing
- Burnishing the clothing
- Grinding the clothing
- High-performance maintenance systems
- Settings
- Auxiliary equipment
- Technical data of three high performance cards
- References
- The Blowroom
- The Combing Section
- Introduction
- Technology of combing
- The noil extraction theory
- Derivation according to Gégauff
- The quality of the combing operation in forward and backward feeding
- The influence of machine components and settings on combing
- Preparation of the stock for combing
- The comber
- Outline
- The feed
- The nipper assembly
- The comb
- Take-off of material
- The drafting arrangement
- Coiling the sliver
- Waste removal
- Machine data
- The Saco Lowell double-sided comber
- Automation in the combing section
- Number of drawframe passages
- Upgrading of raw material
- New market segments due to upgrading of cotton
- Some preconditions
- The Drawframe
- Introduction
- The task of the drawframe
- Operating principle
- Operating devices
- Creel (sliver feed)
- The drafting arrangement (general considerations)
- Requirements
- Influences on the draft
- Elements of drafting arrangements in short staple spinning generally
- Types of drafting arrangement used on drawframes
- Suction systems for the drafting arrangement
- Coiling
- Monitoring and autoleveling
- Aim of autoleveling
- Classification
- Monitoring devices with self-compensation
- Monitoring devices with autoleveling systems
- Leveling drawframes with open-loop control
- Leveling drawframes with closed-loop control
- Correction length
- The Rieter RSB leveling system
- The integrated monitoring system (process control techniques)
- Blending drawframes
- Logistics
- Technical data of a high-performance drawframe
- The Roving Frame
- Introduction
- Description of functions
- The operating zones of the roving frame
- Machine drive system
- Special design (Saco Lowell „Rovematic“ frame)
- Accessories
- Automation
- Technical data (normal values)
- Appendix
- The Combing Section
- The Ring Spinning Machine
- Function and Mode of Operation
- Structural Configuration of the Machine
- Basic frame and superstructure
- The bobbin creel
- The drafting system
- Influence on quality and economy
- Conceptual structure of the drafting system
- The top rollers
- Pressure roller loading
- Fiber guidance devices
- The spindle
- The thread guide devices
- The ring
- The ring traveler
- The Machine Drive
- Cop Buildup
- Automation
- The need for automation
- The potential for automation
- Doffing
- Automated cop transport
- Piecing devices
- Roving stop motions
- Monitoring
- Auxiliary Equipment
- Fiber extraction
- Blowers (traveling cleaners)
- Compact Spinning
- Technological Addenda
- Spinning geometry
- Quality standards
- A new approach to quality
- Quality standards according to Uster Statistics
- The Importance of Rotor Spinning
- Historical background
- Development and current status of rotor spinning
- The potential of rotor spinning
- The principle of rotor spinning
- Performance parameters of rotor spinning machines
- Machinery and Process
- Structure of the rotor spinning machine
- Operating principle of the rotor spinning machine
- The spinning box
- Package formation
- Drives
- Suction systems
- Operating and monitoring
- Quality control systems
- Production monitoring
- Machine and Transport Automation
- General
- Machine automation in rotor spinning
- General
- Application options for operating robots
- Automatic piecing
- Semi-automatic piecing system on manually operated machines
- Automatic package change
- Batch change
- Supplying empty tubes
- Automatic sliver piecing after can change
- Transport automation in the rotor spinning mill
- Applications Engineering
- Raw material selection
- Fiber properties
- Preparation of raw material
- General
- Disturbing materials in the cotton
- Processing problems with man-made fibers
- The processing stages
- Ranges of application of the spinning elements
- General
- Range of application of the opening roller
- Range of application of the rotor
- Range of application of draw-off nozzles and draw-off tubes
- Components for manufacturing fancy yarns
- Selection and influence of draft and yarn twist
- Yarn and machine data for the main rotor-spun yarns
- Ambient conditions in the spinning mill
- Downstream processing and end products
- Technology
- Yarn formation
- Genuine and false twist
- Wrapper fibers
- Yarn structure and physical textile characteristics
- Economics of Rotor Spinning
- References
- The Importance of Rotor Spinning
- Alternative Spinning Systems
- Alternative Spinning Processes
- The Various Spinning Methods
- Open-end spinning processes
- The basic principle of yarn formation
- Electrostatic spinning
- Air-vortex spinning
- Friction spinning
- The University of Manchester Discspinner
- Twist spinning
- Friction (self-twist) method
- Wrap spinning
- Operating principle
- ParafiL system by Suessen
- Technological and economic interrelationships
- The False-twist process
- The false-twist principle
- Two nozzle air-jet spinning
- Dref-3000 process
- PLYfiL spinning process
- Air-jet spinning
- Open-end spinning processes
- Summary and Outlook
- Processing principles
- Field of use
- Yarn characteristics
- Economic comparison
- Outlook
The number of neps in air-jet spun yarns is more or less independent of the thin and thick places. This is particularly true for the 200% neps. The spinning results have actually shown that sometimes wrapping fibers or fiber bundles might be counted as neps. The chances of this happening increase, of course, with increasing wrapping twist levels.
Spinning results in Fig. 44 demonstrate quite clearly that with decreasing spinning speed, i.e. increasing wrapping twist, the number of neps increases quite drastically.
The nep count therefore gives some indication of the yarn structure. Even so, the 200% nep count of the air-jet yarns is similar to the nep count of ring-spun yarns, provided the air-jet yarns do not have an excessively high wrapping twist.
Fig. 44 – Nep count as a function of spinning speed (Rieter)
