The Role of Impact Force and Inclined Water Jets on the Performance of Hydroentangled Fabrics

论文摘要

Hydroentangling is a mechanical bonding process involving the interlocking of fibers in a web structure using fine,closely spaced,high-pressure water jets.The main objective of this research was to investigate the role of impact force and inclined water jets for improve on mechanical performance of hydroentangled fabrics.An experimental apparatus was designed with different inclination angles（-200,-100,00,+100,+200）.The simulation using Phoenics,version 3.4 CFD software was conducted to verify impact force experimental data of water jets flow.The predicted CFD impact force has good agreement with experimental data compared to calculated impact force.The 60 gsm and 100 gsm fiber webs of bicomponent fibers（PET/COPET,PA6/COPET and PA6/PET）were manufactured and tested for their mechanical performance as well as evaluating fiber splitting within fiber webs.The results show that with increases of water jets inclination angle,impact force,and water jets pressure,the mechanical performance and fiber splitting of hydroentangled fabrics were enhanced.The water jets inclination angles of-100& +100 shows higher mechanical performance followed,by -200&+200 and the last 00,while PA6/PET was highly split followed by PA6/COPET（split without dissolution of the sea） and PET/COPET did not split.It can be concluded that the combination of impact force and inclined water jets with low inclination angles in appropriate conditions improved the mechanical performance.The One Way of Analysis of Variance（ANOVA）and the Multicompare Analysis using MATLAB were used for statistical data analyses.This research work addresses issues that are not dealt with in previous publications.

论文目录

• ABSTRACTS
• ACKNOWLEDGEMENT
• NOMENCLATURE
• CHAPTER ONE:INTRODUCTION
• 1.1 Application of Hydroentanglement
• 1.1.1 Hydroentangled Non-wovens Properties
• 1.1.2 Fiber Application in Hydroentanglement
• 1.2 Bicomponent Fibers.
• 1.2.1 Splittable Bicomponent Fibers
• 1.2.2 Application of Splittable Bicomponent Fiber
• 1.3 Splitting Methods
• 1.4 Hydroentanglement Development
• 1.4.1 Hydroentanglement Machines Development
• 1.5 Previous Research Work
• 1.5.1 Hydroentanglement Water Jets/Nozzle Geometry
• 1.5.2 Specific Energy and Jet Pressure
• 1.5.3 Fiber Types
• 1.5.4 Forming Wire
• 1.5.5 Impact Force
• 1.6 Shortcomings of Previous Research
• 1.7 Research Objectives
• 1.8 Research Outlines
• CHAPTER TWO:DESIGNING OF EXPERIMENTAL APPARATUS
• 2.1 Introduction
• 2.2 Statement of Operation
• 2.3 Designing Consideration
• 2.3.1 Path Distance Consideration
• 2.3.2 Velocity Consideration
• 2.4 Designing of Apparatus Components
• 2.4.1 Designing of jet plates
• 2.4.2 Designing of Pressure Water Tank
• 2.4.2.1 Calculation for Checking Stress of Tank Shell
• 2.4.2.2 Calculation for Checking Stress of Top Cover and Bottom Cover
• 2.5 Components Selection
• 2.6 Force Sensor and Personal Computer
• 2.7 Assembled of Designed Experimental Apparatus
• 2.8 Advantages and Limitation of the Apparatus
• 2.9 Summary and Conclusion
• CHAPTER THREE:THEORETICAL ANALYSIS OF IMPACT FORCE
• 3.1 Impact force
• 3.1.1 Flow characteristics in the nozzle orifice
• 3.1.2 Calculation of outlet water jet velocity at nozzle orifice
• 3.1.3 Impact Force Calculation on the Upper Surface of the Web
• 3.1.4 Impact force calculation on the individual fibers within fiber web during hydroentanglement process
• 3.2 Conclusion
• CHAPTER FOUR:NUMERICAL SIMULATION AND IMPACT FORCE EXPERIMENTS
• 4.1 Introduction
• 4.2 CFD-Phoenics Software Package
• 4.3 Physical Model
• 4.3.1.Boundary Conditions
• 4.3.2 Initial Conditions
• 4.4 Numerical Simulation and Grid System
• 4.4.1 Governing Equations
• 4.5 Numerical Results and Discussion
• 4.5.1 Velocity Distribution Depending on Standoff Distance
• 4.5.2 Pressure Distribution Depending on Standoff Distance
• 4.5.3 Impact Force Measurement
• 4.5.3.1 Influence of Water Jet Pressure on Impact Force
• 4.5.3.2.Influence of Water Jet Inclination Angle on Impact Force.
• 1）on Impact Force.'>4.5.3.3 Influence of Standoff Distance（L₁）on Impact Force.
• 4.5.4.Influence of Basis Web Weight on Impact Force
• 4.5.5 Prediction Errors
• 4.6 Conclusion
• CHAPTER FIVE:MATERIALS AND METHODOLOGY
• 5.1 Materials
• 5.1.1 Testing of Fiber Properties
• 5.1.1.1 Tensile Properties
• 5.1.1.2 Fiber Friction Properties
• 5.1.1.3 Fiber Length
• 5.1.1.4 Fiber Diameter
• 5.1.1.5 Linear Density
• 5.1.1.6 Specific Resistance
• 5.1.1.7 Number of Crimps
• 5.1.1.8 Fiber Properties Summary
• 5.2 Equipment
• 5.2.1 Fiber Web Formation
• 5.2.2 Experimental Apparatus
• 5.2.3 Hydroentanglement Unit
• 5.2.4 Web Support
• 5.3 Impact Force
• 5.3.1 Sensor calibration
• 5.3.2 Impact force measurement
• 5.3.3 Apparatus for Impact Force Measurement
• 5.4 Testing of Hydroentangled Fabrics
• 5.4.1 Mechanical Properties
• 5.4.1.1 Tensile Strength
• 5.4.1.2 Tear Strength
• 5.4.1.3 Bursting Strength
• 5.4.1.4 Basis Weight
• 5.5 Images
• 5.5.1 Fabric Images
• 5.5.2 Water jets images
• CHAPTER SIX:INFLUENCE OF PROCESSING VARIABLES ON FIBER SPLITTING
• 6.1 Objective
• 6.2 Fiber Splitting Evaluation
• 6.3 Fiber Splitting Before Hydroentanglement
• 6.4 Fiber Splitting After Hydroentanglement（Based on Designed Apparatus）
• 6.4.1 Fiber splitting of PA6/PET
• 6.4.2 Fiber splitting of PET/COPET
• 6.4.3 Fiber splitting of hydroentangled fabrics（PA6/PET,PA6/COPET and PET/COPET）based on 10 bars with different inclination angles
• 6.5 Fiber Splitting After Hydroentanglement（Hydroentanglement Machine）
• 6.5.1 Fiber splitting of PA6/PET（Based on Hydroentanglement Machine）
• 6.5.2 Fiber splitting of PET/COPET（Based on Hydroentanglement Machine）
• 6.5.3 Fiber splitting of PA6/COPET（Based on Hydroentanglement Machine）
• 6.6 Conclusion
• CHARPTER SEVEN:ROLE OF PROCESSING VARIABLES ON MECHANICAL PERFORMANCE OF HYDROENTANGLED FABRICS
• 7.1 Experimental Approach Based on Preliminary Experiment on Designed Apparatus
• 7.2 Objectives of Preliminary Experiment on Designed Apparatus
• 7.3 Results and Discussions of Preliminary Experiment
• 7.3.1 Tensile Strength of Hydroentangled Fabrics.
• 7.3.2 Bursting Strength
• 7.3.3 Tear Strength
• 7.4 Conclusion of Preliminary Experiments on designed apparatus
• 7.5 Main Experiments on Designed Apparatus and Industrial Machine
• 7.5.1 Experimental Approach of Main Experiments
• 7.5.1.1 Materials
• 7.5.1.2 Processing Parameters Based on Main Experiment
• 7.5.2 Experimental Results,Data Analysis and Discussion of Main Experiments
• 7.5.2.1 The Effects of Water Jets Inclination angle,Fiber Types on Tensile Strength
• 7.5.2.2 The Effects of Water Jets Pressure,Fiber Types on Tensile Strength
• 7.5.2.3 The Effects of Impact Force,Fiber Types on Tensile Strength
• 7.5.2.4 The Effects of Impact Force,Fiber Types on Strain at Break
• 7.5.2.5 The Effects of Water Jets Inclination Angle,Fiber Types on Strain at Break
• 7.5.2.6 The Effects of Water Jets Pressure,Fiber Types on Elongation at Break
• 7.5.3 Stress-Strain Curve
• 7.6 Conclusion
• CHAPTER EIGHT:SUMMARY,CONCLUSION AND FUTURE WORK PROSPECTIVE
• 8.1 Summary and Conclusions
• 8.1.1 Theoretical Analysis,Numerical Simulation and Impact Force Experiments
• 8.1.2 Effects of Processing Variables on Mechanical Performance
• 8.1.3 Influence of Water Jet Pressure,Inclination Angle,and Fiber types on Fiber Splitting
• 8.2 Future Work Prospective
• References
• Appendix