Compression-Recovery Behavior of High Loft 3-D Nonwoven Fabrics Pratik Ichhaporia, Prashanti Alapati, and Bhuvenesh C. Goswami 2007 Beltwide Conference Nonwoven Symposium January 9-12, 2007 New Orleans, LA

Objectives Study the compression-recovery behavior, both from static and dynamic loading of high loft nonwoven fabrics Study the compression-recovery behavior, both from static and dynamic loading of high loft nonwoven fabrics Specifically the study concerns the influence of constituent fiber characteristics such as: Specifically the study concerns the influence of constituent fiber characteristics such as: X-Sectional Shape X-Sectional Shape Round Round Scal-Oval Scal-Oval Cruciform Cruciform Hollow Hollow Tensile Modulus Tensile Modulus Linear Density Linear Density Crimp Density Crimp Density Fiber Characteristics Fiber Characteristics Fabric Density Fabric Density Fabric Thickness Fabric Thickness Nodes Per Unit Length (Perpendicularly Laid Fabrics) Nodes Per Unit Length (Perpendicularly Laid Fabrics)

Earlier Work

Fabric Specimen with 6.0 Denier Base Fibers

Here the sample is identified by the base fiber denier or linear density and also by the fabric roll. For example, , fabrics have the same base fiber denier of 1.65, have the same fiber charactersitics such as cross-sectional shape, crimps per inch and fiber density, but the two fabrics vary with respect to the process parameters such as nodes per inch, density of the fabric and height of the fabric. Fiber & Nonwoven Fabric Specifications

Instron Tensile Tester with Add-ons for Dynamic Compression Testing

Shirley Thickness Tester with Add-ons for Static Compression – Recovery Testing

(a) Specimen with a Bending Modulus Exz (b) Representation of the Coordinate axis © The Direction of Nodes in the Case of Ezy and Exz

Control Panel of a Fiber Orientation Analyser [14]

Tensile Properties of the Base Fibers

Stress-strain curves for various base fibers

Cross-section of 1.65 Denier Fiber at 500X Magnification

Cross-section of 2.5 Denier Fiber at 200X Magnification

Cross-section of 2.62 Denier Fiber at 200X Magnification

Cross-section of 3.60 Denier Hollow-1Fiber at 500X Magnification

Cross-section of 6.00 Denier Mono-component Fiber at 500X Magnification

Cross-section of 6.00 Denier Bi-component Fiber at 500X Magnification

Cross-section of 7.00 Denier Fiber at 500X Magnification

Cross-section of Denier Fiber at 200X Magnification

Fiber Shape Factors [5, 6] and Calculated Flexural Rigidity Values

Compression-Recovery Curves (a) Compression Curves for the First Cycle of Loading (b) Recovery Curves for the First Cycle of Recovery

Compression-Recovery Curves (a) Compression Curves for the Fifth Cycle of Loading (b) Recovery Curves for the Fifth Cycle of Recovery

vf/vo Values at 50% Yield Load – Dynamic Loading

vf/vo Values at 75% Yield Load – Dynamic Loading

The following general conclusion may be drawn: 1. Fiber cross-sectional shape significantly affects the compression and recovery-behavior as determined by the static loading-recovery and the dynamic loading recovery. 2. Combination of the cross-sectional shape and the flexural rigidity have a similar trend that is as the shape deviates from the fiber rigidity increases and so does the compression-recovery behavior of the batts. Initial modules of the fiber is also just as important in the compression-recovery characteristics of high loft batts. 3. Fiber modules is particularly influential in recovery behavior at the higher level of loading. 4. Fabric thickness (node height), nodes frequency, and fiber orientation, all have a direct relationship with recovery but only at higher loading levels. 5. On the other hand fiber crimp and fabric density are influential at recovery at lower loading levels. Conclusion