Elasticity, capillarity and imbibition in textiles

Introduction

Fibrous media are ubiquitous in natural and engineered systems, due to their versatility, flexibility, and functionality. Nonwovens (i.e. entangled fibrous networks), and especially natural fibre-based materials such as paper or flax mats, are heavily used for a variety of applications and could be largely developed as a sustainable alternative for plastics.

Limitations

The first limitation of their widespread use is their response to humidity, wetting, or drying, which is unavoidable in many applications and is a key step of their manufacturing processes.

Project Objectives

The ElCapiTex project aims at characterizing and modelling the specific behaviour and properties of wet non-woven textiles, including:

1. Consolidation
2. Imbibition
3. Mechanical response
4. Deformation

Methodology

In order to characterize the complex interplay between the various physical mechanisms that give rise to the global properties of textiles, we will focus on:

• Hydrodynamics
• Capillarity
• Elasticity
• Swelling

We will combine different approaches coming from three recent active research areas of fluid-structure interactions:

1. The transport of suspensions of elastic objects
2. Elastocapillarity (i.e. the deformation induced by the capillary forces associated with liquid-air interfaces)
3. Poroelasticity

Experimental Approach

We will work with a hierarchy of experimental model systems of increasing complexity, particularly by fabricating model nonwoven sheets from gel fibre suspensions.

Theoretical Models

We will further build theoretical models based on recent statistical approaches used to describe the mechanical properties of dry textiles.

Conclusion

Understanding these physical mechanisms is mandatory to develop innovative processes and materials. Reconciling fundamental pore-scale mechanisms with network behaviour will allow for the design of tailored fibrous media with specific properties.