Real-Time Numerical Simulation for Accurate Soft Tissues Modeling during Haptic Interaction

The simulation of fabrics physics and its interaction with the human body has been largely studied in recent years to provide realistic-looking garments and wears specifically in the entertainment business. When the purpose of the simulation is to obtain scientific measures and detailed mechanical properties of the interaction, the underlying physical models should be enhanced to obtain better simulation accuracy increasing the modeling complexity and relaxing the simulation timing constraints to properly solve the set of equations under analysis. However, in the specific field of haptic interaction, the desiderata are to have both physical consistency and high frame rate to display stable and coherent stimuli as feedback to the user requiring a tradeoff between accuracy and real-time interaction. This work introduces a haptic system for the evaluation of the fabric hand of specific garments either existing or yet to be produced in a virtual reality simulation. The modeling is based on the co-rotational Finite Element approach that allows for large displacements but the small deformation of the elements. The proposed system can be beneficial for the fabrics industry both in the design phase or in the presentation phase, where a virtual fabric portfolio can be shown to customers around the world. Results exhibit the feasibility of high-frequency real-time simulation for haptic interaction with virtual garments employing realistic mechanical properties of the fabric materials.

Tensile and Impact Properties of Hybrid Composites from Textile Waste

The rise of the textile industry in global fashion has caused a high level of post-consumer textile waste generation. Every year, million tons of textile waste has been sent to landfills that consequently leading to environmental pollution. This study aimed to use the textile waste for the development of hybrid composite laminate, together with the existing commercially available fibreglass. This research investigated the tensile properties and impact strength of textile waste hybrid composites. Three textile variants were used in this study, which is lycra, polyester and cotton, and they were either chopped or used as a full fabric. Hand lay-up and hot press technique were used to produce the sample materials, using epoxy resin as the binder. A total of 9 samples were prepared and their tensile and impact properties were assessed. Tensile test results showed that all hybrid composites have a better ultimate tensile strength and tensile modulus compared to their original raw fabrics, but not on the elongation property. It can be seen that the arrangement of fabrics has a distinctive effect on tensile and impact strength. All raw fabrics were greatly punctured during the failure, but all hybrid composites have barely visible impact damage on the front surface, and no penetration was observed. This study reveals that the reuse of textile waste and fibreglass for the development of hybrid composites has a huge potential to be used as substitutes in other composite materials. In the future, this will contribute to improving the sustainability of textile materials.

Compression properties of knitted fabrics printed by sublimation transfer printing technique

Compression properties of textile materials are useful for determining fullness, softness, smoothness, and stiffness. In addition, compression parameters have significant influence on fabric hand value and quality of textile materials. The present paper reports a study of the sublimation printing process influence on the change in compression properties of knitted fabrics (polyester, cotton, and cotton/ polyester) intended for sportswear manufacturing. For that purpose, the KES-FB3-A Compression Tester was used for measuring compression parameters of knitted fabrics. The parameters, which contributed to the smallest reduction percentage in compression properties of polyester knitted fabrics were yarn linear density and weight. For cotton-rich knitted fabrics sublimation coating powder was used for paper modification to bond disperse dyes to cotton fibres. The analysis of the results showed that the printing process had a smaller influence on the change of compression parameters of polyesters in relation to cotton and cotton/polyester knitted fabrics. It was noted that the printing process had the effect of thickness reduction for all knitted fabrics to varying degrees. Printing process contributed to small decrease in compressibility and specific volume values for polyester knitted fabrics. The modification process contributed to the significant reduction of the compressibility for cotton (from 34.46% to 47.89%) and cotton/polyester (from 38.81% to 50.75%) knitted fabrics. In addition, reduction in specific volume values range from 41.86% to 44.19% for cotton and from 42.37% to 45.75% for cotton/ polyester knitted fabrics was notted.

A mathematical model for objective hand evaluation of automotive seat fabrics

A mathematical model for objective evaluation of hand value of car seat fabrics was developed using a step-wise block regression method. The subjective assessment of fabrics was conducted by a panel of judges to identify the primary hand attributes and the related mechanical parameters playing an important role in the fabric hand evaluation. The primary attributes selected by judges were conformability, smoothness, softness and stretchability. The coefficient of concordance was determined to find out the agreement among the judges. From consumer point of view, conformability got the highest weightage in the survey. There is an excellent correlation between the subjective and objective primary hand values. The correlation between the subjective and the objective total hand values found to be very high (R > 0.9) both with and without stretchability parameter.

A New Approach to Evaluate Fabric Hand Based on Three-Dimensional Drape Model

Fabric quality and performance is assessed subjectively by the customer using an important and complex phenomenon of fabric hand. Objectively, it is evaluated with complicated and expensive instruments, such as Kawabata Evaluation System for Fabrics (KES-F) and Fabric Assurance with Simple Testing (FAST). The present research explores a non-touch objective approach, i.e., three-dimensional (3D) drape model to estimate fabric hand. Fabric hand prediction was testified on different commercial fabrics spanning a wide range of areal weight, thickness, yarn count, and fabric density. Fabric objective ranks based on drape indicators using principal component analysis (PCA) were compared with subjective ranks of fabric hand. Additionally, fabric drape is evaluated three dimensionally and a new drape indicator drape height (DH) is proposed. The cosine similarity results have proved fabric drape as an objective alternate to fabric hand.

Evaluation of Quality and Assurance Parameters of Mulberry Silk Waste and Viscose Blended Knitted Fabrics by Using ‘Fabric Assurance by Simple Testing’ (FAST) Technique

Fabric handle is one of the influential properties for any fabric and is a guiding factor for optimum selection of textile materials for specific end uses. The paper deals with objective analysis of knitted fabrics for fabric hand. Present attempt was made on four knitted fabrics, blended in proportions of 50% mulberry silk: 50% viscose and 40% mulberry silk: 60% viscose, each in two different counts. Fabric Assurance by Simple Testing (FAST) was utilized for determination of properties which is precisely associated with apparel construction and its lastingness. Fabric samples were subjected to tests for obtainment of dimensional stability, formability, low load extensibility, bending rigidity, compression and shear rigidity. Knitted fabric blended in proportion of 50% mulberry silk: 50% viscose in 20 Nm count was found to be most feasible to large scale production and garment construction.

Measuring Fabric Sensory Attributes: Theory and Practice

Two major sample configurations are adopted in all the instruments for fabric hand measurement, flat sample as in KES and FAST types machines, and wrinkled sample as in PhabrOmeter. This paper compares the two sample types to examine which one if any offers a better coverage and reflection of the fabric sensory attributes.  Fabrics have unique behaviors of drape, wrinkle and tactile sense which are entirely due to the simultaneous occurrence of both in-plane membrane deformation and out-of-plane bending deformation in multiple curvature. Such singular deformation mode cannot be detected by any machines using flat sample, whereas during a PhabrOmeter test, the fabric sample genuinely produces drape, wrinkle in addition to other related deformations. This paper then introduced the theoretical research pertaining to the measurement. Then a split sample experiment is conducted to demonstrate the importance of the internal connections in fabric during drape and wrinkle processes. As such fabric interconnection will be barely disclosed during tests using flat samples, another important advantage of PhabrOmeter is hence clearly shown.