From fabric to smart T-shirt: fine tuning an improved robust system to detect arrhythmia

Wearable electrocardiogram (ECG) systems should be comfortable, non-stigmatizing, and capable of producing high-quality data. Many different designs of wearable textile ECG systems have recently emerged. Some of them are not considered to be smart garments, whereas most of the others present only the electronic side of the system. Our research work introduces a comprehensive study for an improved single-lead ECG smart shirt to identify automatically premature ventricular contraction as a common form of arrhythmia. For artifact-free results, Marvelous Designer is implemented to design our optimized relaxed slim fit shirt. In addition, a weft-knitted fabric of 80% nylon–20% spandex is used to manufacture the outer part of the shirt. Moreover, lightweight and small size electronic components are integrated to the outer part via low-resistance dry textile electrodes and 100% cotton fabric as an inner layer for easy transmission of weak ECG signals.

Study on the Thermal and Impact Resistance Properties of Micro PA66/PU Synergistically Reinforced Multi-Layered Biaxial Weft Knitted Fabric Composites

In this paper, the influence of micro PA66/PU in multi-layered biaxial weft knitted (MBWK) fabric reinforced composites on thermal and impact resistance was studied. The main objective was to investigate the role of micro PA66/PU in terms of improving material performance. The results showed that the addition of micro PA66/PU improved the thermal stability of the MBWK composite. It is observed that the onset degradation temperatures increased by 1.6°C in thermo-gravimetric analysis (TGA) test and the Tg increased by 2.8°C in the dynamic mechanical analysis (DMA) test. Besides, the impact energy absorption of composites increased by 5.3% after the addition of micro PA66/PU. The addition of micro PA66/PU effectively reduced the impact damage area from the failure morphology after impact. In simple words, the addition of micro PA66/PU effectively improves the comprehensive properties of composites.

Effect of inner layer structures of weft-knitted spacer fabrics on thermal insulation and air permeability

The main goal of this research was to determine the influence of the inner layer thickness and tightness, which depends on the length of the float determined by the float step and number of floats in the pattern repeat, on the thermal insulation and air permeability of the multilayered weft-knitted fabric. For this reason, weft-knitted spacer fabrics were produced by using woolen yarns for the outer layers and polyester filament yarn for the inner layer, with the number of floats in the inner layer varying between two and 20. Results from this research showed that the consequent increase in thickness and tightness of the spacer fabric’s inner layer has unequal effect on the thermal insulation and air permeability. Therefore, similar thermal insulation can be achieved by having significantly higher air permeability. This is especially evident over a long period of time.

Thermal Analysis of Heating–Cooling Mat of Textile Incubator for Infants

On the medical device market there are several types of stationary and portable incubators that can be used in the care of infants. The prototype of a textile incubator made as part of this work consists of five material layers. The textile incubator is equipped with a functional heating and cooling mat, which is made on the basis of 3D channeled weft-knitted fabric. Its function is to generate heat and maintain it inside the textile incubator or to cool the baby's body while using therapeutic hypothermia. The mat is equipped with hoses transporting the heating or cooling medium. The mat, depending on variable input parameters, can emit heat in the range from 1.15 W to 86.88 W. In case of the cooling function, it can receive heat in the range from −4.32 to −27.96 W. This indicates a large adjustment range of the amount of heat supplied and received, which is a positive feature, and enables programming the heat balance to ensure comfort for the baby. The analysis of temperature measurements on the mat surface confirmed that maximum temperature differences do not exceed 1.6°C.

The Effect of Softeners Applications on Moisture Management Properties of Polyester/Cotton Blended Sandwich Weft-Knitted Fabric Structure

Prolonged drying times of terry fabrics is a problem as they can not be re-used until completely dry. To resolve this issue, we have designed a sandwich polyester in the mid-layer with low moisture content that could reduce the drying time with excellent wicking properties. These fabrics are widely used as activewear and sportswear. The effect of different softeners on the moisture management properties of weft-knitted terry fabrics’ for various applications has also been studied. Terry knitted fabrics were prepared using a circular knitting machine. Six different softeners were applied with three different concentrations, i.e., 10 g/L, 15 g/L, and 20 g/L, on the fabric using the pad-dry-cure method. Moisture management tests and rubbing fastness tests were performed to analyze the applied softener’s effect on the fabric comfort and moisture management performance. Results revealed that softener type (i.e., cationic, anionic, and non-ionic) and concentration levels considerably affect the moisture management capability of terry knitted fabrics.

Numerical and experimental study of internal pressure behaviour of integrated and non-integrated weft-knitted reinforced composite elbows

This research aims to study the internal pressure behaviour of integrated and non-integrated composite elbows. For this purpose, weft-knitted integrated preforms were produced on the CMC-330-TC Flat knitting machine. Composite elbows reinforced with integrated weft-knitted preform were fabricated using the bladder molding technique. In addition, the non-integrated composite elbows were provided by wrapping the weft-knitted fabric on a plaster mold and hand lay-up impregnation method. To perform the pressure test, a fixture was designed and manufactured. Produced samples were subjected to the internal pressure test. Experimental results show that integrated composite elbow has higher hydrostatic pressure resistant. The internal pressure behaviour of integrated composite was simulated using the multi-scale model. Results showed that integrated composite elbow has a higher resistance against internal pressure than non-integrated composite elbows, so that the integrated elbows failed at 12.5-bar pressure, while the non-integrated elbow failed at 9.5-bar pressure.

Review on the 3-D simulation for weft knitted fabric

There are different kinds of geometrical models and physical models used to simulate weft knitted fabrics nowadays, such as loop models based on Pierce, piecewise function, spline curve, mass-spring model, and finite element analyses (FEA). Weft knitting simulation technology, including modeling and yarn reality, has been widely adopted in fabric structure designing for the manufacturer. The technology has great potentials in both industries and dynamic virtual display. The present article is aimed to review the current development of 3-D simulation technique for weft knitted fabrics.