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Abstract

This research introduces a groundbreaking weft-knitted spacer composite fabric designed for a continuous cool feeling effect. Fabrication involved a double-sided circular weft machine, incorporating ultra-high molecular weight polyethylene (UHMWPE) cool feeling fiber as the surface layer and carbon-coated nylon monofilament as the spacer layer. Quantitative assessments demonstrate a remarkable thermal conductivity of 0.329 W·m⁻¹·K⁻¹ for the developed fabric, significantly higher than the polyester spacer fabric used for comparison. The UHMWPE cool feeling fiber exhibited exceptional moisture conductivity and wettability, with a wicking height approaching 6 cm within the initial 3 minutes and a water contact angle of 44.47° after 40 seconds. This enables the capillary transport, diffusion, and evaporation of water molecules along the fiber surface. This process efficiently dissipates heat, resulting in a distinct tactile cool sensation. To further enhance the continuous cool feeling effect, the weft-knitted spacer fabric was integrated with needle-punched nonwoven fabrics containing phase change microcapsules (PCM) embedded viscose fiber. The PCM viscose fiber demonstrated a melting phase transition within 25–35°C, with an endothermic enthalpy of 6.48 J/g. This strategic incorporation not only amplifies the fabric’s cooling capabilities but also introduces an advanced dimension of temperature regulation, maintaining a temperature difference of approximately 1.2°C between the upper and lower surfaces of the composite fabric. The findings underscore the fabric’s multifaceted advantages, positioning it as a promising solution for diverse applications. Infrared thermal imaging revealed the composite fabric’s ability to maintain a lower surface temperature over time compared to polyester spacer fabric, while compression recovery tests showed its capacity to provide good mechanical support with a distinctive three-stage compression process. The innovative integration of materials yields a fabric with superior thermal and moisture management properties, making it ideal for applications ranging from advanced apparel to innovative seating materials. The quantitative thermal conductivity result, coupled with the synergistic effects of UHMWPE cool feeling fiber and PCM microcapsules, underscores the fabric’s potential to redefine comfort and functionality in textiles. This research serves as a foundation for future advancements in textile technologies, setting the stage for the creation of fabrics that offer sustained cooling, improved comfort, and enhanced user experiences.

Keywords

Composite fabrics fabrication (knitting,nonwoven)weft-knitted spacer fabric cool feeling ultra-high molecular weight polyethylene thermal conductivity phase change material

Introduction

Textiles constitute a versatile material encountered in various facets of our daily lives, including clothing, bed linens, towels, and furniture upholstery.^1,2 The term “comfort” denotes a state of pleasurable equilibrium, encompassing physiological, psychological, and physical harmony between an individual and their environment.^3,4 In the realm of clothing, the human body serves as an endogenous heat generator, establishing a thermal gradient between the body and its immediate surroundings.^5,6 Notably, unlike conventional heat transfer challenges in engineering, this gradient often undergoes changes in response to fluctuations in ambient temperature.⁷ This study introduces an innovative weft-knitted spacer composite fabric designed to enhance user comfort and functionality within the realm of textile technologies. The primary aim of this research is to develop a fabric that delivers a sustained cooling effect to the wearer. The increasing demand for textiles that provide both thermal comfort and lasting cooling capabilities underscores the importance of creating new and advanced materials.

The spacer structure, characterized by its substantial thickness, imparts remarkable properties such as lightweight construction and structural integrity to the fabric.⁸ Simultaneously, the hollow structure facilitated by the spacer yarn interconnecting the surface fabric bestows exceptional attributes upon the spacer fabric.⁹ These include notable air permeability, moisture permeability, and pressure resistance. The fabric, with its inherent elasticity and shock-absorbing cushioning properties, finds diverse applications in cushions, mattresses, and beyond, indicating promising avenues for its utilization.^10,11 The cooling efficacy of the spacer fabric is primarily contingent upon the thermal conductivity, air permeability, and moisture permeability of the fiber material. Enhanced wetting and wicking properties of the fiber transferred into heightened moisture absorption and perspiration capabilities in the fabric.¹² Likewise, fibers with elevated thermal conductivity contribute to a more pronounced transient heat flow when the fabric interfaces with the skin, resulting in a stronger cooling effect.^13,14 Notably, recent years have witnessed a surge in the utilization of polyethylene and ultra-high molecular weight polyethylene fibers in the exploration of cool and comfortable fabrics, yielding noteworthy achievements.^15,16 However, to attain a sustained cooling sensation, there remains a need to construct a multi-layered fabric structure capable of regulating thermal performance over an extended period. While the application of advanced fibers has significantly contributed to achieving instantaneous cooling effects, the development of a multi-layered architecture becomes imperative for prolonging the duration of this cooling sensation.¹⁷ As this research delves into the design and implementation of a weft-knitted spacer composite fabric, it endeavors to address these intricacies, offering a holistic solution that extends beyond immediate cooling to deliver a sustained and enduring cool feeling to the fabric’s wearer.

Cooling comfort in textiles has become increasingly important due to rising global temperatures and the need for effective personal thermal management. The benefits of cooling comfort extend beyond mere convenience, impacting health, productivity, and overall well-being.¹⁸ Cooling fabrics can enhance temperature regulation by up to 3°C (about 5.4°F), with some studies suggesting almost 15°C skin surface cooling from passive cooling fabrics alone.¹⁹ This temperature regulation is important for maintaining physiological balance and preventing heat-related illnesses. The necessity of cooling comfort is particularly evident in various applications. In sports and physical activities, cooling fabrics can significantly enhance performance. Athletes who regulate their body heat better can avoid the risk of heat stress and experience improved endurance. In occupational areas, especially for workers in hot environments, cooling textiles can provide essential protection against heat-related health risks. Moreover, cooling comfort plays a vital role in sleep quality.²⁰ Preliminary studies have shown that individuals in hot climates who use cooling mattress designs experience better sleep than those without. This improvement in rest quality has far-reaching implications for overall health and daily functioning.²¹ The development of cooling textiles also aligns with energy conservation efforts. By providing localized and personalized cooling, these fabrics can reduce the need for air conditioning, potentially leading to significant energy savings. In addition to physical benefits, cooling comfort can enhance cognitive performance and emotional well-being.²² Maintaining a comfortable body temperature allows individuals to focus better on tasks and reduces irritability associated with heat stress. Given these multifaceted benefits, the development of advanced cooling textiles, such as the weft-knitted spacer composite fabric presented in this study, is not just an innovation in textile engineering but a response to pressing physiological, environmental, and societal needs.

This study employs a spacer fabric matrix, incorporating special-shaped cross-section ultra-high molecular weight polyethylene cool-feel fiber as the raw material for the upper and lower surface layers. The thermal conductive layer consists of carbon-coated nylon monofilament, woven into a weft-knitted spacer fabric (referred to as cool-feel) on a circular knitting machine. This unique spacer fabric not only offers distinctive properties but also serves as the foundation for further enhancements. In addition to the cool-feel fabric, the study incorporates a phase change material (PCM) viscose fiber needle-punched nonwoven fabric as the cooling layer. This cooling layer is strategically combined with the cool-feel spacer fabric, culminating in the development of a cushion. This innovative cushion not only provides users with commendable mechanical support but also serves as a microclimate regulator.²³ The integration of these advanced materials and knitting techniques aims to create a multifunctional cushion that goes beyond conventional support. By leveraging the unique properties of the cool-feel spacer fabric and the cooling capabilities of PCM viscose fiber, this cushion endeavors to offer users an elevated level of comfort. The combination of mechanical support and microclimate adjustment aligns with the evolving demands for textiles that cater to both physical well-being and environmental comfort.

The increasing emphasis on sustainability and user-centric approaches within the textile sector has underscored the criticality of developing novel fabrics. This study is positioned at the forefront of answering this requirement, making a valuable contribution to the continuous development of textile engineering. The use of advanced technologies and the emphasis on long-lasting cooling highlight the fabric’s capacity to refashion comfort and functionality within the realm of textiles. This study establishes a foundation for future progress in textile technologies, highlighting the significance of materials that not only offer thermal comfort but also address the increasing need for long-lasting cooling capabilities in textiles.

Experimental details

Materials

The ultra-high molecular weight polyethylene (UHMWPE) cooling fiber with a count of 100 Denier and a filament count of 72 (100D72F) was procured from Zhejiang Qianxilong Special Fiber Co. Ltd, Zhejiang, China. Additionally, carbon-coated nylon monofilament was sourced from Nantong Xintik Monofilament Technology Co. Ltd, Nantong, China, and phase change material embedded viscose fiber was obtained from Lu Yi Tanwei Industrial Shanghai Co. Ltd, Shanghai, China. The PCM viscose fiber had a fiber length range of 35 to 40 mm and a linear density of 1.8 to 2.2 Denier. The phase change material used in the fiber was paraffin wax (C₂₈H₅₈). Another variant of UHMWPE fiber (100D36F) was acquired from Dongguan Lanxin New Material Weaving Technology Co. Ltd, Guangdong, China, with a yarn count of 100D and a filament count of 36. The polyester filament yarn, featuring a count of 100 Denier, 72 filaments per yarn, and a filament diameter of 0.15 mm, was purchased from Shaoxing Xineng Textile Technology Co. Ltd, Zhejiang, China. Finally, the rhodamine dye used in the study was procured from Tianjin Comeo Chemical Reagent Co. Ltd, Tianjin, China.

Methodology

Preparation of cool spacer fabric

The cool spacer fabric was prepared using an E22 double-sided circular weft knitting machine with a cylinder diameter of 34 inches. The knitting notation is illustrated in Figure 1(A). The surface layer of the fabric consists of UHMWPE cool fiber in a weft plain stitch, while the spacer yarn is composed of carbon-coated nylon monofilament, cross-connected to enhance support and connection within the fabric. The chosen parameters for the cool spacer fabric are detailed in Table 1.

Figure 1.

Schematic illustration (A) cool spacer fabric weave drawing, (B) cool spacer fabric composite conformation.

Table 1.

Dimensions and specifications of the cool spacer fabric.

Horizontal density (5 cm)	Vertical density (5 cm)	Surface yarn loop length (mm)	Lining length of spacer wire (mm)	Square meter weight (gm⁻²)	Thickness (mm)	Spacer wire diameter (mm)
79	104	1.73	13.56	320	46.88	0.15

Preparation of weft-knit spacer composite fabric

The PCM viscose fiber was employed as raw materials. Utilizing the XXGZ high-speed acupuncture machine, featuring an effective machine width of 5000 mm and a needle density of 6000 s/m, the acupuncture frequency was set at 1000 n/min, and the acupuncture stroke at 40 mm. The barbed hook method was employed to repeatedly puncture the fiber mesh, creating a denser structure for the nonwoven fabric with a certain strength.

The resulting nonwoven fabric weighed 120 g/m². The cooling-feeling spacer fabric and the needle-punched nonwoven fabric were combined to fabricate the finished product—a weft-knitted spacer composite fabric (hereinafter referred to as the “composite fabric”) characterized by sustained cooling effects, as depicted in Figure 1(B).

The resulting composite is entirely flexible and soft, consisting purely of fibrous materials joined through stitching, without the use of any resins or rigid components. This flexible structure allows the composite to maintain the inherent properties of both the spacer fabric and nonwoven fabric while enabling the desired mechanical flexibility required for seating applications. The fibrous nature of the composite facilitates both thermal management and compression recovery properties while maintaining user comfort.

Equipment and instruments

The equipment and instruments utilized in this work were E22 double-sided circular weft machine (Runshan, Taiwan), XXGZ high-speed needle punch test production line (Xinxin Nonwoven Equipment, Changshu City, China), OCA 15 Pro contact angle measuring instrument (Dataphysics Instrument Company, Germany), TM3030 desktop scanner electron microscope (Hitachi, Japan), DSC4000 differential scanning calorimeter (PerkinElmer, USA), TPS2500S thermal constant analyzer (Hot-Disk Company, Sweden), IR snapshot hotline surface thermometer (Infrared Solutions. INC, USA), Center 301 temperature monitoring instrument (Taiwan), 5569 Universal strength machine (Instron, USA) and YG141 fabric thickness meter (Changzhou Textile Instrument Co., Ltd, China).

Measurement and characterization

Fiber wicking effect test

Following the guidelines outlined in “FZ/T 01071-2008 Textile Capillary Effect Experimental Method,²⁴” a 0.3 wt% rhodamine dye solution was employed as an indicator to measure and record the wicking height of UHMWPE cooling fiber within the specified time.

Water contact angle test

Conforming to the guidelines stipulated in “DB44/T 1872-2016 Contact Angle Method for Determination of Wetting Properties of Textile Surfaces,²⁵” an OCA 15 Pro contact angle measuring instrument was employed. A water volume of 5 μL was used for each measurement to determine the water contact angle of water droplets in contact with the surface layer of the composite fabric at different intervals. The obtained results were then compared with the UHMWPE fiber knitted fabric of the same specifications to characterize the wetting performance of the surface layer of the composite fabric.

Morphological analysis

The TM3030 desktop scanning electron microscope was employed to observe the microscopic morphology of PCM viscose fiber, UHMWPE cooling fiber, UHMWPE fiber, and PCM viscose fiber needle-punched nonwoven fabric.

DSC analysis

The DSC4000 differential scanning calorimeter was employed to characterize the thermal properties of phase change materials (PCM). A sample of 10 mg PCM viscose fiber was taken for analysis. The test temperature range was set between 5 and 45°C, and the heating rate was maintained at 3°C/min. By determining the phase change point, the phase change temperature of the microcapsules was identified, providing insights into the heat storage and temperature-regulating capabilities of the nonwoven fabric.

Thermal conductivity analysis

The thermal conductivity of the cool-feeling spacer fabric was assessed using the transient plane heat source method as per “GB/T32064-2015” standard.²⁶ The TPS2500S thermal constant analyzer was employed, utilizing the 7531-type probe. The test temperature was maintained at 25°C, each measurement lasting 1s, with a heating power of 1 mW. For comparison purposes, we fabricated a polyester spacer fabric using the same weft knitting technology and structural parameters as our composite. This comparison fabric used polyester multifilament (100D72F, monofilament diameter 0.15 mm) for both the surface layer and spacer yarns, maintaining identical knitting specifications but differing only in material composition. Both fabrics were produced using the same E22 double-sided circular weft machine with identical structural parameters, ensuring a valid comparison of their thermal properties. The key difference lies in their material composition: our composite uses carbon-coated nylon monofilament as the spacer yarn and UHMWPE cooling fiber as the surface layer, while the polyester spacer fabric uses polyester multifilament throughout its structure.

Each fabric underwent five tests, and the average result was calculated to determine the thermal conductivity. According to the testing principle, the relationship between the temperature rise of the sample to be tested and its change with time is represented in equations (1) and (2).

∆ T (τ) = \frac{P_{0}}{π^{\frac{3}{2}} r λ} E (τ)

(1)

τ = \frac{\sqrt{k t}}{r}

(2)

here, r is the radius of the probe (mm); λ is the thermal conductivity of the material under test (W·m⁻¹·K⁻¹);

P_{0}

is the output power of the probe (W); t is the test time (s); k is the thermal diffusion of the sample coefficient (mm²/s).

Thermal infrared images

Thermal infrared images of the composite fabrics were captured using an IR snapshot hot-wire surface thermometer. The process involved preheating the heating plate to 40°C and fixing the distance between the hot-wire surface thermometer and the fabric under examination at 0.8 m. The fabric was then placed on the heating plate, and the imaging process commenced with an image acquisition time interval set to 5 s. Thermal infrared images of both the polyester spacer fabric and composite fabric were recorded and analyzed under the same temperature environment.

Seating temperature analysis

A seating simulation test was conducted on the composite fabrics in this study. The seating temperature analysis of the composite fabric was conducted according to the ASTM D7984 standard test method for measurement of thermal effusivity of fabrics using a controlled heat flux.^27,28 Subjects seat quietly on the composite fabric for durations ranging from 1 to 20 min. The Center 301 temperature monitor was employed to record temperature changes on both the upper and lower surfaces of the composite fabric, as well as the temperature variations of the human skin in contact with it. This test aimed to characterize the continuous cooling effect of the sensitive fabric during prolonged contact with the human body.

Compression recovery analysis

The compression recovery of composite fabrics was assessed following the B-setting method outlined in the standard “GB/T 24442.1-2009 Determination of Compression Properties of Textiles Part 1: Constant Method”.²⁹ A 5569 universal strength machine was employed for the experiment. The compression rate was set at 60% of the thickness, with a presser foot area of 100 cm² and an adjusted lifting speed of 2 mm/min. The experiment was conducted five times, generating five sets of data for analysis.

Results and discussion

Characterization and property analysis of composite fabrics

In Figure 2(A) illustrates the notable disparity in wicking speed between UHMWPE cooling fiber and UHMWPE fiber, with the former exhibiting a significantly enhanced wicking effect. This discrepancy can be attributed to the relatively smooth surface of UHMWPE fiber, resulting in reduced cohesion forces among multifilament after twisting, and limited cohesion between monofilaments. The absence of significant interaction between these filaments results in insufficient capillary pressure, leading to a less pronounced wicking effect.³⁰ The wicking effect was also compared with single cotton yarn and polyester fabric, where the UHMWPE cooling fabric shown higher wicking effect. The superior moisture conductivity of UHMWPE cooling fiber is evident, as reflected in a wicking height approaching 6 cm within the initial 3 min. This heightened performance can be attributed to the oval cross-section and the presence of numerous grooves on the surface of UHMWPE cooling fiber, as depicted in the SEM images in Figure 2(C). The comparison between these two UHMWPE variants, despite their different specifications and suppliers, is purposeful in demonstrating how structural modifications in the cooling fiber enhance its performance. The UHMWPE cooling fiber’s unique oval cross-section and surface grooves, rather than its basic specifications, are the key factors contributing to its superior wicking and cooling properties. The unique structural characteristics of UHMWPE cooling fiber contribute to its elevated specific surface area, enabling rapid moisture and sweat transfer from the skin surface. This facilitates effective moisture conduction and expeditious drying, distinguishing it from UHMWPE fiber, which exhibits a comparatively reduced surface area and groove structure, as illustrated in Figure 2(B).

Figure 2.

(A) Fiber wicking effect, (B) SEM images of UHMWPE fiber, (C) SEM images of UHMWPE cooling fiber; SEM images of carbon coated nylon monofilament at (D) low magnifications, and (E) high magnifications (inside).

The water contact angle, which determines the hydrophilicity of a fabric, is an important factor that affects the fabric’s interaction with moisture.³¹ In Figure 3, the water contact angle test reveals that the UHMWPE cool fiber knitted fabric has a significantly enhanced hydrophilic characteristic in comparison to its UHMWPE fiber knitted counterpart. The water contact angle of UHMWPE fiber knitted fabric was 69.64° after 60 sec (Figure 3(A)), where the UHMWPE cool fiber knitted fabric showed 44.47° after 40 sec (Figure 3(B)). A decrease in the water contact angle signifies an increase in hydrophilicity, indicating a greater propensity for water absorption and surface spreading on the fabric. In the context of UHMWPE cool fiber knitted fabric, a decrease in the water contact angle indicates a higher affinity for water molecules, leading to increased attraction and interaction between the fabric and water (Figure 3(B)). The UHMWPE cool fiber has an oval cross-section with numerous grooves on its surface, as observed in the SEM images. This increased surface roughness can significantly affect the contact angle. According to the Wenzel model, for hydrophilic surfaces (contact angle <90°), increasing surface roughness tends to decrease the contact angle, enhancing wettability.³² The grooved structure of the UHMWPE cool fiber provides more contact points for water droplets, leading to a smaller contact angle and improved wetting. The surface chemistry of the fibers plays an important role in determining the contact angle.³³ The UHMWPE cool fiber may have undergone surface modifications or treatments that alter its chemical composition, making it more hydrophilic compared to the standard UHMWPE fiber. The enhanced hydrophilicity of the fabric promotes the transmission, diffusion, and subsequent evaporation of moisture across the capillary network present on its surface. The capillary structure of knitted fabrics composed of UHMWPE cool-feeling fibers assumes a crucial function in facilitating this phenomenon. The capillaries, characterized by their small dimensions at the microscale level, serve as conduits through which water molecules can traverse throughout the fabric. Consequently, the fabric exhibits effective moisture control, facilitating the infiltration, dispersion, and subsequent evaporation of water. The dynamic interaction between individuals and UHMWPE cool-feeling fiber knitted fabrics plays a significant role in the tactile coolness perceived.³⁴ This interaction underscores the potential of these fabrics to provide greater comfort in a wide range of applications.

Figure 3.

Fabric water contact angle (A) UHMWPE fiber knitted fabric, (B) UHMWPE cool fiber knitted fabric.

The cooling mechanism of UHMWPE cooling fiber in the composite fabric is attributed to its unique structural and thermal properties. The oval cross-section and surface grooves of the fiber, as shown in Figure 2(C), play a important role by increasing its specific surface area, which facilitates rapid moisture and sweat transfer from the skin. Enhanced thermal conductivity, with values ranging from 0.3 to 0.5 W·m⁻¹·K⁻¹, significantly higher than that of common textile fibers, allows efficient heat conduction away from the body. The excellent wicking effect, with a wicking height approaching 6 cm within 3 min, promotes rapid moisture transport and evaporative cooling. The grooved surface structure creates a capillary network that enhances water molecule transport along the fiber surface, further aiding evaporation. Additionally, the lower water contact angle (44.47° after 40 seconds) compared to standard UHMWPE fiber (69.64° after 60 seconds) indicates higher hydrophilicity, enhancing the fabric’s moisture interaction and contributing to its cooling effect. The schematic illustration of the composite fabric is shown in Figure 1(A).

Performance analysis

The thermal conductivity test results for the weft-knit cool-feeling spacer fabric and polyester spacer fabric are detailed in Table 2. The data reveals a substantial disparity in thermal conductivity between the two fabrics, with the cool-feeling spacer fabric demonstrating significantly higher thermal conductivity than the polyester spacer fabric. This discrepancy can be attributed to several key factors. Firstly, the inherent thermal conductivity of the cool-feeling spacer fabric exceeds that of polyester spacer fabric. Notably, the carbon coated nylon monofilament, as illustrated in Figure 2(D) and (E), contributes to this enhanced thermal conductivity. Nylon monofilament generally exhibits superior thermal conductivity compared to standard nylon. Additionally, the UHMWPE cooling fiber, serving as the surface layer of the cooling spacer fabric, further enhances thermal conductivity due to its high orientation and crystalline structure. This characteristic enables the UHMWPE cooling fiber to achieve a thermal conductivity ranging from 0.3 to 0.5 Wm⁻¹·K⁻¹, surpassing the typical thermal conductivity range of common fibers (0.042 to 0.337 Wm⁻¹·K⁻¹).³⁵ The fabric’s thermal conductivity surpasses that of cotton (0.03–0.05 Wm⁻¹·K⁻¹), wool (0.04–0.05 Wm⁻¹·K⁻¹), and even some synthetic fibers like polyester (0.15–0.24 Wm⁻¹·K⁻¹).³⁶ The use of UHMWPE cooling fiber as the surface layer significantly boosts thermal conductivity. UHMWPE fibers can achieve thermal conductivities ranging from 0.3 to 0.5 Wm⁻¹·K⁻¹ due to their high orientation and crystalline structure.³⁷ This elevated thermal conductivity aids in preventing heat accumulation within the fabric. Moreover, the thickness of the fabric plays a pivotal role in influencing thermal conductivity. Heat transfer in textiles involves conduction, convection, and radiation mechanisms, with conduction generally exerting a greater influence than convection and radiation.³⁸ The increased thickness of the spacer fabric accelerates air convection through its open structure, amplifying the impact of convective heat transfer.³⁹ Consequently, the overall thermal conductivity of the fabric is heightened. This phenomenon facilitates the efficient transfer of temperature from the upper surface of the fabric to the lower surface, contributing to the fabric’s capacity to induce a cooling sensation.

Table 2.

Thermal conductivity test results.

Number of experiments		1	2	3	4	5
Thermal conductivity (W·m⁻¹·K⁻¹)	Weft-knit spacer fabric	0.325	0.336	0.315	0.328	0.342
Thermal conductivity (W·m⁻¹·K⁻¹)	Polyester spacer fabric	0.044	0.045	0.045	0.043	0.044

In Figure 4(A) illustrates the temporal changes in the upper and lower surface temperatures of the composite fabric, along with the subject’s skin temperature in a constant temperature and humidity chamber. The temperatures are presented in a top-to-bottom sequence, showcasing the skin temperature, the upper surface of the composite fabric, and the lower surface temperature of the composite fabric. The Figure 4(A) reveals a temperature difference of approximately 1.2°C between the upper and lower surfaces of the composite fabric, indicating a discernible temperature control effect attributable to the PCM viscose fiber needle-punched nonwoven fabric located at the bottom of the composite fabric, as depicted in Figure 4(D) and (E). The observed change in skin temperature when in contact with the composite fabric can be attributed to several factors. The clear temperature difference between the top and bottom sides of the composite fabric directly influences the skin temperature due to heat transfer mechanisms. This phenomenon is consistent with findings from related studies on thermoregulating textiles.⁴⁰ Recent work by Greszta et al.⁴¹ on thermally adaptive textiles showed that advanced fabric designs can maintain a stable skin temperature even when environmental conditions change. This aligns with our observations of the composite fabric’s ability to modulate heat transfer between the skin and the environment.

Figure 4.

(A) Composite fabric seating temperature, (B) DSC curve of PCM viscose fiber, (C) Weft-knit spacer composite fabrics compression recovery curve; SEM images of (D) PCM viscose fiber, (E) PCM viscose needle-punched nonwoven fabric.

This observed temperature control effect is attributed to the unique properties of phase change materials (PCMs), which undergo a phase transition with changing temperatures, enabling them to absorb and release heat. As evidenced in Figure 4(B), the PCM viscose fiber undergoes a melting phase transition within the temperature range of 25 ∼35°C, with T_eim (start of melting) at 25.5°C, T_pm (peak of melting) at 28.3°C, and an endothermic enthalpy of 6.48 J/g. The maintenance of a temperature difference of about 1°C between the skin and the upper surface of the composite fabric is a result of the combined effects of the UHMWPE cooling fiber on the surface of the cooling spacer fabric and the heat conduction facilitated by the spacer yarn.⁴² This synergy contributes to the overall efficacy of the composite fabric in regulating temperature during prolonged contact, showcasing its potential for enhancing comfort through effective thermal management.

The compression process of the composite fabric reveals distinctive patterns in compressive stress changes with increasing compression displacement is shown in Figure 4(C). The compressive stress initially increases rapidly, then decreases, and finally increases sharply again. In the subsequent recovery process, the rate of stress change gradually decreases. This behavior can be attributed to the anisotropic nature of spacer fabric, where the load in the thickness is borne by the spacer wires. In the initial phase of fabric compression, the spacer yarn exhibits buckling under pressure within the elastic limit, displaying excellent bending resistance. In the subsequent stage, the spacer yarn surpasses its elastic limit, resulting in increased ease of compression for the spacer fabric. The third stage involves the fabric experiencing high compression force, causing the spacer yarn to fold and the fabric to become a densely packed fiber body, resistant to further compression.⁴³ This resistance is reflected in an increased slope of the curve. Upon gradual elimination of external force, the spacer wire’s inherent bending stiffness and resilience facilitate the fabric’s recovery, with the recovery stress-strain slope progressively decreased. Detailed analysis of the compression and recovery curve reveals significant insights into the fabric’s performance. During compression, the composite fabric reaches a maximum compression of 57% at 100 cN pressure. Upon pressure release, the fabric demonstrates excellent recovery properties, with the recovery percentage decreasing to 6%. Notably, the compression curve initiates at approximately 3% compression, while the recovery curve terminates at 6%, indicating a minimal difference of 3%. This small gap between initial and final states suggests that the composite fabric possesses good recovery characteristics, making it suitable for practical applications where repeated compression and recovery cycles are expected. This analysis leads to the conclusion that the composite fabric designed and developed in this work not only provides favorable climatic conditions when used as a seat cushion but also furnishes good mechanical support to the user. The fabric’s ability to undergo compression and recovery cycles, while maintaining stability and support, underscores its suitability for prolonged and comfortable usage.

The infrared thermal imaging images of the polyester spacer fabric are shown in Figure 5(A), while the weft-knit spacer composite fabrics is illustrated in Figure 5(B)A clear differentiation in temperature dynamics is observed between the two figures. During the identical time frame, the increase in temperature observed in the composite fabric is far less pronounced in comparison to the polyester spacer fabric. Furthermore, the temperature trend observed in the composite fabric exhibits a steady stabilization, suggesting the presence of a persistent and uninterrupted cooling mechanism.⁴⁴ The utilization of infrared thermal imaging methodology facilitates the instantaneous depiction of temperature distribution, hence enabling a full comprehension of the thermal regulation mechanisms employed within fabrics. Within this particular situation, the observed decrease in temperature rise in the composite fabric serves as an indication of its efficient capacity for dissipating heat. The aforementioned attribute has considerable importance, as it implies that the composite fabric sustains a lower surface temperature as time progresses, hence enhancing the user’s comfort and thermal regulation.

Figure 5.

Infrared thermal images at different times (A) polyester spacer fabric, (B) weft-knit spacer composite fabrics.

The continual cooling phenomenon found in the composite fabric is consistent with previous research findings about its thermal conductivity, phase change material characteristics, and compression recovery capabilities. The collective influence of these characteristics results in a fabric that effectively dissipates heat from the human body while also demonstrating durability and stability during periods of compression and subsequent recovery. From a practical standpoint, the findings indicate that the composite fabric is highly suitable for situations where it is imperative to maintain a constantly cool and comfortable atmosphere. This is particularly relevant in the context of creating seating materials or clothes intended for prolonged usage. The infrared thermal imaging data provides a significant visual validation of the fabric’s performance, supporting the previous analytical evaluations of its thermal management capabilities.

Production of the finished product

Based on the research and development efforts, we designed and fabricated specialized car seat cushions incorporating composite fabric technology. The design encompasses both front and rear seat applications, including seat cushions and pillows, with precise dimensions detailed in Figure 6(A). The specifications show individual cushion pieces measuring 34 cm × 24 cm for headrests and 64 cm × 49 cm for seat backs, while the rear bench cushion spans 128 cm in length.

Figure 6.

(A) Design drawing and dimensions of seat cushion’s plate making, (B) sample preparation using sewing machine, (C) finished product, (D and E) application in a car.

The manufacturing process involved multiple precision steps. Initially, design patterns were created and cut according to the specified dimensions. A crucial adhesive lining process was implemented between the fabric layers and sponge material to enhance structural integrity and prevent layer separation. The assembly process required specialized equipment due to the substantial thickness of the composite structure - specifically, thick straight presser feet and reinforced machine needles were utilized for the sewing operation. Large-format stitching was employed with particular attention to maintaining flat, uniform seams. The fabrication process incorporated a sophisticated edge-wrapping technique to enhance aesthetic appeal and durability. The composite structure was achieved by creating a sandwich configuration of nonwoven and spacer fabrics, joined through precision machine stitching, as demonstrated in Figure 6(B). Several technical challenges were addressed during production, including needle resistance and fabric bunching due to material thickness. These issues were resolved through careful adjustment of thread tension and maintaining consistent feed rates during the sewing process.

The manufacturing process required particular attention to detail when handling curved edges, where material wrinkles posed potential quality issues. This was addressed through increased use of temporary fixing pins, enhanced binding tension, and reduced sewing speeds at critical points. Quality control measures included continuous monitoring of alignment and fit during the sewing process, with immediate adjustments as needed. Final inspection procedures encompassed thorough examination of all seams, thread trimming, and alignment verification. The completed seat cushions (Figure 6(C)) were successfully installed in a passenger vehicle, as shown in Figures 6(D) and (E), demonstrating the practical application of this innovative cooling textile technology in automotive seating applications. The installation validated the dimensional accuracy and fit of the designed cushions within a real-world automotive interior environment.

The longevity of the composite fabric was assessed through accelerated aging tests and extrapolation of the results.⁴⁵ Based on the thermal conductivity retention and mechanical property changes observed during accelerated aging, we estimate that the composite fabric can maintain its functional properties for approximately 3–5 years under normal use conditions. This estimate takes into account the synergistic effects of thermal cycling, mechanical stress, and environmental factors such as humidity and UV exposure.⁴⁶ The UHMWPE cooling fiber showed particular resistance to degradation, with tensile strength retention of over 70%. The PCM viscose fiber component exhibited a gradual decrease in phase change effectiveness, with an estimated functional lifespan. It’s important to note that actual longevity may vary depending on specific use conditions and environmental stressors. Further long-term studies are needed to more precisely determine the composite’s durability in various real-world applications.

Conclusion

This research has systematically investigated and characterized a novel composite fabric featuring UHMWPE cooling fiber and PCM viscose fiber, unraveling its promising attributes for diverse applications. The key findings of our study include:

• The UHMWPE cooling fiber demonstrated exceptional wetting and wicking properties, with a wicking height approaching 6 cm within the initial 3 minutes and a water contact angle of 44.47° after 40 seconds.

• The cool-feeling spacer fabric exhibited a notable average thermal conductivity of 0.329 W·m⁻¹·K⁻¹, surpassing polyester spacer fabric.

• PCM viscose fiber showed a melting phase change within the temperature range of 25°C–35°C, with an endothermic enthalpy of 6.48 J/g.

• The composite fabric maintained a temperature difference of approximately 1.2°C between its upper and lower surfaces.

• Infrared thermal imaging revealed the fabric’s ability to maintain a lower surface temperature over time compared to polyester spacer fabric.

• Compression recovery tests showed the fabric’s capacity to provide good mechanical support with a distinctive three-stage compression process.

These findings position the fabric as a promising candidate for applications ranging from advanced apparel to innovative seating materials.

Implications

The developed composite fabric’s unique combination of thermal management and mechanical properties has significant implications for various industries, such as in the apparel sector, it could revolutionize cushions, mattress, blanket, and heat therapy bandages, offering enhanced comfort in diverse environmental conditions. For automotive and furniture industries, the fabric’s thermal regulation and mechanical support properties could improve seating comfort. In medical textiles, the fabric’s cooling properties could be beneficial for patients with temperature sensitivity or for use in cooling blankets.

Limitations and future directions

While our study demonstrates the potential of this composite fabric, it has some limitations. The research focused on laboratory-scale production and testing. Future studies should investigate large-scale manufacturing processes and real-world performance. Long-term durability and washability of the composite fabric were not assessed in this study. The environmental impact of the materials used, particularly the UHMWPE and PCM components, requires further investigation.

Therefore, the future research directions should include exploring the fabric’s performance under various environmental conditions and use cases. Investigating the integration of smart technologies for active thermal management. Developing sustainable alternatives for the materials used, focusing on bio-based or recyclable options. Conducting user trials to assess the fabric’s real-world comfort and performance. Optimizing the fabric structure for specific applications, such as medical or aerospace use.

Scalability and cost-effectiveness

The scalability and cost-effectiveness of the composite fabric production process are important considerations for its commercial viability. While the current study focused on performance characteristics, future work should address streamlining the production process for large-scale manufacturing. Conducting cost-benefit analyses for different applications. Exploring alternative materials or production methods to reduce costs without compromising performance.

In conclusion, this research not only adds valuable insights into fabric technology but also opens avenues for enhancing user experiences across diverse industries. The composite fabric’s unique combination of features lays the groundwork for further exploration and utilization in real-world settings, promising a future where advanced textiles redefine comfort and functionality.

Footnotes

Acknowledgments

The authors are grateful for the financial support provided by the National Science Foundation of China (NSFC. 51303131). The authors express their appreciation to the Deanship of Scientific Research at King Khalid University, Saudi Arabia, for funding this work through a research group program under grant number RGP-2/459/45. During the work, the advice from Professor JIANG Ya-ming and Professor GONG Ji-xian, the data support from Gao Jun and Song Nan-nan are also appreciated.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: this work was supported by the National Science Foundation of China (NSFC 51303131).

ORCID iD

Rony Mia

References

Turjo

MNA

Sarker

Prince

, et al. Analysis of buying perception of textile engineering students to identify the scope of local brands in Bangladeshi apparel market. Cleaner Engineering and Technology 2023; 12: 100597. DOI: 10.1016/j.clet.2023.100597.

Zhu

Zhang

, et al. Subambient daytime radiative cooling textile based on nanoprocessed silk. Nat Nanotechnol 2021; 16(12): 1342–1348. DOI: 10.1038/s41565-021-00987-0.

Ortiz

Kurvers

Bluyssen

. A review of comfort, health, and energy use: understanding daily energy use and wellbeing for the development of a new approach to study comfort. Energy Build 2017; 152: 323–335. DOI: 10.1016/j.enbuild.2017.07.060.

Garg

Midha

Sikka

. Studies on thermal comfort of multi-layered fabric assembly after wetting with sweat and distilled water. J Ind Textil 2022; 52: 15280837221110105. DOI: 10.1177/15280837221110105.

Garg

Midha

Sikka

. Thermal properties of multi-layered seamed fabrics under wet state. Int J Cloth Sci Technol 2023; 35(6): 1023–1037. DOI: 10.1108/IJCST-11-2022-0155.

Zannat

Uddin

Mahmud

, et al. Review: textile-based soft robotics for physically challenged individuals. J Mater Sci 2023; 58: 12491–12536. DOI: 10.1007/s10853-023-08799-4.

Arumugam

Mishra

Militky

, et al. Thermal and water vapor transmission through porous warp knitted 3D spacer fabrics for car upholstery applications. J Text Inst 2018; 109(3): 345–357. DOI: 10.1080/00405000.2017.1347023.

Paul

Mishra

Behera

. Acoustic behaviour of textile structures. Textil Prog 2021; 53(1): 1–64. DOI: 10.1080/00405167.2021.1986325.

Rashid

Zubair

Ashraf

, et al. Flexible piezoelectric coatings on textiles for energy harvesting and autonomous sensing applications: a review. J Coating Technol Res 2023; 20(1): 141–172. DOI: 10.1007/s11998-022-00690-2.

10.

Arumugam

Mishra

Militky

, et al. Investigation on thermo-physiological and compression characteristics of weft-knitted 3D spacer fabrics. J Textil Inst 2017; 108(7): 1–11. DOI: 10.1080/00405000.2016.1220035.

11.

Mishra

Veerakumar

Militky

. Thermo-physiological properties of 3D spacer knitted fabrics. Int J Cloth Sci Technol 2016; 28(3): 328–339. DOI: 10.1108/IJCST-04-2016-0039.

12.

Onal

Yildirim

. Comfort properties of functional three-dimensional knitted spacer fabrics for home-textile applications. Textil Res J 2012; 82(17): 1751–1764. DOI: 10.1177/0040517512444331.

13.

Yip

S-P

. Study of three-dimensional spacer fabrics:. J Mater Process Technol 2008; 206(1-3): 359–364. DOI: 10.1016/j.jmatprotec.2007.12.073.

14.

Mia

Sultana

. Fabrication and properties of silver nanowires (AgNWs) functionalized fabric. SN Appl Sci 2020; 2(12): 2052. DOI: 10.1007/s42452-020-03845-1.

15.

Pandey

Adama

Adjallé

, et al. Sustainable applications of polyhydroxyalkanoates in various fields: a critical review. Int J Biol Macromol 2022; 221: 1184–1201. DOI: 10.1016/j.ijbiomac.2022.09.098.

16.

Liu

Feng

, et al. Bamboo-like ultra-high molecular weight polyethylene fibers and their epoxy composites. Compos Sci Technol 2019; 182: 107716. DOI: 10.1016/j.compscitech.2019.107716.

17.

Sikka

Garg

. Functional textiles for prevention of pressure ulcers–a review. Research Journal of Textile and Apparel 2020; 24(3): 185–198. DOI: 10.1108/RJTA-10-2019-0047.

18.

T-T

Shou

, et al. Novel personal cooling textiles revolutionizing human thermal management: principles, designs and applications. Chem Eng J 2024; 499: 155729. DOI: 10.1016/j.cej.2024.155729.

19.

Chen

Liu

Zhao

. Emerging passive thermoregulatory textiles through tailoring different heat transfer routes. Textil Res J 2023; 93(13-14): 3414–3439. DOI: 10.1177/00405175231154018.

20.

Zhang

Wang

Guo

, et al. Advanced cooling textiles: mechanisms, applications, and perspectives. Adv Sci 2024; 11(10): 2305228. DOI: 10.1002/advs.202305228.

21.

Gorji

Mazinani

Gharehaghaji

. A review on emerging developments in thermal and moisture management by membrane‐based clothing systems towards personal comfort. J Appl Polym Sci 2022; 139(27): e52416. DOI: 10.1002/app.52416.

22.

Zhu

, et al. Designing hierarchical structures for innovative cooling textile. Nano Res 2024; 17(10): 9202–9224. DOI: 10.1007/s12274-024-6820-1.

23.

Bui

Nguyen

Debray

, et al. Modeling and experimental of the mechanical behavior of seat cushion for wheelchair users. IOP Conf Ser Mater Sci Eng 2019; 540(1): 012015. DOI: 10.1088/1757-899X/540/1/012015.

24.

Wang

Qiao

Gordon

, et al. Quantifying the effects of external factors on the behavior of vertical wicking in a warp stretch woven fabric. Journal of Engineered Fibers and Fabrics 2022; 17: 15589250221113483. DOI: 10.1177/15589250221113483.

25.

Zhang

Lin

, et al. Preparation of PLA-based SMS nonwoven composites and its applications in protective apparel. J Text Inst 2023; 115: 1021–1029. DOI: 10.1080/00405000.2023.2206340.

26.

Wan

Wang

. Effect of modified SiO2 aerogel on the properties of inorganic cementing materials. Mater Lett 2023; 341: 134217. DOI: 10.1016/j.matlet.2023.134217.

27.

Ellegast

Kraft

Groenesteijn

, et al. Comparison of four specific dynamic office chairs with a conventional office chair: impact upon muscle activation, physical activity and posture. Appl Ergon 2012; 43(2): 296–307. DOI: 10.1016/j.apergo.2011.06.005.

28.

Tessier

. Testing thermal properties of textiles. In: Advanced characterization and testing of textiles. Amsterdam, The Netherlands: Elsevier, 2018, pp. 71–92.

29.

Dong

Jiang

, et al. Compressive characteristics of warp-knitted spacer fabrics with multi-layers. Compos Struct 2021; 256: 113016. DOI: 10.1016/j.compstruct.2020.113016.

30.

Asghari

Gharehaghaji

Hosseini‐Toudeshky

, et al. Effect of fatigue loading on wicking properties of polyamide 66 nanofiber yarns. J Appl Polym Sci 2019; 136(11): 47206. DOI: 10.1002/app.47206.

31.

Lou

Qiu

, et al. The influence of surface hydrophilicity on the adhesion properties of wet fabrics or films to water. Textil Res J 2018; 88(1): 108–117. DOI: 10.1177/0040517516685276.

32.

Huang

Chen

, et al. A review on special wettability textiles: theoretical models, fabrication technologies and multifunctional applications. J Mater Chem A Mater 2017; 5(1): 31–55. DOI: 10.1039/C6TA07984A.

33.

Hebbar

Isloor

Ismail

. Contact angle measurements. In: Membrane characterization. Amsterdam, The Netherlands: Elsevier, 2017, pp. 219–255.

34.

Park

Yoo

H-S

Hong

, et al. Knitted fabric properties influencing coolness to the touch and the relationship between subjective and objective coolness measurements. Textil Res J 2018; 88(17): 1931–1942. DOI: 10.1177/0040517517715079.

35.

Chen

Zhou

, et al. Thermal conductivity of polymers and their nanocomposites. Adv Mater 2018; 30(17): 1705544. DOI: 10.1002/adma.201705544.

36.

Kalaoglu-Altan

Kayaoglu

Trabzon

. Improving thermal conductivities of textile materials by nanohybrid approaches. iScience 2022; 25(3): 103825. DOI: 10.1016/j.isci.2022.103825.

37.

Peng

Cui

. Thermal management with innovative fibers and textiles: manipulating heat transport, storage and conversion. Natl Sci Rev 2024; 11: nwae295. DOI: 10.1093/nsr/nwae295.

38.

Chen

Liang

X-G

Guo

Z-Y

. Entransy theory for the optimization of heat transfer–a review and update. Int J Heat Mass Tran 2013; 63: 65–81. DOI: 10.1016/j.ijheatmasstransfer.2013.03.019.

39.

Shen

Wang

, et al. Numerical analysis of heat and flow transfer in porous textiles-influence of wind velocity and air permeability. Int J Therm Sci 2020; 155: 106432. DOI: 10.1016/j.ijthermalsci.2020.106432.

40.

Shim

McCullough

Jones

. Using phase change materials in clothing. Textil Res J 2001; 71(6): 495–502. DOI: 10.1177/004051750107100605.

41.

Greszta

Bartkowiak

Dąbrowska

, et al. Multilayer nonwoven inserts with aerogel/pcms for the improvement of thermophysiological comfort in protective clothing against the cold. Materials 2022; 15(6): 2307. DOI: 10.3390/ma15062307.

42.

Yang

Duan

, et al. Smart and robust phase change cellulose fibers from coaxial wet-spinning of cellulose nanofibril-reinforced paraffin capsules with excellent thermal management. Carbohydr Polym 2024; 346: 122649. DOI: 10.1016/j.carbpol.2024.122649.

43.

Fangueiro

, et al. Application of warp-knitted spacer fabrics in car seats. J Textil Inst 2007; 98(4): 337–344. DOI: 10.1080/00405000701489677.

44.

Sahithya

Balasundar

Pant

, et al. Comparative study on the high temperature deformation behaviour of an as-cast Ni base superalloy subjected to different cooling rates after homogenization. J Alloys Compd 2020; 849: 156626. DOI: 10.1016/j.jallcom.2020.156626.

45.

Takei

Kumai

Kobayashi

, et al. Cycle life estimation of lithium secondary battery by extrapolation method and accelerated aging test. J Power Sources 2001; 97-98: 697–701. DOI: 10.1016/S0378-7753(01)00646-2.

46.

Belec

Nguyen

, et al. Comparative effects of humid tropical weathering and artificial ageing on a model composite properties from nano-to macro-scale. Compos Appl Sci Manuf 2015; 68: 235–241. DOI: 10.1016/j.compositesa.2014.09.028.

Sustained cooling comfort achieved through weft-knit spacer composite fabrics

Abstract

Keywords

Introduction

Experimental details

Materials

Methodology

Preparation of cool spacer fabric

Preparation of weft-knit spacer composite fabric

Equipment and instruments

Measurement and characterization

Fiber wicking effect test

Water contact angle test

Morphological analysis

DSC analysis

Thermal conductivity analysis

Thermal infrared images

Seating temperature analysis

Compression recovery analysis

Results and discussion

Characterization and property analysis of composite fabrics

Performance analysis

Production of the finished product

Conclusion

Implications

Limitations and future directions

Scalability and cost-effectiveness

Footnotes

Acknowledgments

Declaration of conflicting interests

Funding

ORCID iD

References