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The objective of this study is to investigate the feasibility of using selective laser melting (SLM) process to print fine capillary wick porous structures for heat pipe applications and clarify the interrelations between the printing parameters and the structure functional performance to form guidelines for design and printing preparation.

A new toolpath-based construction method is adopted to prepare the printing of capillary wick with fine pores in SLM process. This method uses physical melting toolpath profile with associated printing parameters to directly define slices and assemble them into a printing data model to ensure manufacturability and reduce precision loss of data model transformation in the printing preparation stage. The performance of the sample was characterised by a set of standard experiments and the relationship between the printing parameters and the structure performance is modeled.

The results show that SLM-printed capillary wick porous structures exhibit better performance in terms of pore diameter and related permeability than that of structures formed using traditional sintering methods, generally 15 times greater. The print hatching space and infilling pattern have a critical impact on functional porosity and permeability. An empirical formula was obtained to describe this impact and can serve as a reference for the design and printing of capillary wicks in future applications.

This research proves the feasibility of using SLM process to printing functional capillary wicks in extremely fine pores with improved functional performance. It is the first time to reveal the relations among the pore shapes, printing parameters and functional performance. The research results can be used as a reference for heat pipe design and printing in future industrial applications.

An integral component in heat pipes (HPs) and vapor chambers (VCs) is a porous wicking structure. Traditional methods for manufacturing wicking structures within HPs and VCs involve secondary manufacturing processes and are generally limited to simple geometries. This work aims to leverage the unprecedented level of design freedom of laser powder bed fusion (LPBF) additive manufacturing (AM) to produce integrated wicking structures for HPs and VCs.

Copper wicking structures are fabricated through LPBF via partial sintering and via the formation of square, hexagonal and rectangular arrangements of micro-pins and micro-grooves, produced in multiple build directions. Wicks are characterized by conducting capillary performance analysis through the measurement of porosity, permeability and capillary rate-of-rise.

Copper wicking structures were successfully fabricated with capillary performance, K/reff, ranging from 0.186–1.74 µm. The rectangular-arrangement micro-pin wick presented the highest performance.

This work represents the first published report on LPBF AM of copper wicking structures for HPs/VCs applications and represents foundational knowledge for fabricating complete assemblies of copper VCs and HPs through LPBF AM.

Polyester multifilament is used to produce the face and back layer of warp knitted spacer fabric (WKSF) and these two layers are connected by polyester monofilament as a middle layer. This fabric has unique and extraordinary characteristics, and different possibilities of fabric structure and the middle layer thickness are tried to find out the moisture management properties. The paper aims to discuss these issues.

This study investigates the influence of fabric thickness and structure on moisture management properties.

Polyester monofilament quickly up takes the water molecule from the water reservoir and transfers it by capillary action. The gravitational force and the availability space between the two outer surface layers restrict the movement of water molecules, although the pressure develops to push the molecules from the water reservoir. As a result, all the spacer fabric samples attain the equilibrium state very quickly. WKSF and the hexagonal net structure prove to be better in vertical wicking.

The liquid movement is quick in the front side of the spacer fabric, and the rate of wicking is higher in open structure than in the closed structure. It confirms that the hexagonal net structure produces high pore size on fabric and it reaches maximum wicking values. Fabric thickness does not have much influence on the vertical wicking properties of all fabric samples, and the rate of liquid movement produces a similar trend. In in-plane wicking, the polyester monofilament in the middle layer of spacer fabric plays a major role rather than the outer surface layers of fabric.

The purpose of this paper is to optimize the linear densities of polyester yarn and filament for inner layer and elastane for middle layer with cotton yarn outer layer in plain knitted plated structure for hot and dry environment clothing.

Three levels of polyester yarn linear densities (11.1, 8.4 and 5.6 Tex), filament linear densities (0.8, 1.55 and 2.3 Decitex) and elastane (0, 4 and 8 percent) with 14.75 Tex cotton yarn have been used to knit 15 single jersey plated fabrics based on Box and Benhens experimental design with same loop length. Three cotton–elastane core-spun fabrics were also produced. All the fabrics were analyzed for moisture and ergonomic comfort properties and wet fabric coefficient of friction.

The increase in elastane content and yarn linear density decreases water vapor and air permeability; the increase in filament linear density decreases wicking rate and water absorbency. The optimum solution is 5.55 Tex polyester yarn of 0.8 Decitex filament as inner layer and 14.75 Tex cotton yarn as outer layer which gives good heat and moisture transfer without stickiness.

The implication of this paper is to study thinner polyester, polypropylene and polyethylene fabrics with more micro pores as skin contact layer for quicker heat and moisture transfer.

Outward wickability of sweat from the skin is the prime requirement of all skin contact layer fabrics.

It shifts the social attitude of most comfortable fabric to polyester–cotton plated for hot and dry climate.

This paper employs a more practical method for the selection of fabric.

Miniature loop heat pipes (MLHPs) are highly efficient passive heat transfer devices, which have considerable advantages over conventional heat pipes. Currently, miniature LHPs with ammonia and water as working fluids have been developed and utilized in electronics cooling within temperature range of 50°C-70°C at any orientation in 1-g conditions.

The authors studied the standard procedure for the development of bi-porous nickel wicks and their characterization. Three different shaped nickel powders were studied, and best fitting nickel powder for electronics cooling application was reported. The manufacturing of bi-porous wick structures was analyzed with parameters such as porosity, permeability, capillary pressure and effective thermal conductivity for efficient performance of MLHP.

The study investigated the sintering process for number of samples to identify effective sample for the particular application. It is found that carbonyl nickel powder (type 287) with particle size of 2.6-3.3 µm gives promising results. Permeability and porosity were found to be highest in this case.

It is found that carbonyl nickel powder type with particle size gives promising results. Permeability and porosity was found to be highest in this case.

The objective of this research is to systematically compare two methods of wicking test for evaluating the quality of the non-medical-mask fabric, i.e. its absorbency property at various conditions, using a design of experiment approach. This research also evaluates the suitability of several fabrics to be used for non-medical masks.

Horizontal and vertical wicking tests were selected to evaluate the absorbency property of five fabrics commonly used for the non-medical mask. The tests were performed at three temperatures and using two types of liquid. The design of experiment approach was employed to determine the relationship between the path length of liquid movement in fabric and type of test method, temperature and type of liquid.

Both vertical and horizontal wicking tests show the same order of fabrics according to their absorbency. The order is cotton twill, local cotton, Japanese cotton, Oxford and Scuba, where the first in the order has the lowest absorbency and the last has the highest absorbency. Based on the analysis of variance (ANOVA), the range of temperature and types of liquid employed in this research do not affect the path length of the liquid movement in the fabric.

This research proposes horizontal and vertical wicking tests as a practical tool to evaluate absorbency property of fabric for the non-medical mask. This research also presents a design of experiment approach to evaluate the effect of the test method, temperature and type of liquid on the path length of the liquid movement in the fabric.

The purpose of this paper is to measure the thermal and moisture resistance of the knitted upper fabrics with the foot model, which provided basis for designing and producing sports shoes with thermal-moisture comfort.

In this paper, different yarn materials and fabric stitches were selected as the changing factors. The three kinds of yarn materials and the three kinds of fabric stitches were combined to design and weave eight pieces of knitted upper fabrics. Human sweating was simulated by the thermal-moisture comfort foot model, and then tested the thermal and moisture resistance of eight pieces of fabrics in different parts of the foot. Finally, the relationship between yarn material, fabric stitch, and the thermal and moisture resistance in different parts of the foot was analyzed by data.

The composition of the yarn material and fabric stitch has certain effect on the thermal-moisture comfort in different sections of the foot. When the yarn material of the four parts of the lateral arch, medial arch, ankle and heel is composed of 31.1tex moisture wicking polyester/33.3tex spandex coated yarn, the yarn material of the instep and toes is composed of 31.1tex ordinary polyester/33.3tex spandex coated yarn, and all parts of fabric stitch choose single-sided loop transfer stitch, the knitted sports shoes have the best thermal-moisture comfort.

The study used the thermal-moisture comfort foot model to simulate the human body metabolism and sweating system. Through the quantitative analyze of the thermal and moisture resistance of knitted upper fabrics to provide basis for the producers to design and product knitted sports shoes with good thermal-moisture comfort.

The copyright of this paper belongs to the Society of Manufacturing Engineers of Dearborn, Michigan, by whose kind permission it is reproduced here. It was written for their Creative Manufacturing Engineering Programmes. The internal method of cooling metal‐cutting tools is explained and it is shown that this method can provide 50% reduction in wear on the flank surfaces of cutting tools. A sintered copper wick shim also effects improvement.

Perspiration and heat are produced by the body and must be eliminated to maintain a stable body temperature. Sweat, heat and air must pass through the fabric to be comfortable. The cloth absorbs sweat and then releases it, allowing the body to chill down. By capillary action, moisture is driven away from fabric pores or sucked out of yarns. Convectional air movement improves sweat drainage, which may aid in body temperature reduction. Clothing reduces the skin's ability to transport heat and moisture to the outside. Excessive moisture makes clothing stick to the skin, whereas excessive heat induces heat stress, making the user uncomfortable. Wet heat loss is significantly more difficult to understand than dry heat loss. The purpose of this study is to provided a good compilation of complete information on wet thermal comfort of textile and technological elements to be consider while constructing protective apparel.

This paper aims to critically review studies on the thermal comfort of textiles in wet conditions and assess the results to guide future research.

Several recent studies focused on wet textiles' impact on comfort. Moisture reduces the fabric's thermal insulation value while also altering its moisture characteristics. Moisture and heat conductivity were linked. Sweat and other factors impact fabric comfort. So, while evaluating a fabric's comfort, consider both external and inside moisture.

The systematic literature review in this research focuses on wet thermal comfort and technological elements to consider while constructing protective apparel.

The purpose of this paper is to conduct a full three‐dimensional numerical analysis to simulate the thermal behavior of high speed steel (HSS) cutting tool, with temperature dependent thermal properties, in dry machining with embedded heat pipe (HP), and investigate the effects of HP installation, variable thermal properties, generated heat flux and cutting speed.

The heat transfer equation used to predict cutting tool temperature is parabolic partial differential equation. Grid points including independent variables are initially formed in solution of partial differential equation by finite element method (FEM). In this paper, one‐dimensional heat transfer equation with variable thermophysical properties is solved by FEM.

In this paper, the heat transfer equation in cutting tool is solved for variable thermophysical properties and the temperature field and temperature history are obtained. Variable thermophysical properties are considered to display the temperature fields in the cutting tool.

A full three‐dimensional numerical analysis is conducted to simulate the thermal behavior of HSS cutting tool, with temperature dependent thermal properties, in dry machining with embedded HP. The heat conduction equation is solved by FEM analysis.