Thermal Mannequin Research Articles

Technological Developments in Thermal Mannequin Systems

Technological advancements in thermal mannequin systems have significantly contributed to the progress of wearable technology and the textile industry. These systems, utilized for testing and optimizing garment thermal properties, have undergone notable developments in recent years. Enhanced sensor technologies have enabled thermal mannequin systems to furnish more precise and accurate data, facilitating improved analysis of garment-body interaction. Moreover, refined mannequin designs now more accurately simulate real-world conditions, aiding in the assessment of garment performance. Furthermore, the integration of data analytics and artificial intelligence has emerged as a pivotal aspect, providing valuable insights for optimizing garment thermal performance. Overall, these technological advancements underscore the pivotal role of thermal mannequin systems in driving innovation in wearable technology and textile design, ultimately leading to the development of more functional and performance-oriented garments. The purpose of this article is to assemble the articles on thermal mannequin systems and briefly summarize the latest technological developments.

Use of a Novel Mathematical Model to Assess the Effectiveness of Skin-to-Skin Care for the Prevention of Hypothermia in Low-Birth-Weight Neonates

The effectiveness of skin-to-skin care (SSC) notably depends on the delivery room air temperature (Ta), the thermal insulation provided by the fabrics or clothes covering the mother and the neonate (Icl), and the neonate’s metabolism (M). The objective of the present study was to model the influence of these variables on the effectiveness of SSC for premature newborns. To this end, we used an appropriate thermal mannequin and applied a mathematical model of body heat exchanges. We performed experiments at Ta values (20.9 °C and 25.9 °C) and two Icl values (sheet only and sheet + blanket). At a Ta of 25.9 °C, normothermia was estimated after one hour of SSC with the sheet (Icl = 0.15 m2 °C/W; 36.52 °C) and the sheet + blanket (Icl = 0.21 m2 °C/W; 37.09 °C) but only with the highest value of M (2.70 W/kg). With a Ta of 20.9 °C, moderate hypothermia (requiring monitoring of the neonate’s thermal status) was estimated—except for M = 2.70 W/kg and Icl = 0.21 m2 °C/W. During early SSC, homeothermy can be maintained when Ta is 25 °C (the temperature recommended by the World Health Organization) but only when the neonate’s tissue insulation is high (Icl ≥ 0.15 m2 °C/W) and when the level of metabolic heat production is high.

Influence of structural and constructional parameters of knitted fabrics on the thermal properties of men's socks

The research is focused on determining the influence of structural and constructional parameters of rib knitted fabrics on the thermal properties of men's socks. Men's socks are made in three different pattern constructions of three types of basic yarns: bamboo, cotton and a cotton/polyester blend with the additional filament polyamide yarn and wrapped rubber wire for the so-called render socks. For all analyzed sock rib patterns, the most important structural parameters of the yarn and construction parameters of the knitted fabrics were determined. Thermal properties of socks such as the cool touch feeling property, thermal conductivity, heat retention coefficient and thermal resistance were determined by using Thermal Labo and Thermal Mannequin measuring devices. The structural and constructional parameters of knitted fabrics were shown to affect the investigated thermal properties of the socks, making them more or less insulating or heat conducting. Values of the warm-cold feeling parameter as well as thermal conductivity vary depending on the construction pattern, showing a decrease as the number of face loops is increased i.e. in the sequence R1:1> R3:1> R7:1. The ability to retain heat decreases in the opposite sequence R7:1 > R3:1 > R1:1. The highest values of heat retention were determined for R7:1 rib knitted socks by both methods. A regression equation has been established with thickness, loop length, mass per unit area and porosity as independent variables, and thermal resistance (determined by the Thermo Labo method) as the dependent variable. The loop length and mass per unit area were shown to contribute significantly to the model.

Development of a Novel Thermal Mannequin System for Thermal Comfort Measurements

Giving comfort to the wearer without feeling physiologically and psychologically by the wearer, assuming the role of thermoregulation system against environmental temperature changes, and making them psychologically happy with their appearance and attitude characteristics makes it easier to adapt to the environment in which they live. Since all these functions of garments are generally defined as ‘clothing comfort' and aim to increase the living standards of people, the studies carried out to measure clothing comfort in the most realistic way are of great importance both academically and sectorial. In this study, it is planned to carry out the thermal mannequin system that can act to objectively evaluate together with the important parameters of thermal, humidity and pressure comfort, which are the most important criteria in determining the clothing choice of consumers, that can provide measurement in different ambient conditions, and that allows instantaneous measurements of temperature, humidity and pressure. Within this plan, a practical mannequin system has been designed for thermal, humidity and pressure comfort measurements and will allow measuring and evaluating many features at the same time. The thermal mannequin system will be produced with practical and reconfigurable 3D printing technology, which allows re-production, unlike the thermal mannequin mechanisms in the literature.

Study of Influence of Atmospheric Conditions on the Thermal Properties of Sleeping Bags.

The thermal properties of clothing products are influenced by external environmental parameters, such as temperature, humidity, air flow and parameters related to the user’s body, which mainly include temperature and humidity. Depending on the type of raw material, its thickness and the material manufacturing technique, clothing products are characterised by certain insulating properties to protect the human body from external factors. A multilayer system made of different material groups can change the thermal insulating capacity significantly, which cannot be determined by the testing of individual layers used in the production. In order to determine the influence of weather conditions on thermal insulation and air permeability, tests were carried out for two types of sleeping bags (summer and autumn) produced by the same manufacturer, differing in insulation thickness. Simulations were carried out using SolidWorks and verified using a Newton thermal mannequin. During tests, both the temperature (range from −20 °C to 20 °C) and humidity values were changed (range 40–80% humidity). For sleeping bags, the effective thermal insulation decreases along with the increase of temperature and decrease of humidity. It can be observed, for the autumn sleeping bags, that for a temperature of 20 °C and humidity of 60%, the thermal insulation is 1.063 m2·K·W−1, while for a temperature of −20 °C and humidity of 60% thermal insulation increases significantly and amounts to 1.111 m2·K·W−1. A similar situation occurs for the effective thermal insulation of a summer sleeping bag (20 °C/60% thermal insulation is 0.794 m2·K·W−1, while for −20 °C/60%—0.851 m2·K·W−1. During the tests, the humidity and temperature between the layers of the clothing system were also controlled, in order to learn more about the influence of these parameters on the thermal insulation properties of the sleeping bags.

Measurement Method for the Simultaneous DeterMination of Thermal Resistance and Temperature Gradients in the DeterMination of Thermal Properties of Textile Material Layers.

The thermal properties of most clothing products are still not designed according to engineering science due to the lack of simple and acceptable measuring equipment and methods; the type of thermal insulation material, the number of layers of clothing and their thickness are thus chosen empirically. The novelty of this study was the development of a new measuring device and method for simultaneous measurements in the determination of the thermal resistance in one or more textile material layers, such as in multilayer composite clothing. Temperature gradients of textile material layers are presented, as well as the theoretical principles of operation and practical results. Four materials for the production of protective jackets were selected, from which different combinations of composite clothing were constructed and the thermal parameters were measured with a new method and a new device, both individually for the built-in materials and for the composites. Subsequently, five test jackets with the same arrangement of textile material layers as the previously tested composites were produced, and measurements of important thermal parameters were recorded with a thermal mannequin. The determined temperature gradients and measurement results are presented, and based on these it was determined that the total thermal resistance was not equal to the algebraic sum of the resistances of the individual textile material layers in the horizontal position; it was, however, higher, increasing from 30% to 94% due to small air layers caused by crimping and protruding fibres of yarn in the textile fabrics. The same textile material layers built into clothing in the vertical position allowed the formation of significantly wider air layers that increased the thermal resistance by between 2.5 and 9 times.

Complex Approach to Thermal Testing of Firefighters’ Protective Clothing

Aim: An extremely important property of firefighters’ special clothing is thermal resistance of the clothing materials to heat transfer from radiation or flame. Performing tests with the use of thermal mannequins may contribute to the improvement of clothing sets, as such tests indicate weak points of the tested products. The review article presents information on the testing of special clothing on mannequins and a short history of test stands with the use of thermal mannequins. Introduction: Using innovative techniques and technologies provides firefighters-rescuers with an appropriate level of safety. Special clothing is a barrier between the human body and the heat and water vapour from the environment. It is this garment that protects the human body from overheating or cooling down. Methodology: The general test procedure for using thermal mannequins is described in ASTM standards (for instance ASTM F2370 – 10 [1], ASTM F2371 – 10 [2]). Testing of special clothing allowing for an accurate assessment of the degree of protection of the human body against the effects of fire, flame and heat was initiated in the United States. The assumption of these works was to create a mannequin for testing the resistance of clothing equipped with heat sensors to flash fires. Currently, there are around 100 different models of thermal mannequins around the world. Technological progress in the post-war period resulted in the rapid development of mannequins built with a multi-segment structure. This allowed to increase the accuracy of the measurements that simulated heat exchange between the human body and the environment. The data obtained in this manner is repeatable, which allows for standardization of the test requirements for thermal insulation of clothing sets. Conclusions: Performing tests using thermal mannequins contributes to the improvement of clothing sets in order to increase the safety of the users. The results obtained under the test conditions very accurately indicate the number, location and degree of burns to which the user of such clothing may be exposed. Keywords: protective clothing, special clothing, thermal mannequin, thermal resistance, test stands to determine thermal loads Type of article: review article

Evaluation of thermally activated furniture on thermal comfort and energy consumption: An experimental study

Personalized Comfort Systems (PCS) have been seen as an effective alternative to provide thermal comfort along with reducing energy consumption. This paper contains the methodology and results of a study conducted in a laboratory environment that aims to evaluate Thermally Activated Furniture (TAF) panels. These panels mounted in front and on the side of a workstation as space partition panels, can provide thermal comfort and have the potential to save energy. The experiments were carried out in a controlled thermal comfort chamber using a thermal mannequin having 22 body segments and TAF. A total of 15 cases were examined against a reference case with an aim to understand the impact of TAF on the change in PMV, Skin Temperature (Tskin) and Heat Flux (Φ) of 22 individual body segments and change in the energy consumption. The combinations of three Room Air Temperatures (Tair) i.e. 26 °C, 28 °C and 30 °C were tested with a combination of four surface temperature (Tsur) ranging from the difference between Tair and Tsur 2 to 8 °C. For the entire study, Relative Humidity (RH) was maintained at 50%. The results indicate a change in PMV by about 0.15 votes towards the cooler side when the difference between Tair and Tsur was Δ2°C for the three Tair cases. The PMV changed by about 0.5 votes in the case of the Δ8°C difference between Tair and Tsur. The increase in ΔT values was found to increase the cooling thermal energy consumption relative to the baseline case without having PCS in operation, whereas the increase in Tair caused a decrease in the cooling thermal energy consumption.

Application of a Thermal Mannequin to the Assessment of the Heat Insulating Power of Protective Garments for Premature Babies

Abstract In this study, the new tool for measuring thermal insulating power of garments for premature babies under coupled heat and moisture transport was developed. The thermal mannequin corresponds to the body weight and size of a premature baby born in the thirty fourth week of pregnancy. The mannequin surface temperature can be set at various levels, while the heat loss is measured in W/m2. The mannequin is divided into eleven independent heating zones and seven independent zones of moisture evolution. The study also presents the test results of heat insulating power obtained for the newly developed garment set with commercially available garment set for babies, conducted under different climatic conditions. The results exhibit the advantage of the new material construction of the garment over the commercially available one.

Thermal comfort measurement using thermal-depth images for robotic monitoring

Abstract This paper describes an application of thermal-depth images to human thermal comfort measurement. A mobile monitoring of the elderly and residents of care houses is one of the promising applications of mobile assistive robots. Monitoring if a person feels comfortable is an important task of such robots. We rely on an established comfort measure in the architecture domain, namely, predicted mean vote (PMV). PMV is calculated mainly by six factors and one of which is the clothing insulation or clo-value. Clo-values are usually measured by a thermal mannequin, a specially-designed apparatus for the purpose. We apply human recognition techniques in thermal-depth images to efficiently measure clo-values, thereby enabling on-line assessment of thermal comfort. We evaluate the method and develop a mobile robot system for experimental testing.

Analysis of bus air conditioning system by finite elements method (ANSYS)

Air conditioning systems used for the cooling of vehicles to create a uniform temperature distribution in terms of providing thermal comfort to people is an important parameter. From this point, realization of appropriate computer simulations of these systems during the design phase provides a significant convenience to the success of the design. In this study, determination of the time required to reduce the bus indoor initial temperature at  310 K ( 37 °C) of a bus for 49 passengers including the driver to  293 K ( 20 °C) gradually with a uniform temperature distribution and the temperature, pressure and velocity distribution were analyzed using finite elements method (ANSYS). In finite element program, developed for this purpose indoor thermal load of 49 people including the driver in the bus has been calculated by using thermal mannequin modeling, the internal conditions were integrated to real conditions. As a result of the temperature pressure and velocity distribution graphics obtained at 5 minutes intervals depending on real conditions case scenario in ANSYS program, it was determined that in about 15 minutes the indoor temperature distribution of the bus has reached to  293 K value uniformly

Additional double-wall roof in single-wall, closed, convective incubators: Impact on body heat loss from premature infants and optimal adjustment of the incubator air temperature

Radiant heat loss is high in low-birth-weight (LBW) neonates. Double-wall or single-wall incubators with an additional double-wall roof panel that can be removed during phototherapy are used to reduce Radiant heat loss. There are no data on how the incubators should be used when this second roof panel is removed. The aim of the study was to assess the heat exchanges in LBW neonates in a single-wall incubator with and without an additional roof panel. To determine the optimal thermoneutral incubator air temperature.Influence of the additional double-wall roof was assessed by using a thermal mannequin simulating a LBW neonate. Then, we calculated the optimal incubator air temperature from a cohort of human LBW neonate in the absence of the additional roof panel.Twenty-three LBW neonates (birth weight: 750–1800g; gestational age: 28–32 weeks) were included. With the additional roof panel, R was lower but convective and evaporative skin heat losses were greater. This difference can be overcome by increasing the incubator air temperature by 0.15–0.20°C.The benefit of an additional roof panel was cancelled out by greater body heat losses through other routes. Understanding the heat transfers between the neonate and the environment is essential for optimizing incubators.

A study of thermal comfort enhancement by the optimization of airflow induced by a ceiling fan

In this study, the air flow generated by a ceiling fan inside a room is investigated by Computational Fluid Dynamics (CFD) simulation. In the model, a thermal mannequin sits in front of a computer desk with a rotating ceiling fan above the thermal mannequin around which the flow and thermal field was analyzed. The objective of this study is to optimize a ceiling fan’s parameters which include the rotation speed, diameter, blade count, horizontal inclination angle, vertical inclination angle, camber angle, stagger angle, flow angles at inlet/ outlet, incidence angle, glide angle, etc. by conducting comprehensive CFD simulation. For a ceiling fan to generate a preferable flow and thermal field, the effect of convective heat transfer needs to be enhanced so that the air flow can effectively take the heat generated by a human body away. The CFD analyses provide a better understanding of the velocity and temperature distributions around a human body so that the effects of various fan parameters can be estimated. The results indicated that the airflow velocity on the rotation plane of a blade is the most important indicator. By changing the rotational speed in the simulation model, the resulting effects on thermal comfort characteristics can be investigated. It was found in this study that, the circulation of air is optimized by an optimal rotation speed at which the thermal characteristics are greatly enhanced while the comfort level perceived by a human body is kept to a reasonable extent. Since the cooling condition can be optimized without the need of turning on any air conditioner at a higher outside ambient temperature, the electric bill can be greatly reduced without affecting the degree of thermal comfort. The results of this study indicated that, a ceiling fan can keep the thermal comfort at a reasonable level and greatly save the power cost as compared to air conditioners.

発汗歩行サーマルマネキンを用いた着衣の温熱的快適性評価

発汗歩行サーマルマネキンを用いた着衣の温熱的快適性評価

微気流を併用した放射冷暖房を行うオフィスの温熱環境に関する実験研究 （第4報）微気流によるサーマルマネキン表面温度への影響把握ならびに温湿度条件緩和と快適範囲拡大の検討

微気流を併用した放射冷暖房を行うオフィスの温熱環境に関する実験研究 （第4報）微気流によるサーマルマネキン表面温度への影響把握ならびに温湿度条件緩和と快適範囲拡大の検討

Study of thermal properties, toxicity emissions and rebreathing avoidance as exogenous stressors of sudden infant dead syndrome in baby mattresses. Design recommendations

Introduction Sudden Infant Death Syndrome (SIDS) is the highest cause of death in the post- neonatal period. According to the Triple Risk Model (Kinney et al., 2009), SIDS results when three factors simultaneously influence the infant: (a) an underlying vulnerability in the infant, (b) a critical developmental period, and (c) an exogenous stressor. Considering exogenous stressor evidences, the objectives were: to determine the thermal behavior of current baby mattresses, to test improvements reached by new materials, to confirm the viability to design harmfulness mattresses according to Oeko-tex, to confirm that rebreathing of exhaled air is above the safety threshold concluding with a design criteria including the properties mentioned above. Materials and methods Thermal test It was used a thermal mannequin ST-2 made by Measurement Technology Northwest. Test specimens were: (1) spring mat.-foam-textile cover sewed. (2) Fiber mat.-foam 3d textile. (3) PU mat. core low density PU-PVC cover. (4) PU Mat. core with low density PU. (5) Babykeeper®mat. core. (6) Babykeeper®mat. core-3D foam textile. (7) Babykeeper®mat. core-Smart textile. Toxicity and Rebreathing test Oekotex test was performed by AITEX following label standards. To study rebreathing avoidance an infant mannequin was simulated as a head box which was placed with its open face on the mattress and connected with tubing to a gas reservoir filled with 5% CO2. Also it was used 50 cc syringe with two one-way valves which simulates infant breathing. Finally a CO2 analyzer was placed in the head box (tested by Bar-Yishay Phd). Both tests were executed to confirm liability of new materials: spec. 2 and 7. Results Thermal Test Results (Test Specimen (Temperature average last 30 min, Thermal Resistance Rt (C m2/W)): 1: (38.4oC, 3.2) 2: (40.1oC, 3.34) 3: (38.4oC, 3.2) 4: (38.1oC, 3.17) 5: (37.2oC, 3.1) 6: (38.5oC, 3.20) 7: (38.3oC, 3.19) Oekotex: Not toxic class1; and Rebreathing results (specimen (Max CO2(%),Time to reach plateau (sec)): Fiber core with 3D Foam (4.36 ± 0.11, 324 ± 1.4) Babykeeper®mat. (3.35 ± 0.14, 298 ± 19) In this sense both systems had a significantly faster rate of CO2 elimination (4–5 min) compared to 15–18.7 min. for other mattresses (P Conclusion As a conclusion design recommendation are: RT Acknowledgements Authors give thanks to IBV and AITEX for collaboration during laboratory test.

Inhalation Exposure to Cleaning Products: Application of a Two-Zone Model

In this study, modifications were made to previously applied two-zone models to address important factors that can affect exposures during cleaning tasks. Specifically, we expand on previous applications of the two-zone model by (1) introducing the source in discrete elements (source-cells) as opposed to a complete instantaneous release, (2) placing source cells in both the inner (near person) and outer zones concurrently, (3) treating each source cell as an independent mixture of multiple constituents, and (4) tracking the time-varying liquid concentration and emission rate of each constituent in each source cell. Three experiments were performed in an environmentally controlled chamber with a thermal mannequin and a simplified pure chemical source to simulate emissions from a cleaning product. Gas phase concentration measurements were taken in the bulk air and in the breathing zone of the mannequin to evaluate the model. The mean ratio of the integrated concentration in the mannequin's breathing zone to the concentration in the outer zone was 4.3 (standard deviation, σ = 1.6). The mean ratio of measured concentration in the breathing zone to predicted concentrations in the inner zone was 0.81 (σ = 0.16). Intake fractions ranged from 1.9 × 10−3 to 2.7 × 10−3. Model results reasonably predict those of previous exposure monitoring studies and indicate the inadequacy of well-mixed single-zone model applications for some but not all cleaning events. [Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Occupational and Environmental Hygiene for the following free supplementary resource: MATLAB code.]

착용쾌적성이 향상된 방탄복 개발과 성능평가

This study helps develop a cool body armor that maintains a tight-fit configuration to the body surface and evaluates the performance of newly developed body armor in a wear test. Three types of body armor were used for evaluation. One was a tight fitting body armor that was constructed to improve the degree of fit and ease of movement for Korean soldier using 3D technology. Another was ventilating body armor with attached spacers on the shoulder to reduce the thermal stress on the soldier. The third was a prevailing body armor produced by a Korean body armor company. In order to evaluate the performance of the body armor, a human wear test, a thermal mannequin test, and computational fluid dynamics (CFD) were executed. Five subjects participated in the wear test. Subjective wear sensation, total amount of sweat and dynamic change of clothing microclimate were observed during and after exercise on a treadmill; subsequently, it was found that subjects rated tight fitting body armor and ventilating body armor lighter, drier, and easier to move than the conventional body armor (p<.05). Total amount of sweat was the least in the case of ventilating body armor. The thermal resistance and vapor resistance of the ventilating body armor were improved remarkably. In addition, the skin temperature of the ventilating body armor with spacers was lower than the tight fitting body armor by at least <TEX>$1^{\circ}C$</TEX> in the CFD result. It is noted that thermal-wet comfort of the 3D body armor with ventilating feature is superior to the conventional body armor, especially when the ventilating channel is not closed due to a backpack.

Thermal comfort of cricket helmets: An experimental study of heat distribution

This research aims to characterize thermal comfort of sports helmets. For this purpose heat distribution of four selected cricket helmets was investigated using a special purpose thermal mannequin head. The tests were conducted in a laboratory with still air and controlled indoor temperature. K-type thermocouples and an infrared imaging camera were used for the study of temperature distribution. Mean temperature increment varied from 0.9±0.1°C (temporal region) to 1.7±0.1°C (parietal region). Temperature increment largely depended upon the location under the helmet at which temperatures were measured - higher temperatures were recorded around the frontal and parietal regions of the mannequin head. However, the differences in mean temperatures between these regions were not statistically significant (p>0.005). It was found that under standard laboratory test conditions with still air, some helmet vent designs enable more effectively heat to radiate out, and vice versa depending upon the temperature gradient. The paper presents the results of this experimental investigation with specific reference to thermal comfort.

A Simulation Study of Gel Pillow Heat Conductance

The gel-filled pillow is a device used to provide a soft surface to support and cradle an infant's head. Little is known about the thermal conductive properties of this device when used in an open crib. This simulation study evaluated the use of the Squishon 2 gel pillow in an open crib to determine the potential cooling effects on a mannequin infant. This simulation study was conducted on a thermal mannequin. A descriptive comparative repeated-measures design was employed. A thermal mannequin with the head placed on the gel pillow was used. The energy required to keep the mannequin head at 37 degrees C in 4 conditions was measured. The 4 conditions were as follows: (1) lying in an open crib on a standard mattress (baseline), (2) lying on the gel pillow with the disposable cover from the manufacturer, (3) the head wearing a cap and lying on the gel pillow, and (4) the head without the hat lying on the gel pillow with an insulated cover over the pillow. Univariate analysis of variance (ANOVA) revealed significant differences in energy required to maintain the mannequin head at 37 degrees C among the 4 conditions (F3 = 283.23, P = .0001). The hat on head condition was found to decrease energy utilization by an average of 6.36 kcal/d when compared with the head on mattress condition (P = .0001). Extrapolation of energy to maintain mannequin head warmth into potential kilocalories utilized revealed that a potential increase in kilocalories needed to maintain thermoneutrality would be needed. The most effective way of conserving heat was in the hat on the mannequin head while lying on a gel pillow condition. The use of a gel pillow without a hat or an insulated barrier caused an increase in energy requirements and kilocalorie usage in this mannequin model. The results of this simulation study suggest that use of the gel pillow outside of a thermally controlled environment and in an open crib environment may increase energy use to maintain thermoneutrality. The Squishon 2 gel pillow conducts heat from the mannequin head and may increase kilocalories per day consumption in the preterm infant. Furthermore, the results of the study support previous findings that a hat helps conserve energy.