Footwear Materials Research Articles

Footwear for Diabetics – Structural and Material Elements for the Prevention and Alleviation of Foot Lessions

Abstract Diabetic foot syndrome is a syndrome of specific conditions affecting the foot. It is a complication of diabetes. It occurs in 12–25% of patients with diabetes. Untreated, it leads to irreversible deformities and necrosis of the foot, often resulting in amputation. In this study the statistics and consequences of diabetic foot syndrome are described. Patients with diabetes need to take care of their lower limbs. Proper footwear can prevent foot wounds. Available solutions for the prevention and treatment of diabetic foot syndrome are presented herein: footwear, insoles and requirements for footwear materials. Appropriate equipment for a person with diabetes, especially one who has been diagnosed with diabetic foot syndrome or is at risk of such a condition, includes footwear and replaceable insoles. The parameters of footwear, insoles and footwear materials that are most optimal for patients with diabetes and diabetic foot syndrome were defined. The effect of a pulsed electromagnetic field and pulsed ultrasound on diabetic foot problems was evaluated.

IMPROVING THE CIRCULAR ECONOMY IN THE FOOTWEAR INDUSTRY

The article presents a circular economy proposal as a way to promote greater sustainability in the footwear industry. As part of the work, we analysed the essential components for a shoe and the materials used in the production of footwear. Currently, new proposals have emerged for footwear that use materials derived from waste and the forwarding of specific end-of-life products. These new concepts are associated with added value and targeted marketing towards sectors of society more concerned with the industry's environmental impact. This reinforces the interest in the positioning of the footwear industry in relation to the circular economy. The purpose of this article focuses on the last phase of the circular economy – recycling, educating, and valuing the role of the consumer through the collection, treatment and forwarding of used footwear materials with the aim of reducing waste in landfills but simultaneously increasing awareness of the footwear industry.

Numerical calculation of air permeability of warp-knitted jacquard spacer shoe-upper materials based on CFD

Abstract In order to realize the rapid design of warp-knitted jacquard spacer shoe-upper materials and to explore the influence of different fabric surface organization structures on their air permeability, it is proposed to numerically simulate the air permeability performance of jacquard shoe-upper materials using ANSYS fluid analysis. First, four kinds of shoe material specimens with different upper and lower layer mesh alignment relationships are designed and tested, then the corresponding geometric structure models of the fabric are established based on the samples and appropriately processed, and finally the air permeability of the shoe material is numerically simulated and calculated based on computational fluid dynamics. The results show that, under the same conditions, the air permeability of double-sided mesh structure is significantly better than that of single-sided mesh structure, and its air permeability can be optimized by adjusting the relationship between the upper and lower layers of the fabric mesh; the airflow mainly passes through the fabric pores and gaps between the yarns, and the closer the fabric structure is, the more the air flow is hindered, and the worse the air permeability is. The simulation results of the established numerical model are consistent with the measured results, and the error is less than 10%, so it can be used to simulate and predict the air permeability of the warp-knitted jacquard spacer footwear materials, and provide theoretical support for the design and performance research of footwear materials.

Numerical study of thermal comfort and energy efficiency about electrically heated footwear under a cold environment

PurposeThe paper aims to reveal the relationship among energy efficiency, thermal comfort and thermal regulation of electrically heated footwear and to investigate influencing factors on the energy efficiency and thermal comfort.Design/methodology/approachA finite volume model was proposed to simulate the two-dimensional heat transfer in electrically heated footwear (EHF) under an extremely cold condition. The model domain consists of three-layer footwear materials, a heating pad, a sock material, an air gap and skin tissues. Model predictions were verified by experimental data from cold-contact exposure. Then the influencing factors on the energy efficiency and thermal comfort were investigated through parametric analysis.FindingsThe paper demonstrated that the skin temperature control (STC) mode provided superior thermal comfort compared to the heating pad temperature control (HPTC) mode. However, the energy efficiency for the HPTC mode with a heating temperature of 38 °C was 18% higher than the STC mode. The energy efficiency of EHF while reaching the state of thermal comfort was strongly determined by the arrangement and connection of heating elements, heating temperature, thickness and thermal conductivity of footwear materials.Originality/valueThe findings obtained in this paper can be used to engineer the EHF that provides optimal thermal comfort and energy efficiency in cold environments.

Harnessing leather waste in polymer matrix for sustainable smart shape‐stable phase change materials

AbstractThe utilization of leather waste (LW) in a polyurethane (PU) matrix makes a smart and novel shape stable phase change material (SSPCM). This is essential for sustainability as it reduces landfill waste after use. The PU is synthesized in bulk with a 90% yield, using biodegradable polycaprolactone diol and bio‐based polyol (castor oil), along with tolylene‐2,4‐diisocyanate. PL and PLG composites are prepared by blending of constituent components PU (P), LW (L), and poly(glycidyl methacrylate) (PGMA, G), as specified by their code names. Role of LW (hydrogen bonding and chemical crosslinking) and morphology are elucidated by FTIR and SEM, respectively. Self‐healing time (2 h), shape fixity ratios (Rf) (PL: 60–80% and PLG: 60–70%) and shape recovery ratios (Rr) (100% for both) are determined at 60°C. PLG displays faster shape recovery in water (<30 s) compared to air (>300 s). Shape stability and thermal properties of the SSPCM are examined using the temperature responsive leakage study, TGA, and DSC. This research introduces a new approach for using leather waste (LW) in SSPCM, with self‐healing and 100% Rr. This material may find application where SSPCM with high durability and flexibility is essential such as textile and footwear materials.

Comparison of mechanical and comfort properties of natural fiber-based spacer fabrics for shoe insole

The objective of this study is to develop an improved shoe insole that enhances heat and moisture transmission (thermo-physiological comfort) qualities, as well as its mechanical characteristics, through the utilization of weft knitting spacer fabric. Two samples were prepared. One sample was comprised of Tri-Blend knitted fabric layers, while the other sample was made using cotton knitted fabrics in both layers. These layers, in both samples, were connected by spacer yarns of monofilament nylon. Tri-blend fabric was made from Bamboo (80%), flax (15%), and polypropylene (5%). Monofilament nylon was used in spacer layer. Thermo-physiological comfort testing i.e., air permeability, moisture management and thermal resistance test were performed for all the samples. The investigation also established the correlation between the mechanical properties, such as puncture resistance and tactile comfort, of footwear materials and their interaction with the human body. The prepared samples of shoe insole were also compared with the commercially available insoles made from synthetic materials. The outcome of the study suggests that the natural fiber spacer fabric can be used as an alternative to rubber. In conclusion, the results of this study offer valuable insights for product developers seeking sustainable alternatives that can meet consumer demands for both wearability and comfort.

The Initial Development and Evaluation of Cross-Linked Casein Films for Sustainable Footwear

To increase the sustainability of footwear and align it with the circular bioeconomy, there is a pressing need to develop novel bio-based materials to replace the synthetic polymers currently used. In this study, casein-based films were prepared by solution casting with a tannic acid cross-linker, and a glycerol plasticizer. The properties important to footwear materials were characterised, including tensile strength and elongation, stitch strength, hardness, grain cracking strength, water vapour permeability, and thermal properties. The tannic acid imparted a brown colour to the films with good resistance to light-induced fading. Their tensile strengths were 4–5 N/mm2, elongation at break 45%–73%, and water vapour permeability 0.2–0.6 mg/(cm2h), depending upon the levels of the cross-linker and plasticiser. The strength of the films was close to those of some non-leather footwear materials such as compact rubbers and insock materials, but below that required for leather shoe vamps/uppers. The casein films were successfully used in sneaker- and ballerina-style shoes as components of the insock and decorative design elements on the vamp. This work has demonstrated the concept of using casein films in footwear. The properties of the films could be improved by further research, particularly with respect to cross-linking, plasticizing, and combining with bio-based fibers and fabrics.

UJI BANDING ANTAR LABORATORIUM DALAM RANGKA PENINGKATAN KEPERCAYAAN TERHADAP LABORATORIUM PENGUJIAN FISIS POLITEKNIK ATK

One of the raw materials for footwear is Chrome tanned box leather with a thickness according to the applicable SNI quality standards. The problem with measuring skin thickness has received less attention from laboratory personnel during testing. The Quality Control Section is responsible for the implementation of quality assurance and quality control of test results. External quality control is carried out by cross-laboratory comparisons. The purpose of this research is to find out the competence of the Physical Testing laboratory as an executor in inter-laboratory comparison tests with skin thickness test parameters. The material used is cow leather. The test method uses SNI-06-7128-2005. stationary. The comparative test was carried out from June to August 2022 followed by the Physical Testing Laboratory as the executor of the activities (laboratory A), laboratories B and C. The test results obtained standard deviation for laboratory A vs B 0.1396 and laboratory A vs C 0.0795 . The t value for laboratory A vs B was 0.625 and laboratory A vs C was 1.85. Based on t table at 95% confidence level for laboratory A vs B 2.228 and laboratory Avs C 2.201, t count < from t table comparative test between laboratories is declared not significantly different or acceptable. Physical Testing laboratory personnel can be declared competent for the skin thickness test.

Influence of Upper Footwear Material Properties on Foot Skin Temperature, Humidity and Perceived Comfort of Older Individuals.

Studying the in-shoe microclimate of older individuals is important for enhancing their foot comfort and preventing foot diseases. However, there is a lack of scientific work that explores the thermo-physiological wear comfort of older individuals with different footwear. This study aims to examine the effects of upper footwear materials on changes and distributions in the foot skin temperature and relative humidity for older individuals. Forty older individuals are recruited to perform sitting and walking activities under four experimental conditions in a conditioning chamber. The findings indicate that footwear upper constructed of highly permeable mesh fabric with large air holes shows fewer changes in foot skin temperature (ranging from 1.3 to 3.3 °C) and relative humidity (ranging from −13.3 to 5.7%) throughout the entire foot during dynamic walking, as well as higher subjective ratings on perceived thermal comfort when compared to footwear made of synthetic leather and composite layers. The findings serve to enhance current understanding of designing footwear with optimum comfort for older adults.

A foot and footwear mechanical power theoretical framework: Towards understanding energy storage and return in running footwear

There is extreme interest surrounding the influence of advanced running footwear on running performance. The magnitude, timing, and location of mechanical energy storage and return in footwear may elucidate one way footwear influences running performance. However, the complexity of footwear makes it challenging to model footwear energy storage and return during running. The purpose of this study was to develop a practical framework for evaluating foot and footwear mechanical power profiles during running. First, a unified deformable power analysis (distal rearfoot power) was used to quantify mechanical power of the foot + footwear system. Then, qualitative mechanical power profiles of individual foot and footwear structure were developed using prior literature, benchtop footwear material properties, and experimental kinetics and kinematics. The result is a framework for understanding foot and footwear mechanical power during running using a two-stage analysis. First, foot + footwear power can be experimentally compared when running in various footwear constructions. Second, the developed framework can provide qualitative insights into which foot and footwear structures may contribute to differences in measured foot + footwear power. To highlight the utility of this framework, the timing, magnitude, and location of foot + footwear power is compared when running in different footwear constructions and with different running styles. The framework developed here provides a practical tool for footwear developers and researchers to gain intuition about the timing, relative magnitude, and location of energy storage and return from footwear during running. There are opportunities to expand on this framework to further connect footwear construction to running performance.

Running pattern changes after a 38-km trail running race: does shoe fatigue play a role?

The aim of this study was to investigate if acute impairments of the footwear midsole materials could interact with the modifications of the running patterns after a fatiguing trail running race. We hypothesized that introducing a control pair of shoes after the race, would modify running mechanics by partially correcting the alterations generated by the deteriorated properties of the shoes worn during the race. Eighteen participants ran on a treadmill at 10 km·h−1 pre- and post-race in three conditions varying the step frequency (free or fixed) or the footwear (control or personal shoes). Spatiotemporal parameters, tibial accelerations across the running conditions and shoe mechanical properties were measured. Significant changes in shoe characteristics (i.e. reduced thickness and increased stiffness) were measured after the race in the personal footwear. At free step frequency, significant changes in contact (+1.3 ± 3.5%) and flight (−19.4 ± 23.7%) times, step frequency (+2.9 ± 2.9%) and peak-to-peak amplitude acceleration at the tibia level (−3.6 ± 18%) were found. The peak-to-peak amplitude of the mediolateral axis showed a significant shoe × time interaction meaning that the control footwear could have had an impact in the running pattern. However, contrary to our hypothesis, no interaction effects were found between the changes in footwear and the changes in spatiotemporal parameters. In conclusion, impairments of shoes characteristics affect impact but not running mechanics.

Effect of footwear material wear on slips and falls

Recurrent injuries related to slips and falls are common in workplaces, caused due to reduction of friction between the floor and footwear, due to material wear. However, due to lack of public awareness, such events are usually neglected and the role of footwear wear is underestimated. To date, a plethora of studies have tested footwear traction across floorings and contaminants, however the effect of shoe material wear on the friction has not been studied much. In this study, the outsole features of four common formal shoes were modelled and tested in their new and progressively worn conditions. The available coefficient of friction (ACOF) of the outsoles were estimated using a mechanical slip testing device across three common floorings (i.e., gloss, matt, and anti-skid), and in dry and slippery conditions such as with floor cleaner and canola oil. ACOF reductions in the range of 25–80% were observed in progressively worn outsoles. Outsoles with vertical tread orientation were found to generate higher ACOF in fluid contaminant conditions. Outsoles which had larger treads at the heel region showed consistent trend in the traction performance across all the conditions. The outsoles were found to produce generalizable results in the presence of canola oil as a contaminant. The results are anticipated to provide important guidelines for selection and design of footwear outsole features, and also in determining the replacement threshold of formal shoes.

EVA/starch/POE composite for footwear material: How the chemical composition affects its properties compared to standards

The usage of biodegradable foam material in footwear components has positive impacts on environmental sustainability when disposed into landfills. This study was aimed to investigate the effects of polyolefin elastomer (POE) on its properties of foamed EVA/cassava starch composites compared to standards. Foamed EVA/cassava starch composites were prepared by mixing EVA, cassava starch, and additives using a two-roll mill laboratory scale. Content of POE was varied 10-20 phr. The ratios of EVA/cassava starch were varied from 90/10; 80/20; 70/30; and 60/40. Effects of POE were characterized its density, tensile properties, tear strength, permanent set, abrasion resistance, flex resistance, morphology, and biodegradability. It was found that the increase of POE content in EVA/starch composites increased the density and abrassion resistance, but decreased the tensile strength, elongation at break, and permanent set properties. The best formula of foamed EVA/cassava starch/POE composites for footwear materials contains EVA 80 phr, starch 20 phr and POE 20 phr with density 0.983 g/cm³, tensile strength 22.27 kg/ cm², elongation at break 645.67%, tear strength 9.42 N/mm, volume loss 88.907 mm, no crack when flexed 150 kcs. These results met the requirements of SNI 0778:2009-Sol Karet Cetak for quality classifcation 3 of outsoles. The foamed composite containing POE20 has denser morphology than POE10, while the addition of POE has no signifcance in weight loss after burial test

Long-Term Autonomic Thermoregulating Fabrics Based on Microencapsulated Phase Change Materials.

Microcapsules loaded with n-docosane as phase change material (mPCMs) for thermal energy storage with a phase change transition temperature in the range of 36–45 °C have been employed to impregnate cotton fabrics. Fabrics impregnated with 8 wt % of mPCMs provided 11 °C of temperature buffering effect during heating. On the cooling step, impregnated fabrics demonstrated 6 °C temperature increase for over 100 cycles of switching on/off of the heating source. Similar thermoregulating performance was observed for impregnated fabrics stored for 4 years (1500 days) at room temperature. Temperature buffering effect increased to 14 °C during heating cycle and temperature increase effect reached 9 °C during cooling cycle in the aged fabric composites. Both effects remained stable in aged fabrics for more than 100 heating/cooling cycles. Our study demonstrates high potential use of the microencapsulated n-docosane for thermal management applications, including high-technical textiles, footwear materials, and building thermoregulating covers and paints with high potential for commercial applications.

Numerical simulation of heat transfer in electrically heated footwear in a severely cold environment

The purpose of this study was to investigate the mechanisms of heat transfer and thermal regulation of electrically heating pad in footwear through numerical simulation. A one-dimensional heat transfer model was developed based on parameters of footwear materials, heating pad and skin tissues, which was validated by small-scale fabric experiments. Two modes of temperature control for the heating pad (HPTC) and human skin (STC) were compared, and a parametric analysis was conducted. It was showed that the model predictions were in agreement with the experimental results. Generally, the STC mode had better thermal regulative performance and less energy consumption than the HPTC mode. Results from the parametric analysis demonstrated that the properties of the heating pad and inner fabric layer were the most important factors for affecting the thermal regulative performance of the electrically heated footwear. No significant changes were found in the thermal regulative performance, but the environmental temperature had a clear influence on the energy saving effect. Besides, the energy efficiency could be remarkably improved by lowering the heating power. Even in a severely cold environment of −30 °C, the common lithium battery was able to function the HPTC mode of the typical four-layer fabric system for 7.7 h. This research provides suggestions for the design of the heating pad as well as the upper of the electrically heated footwear.

A study of consumer awareness on footwear manufacturing materials

The purpose of the study is to find out the level of customer awareness related to material used and its environmental impact awareness in the manufacturing of the footwear products in Delhi-NCR region. The study is exploratory in nature and uses descriptive to analyze the data. The study shows the low level of customer awareness related to footwear materials usage and its environment impact.

Running biomechanics, footwear material properties and the perception of ride

In the 1980s, researchers began to explore how mechanical properties of running shoes affect the runners’ biomechanics and their perception of the shoes. These studies were conducted to provide inf...

Measurement of the Inside Microclimate of Footwear Constructed from Different Material Sets

The aim of the research was to determine the effect of footwear materials used on the microclimate inside shoes and to identify which material set provides optimal comfort to users. The microclimate of the interior of 21 pairs of footwear was tested. Selected nonwovens, natural leather, and leather-like materials were used to make the upper, lining and insole lining. Determined was the amount of water absorbed on the sock fibres, and measurement was taken of the relative humidity and temperature, as well as the permeability and sorption of outer materials and lining elements.Results of the researches carried out showed that in order to ensure adequate footwear comfort, materials for the upper should have high permeability, while lining materials should have both high sorption and permeability.

Проектирование авторской обуви с применением инновационных технологий

The article discusses methods for creating smart things, using the example of the use of innovative technologies in the field of materials for clothing and footwear. The factors of form formation are substantiated by the example of the preferences of an individual customer who forms its image through accessories and shoes. The author considers the factors of shaping, based on the special functional features of shoes in connection with ergonomic factors. The designer is able to foresee the factor of transformability in modern footwear, changes in functional qualities, appearance, and design features of new footwear. As a result, on the basis of these transformations, to get a new emotional image and a new form. The shape of the shoe becomes a factor for transformations at the request of the customer. The article discusses the functional tasks of this shoe, plastic characteristics, technical and design tasks. As research methods, the article proposes variants of experimental models with possible stages of transformation, presents preliminary technical data, conducts a comparative analysis with innovative footwear samples of famous world designers, and makes assumptions about the development of this model in the future. An experimental method was used during the study. A shoe shape was developed, which took into account the preferences of the age group of 12-16 years old, relying on this category of consumers, we were able to go beyond the rational understanding of shoes as a functional form and gave it the meaning of a fantastic image, which allowed us to consider the form in the semantic and artistic context dictated by this age group of consumers. In addition, investing in this model the concept of "smart shoes", we considered not only the ability of modification and transformation by rearranging replaceable parts, the possibility of designing and reincarnating from one form to another, combining the constituent elements of the shoe into one whole, but also the development of the creative potential of the consumer, who at its own discretion can rebuild the structure and, in fact, as a designer itself, form a new model. The article makes assumptions about its further development in various fields of activity. For example, medicine, sports, art, etc. Considering the introduction of new materials, we relied on discoveries in the field of nanotechnology and considered among the possible features of this model the change in color on the basis, the reaction of materials to light, temperature, etc. The project is aimed at creating such shoes that will be developed for a wide range of consumers thanks to the wide range of possibilities contained in the design of the form and the features of modern materials.

Biomechanics of lower limb in badminton lunge: a systematic scoping review.

BackgroundBadminton is a popular sport activity in both recreational and elite levels. A lot of biomechanical studies have investigated badminton lunge, since good lunge performance may increase the chances to win the game. This review summarized the current trends, research methods, and parameters-of-interest concerning lower-extremity biomechanics in badminton lunges.MethodologyDatabases including Web of Science, Cochrane Library, Scopus, and PubMed were searched from the oldest available date to September 2020. Two independent authors screened all the articles and 20 articles were eligible for further review. The reviewed articles compared the differences among playing levels, footwear designs, and lunge directions/variations, using parameters including ground reaction forces, plantar pressure distribution, kinematics, and kinetics.ResultsElite badminton players demonstrated higher impact attenuation capability, more aggressive knee and ankle strategy (higher mechanical moment), and higher medial plantar load than amateur players. Footwear modifications can influence comfort perception and movement mechanics, but it remains inconclusive regarding how these may link with lunging performance. Contradicting findings in kinematics is possibly due to the variations in lunge and instructions.ConclusionsPlaying levels and shoe designs have significant effects on biomechanics in badminton lunges. Future studies can consider to use an unanticipated testing protocol and realistic movement intensity. They can study the inter-limb coordination as well as the contributions and interactions of intrinsic and extrinsic factors to injury risk. Furthermore, current findings can stimulate further research studying whether some specific footwear materials with structural design could potentially compromise impact attenuation, proprioception, and performance.