Modeling the relationship between tactile sensation and physical properties of synthetic leather

2019 ◽  
Vol 50 (3) ◽  
pp. 346-363 ◽  
Author(s):  
Tsuyoshi Chiba ◽  
Shota Kuroda ◽  
Masaki Yamaguchi

Surface texture plays an important role in expressing the tactile sensation of leather. The purpose of this study was to develop a combinational panel of physical properties that express the tactile sensations of coarse/fine, uneven/flat, soft/hard, sticky/slippery, and moist/dry. Thirteen synthetic leather samples were fabricated from polyurethane, and eight physical properties were measured as storage modulus, loss modulus, surface roughness, waviness, mean frictional coefficient, apparent contact angle, contact angle hysteresis, and urethane thickness. Thirty adult women performed sensory evaluation of the five tactile sensations by using a semantic differential method based on a five-point scale. The tactile sensation–physical property model for each tactile sensation was explored with logistic regression analysis. Receiver operating characteristic analysis showed that the proposed models based on multiple physical properties clearly distinguish the tactile sensations with higher sensitivity and specificity compared to using a single physical property. The dynamic viscoelasticity contributed to all the tactile sensations when polyurethane was used as synthetic leather. Additionally, the difference of five tactile sensations might be caused by the surface roughness, the mean frictional coefficient, and the polyurethane thickness.

2019 ◽  
Vol 6 (7) ◽  
pp. 190039 ◽  
Author(s):  
Kana Kikegawa ◽  
Rieko Kuhara ◽  
Jinhwan Kwon ◽  
Maki Sakamoto ◽  
Reiichiro Tsuchiya ◽  
...  

Shittori feel is defined as a texture that is moderately moisturized; however, many people experience ‘ shittori feel’ when they touch a dry solid material containing little liquid. Here, shittori feel was evaluated for 12 materials. We found that the highest score of shittori feel was achieved by powders. Multiple regression analysis showed that shittori feel is a complex sense of moist and smooth feels. We analysed the relationship between the physical properties and the moist/smooth feels to show how subjects felt certain feels simultaneously. The moist and smooth feels are related to the surface roughness and friction characteristics of the materials. The moist and smooth feels can be perceived when the finger starts to move on the material surface and when the finger moves and rubs the material surface, respectively.


2014 ◽  
Vol 910 ◽  
pp. 157-160 ◽  
Author(s):  
Ching Wen Lou ◽  
Po Ching Lu ◽  
Jin Jia Hu ◽  
Jia Horng Lin

This study examine the influence of gelatain with different concentrations on the physical property of the PET/Gelatin composite tubular braids. PET fibers are braided into tubular braids on a braider, and then immersed in gelatin solution with various concentrations to form PET/Gelatin composite tubular braids. The tensile strength and water contact angle of the braids are then tested to determine the their physical properties. The experiment results show that an increasing concentration of gelatin does not result in a significant varation in tensile strength, but a decreased displacement only.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 89
Author(s):  
Wei Yuan ◽  
Qian Hu ◽  
Jiao Zhang ◽  
Feng Huang ◽  
Jing Liu

This study modified graphene oxide (GO) with hydrophilic octadecylamine (ODA) via covalent bonding to improve its dispersion in silicone-modified epoxy resin (SMER) coatings. The structural and physical properties of ODA-GO were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle tests. The ODA-GO composite materials were added to SMER coatings by physical mixing. FE-SEM, water absorption, and contact angle tests were used to evaluate the physical properties of the ODA-GO/SMER coatings, while salt spray, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe (SKP) methods were used to test the anticorrosive performance of ODA-GO/SMER composite coatings on Q235 steel substrates. It was found that ODA was successfully grafted onto the surfaces of GO. The resulting ODA-GO material exhibited good hydrophobicity and dispersion in SMER coatings. The anticorrosive properties of the ODA-GO/SMER coatings were significantly improved due to the increased interfacial adhesion between the nanosheets and SMER, lengthening of the corrosive solution diffusion path, and increased cathodic peeling resistance. The 1 wt.% ODA-GO/SMER coating provided the best corrosion resistance than SMER coatings with other amounts of ODA-GO (including no addition). After immersion in 3.5 wt.% NaCl solution for 28 days, the low-frequency end impedance value of the 1 wt.% ODA-GO/SMER coating remained high, at 6.2 × 108 Ω·cm2.


Author(s):  
S. Antusch ◽  
R. Custers ◽  
H. Marien ◽  
H. Aarts

AbstractPeople form coherent representations of goal-directed actions. Such agency experiences of intentional action are reflected by a shift in temporal perception: self-generated motor movements and subsequent sensory effects are perceived to occur closer together in time—a phenomenon termed intentional binding. Building on recent research suggesting that temporal binding occurs without intentionally performing actions, we further examined whether such perceptual compression occurs when motor action is fully absent. In three experiments, we used a novel sensory-based adaptation of the Libet clock paradigm to assess how a brief tactile sensation on the index finger and a resulting auditory stimulus perceptually bind together in time. Findings revealed robust temporal repulsion (instead of binding) between tactile sensation and auditory effect. Temporal repulsion was attenuated when participants could anticipate the identity and temporal onset (two crucial components of intentional action) of the tactile sensation. These findings are briefly discussed in the context of differences between intentional movement and anticipated bodily sensations in shaping action coherence and agentic experiences.


2019 ◽  
Vol 60 ◽  
pp. 124-141 ◽  
Author(s):  
Naser Ali ◽  
Joao Amaral Teixeira ◽  
Abdulmajid Addali

This research investigates the effect of surface roughness, water temperature, and pH value on the wettability behaviour of copper surfaces. An electron beam physical vapour deposition technique was used to fabricate 25, 50, and 75 nm thin films of copper on the surface of copper substrates. Surface topographical analysis, of the uncoated and coated samples, was performed using an atomic force microscopy device to observe the changes in surface microstructure. A goniometer device was then employed to examine the surface wettability of the samples by obtaining the static contact angle between the liquid and the attached surface using the sessile drops technique. Waters of pH 4, 7, and 9 were employed as the contact angle testing fluids at a set of fixed temperatures that ranged from 20°C to 60°C. It was found that increasing the deposited film thickness reduces the surface roughness of the as-prepared copper surfaces and thus causing the surface wettability to diverge from its initial hydrophobic nature towards the hydrophilic behaviour region. A similar divergence behaviour was seen with the rise in temperature of water of pH 4, and 9. In contrast, the water of pH 7, when tested on the uncoated surface, ceased to reach a contact angle below 90o. It is believed that the observed changes in surface wettability behaviour is directly linked to the liquid temperature, pH value, surface roughness, along with the Hofmeister effect between the water and the surface in contact.


2011 ◽  
Vol 214 ◽  
pp. 133-137 ◽  
Author(s):  
Xu Dong Shi ◽  
Shou Wen Shi ◽  
Lu Zhang ◽  
Jian Li Li

Airport runway friction coefficient is an important parameter to evaluate the quality of runway which is usually measured by runway friction coefficient measuring vehicle. In order to reduce the airport runway friction coefficient measuring error which comes from runway vibration caused by road roughness and vehicle its own structural characteristics, an impedance diagram is used to model the suspending system and measuring system of the measuring vehicle. The power spectral density of pavement and inverse discrete Fourier transformation are introduced to model runway surface roughness as excitation input. The rationality of the stimulating established model is validated by comparing with an airport runway surface roughness measurement data. Runway friction coefficient measuring vehicle′s measuring error can be reduced and the measurement accuracy can be improved by using the impedance diagram modeling method.


2005 ◽  
Vol 8 (1) ◽  
Author(s):  
Jeou-Long Lee ◽  
Chung-Ming Liu ◽  
Kuen Ting ◽  
Wei-Kung Cheng ◽  
Takayoshi Tsuchida ◽  
...  

AbstractSurface modification of the carbon included polyethylene (semi-conductive PE) surface for metallizing using a low pressure RF discharge plasma has been carried out. The contact angle was used as a measure of the wettability of the PE surface. The roughness and the chemical bondings in PE surface layer were analized by DFM and XPS, respectively. Typical results show that the contact angle decreases from approximately 94° to below 10° after several minutes' treatment and recovers to a saturation value when it was put open to the air after treatment. The saturation value of the contact angle is smaller as the gas pressure for treatment is higher and the treatment time is longer but all are below approximately 60° which is still smaller than that of untreated. DFM and XPS results show that the surface roughness and the bondings C-O and C=O in the PE surface layer also increase with increasing the treatment time and seem to be responsible for improving the hydrophilic property of PE. After pretreatment process, nickel was coated on the PE sheet by electrodeposition method and a good adhesion between the nickel layer and the PE surface compared with that of untreated was obtained.


1978 ◽  
Vol 57 (11-12) ◽  
pp. 983-988 ◽  
Author(s):  
J.W. Osborne ◽  
E.N. Gale ◽  
C.L. Chew ◽  
B.F. Rhodes ◽  
R.W. Phillips

An assessment of the marginal failure rate of 1,041 restorations of twelve alloys was made at one year. In addition, physical property tests were conducted. A correlation was found between the clinical performance and creep (.79), flow (.62) and 24-hour compressive strength (.60).


Author(s):  
M.N. Obaid ◽  
S.H. Radhi

Purpose: The number of people suffering from Degenerative Disc Disease (DDD) is increasing. The disease causes heavy pain and restrict a number of day-to-day life activities. In extreme cases, the degraded disc is removed under total disc replacement which is usually made up of Ultra-High Molecular Weight Polyethylene (UHMWPE). The material has astounding biocompatible characteristics mechanical properties and wear resistance. However, these characteristics are insufficient in arthroplasty application. Therefore, research investigations are ongoing to improve tribological properties through reinforcement that may result in a composite material of UHMWPE. Thus the current study is aimed at reinforcing UHMWPE with short fibres of polyesters to enhance the tribological properties and surface characteristic so as to improve wear resistance and nourish the fibroblast cells on synthetic disc. Design/methodology/approach: The researcher prepared UHMWPE composite material, reinforced with different weight fractions of short polyester fibres (2, 4, 6, 8 and 10% following hot press method. Further pin-on-disc device was used to study the tribological properties (coefficient of friction and volume of wear). The study tested surface roughness and surface characteristics by atomic force microscopy (AFM) device, hardness by shore D device, contact angle to study the effect of polyester short fibres on wettability of UHMWPE surface and tested the thermal properties and crystalline degree using Differential Scanning Calorimetry measurement (DSC) device. Findings: The results infer that the wear resistance got improved when using 2% w.t polyester though it got decreased initially. However, the value was still more than neat UHMWPE. There was a decrease observed in coefficient of friction, but after 4 w.t% polyester, the coefficient of friction got increased due to increasing percentage of fibres which make it harder and stiff compared to UHMWPE. There was a decline observed in surface roughness due to alignment of the fibres with smooth surface. The contact angle got increased in a moderate range while the roughness enhanced the growth of fibroblast cell. The hardness of composite material got increased, because the fibres turned stiffer and harder than the matrix. DSC results infer the improvements in thermal stability due to high thermal properties of polyester fibres compared to UHMWPE. The degree of crystallinity got increased which in turn enhanced wear resistance, especially at 6 w.t % polyester fibres. There was a mild increase observed in density since the density of polyester is higher than polymer. Research limitations/implications: The major challenge was the dispersion of fibres. Uniform distribution of fibres within the matrix (UHMWPE) was achieved through two steps of mixing processes such as mechanical mixture and twin extruder. In future studies, fatigue tests must be conducted to study the behaviour of prepared composite materials under fatigue cycle. Practical implications: A significant objective is how to connect among different properties to obtain good improvement in tribological and surface properties so as to enhance wear resistance and growth of fibrolase cells. Originality/value: In this study, polymeric short fibres were used as reinforcement with polymeric matrix to enhance the wettability of fibres with matrix. In this way, the bonding among them got increased which supports the tribological, surface, and crystalline behaviour.


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