Acoustic emission studies for leather coatings / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 10 (10/2002)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVII, N° 10 (10/2002) . - p. 389-399 Titre : Acoustic emission studies for leather coatings Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Gary L. DiMaio, Auteur ; Nicholas P. Latona, Auteur Année de publication : 2002 Article en page(s) : p. 389-399 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Finishing, the final step in the leather-making process, contributes to the beauty and durability of leather. Choosing the right coating is critical in obtaining a satisfactory finishing result, such as good flexing endurance and no surface cracking. Acoustic emission has been known to be a useful method to characterize the coating properties for the automobile industry. As a continuation of our efforts to investigate the applications of acoustic emission technology to leather manufacture, we exploited the AE technique to measure the flexing endurance of leather coatings. An acoustic sensor was clipped to the grain layer of finished leather in a tensile test to collect various acoustic quantities. Observations showed that differences in the flexibility of the coatings can be analyzed by examining the plot of the AE count rate as a function of time. We have concluded that a quantitative association exists between the flexibility of coatings and the cumulative acoustic counts produced at an initial tensile stretch. The results of this AE research may provide a route to examine the flexing endurance of leather coatings. En ligne : https://drive.google.com/file/d/17XHDAPdWdQ7O00GaBVyeWxcxXqZAELad/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4267 [article]

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Acoustic emission studies for leather using dual sensors / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CV, N° 4 (04/2010)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CV, N° 4 (04/2010) . - p. 109-115 Titre : Acoustic emission studies for leather using dual sensors Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Nicholas P. Latona, Auteur ; Joseph Lee, Auteur Année de publication : 2010 Article en page(s) : p. 109-115 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Capteurs (technologie) Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés mécaniques Emission acoustique Rigidité (mécanique) Rupture (mécanique) Traction (mécanique) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Since leather is sold by the square foot, destructive tests lessen the square footage of the material and infringe on the leather manufacturer's total profit. Therefore there is a need for developing an instrument to perform nondestructive testing of the physical properties of leather. In this investigation, experiments were designed to pass leather test samples through a pair of rotational acoustic sensors, thereby enabling the collection of acoustic emission (AE) signals from both the grain and corium and provide a more accurate assessment of the quality of leather. Observations showed a strong correlation between the mechanical properties of leather and the corresponding cumulative acoustic energy. We also used this dynamic method to characterize the grain break of leather. Results showed that the difference in grain break could be determined form the amount of acoustic hits collected from moving the AE sensors over a leather sample. Observations showed the poorer the grain break ; the more AE energy was detected. Data also demonstrated that thicker samples tended to have poorer grain break. In short, this study demonstrated that the tensile strength, stiffness, toughness ans grain break could be nondestructively determined by measuring acoustic quantities with a pair of rotational sensors. Note de contenu : - EXPERIMENTAL : Materials - AE methods and apparatus - Tensile property measurements - RESULTS AND DISCUSSION : Correlation between AE quantities and physical properties - Leather stiffness - AE evaluation of break En ligne : https://drive.google.com/file/d/1wnXpDZQhYpMFyJR0RdXJp95cXy-G6hX1/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9075 [article]

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Airborne ultrasonic inspection for hides and leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 11 (11/2011)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 11 (11/2011) . - p. 326-331 Titre : Airborne ultrasonic inspection for hides and leather Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Nicholas P. Latona, Auteur Année de publication : 2011 Article en page(s) : p. 326-331 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Analyse Ultrasons Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Currently, hides and leather are visually inspected and ranked for quality, sale price and usable area. Visual inspection is not always reliable for detecting defects, particularly when they are hidden inside the material. This manual assessment is non-uniform among operators, and often leads to disputes over fair price. Development of a nondestructive method to accurately evaluate the quality of hides and leather is needed. We have investigated airborne ultrasonic (AU) testing using non-contact sensors for the nondestructive evaluation of hides and leather. The AU test system is an ideal inspection method for large hides or leather and is designed for automated and moving process applications. The AU sensors are mounted on a computer-controlled X-Y scanner that allows the sensor array to be moved over the entire surface of the hide. The AU testing involves pulsing ultrasonic signals and measuring the amplitude of those signals that traveled through the material. This research examines the ability of AU techniques to reveal defects in hides and leather that are difficult to be found during visual inspection. The key for success in AU testing is to use AU sensors with low resonant frequencies, which leads an effective penetration of waves through the leather or hides. Observation showed that test areas with different amplitudes in the C-scans obtained from AU testing is an indication of the presence of defects or some other physical discontinuity that could affect the hides or leather quality. Using the AU C-scan images could advance the industry in how it assesses and grades raw hides, wet blue, wet white and finished leather. En ligne : https://drive.google.com/file/d/1BquSlyIjzaWHuc88F6j3ntdcfs2jLJLx/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12521 [article]

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Airborne ultrasonics for nondestructive evaluation of leather quality / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 7 (07/2008)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIII, N° 7 (07/2008) . - p. 209-214 Titre : Airborne ultrasonics for nondestructive evaluation of leather quality Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Valery F. Godinez-Azcuaga, Auteur ; Nicholas P. Latona, Auteur Année de publication : 2008 Article en page(s) : p. 209-214 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Our recent research has shown that besides Acoustic Emission (AE), Airborne Ultrasonics (AU) can also be applied for the nondestructive evaluation (NDE) of leather quality. Implementation of these methods in the manufacturing process could save a considerable amount of money, decrease the use of chemicals, reduce production time, increase the value of the leather and increase quality. Our previous paper reported a portable AE system for the evaluation of leather quality. This paper discusses the results of research carried out for nondestructive evaluation by AU. Our experiments showed that this novel technique reveals the presence of areas of different acoustic properties, which are an indication of local variations of the leather material properties. This system offers a great potential for testing entire hides in the manufacturing plant. Our research also showed that data can be gathered from different sections of the hide and along different directions with respect to the backbone. Observation also indicated these AU imaging techniques can reveal the presence of defects in the leather created by healed wounds, insect bites, knife cuts or any other physical discontinuity that could affect the leather quality. Scars, insect bites or major defects can be detected electronically, causing the hide or semi-product to be downgraded before it is subjected to any expensive leather making operations, thus saving money in processing time, chemicals, etc. AU testing showed some degree of correlation with the Nissan Shirley Stiffness data, but it is not as robust as AE with the rolling sensors. Selection of the right AU sensors is critical to achieve enough penetration in order to extract important information related to the properties of leather such as strength and softness. A better correlation between tensile strength and AU data could be achieved when AU tests are performed on a group of leather samples with the same manufacturing process and surface finish. En ligne : https://drive.google.com/file/d/1KsYc95_-Q9Rs702LP7RimaFN-D-qvd2Z/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=2556 [article]

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An energy approach to the characterisation of the fracture resistance of leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCII, N° 5 (05/1997)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCII, N° 5 (05/1997) . - p. 103-118 Titre : An energy approach to the characterisation of the fracture resistance of leather Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Michael D. Mcclintick, Auteur Année de publication : 1997 Article en page(s) : p. 103-118 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The fracture resistance of chrome-tanned bovine hides was quantitatively characterized by measuring the total energy required to break the leather. This physical quantity named fracture energy is observed to more truthfully represent the fracture resistance of leather than the tensile strength or breaking elongation. Three major independent variables, moisture content, strain rate, and sampling angle were arranged according to Box Hunter's experimental design matrix, thereby deriving a second order polynomial equation. The statistical model so obtained concisely expressed the relationship between the variables and corresponding fracture resistance. The results showed that water acting as a plasticizer enhances the fracture resistance of leather. However, fracture energy started to decrease once the moisture content increased to around 90%. Contrary to its effect on tensile strength, the sampling angle has shown little effect on the fracture energy of leather. The effect of strain rates on fracture energy is not straightforward. The fracture energy at first decreases then increases with increasing strain rates. The ratio of tensile strength of Young's modulus was used to represent the toughness of leather. This parameter is dimensionless, independent of the geometric shape of the leather samples. A correlation was observed between this parameter and fracture energy. En ligne : https://drive.google.com/file/d/145d8ZUpXvdWiouUdTVcxsf2uiTzkSgjM/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=7674 [article]

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Application of tocopherol to improve the durability of leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 10 (10/2003)  

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Area retention studies for vacuum-dried leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 10 (10/2002)  

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Biobased films prepared from collagen solutions derived from un-tanned hides / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 2 (02/2015)  

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Biopolymers produced from gelatin and chitosan using polyphenols / M. M. Taylor in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 12 (12/2015)  

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Characterization and thermal properties of polygenipin-crosslinked hide powders / Jie Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 4 (04/2018)  

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Characterization of mechanical properties of leather with airborne ultrasonics / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 3 (03/2015)  

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Composite drying with simultaneous vacuum and toggling / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIV, N° 4 (04/2009)  

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Degree of opening-up of the leather structure characterized by acoustic emission / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 10 (10/2001)  

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Development and characterization of genipin cross-linked gelatin based composites incorporated with vegetable-tanned collagen fiber (VCF) / Jie Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 12 (12/2017)  

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Drying leather with vacuum and toggling sequentially / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 3 (03/2011)  

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A drying study for glutaraldehyde-tanned leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 1 (01/2005)  

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Effect of cyclic stress while being dried on the mechanical properties and thermostability of leathers / Jinbao Huang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 10 (10/2018)  

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Effect of the composition of vinyl polymer tannages on the physical properties of leather / Jianzhong Ma in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 1 (01/2001)  

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Effects of bating, pickling and crosslinking treatments on the characteristics of fibrous networks from un-tanned hides / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVIII, N° 3 (03/2013)  

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Effects of dehydration methods on the characteristics of fibrous networks from un-tanned hides / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 3 (03/2012)  

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