+

WO2002003059A1 - Test effectué sur du cuir - Google Patents

Test effectué sur du cuir Download PDF

Info

Publication number
WO2002003059A1
WO2002003059A1 PCT/GB2001/002905 GB0102905W WO0203059A1 WO 2002003059 A1 WO2002003059 A1 WO 2002003059A1 GB 0102905 W GB0102905 W GB 0102905W WO 0203059 A1 WO0203059 A1 WO 0203059A1
Authority
WO
WIPO (PCT)
Prior art keywords
leather
sample
acoustic
applying
testing
Prior art date
Application number
PCT/GB2001/002905
Other languages
English (en)
Inventor
Amanda Long
Peter Jardine
Terry Deadman
Original Assignee
Blc Leather Technology Centre Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Blc Leather Technology Centre Limited filed Critical Blc Leather Technology Centre Limited
Priority to GB0203930A priority Critical patent/GB2370356A/en
Priority to AU2001267699A priority patent/AU2001267699A1/en
Publication of WO2002003059A1 publication Critical patent/WO2002003059A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/36—Detecting the response signal, e.g. electronic circuits specially adapted therefor
    • G01N29/42—Detecting the response signal, e.g. electronic circuits specially adapted therefor by frequency filtering or by tuning to resonant frequency
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/223—Supports, positioning or alignment in fixed situation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/227—Details, e.g. general constructional or apparatus details related to high pressure, tension or stress conditions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/44—Resins; Plastics; Rubber; Leather
    • G01N33/447—Leather
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/01—Indexing codes associated with the measuring variable
    • G01N2291/015—Attenuation, scattering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/023—Solids
    • G01N2291/0237—Thin materials, e.g. paper, membranes, thin films
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/10—Number of transducers
    • G01N2291/101—Number of transducers one transducer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/10—Number of transducers
    • G01N2291/106—Number of transducers one or more transducer arrays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/26—Scanned objects
    • G01N2291/263—Surfaces
    • G01N2291/2632—Surfaces flat

Definitions

  • the present invention relates to the testing of leather, in particular the testing of leather for grain surface cracking.
  • the present invention provides, in one aspect, a method for the determination of physical characteristics of a leather sample, the method including the steps of applying a physical procedure to the sample of leather; and monitoring and analysing audible acoustic emissions from the sample.
  • the present invention also provides, in a second aspect, apparatus for the determination of physical characteristics of a leather sample, the apparatus comprising application means to apply a physical procedure to the sample; an acoustic sensor providing an output in response to detected audible acoustic emissions from the sample; and analysis means to analyse the output and provide a indication of the physical characteristic to be determined.
  • the acoustic sensor detects emissions up to around 22 kHz.
  • the acoustic sensor is a microphone.
  • the acoustic sensor comprises a plurality of transducers equidistantly positioned from the sample of leather.
  • the apparatus is a lastometer and the physical procedure application means comprises a clamp to retain a circular sample of leather with a uniform tension and a probe to apply a force of known magnitude to the centre of the sample.
  • the analysis means comprises a suitably programmed computer.
  • Figure 1 is a schematic representation of an embodiment of the apparatus of the present invention
  • Figure 2 is a schematic perspective view of a transducer array for use as an acoustic sensor in the embodiment of Figure 1;
  • Figure 3 is a cross-section of the transducer array of Figure 2;
  • Figure 4 represents schematically a summing amplifier for the transducer array of Figure 2
  • Figure 5 is a graph showing the output of an acoustic sensor in a lastometer test using the apparatus of Figure 1;
  • Figure 6 is a graph showing the force applied to the sample of leather in the same test.
  • Figure 7 is a graph showing the correlation between results of lastometer tests on a range of specially prepared leathers using conventional methodology and the apparatus of the present invention
  • Figure 8 is a graph showing the correlation for a range of commercial leathers.
  • Figures 9 to 12 are waveforms obtained from a leather tearing tests of a range of samples of leather.
  • Figure 12 is a plot illustrating the effect of fat Uquor offer on the number of acoustic events.
  • amplitude and frequency are a measure of loudness
  • the frequency is the number of cycles per second and is perceived as the pitch of the sound.
  • the frequency range that is studied is the ultrasound region. In fewer cases is the audible range evaluated.
  • Acoustic testing is an area that has been incorporated into many industries. Typically it is used for the non-destructive testing of materials such as pressure vessels, but it has been used in a wide range of other applications (K Ono, R Stem, M Long Jr, (1972), 'Application of Correlation Analysis to Acoustic Emission ' f -rom Acoustic Emissio ' ASTM, STP 505, American Society for Testing and Materials, pp 152 - 163). Results obtained have been correlated with properties such as the applied stress and the stress intensity at a crack tip.
  • the apparatus comprises a jig into which can be secured a sample disc 10 of leather in such a way that tensioning forces 11 can be applied to the sample disc, typically by means of a probe (not shown) pressing into the centre of the sample in a direction perpendicular to the plane of the sample.
  • a probe not shown
  • Such an arrangement is conventional in the field of materials testing (for example, the Stable Micro Systems MT-RQ Material Tester) and will not be described in further detail.
  • the apparatus also includes an acoustic sensor 12.
  • the acoustic sensor is simply a microphone, such as a standard tie-clip microphone, typically monitoring frequencies from about 200Hz up to 22 kHz.
  • a simple microphone has been found to be the most suitable acoustic sensor for certain tests such as tear testing. Indeed, in preliminary tests, a simple Altai tie-clip was found to perform substantially as well as an Audio Technica AT30M Studio microphone. However, for the lastometer test, a transducer array has been developed and provides advantageous results.
  • a transducer array 20 is illustrated schematically in Figures 2 and 3.
  • a plurality of transducers 21, typically four are mounted in a ring 22 typically formed of a resilient foamed material.
  • the ring 22 is positioned adjacent the sample under test, such that the transducers are all equidistant from the probe of the testing jig.
  • the use of an array of transducers allows summing of the outputs of all transducers to provide additional gain to the desired signal against unwanted background signals. Sound emanating from the centre of the jig will have a wave front 15 which reaches all the transducers simultaneously.
  • FIG. 4 shows a block diagram of a suitable Summing Amplifier which was constructed to allow combination of the signals from the separate transducers.
  • N is approximately 344 metres per second at 20 degrees centigrade. So as ⁇ is 0.004 metres, f is calculated to be 344/0.004 which is 86kHz.
  • the array will therefore be vulnerable to operational difficulties due to assembly tolerances at around 86kHz. This is a good result as the transducers have little output signal above 20kHz due to their internal design and so the principle should hold across the frequency range of interested.
  • the acoustic sensor 12 is connected to a sound input device such as a conventional sound card, of a conventional computer 13.
  • the data obtained by the acoustic sensor is processed using conventional software to provide a useful graphical output of the acoustic data obtained.
  • One particularly suitable program is 'Texture Expert Exceed' from Stable Micro Systems Limited of Vienna Court, Lammas Road, Godalming, Surrey. This program is well known in the field of materials testing and, for our purposes, allows control of the jig and allows multi-channel data to be displayed graphically.
  • Figures 5 and 6 An example output from the apparatus of the present invention acting as a lastometer is shown in Figures 5 and 6.
  • Figure 5 shows the relative amplitude of the acoustic data 30 obtained as a function of time.
  • Figure 6 shows the corresponding force applied by the probe, again plotted as a function of time.
  • a sharp peak 31 is shown in the acoustic data at approximately 18.3 seconds, corresponding, by reference to Figure 6, to an applied mass of around 19.4 kg (equivalent to a force of 190.3N)
  • the waveform in Figure 9 is typical of those seen for tearing tests and illustrates some interesting features.
  • the waveform is comprised of a series of acoustic events or sound bursts. These have a characteristic shape. It should be noted that initially the shape was typical of a "ringing" effect, and was an artefact of the test jig vibrating after each pulse from the leather. Damping of the test jig jaws removed this problem and Figure 9 illustrates the results after this. These pulses are typical of damped harmonic motion seen for example, in a musical string being plucked. It was considered initially that the breakage of individual fibres or fibre bundles was being monitored using this technique.
  • Figure 10 and Figure 11 show the waveforms obtained from leathers treated with different offers of mimosa. It is clear that there are more acoustic events occurring in the sample treated with a higher offer of mimosa. It is also possible that the amplitude distribution may be different, however it is not possible to quantify this currently.
  • Figure 10 shows the waveform obtained by tear testing leather containing 4% w/w Mimosa
  • Figure 11 that obtained with leather having an 8% content of mimosa
  • Figure 12 shows that obtained from leather containing a waterproofing fatliquor.
  • the program applied a user specified amplitude threshold to the acoustic emissions waveform to allow the detection and time stamping of individual events.
  • the program also applied a "dead time" after identified events during which any further acoustic information was ignored. This was to allow the exponential decay of the event to have fallen to a level below the detection threshold before continuing with the detection process. Hence multiple triggers from single events could be avoided, provided the threshold and dead time were set to suitable levels.
  • Output from the program was in the form of an ASCII text file consisting of a list of times that corresponded to detected events. This file was then imported to analysis software in order that the event density against time could be calculated.
  • the RMS power is a parameter that was calculated through software and is a measure of the perceived "loudness" of the noise or effective energy of the signal.
  • the acoustic emission data shows good correlation with the subjective parameters of leather, allowing the development of a mathematical model to allow these parameters to be quantified. It is therefore of interest to compare the results from the two techniques and indeed combine them to determine if improvements can be made in the prediction of handle.
  • the acoustic emission data alone can be used as an indication of properties such as the stiffness/softness and fullness of the leather.
  • the data is illustrated in Table 1 below.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

L'invention concerne un test effectué sur du cuir, notamment un test effectué pour détecter un éventuel criquement superficiel du grain. On teste la résistance et la distension du grain du cuir afin de déterminer si ce dernier convient pour un usage particulier, tel que la fabrication de chaussures. D'une manière plus spécifique, l'invention concerne un procédé permettant de déterminer des caractéristiques physiques d'un échantillon (10) de cuir, ce procédé consistant à appliquer un processus physique audit échantillon de cuir, puis à surveiller et à analyser des émissions audibles acoustiques provenant de l'échantillon. L'invention concerne également un appareil conçu pour ledit procédé, cet appareil comprenant un dispositif permettant d'appliquer un processus physique à un échantillon (10) de cuir et un détecteur (12) acoustique. D'une manière générale, le détecteur acoustique comprend au moins un transducteur, tel qu'un microphone, et surveille les émissions acoustiques comprises entre 200 Hz et 22kHz. Pour certaines analyses, le détecteur comprend une matrice annulaire comprenant une pluralité de transducteurs montés de manière équidistante à partir du dispositif appliquant le processus physique.
PCT/GB2001/002905 2000-06-30 2001-06-29 Test effectué sur du cuir WO2002003059A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0203930A GB2370356A (en) 2000-06-30 2001-06-29 Testing of leather
AU2001267699A AU2001267699A1 (en) 2000-06-30 2001-06-29 Testing of leather

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0016063A GB0016063D0 (en) 2000-06-30 2000-06-30 Testing of leather
GB0016063.0 2000-06-30

Publications (1)

Publication Number Publication Date
WO2002003059A1 true WO2002003059A1 (fr) 2002-01-10

Family

ID=9894740

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2001/002905 WO2002003059A1 (fr) 2000-06-30 2001-06-29 Test effectué sur du cuir

Country Status (3)

Country Link
AU (1) AU2001267699A1 (fr)
GB (2) GB0016063D0 (fr)
WO (1) WO2002003059A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1398628A3 (fr) * 2002-09-11 2006-02-01 Fuji Photo Film Co., Ltd. Procédé et dispositif de classification de la fragilité de substance de revêtement
US8077163B2 (en) 2006-08-24 2011-12-13 Qualcomm Incorporated Mobile device with acoustically-driven text input and method thereof
CN105096566A (zh) * 2015-08-13 2015-11-25 库天下（北京）信息技术有限公司 一种皮革制品的监测方法和服务器

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2265215C1 (ru) * 2004-07-19 2005-11-27 Восточно-Сибирский государственный технологический университет Способ определения пропикелеванности кожевой ткани
RU2460996C2 (ru) * 2010-09-30 2012-09-10 Государственное образовательное учреждение высшего профессионального образования Московский государственный университет дизайна и технологии Устройство для определения физико-механических характеристик кожи и подобных ей мягких композитов

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3477288A (en) * 1966-10-21 1969-11-11 Vyzk Ustav Kozedelny Testing apparatus and method for sheet material

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3477288A (en) * 1966-10-21 1969-11-11 Vyzk Ustav Kozedelny Testing apparatus and method for sheet material

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
KRONICK P ET AL: "NONDESTRUCTIVE FAILURE TESTING OF BOVINE LEATHER BY ACOUSTIC EMISSION", JALCA, vol. 87, no. 7, 1992, pages 259 - 266, XP001029652 *
LIU CHENG-KUNG ET AL: "Tear resistance of leather characterized by acoustic emission", J AM LEATHER CHEM ASSOC;JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION 2000 AMERICAN LEATHER CHEMISTS ASSOC, CINCINNATI, OH, USA, vol. 95, no. 5, 2000, pages 170 - 178, XP001022875 *
LONG A J ET AL: "The use of acoustic emission to detect grain crack during the lastometer test", J SOC LEATHER TECHNOL CHEM;JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGIES AND CHEMISTS MARCH/APRIL 2001, vol. 85, no. 2, March 2001 (2001-03-01), pages 80 - 84, XP001037555 *
MARMER W N: "Overview of the USDA hides and leather research program", J AM LEATHER CHEM ASSOC;JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION MARCH 2001, vol. 96, no. 3, March 2001 (2001-03-01), pages 88 - 93, XP001037565 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1398628A3 (fr) * 2002-09-11 2006-02-01 Fuji Photo Film Co., Ltd. Procédé et dispositif de classification de la fragilité de substance de revêtement
US8077163B2 (en) 2006-08-24 2011-12-13 Qualcomm Incorporated Mobile device with acoustically-driven text input and method thereof
CN105096566A (zh) * 2015-08-13 2015-11-25 库天下（北京）信息技术有限公司 一种皮革制品的监测方法和服务器

Also Published As

Publication number Publication date
GB2370356A (en) 2002-06-26
AU2001267699A1 (en) 2002-01-14
GB0203930D0 (en) 2002-04-03
GB0016063D0 (en) 2000-08-23

Similar Documents

Publication Publication Date Title
Sung et al. Monitoring of impact damages in composite laminates using wavelet transform
Barile et al. Experimental wavelet analysis of acoustic emission signal propagation in CFRP
Mori et al. A new non-contacting non-destructive testing method for defect detection in concrete
Stephens et al. Waveforms and frequency spectra of acoustic emissions
US5621172A (en) Method and apparatus for testing material strengths
US7043990B2 (en) System for and method of performing evaluation techniques on a log or round timber
US20020029116A1 (en) Apparatus and method for analysis of guided ultrasonic waves
WO2002003059A1 (fr) Test effectué sur du cuir
Montiel-Zafra et al. Monitoring the internal quality of ornamental stone using impact-echo testing
Chen et al. Monitoring the fracture of wood in torsion using acoustic emission
KR100707389B1 (ko) 음향 분석 기법을 이용하여 콘크리트 구조물의 건전도를평가하기 위한 장치 및 방법
Cox The four-point bend test as a tool for coating characterization
JP2005148064A (ja) 圧力テスト中またはテスト後の圧力容器の変化または損傷の検出装置と検出方法
Ross Using sound to evaluate standing timber
JP2899699B1 (ja) 岩盤の損傷度診断方法
Kaphle et al. Effective discrimination of acoustic emission source signals for structural health monitoring
Berthelot et al. Damage evaluation of concrete test specimens related to failure analysis
Woodward et al. The use of signal analysis to identify sources of acoustic emission
Alchakra et al. Acoustical emission technique applied to the characterisation of brittle materials
Lee et al. Guided wave acoustic emission from fatigue crack growth in aluminium plate
Kim et al. The natural frequencies of AISI 316 stainless steel and analytical simulation of a Lamb wave excited by a point source
Mazal et al. Advanced acoustic emission signal treatment in the area of mechanical cyclic loading
Kharrat et al. A signal processing method for hits detection and separation in high AE activity systems: Application to composite materials under fatigue tests
Wiranata et al. The implementation of fast fourier transform and coherence function to detect the millimetric hole on strip iron plate
Marinho et al. Impact Identification Method for Structural Health Monitoring of Stiffened Composite Panels using Passive Sensing Systems

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

ENP Entry into the national phase

Ref country code: GB

Ref document number: 200203930

Kind code of ref document: A

Format of ref document f/p: F

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载