Dépouillements

Assessment of the thermal resistance of leather / Anna Matz in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 1-7 Titre : Assessment of the thermal resistance of leather Type de document : texte imprimé Auteurs : Anna Matz ; Czeslaw Krawiecki, Auteur ; Miroslaw Mrozowski, Auteur Année de publication : 1984 Article en page(s) : p. 1-7 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Contraintes thermiques Cuirs et peaux -- Propriétés thermiques Evaluation Résistance thermique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A great deal of attention has been paid recently to leathers designed for production of protective clothing worn under "hot" conditions. Several tanning technologies and methods for assessing leather properties have been developed. Relatively few papers have appeared which discussed the phenomena occurring in leather under the influence of heat in an air-dry medium. The practical measure of the leather thermal resistance, which cannot be overlooked in its assessment, is the temperature at which the visible deformation of leather occurs. Depending on conditions in which the leather remains while heated, we may differentiate between (a) the autonomous deformation occurring under the influence of leather-free shrinkage and (b) the deformation under the influence of stresses in leather. The first case of deformation occurs in leathers of small area used in a loose state. Macromolecules, under the influence of heating in such samples, are subjected only to small internal stresses. When affected by a given thermal energy they may increase their entropy and assume the most thermodynamically advantageous shape at a given degree of their crossilinkage. On a macroscale this appears as a certain shrinkage of material. In the case of leathers of greater area or of those used for products with more rigid construction, e.g. footwear, the shrinkage proceeds under slightly different conditions. On a macroscale, the shrinkage does not occur freely as a result of immobilisation of leather edges. On a microscale, the macromolecules have a limited possibil¬ity of changing their shape for they are interconnected by cross-linking. Considering this fact, there tends to be a maximum entanglement of chains, under given conditions, the stresses within the leather being higher the greater the number of macromolecules orientated towards the tested direction which participate in this phenomenon. An outer stress applied to the specimen influences the shrinkage rate and the temperature at which intensive shrinkage begins. The effect of temperature on leathers, under isometric conditions, is a limiting example of the shrinkage to stress ratio. The purpose of our work was to evaluate the thermal resistance of leathers heated in an air-dry medium. The behaviour of leathers heated under free and isometric conditions has been investigated. Note de contenu : - Conditions of test - Examination of thermal resistance of leathers deformed under free conditions - examination of the thermal resistance of leathers undergoing deformation in a stressed state - Cyclic heating cooling of specimens - Changes in leather subjected to constant temperature En ligne : https://drive.google.com/file/d/1xc3X6iSqmmDPSKw6kXXdfr6G8kuHGcbu/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34141 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Investigation of the structure of leathers tanned with chrome-zirconium complex tanning material / T. Karnitscher in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 8-12 Titre : Investigation of the structure of leathers tanned with chrome-zirconium complex tanning material Type de document : texte imprimé Auteurs : T. Karnitscher, Auteur ; F. J. Tothné, Auteur ; I. T. Skaranda, Auteur Année de publication : 1984 Article en page(s) : p. 8-12 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chrome Cuirs et peaux -- Analyse Microscopie électronique à balayage Tannage minéral Tannage dans lequel interviennent différents minéraux. Le plus répandu est le tannage aux sels de chrome, mais aussi à l’aluminium Zirconium Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In recent years there came to the fore the use of those tanning preparations which confer more advantageous leather properties because of their many functional groups. In order to extend the influence of the widely used chrome tannage there are available in the leather industry several products which are chemically modified with other metal salts including zirconium salts. We are well aware of the problems of the zirconium tannage and of the succeeding operations, e.g that the process is suitable for the tannage of upper leathers only to a limited extent. The leathers tanned by this method are very well filled and are also tight. They do not possess the softness and elasticity required for shoe upper leather. These negative properties do not appear if the tannage is performed with a chrome-zirconium complex compound because the chrome-zirconium complex is linked in a different manner to the collagen. Tannages performing differently yield leather with different properties which can be characterised both by organoleptic tests and by means of objective instrument measurements. The differences in the macroscopic dimension are followed in all cases by the change of microstructure. In order to follow these alterations many researchers have applied -die scanning electron microscope (SEM) which has turned out to be a useful instrument for gaining knowledge of fibre structure relationships which were not known before, e.g. for the study of the influence of enzymes on leather structure, for the investigation of the structure of pigskins during the leather process and in other fields of leather research. This instrument, developed on the basis of the technical results of the last ten years, makes possible the study of the least fibre structure units of leather, i.e. the study of the fibres and fibrillae. This instrument has the advantage that no preparation of ultrathin sections is needed, but is unavoidable for tests performed with transmission electron microscopes working similarly with several ten thousand-fold magnification. The stereoscopic micrographs that can be made with the scanning electron microscope (SEM) greatly advance the study of the arrangement of the structural units investigated. In the course of examining the influence of the chrome-zirconium complex tanning material, we studied (with the aid of scanning electron microscope investigations) the connection between the structure and properties of leathers tanned with different minerai tannages. Note de contenu : - Preparation of the leather for the SEM investigations - Evaluation of the SEM micrographs - Fig. 1 : Scanning electron microscope micrograph of fibres of cattlehide tanned with zirconium salt - Fig. 2 : Scanning electron microscopemicrograph of cattlehide tanned with chrome-zirconium mixture tanning material - Fig. 3 : Scanning electron microscope micrograph of fibres of cattlehide tanned with chrome-zirconium complex material - Fig. 4 : Cross-section and torn surface of elementary fibres cattlehide tanned with chrome-zirconium complex tanning material - Fig. 5 : Scanning electron microscope micrograph of elementary fibres En ligne : https://drive.google.com/file/d/1_TPAmjW9dOTPfKX_13h3VmBhiH5QlQju/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34142 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Basic titanum sulphate - A versatile tanning agent / S. Bangaruswamy in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 13-14 Titre : Basic titanum sulphate - A versatile tanning agent Type de document : texte imprimé Auteurs : S. Bangaruswamy, Auteur ; M. P. Swamy, Auteur ; J. B. Rao, Auteur Année de publication : 1984 Article en page(s) : p. 13-14 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Sulfate de titane Tannage minéral Tannage dans lequel interviennent différents minéraux. Le plus répandu est le tannage aux sels de chrome, mais aussi à l’aluminium Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the leather industry, the dioxide of titanium finds extensive use as a whitening agent either alone or in the form of composites with barium sulphate and calcium sulphate. The thin film does not obscure or harshen the leather grain. Titanium dioxide is also used in combination with other materials for tinting leathers. As regards its inertness towards tanning materials in leathers, it does not suffer from darkening by ageing. Titanium has the best corrosion resistance as a result of its passivation (less than 0.007 mm/year) and hence it imparts better corrosion resistance than any other material usually employed in tanning systems. The white leather with anticorrosive properties produced by titanium tannage finds extensive utilisation in the production of protective gloves, clothing leathers and other outfits required to be used in corrosive atmospheres. With regard to its function as a tannage agent, the studies carried out so far have been based on predominantly anionic titanium and the leathers obtained possessed lower hydrothermal stability, abrasive resistance and strength. In these studies, titanium exists as a double salt, viz. {(NH4)2SO4TiO(SO4)2x H201 and is in the anionic form. This double salt, when used alone as well as in combination with certain organic and inorganic salts, is found to have filling and tanning effects in the production of leathers. A literature survey indicates that titanium forms very stable complexes in its quadrivalent state, the metal itself remaining cationic. Thus, it seems interesting to study the complexes of Ti(IV) with reference to pre-tanning, retanning and simultaneous tanning systems involving titanium, leading to fixation/ stripping of the components of the systems taken up for such tannages. Note de contenu : - Application of titanium in general - Applications of titanium in leather industry - R&D work at CLRI - Merits of basic titanium sulphate tannages En ligne : https://drive.google.com/file/d/1hSm8qvJSuZJLp2zzWXAgNe7q_5AKFXrR/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34143 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The simultaneous transfer of heat and moisture in leather / A. Sàra in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 23-30 Titre : The simultaneous transfer of heat and moisture in leather Type de document : texte imprimé Auteurs : A. Sàra, Auteur ; F. Langmaier, Auteur Année de publication : 1984 Article en page(s) : p. 23-30 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Analyse Cuirs et peaux -- Effets de l'humidité Cuirs et peaux -- Effets de la température Thermocinétique Transfert d'humidité Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : This paper deals with the transfer of heat and moisture in a pile of leathers with impermeable boundaries, which is caused by a jump in temperature at the boundaries. It is proved mathematically that changes in temperature take place in two "waves", with diffusion coefficients derived using the Henry theory of the simultaneous diffusion in porous sorbing materials, although the resulting relationships may be obtained only by use of a more common procedure under even more common assumptions than Henry's method. The results are compared with the experimental and theoretical data of Mitton and Dowsett obtained by use of an approximate solution with which they provide a good agreement. In conclusion, some important practical consequences of both the process and mathematical theory are mentioned. Note de contenu : - Introduction - Experimental - Parameters of the modified Henry equations - Theoretical - Comparison of theoretical and experimental values En ligne : https://drive.google.com/file/d/1XNS5NNKfVjKaaOhOxeEUNWfAmwc3RlAq/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34144 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Methods for the treatment and preservation of raw hides and skins : a review / R. G. H. Elliott in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 31-34 Titre : Methods for the treatment and preservation of raw hides and skins : a review Type de document : texte imprimé Auteurs : R. G. H. Elliott, Auteur Année de publication : 1984 Article en page(s) : p. 31-34 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Conservation Cuirs et peaux de moutons Peaux brutes Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : During the last ten years or so varions methods have been applied to the cure and preservation of rawstock. In addition to the traditional treatment with common salt, sodium chloride, in different forms, other inorganic salts have been employed for this purpose and organic biocides have also been introduced. It is accepted that the onset of deterioration, particularly in the case of sheepskins, can readily occur if there is any significant delay between flay and cure. In support of this view it was demonstrated by Haines and Raistrick of the British Leather Manufacturers' Research Association, that a marked advantage could be gained by the application of forced cooling. They showed that, by conveying the freshly flayed skins under cold air fans, it was possible to extend the period of good preservation up to 30h without extra labour costs. It was also shown that, if further treatment such as brining or salting was applied within that period, a reliable cure with minimum breakdown could be achieved. The need for a rapid cure to be applied as soon as possible after flaying has been confirmed by a number of workers dealing with sheepskins and with green hides. En ligne : https://drive.google.com/file/d/1tq0kSW8csZNyI4mGmanMzJkgVwSQEJi5/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34145 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Confirmation of the recessive mode of inheritance of the vertical fibre hide structure in hereford cattle / J. H. Dufty in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 35 Titre : Confirmation of the recessive mode of inheritance of the vertical fibre hide structure in hereford cattle Type de document : texte imprimé Auteurs : J. H. Dufty, Auteur ; D. E. Peters, Auteur Année de publication : 1984 Article en page(s) : p. 35 Langues : Anglais (eng) Catégories : Bovins -- Races Cuirs et peaux -- Analyse Cuirs et peaux de veaux Peau -- Anatomie Index. décimale : 675 Technologie du cuir et de la fourrure Note de contenu : - Table : Approximate age at which the vertical fibre hide condition was identified in hereford calves En ligne : https://drive.google.com/file/d/1EZ0ZiPYfJ1qjB9vlZJ5Q-Lsf3yUQ_rvP/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34146 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The skin before tannage - Procter's view and now / Betty M. Haines in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 57-70 Titre : The skin before tannage - Procter's view and now Type de document : texte imprimé Auteurs : Betty M. Haines, Auteur Année de publication : 1984 Article en page(s) : p. 57-70 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Analyse Peau -- Anatomie Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : This paper has been prepared in order to pay tribute to the memory of a truly remarkable man, H. R. Procter, the founder of leather science. He, who had no formai university training, achieved academic distinction culminating in the Fellowship of the Royal Society. His intense interest in scientific matters, chemistry in particular, and his family's association with leather manufacture led to a life-long combination of these interests, chemistry and tanning, to the benefit of the leather industry world-wide. Note de contenu : - The structure of skin - Fig. 1 : H. R. Procter - Fig. 2 : Vertical section through butt region of cattle hide (LM) - Fig. 3 : Vertical section through : grain layer (SEM and corium of a dressed wollskin (SEM) - Fig. 4 : Cross-section of corium fibre bundles in firmside leather-coarse splitting up (SEM) and soft side leather-fine splitting up (SEM) - Fig. 5 : Cross-section of corium fibre bundles in leather prepared from mature ox hide (SEM), calfskin (SEM) and sheepskin (SEM) - Fig. 6 : Cross-section of corium fibre bundles of raw ox hide showing constituent collagen fibrils (TEM) - Fig. 7 : Surface of an elementary fibre bundle showing the spiral arrangement of the collagen fibrils (SEM) - Fig. 8 : Cross-section of collagen fibrils : at the grain surface (TEM) and elsewhere in the underlying dermis (TEM) - Fig. 9 : Longitudinal section of collagen fibrils in an acid swollen condition showing spiral arrangement of the subfibrillar units (TEM) - Fig. 10 : Regular distribution of dermatan sulphate over the sruface of the collagen fibrils. Raw ox hide stained with Cupromeronic blue (TEM) - Fig. 11 : Dermatan sulphate over surface of collagen fibrils immediately below the epidermis-ox hide stained with Cupromeronic blue (TEM) - Fig. 12 : Sheats of fine collagen fibrils encircling corium fibre bundles in the butt region (SEM) - Fig. 13 : Sheaths around corium fibre bundles in the neck region (SEM) - Fig. 14 : Vertical section through grain surface of nappa leather (SEm) - Fig. 15 : Breaks in the grain surface exposing relatively coarse underlying fibres (SEM) - Fig. 16 : Dermal/epidermal boundary of cattle hide stained with silver. Black reticulin fibres at the dermal surface (LM) - Fig. 17 : Boundary between dermis and epidermis in raw pigskin stained with ruthenuim red (TEM) - Fig. 18 : Schematic diagram of the epidermal/dermal boundary - Fig. 19 : Diagram illustrating structure of basement membrane-Type IV collagen - Fig. 20 : Cross-section through the dermal/epidermal boundary in raw ox hide stained with Cupromeronic blue (TEM) x20,000; E=epiderm basal cells ; HS=densely stained material in the location of heparin sulphate ; C=collagen fibrils - Fig. 21 : Collagen fibrils immediately below the epidermis (TEM), x20,000: E=epidermal basal cell; B=basement membrane ; CF=individu collagen fibrils; C=collagen fibrils organised into bundles - Fig. 22 : Cross-section of grain surface of ox hide after 4 h in lime and sulphide - Fig. 23 : Cross-section of grain surface of ox hide after bating - Fig. 24 : surface of nappa leather produced from hair sheep. The high resolution scanning electron microscope shows the surface to be fibrillar En ligne : https://drive.google.com/file/d/1kBHsZazEba2UstISseK1krIeiY8GSOup/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34147 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The analysis of enzymatic leather auxiliaries / T. Taegar in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 105-108 Titre : The analysis of enzymatic leather auxiliaries Type de document : texte imprimé Auteurs : T. Taegar, Auteur ; E. Pfleiderer, Auteur Année de publication : 1984 Article en page(s) : p. 105-108 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse quantitative (chimie) Caséine Les caséines sont des protéines qui constituent la majeure partie des composants azotés du lait. La première phase de la fabrication du fromage est leur précipitation par adjonction d'un acide ou de présure. Le mot caséine est issu du latin caseus, "fromage". - Caractéristiques : La quantité des caséines d'un lait varie selon les espèces animales : 82 % (des protéines) pour le lait de vache et 40 % pour le lait humain. L'hydrolyse d’une caséine fait ressortir des teneurs élevées en acide glutamique, proline, leucine, lysine, sérine et thréonine. - Caséines bovines : Il y a plusieurs types de caséines dans le lait de vache. Les plus présentes sont les caséines αS1 (40 %), β (35 %), κ (12 %), αS2 (10 %) et γ (3 à 7 %). La caséine du lait de vache précipite facilement en caillots blancs, soit par abaissement du pH au voisinage de son point isoélectrique (pH 4,6), soit par action enzymatique (présure). La caséine du lait humain ne précipite pas par simple acidification. Cependant, la précipitation à un pH de 6 est immédiate en présence du suc gastrique du nourrisson à cause de la présure qu'il contient (la chymosine pour être précis). - Caséines humaines : Les caséines représentent 40 % des protéines du lait humain contre 82 % dans le lait de vache. Elles forment également des micelles plus petites qui expliquent en plus de la haute teneur en protéine solubles la coagulation plus fine du lait maternel dans l’estomac du nourrisson. (Wikipedia) Cuirs et peaux Echantillonnage Enzymes Une enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes. Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie. Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums. Peptidases Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Originally, the analysis of enzymatic leather auxiliaries was intended to establish the quantity of a bate necessary to be used in the tannery when using materials of unknown strength. The relevant literature from the 1920s and 1930s confirms this opinion. Before giving details of the existing methods we would like to mention the basic difficulties in the analysis of enzymatic leather auxiliaries. Note de contenu : - Sampling - Choice of substrate - Other enzyme preparations - Enzyme sources for the manufacture of leather auxiliaries - Application of enzymatic leather auxiliaries - Analytical methods using casein as a substrate - Assays on hides and skins - Fig. 1 : Range of activity of different proteolytic enzymes - Fig. 2 : Bating agents standardised to 1000 LVU/g (TEGEWA) En ligne : https://drive.google.com/file/d/1iAarzlgUy4NL-Lq0FTQ6-lFQImc40_1R/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34148 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

A simple approach to leather process investigation part 3 - The development of the modified standard process for side leather / Ibrahim Elrufai abuelhassan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 125-138 Titre : A simple approach to leather process investigation part 3 - The development of the modified standard process for side leather Type de document : texte imprimé Auteurs : Ibrahim Elrufai abuelhassan, Auteur ; Alan Gordon Ward, Auteur ; S. Wolstenholme, Auteur Année de publication : 1984 Article en page(s) : p. 125-138 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux Essais (technologie) Procédés de fabrication Statistique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A standard process for the production of segments of chrome side leather, in a controlled manner, has been reported in T. Soc. Leather Technol. Chem., (1974), 58, 88. This process has been further developed to give a modified standard process in which the three main changes are (I) the use of whole sides in place of segments, (II) a drum liming procedure to replace the circulatory system employed previously for liming stationary segments, and (III) the transfer of the operation of splitting from the stage after liming to after chrome tanning. The course of development of the modified standard process is described, including details of consequential changes to deliming, pickling, tanning, basifying and neutralisation. It was also necessary to modify drying and conditioning, to enable whole sides to be handled. The properties of leather made by the modified process have been compared with those of standard process leathers. Although minor differences can be detected between the subjective properties (break, temper and grain quality) of leathers made by the two processes and also between a minority of the physical properties measured at corresponding locations on a side or segment, the similarities are sufficient to regard the new process as a near equivalent of the original process. Leathers made by the modified standard process on different occasions have highly reproducible properties and so the process is suitable for the study of the effect of variants in the leather-making operations on properties of the final leather. Note de contenu : - DEVELOPMENT OF THE MSP FOR WHOLE SIDES : Raw material - Siding - Brining, soaking and liming - Defining, pickling and tanning - Washing and neutralisation - Drying - Conditioning - Operation of the temperature and pH controlled drum - Machine operations - THE MODIFIED STANDARD PROCESS : Farm environment - Slaughterhouse procedure - Siding - Washing - Green fleshing - Brining - Brine pile - Soaking - Liming - Lime fleshing - Hair and scud removal - White liming - Washing - Deliming - Flushing - Bating - Flushing - Pickling and tannage - Chrome pile - Samming - Chrome splitting - Shaving - Washing - Neutralisation - Flushing - Dyeing - Flushing - Fatliquoring - Fatliquor pile - Samming and setting - Conditioning - Toggling - Storage - Process control - TEST METHOD DETAILS : Weight and area measurements - Sample squares for subjective and physical tests - Subjective and objective physical testing - Chemicsal tests - STATISTICAL ANALYSES AND EXPERIMENTAL PLANNING : The sign test for the paired case - Mann-Whitney test - Wilcoxon test - The Kruskall-Wallis test - PROCEDURES FOR PREPARING PACKS 1-4 : Pack 1. Check of SP operations - Pack 2. Introduction of drum liming and chrome splitting variants - Pack 3. Comparison of SP and MSP for whole sides - Pack 4 : The standard pack - EXPERIMENTAL RESULTS AND DISCUSSION : Reproducibility of the standard process for segments - Effect of the drum liming and chrome splitting variants (for segments) - The change to processing whole sides (pack 3) - The standard pack of MSP leather (pack 4) - Fig. 1 : Location of segment required for the standard process of laight and of the area of the 20 squares available for test samples from modified standard process leather, within the side used for the modified standard process - Fig. 2 : Squares within the area of the side used for test purposes, together with the arrangement and orientation of samples within the 12 squares usef for lastometer and Instron testing En ligne : https://drive.google.com/file/d/19qG8HFhp0_MD1IyHdLXox-NwG0mvfEX2/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34149 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

From tannery to table : an account of gelating production / F. A. Johnston-Banks in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 141-15 Titre : From tannery to table : an account of gelating production Type de document : texte imprimé Auteurs : F. A. Johnston-Banks, Auteur Année de publication : 1984 Article en page(s) : p. 141-15 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Eaux usées -- Epuration Flottation La flottation est une technique de séparation fondée sur des différences d'hydrophobicité des surfaces des particules à séparer. Elle est utilisée en minéralurgie pour séparer des minéraux entre eux et dans le traitement des eaux usées pour éliminer les graisses. Gélification Peaux brutes -- Trempe Procédés de fabrication Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : How many leather producers realise that the table-jelly they may have been served up for dinner a week ago could well have started its life in their own tannery ? Indeed the very same producer may well have dragged the hides from which the gelatine in the dessert was made, out of a washing or dehairing drum, or passed the same hide through a flesher or splitter. Would the secretarial staff know that the carbonless copy paper may contain derivatives of the same gelatine material? Any photographes will have a reasonable idea as to where a particular ingredient (and a very important one it is) of the film in their camera originates. Fewer people may be aware that the pork pies in their lunch box, the marshmallows, pastilles, mints and wine gums they pick up at the local supermarket, all have gelatine incorporated into them and that this gelatine or its precursor will have originated in a tannery. I will attempt to describe how this becomes possible in the following paper which is a description of the process of gelatine manufacture as practised by my company, Gelatine Products Ltd, which manufactures edible gelatines solely from bovine hide pieces and splits, collected from many UK tanneries. Note de contenu : - Fig. 1 : Time in alkali soak (caustic or lime) - Fig. 2 : The Runcorn hide process. Points at which rigorous contamination monitoring is applied are indicated (QC) - Fig. 3 : Dissolved air flotation effluent treatment process En ligne : https://drive.google.com/file/d/1tEcLm7rWNbS7p_N-r1C3BZVWag5MvU7A/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34150 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The recycling of silicofluoride and boric acid liquors for hide preservation / J. C. Barrett in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 146-149 Titre : The recycling of silicofluoride and boric acid liquors for hide preservation Type de document : texte imprimé Auteurs : J. C. Barrett, Auteur ; I. B. Leach, Auteur ; M. R. Ascough, Auteur Année de publication : 1984 Article en page(s) : p. 146-149 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bain de trempe -- Recyclage Borique, Acide Cuirs et peaux -- Conservation Fluorure de silicium Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Suspension drying is a long-established method of curing hides and skins still practised today in many parts of the world, but a major disadvantage is that adverse climatic conditions can cause major Tosses. For example, in West Africa during the wet season putrefaction of hides caused by delayed drying is extensive. Barrette reviewed bactericidal chemicals potentially suitably for treatment of hides and skins prior to drying to avoid this problem and selected methods were evaluated in field trials in the Gambia in 1981. The immersion of cattle hides in a saturated solution of either sodium silicofluoride (SSF) or boric acid for 60 min after flaying and fleshing prior to conventional suspension drying was found to give effective protection against putrefaction during drying periods of up to six days. No adverse effects on leather-making qualities of the raw stock could be attributed to the bactericidal pre-treatments. A practical system for pre-treating hides with bactericides will benefit from recycling of dip liquors to achieve economy in chemical usage. This paper describes experiments carried out in the Gambia in 1982 to investigate the scope for recycling SSF and boric acid liquors for hide preservation. Experiments were also carried out to investigate the scope for reducing the period of immersion of hides while retaining effective preservation. Note de contenu : - Raw material - Preliminary experiments on reduced treatment time - Experiments on receiving unreplenished bactericide liquors : Results with SSF - Results with boric acid - Experiments on recycling replenished SSF liquors - Investigation of the "exhaustion" of recycled SSF liquors - Table 1 : Assessment of hide quality in unreplenished SSF liquor recycling experiments - Table 2 : Assessment of hide quality in unreplenished boric acid liquor recycling experiments - Table 3 : Assessment of hide quality in unreplenished boric acid liquor recycling experiments En ligne : https://drive.google.com/file/d/1xqamOshukt7PNwdxPWvhdu4ixPXuqhni/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34151 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

A simple approach to leather process investigation part 4 - The introduction of variants in the drying process / Ibrahim Elrufai abuelhassan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 159-177 Titre : A simple approach to leather process investigation part 4 - The introduction of variants in the drying process Type de document : texte imprimé Auteurs : Ibrahim Elrufai abuelhassan, Auteur ; A. G. Ward, Auteur ; S. Wolstenholme, Auteur Année de publication : 1984 Article en page(s) : p. 159-177 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Séchage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Details of the Modified Standard Process (MSP) for the controlled experimental production of side upper leather have been recorded in Part 3 (J. Soc. Leather Technol. Chem., 1984, 68, 125). The present part of the investigation examines the drying stage of the experimental procedure. MSP leather is dried, in the standard operation, using free hanging for the first drying and toggle drying for the second stage. The consequences of using different air temperatures and humidities for each of the two stages have been investigated. Leather produced using higher air temperatures for both drying stages was shown to differ from MSP leather in some properties. In particular, the leather has a tighter break but a firmer temper. Much more marked changes resulted from the use of paste drying, toggle drying or vacuum drying in place of free hanging for the first stage of drying. These first stage drying techniques were combined with the use of vacuum drying for the second stage. The leather dried initially either by paste drying or by toggle drying showed a coarser break, firmer temper, poorer grain quality and lower cutting value than the leathers dried initially by free hanging or vacuum drying. The differences were further shown in the physical tests, where the lastometer distension at grain crack was unacceptably low for the paste and toggle dried leathers and was reduced (to some degree) even for the vacuum dried leather, in comparison with free hanging. A limited study was made of the effect of the slicking direction, before paste drying, on the resulting leather properties. Only a small effect was noticed, the statistical significance of which could not be fully established. The study of how to improve the adversely affected properties of the paste dried leathers is described in Part 5, J. Soc. Leather Technol. Chem. (awaiting publication). Note de contenu : - INTRODUCTION : Variation of operating conditions using MSP drying procedures - Variation of the methods of drying - Variation of slicking direction in paste drying - THE DRYING OPERATION : Free-hanging - Toggling, nailing - Paste-drying - Vacuum drying - Non-vacuum conduction drying - EXPERIMENTAL METHODS : Samming-setting - Drying-free-hanging and toggling - Drying-Paste drying - Slicking out - Drying-Vacuum drying - Methods used for control during drying - Terst methods for the final leathers - Statistical techniques and experimental planning - PROCEDURES FOR PREPARING PACKS 5-10 : Packs 5 and 6, drying conditions experiment 1 - Pack 7, drying conditions experiment 2 - Packs 8 and 9, drying methods experiment - Pack 10, slicking direction in paste drying experiment - EXPERIMENTAL RESULTS AND DISCUSSION : Drying conditions, experiment 1, packs and 6 - Drying conditions, experiment 2, pack 7 - Packs 8 and 9, drying and methods experiments - General observations - Slicking direction in paste drying experiment, pack 10 En ligne : https://drive.google.com/file/d/1aacM-aFOH_q0yrFh5sCdNDtgDHjfz3ac/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34152 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The manufacture of leatherboard / Duncan Ferguson in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) Titre : The manufacture of leatherboard Type de document : texte imprimé Auteurs : Duncan Ferguson, Auteur Année de publication : 1984 Langues : Anglais (eng) Catégories : Cuir -- Déchets Cuirs et peaux -- Déchets -- Recyclage Panneaux de fibres Procédés de fabrication Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In basic terms, leatherboard is made by extracting fibres from scrap leather, treating those fibres with chemicals and binders, adding copious amounts of water to make a slurry, floating the slurry on to a wire gauze, allowing the water to drain off and then drying out the resulting sheet of matted fibres—which is the leatherboard. This process was developed from the principles of paper-making to which it still bears a close resemblance. Note de contenu : - Raw materials - The process : The batch process - The continuous Fourdrinier process - Drying En ligne : https://drive.google.com/file/d/11tO4OeY4sQY9ij--ujp1sQY2imv-em_-/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34153 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The complex ions in basic chromium sulphate solutions : a short note / Stanley G. Shuttleworth in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 180 Titre : The complex ions in basic chromium sulphate solutions : a short note Type de document : texte imprimé Auteurs : Stanley G. Shuttleworth, Auteur Année de publication : 1984 Article en page(s) : p. 180 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Composés complexes Conductimétrie Ions complexes Liqueurs de tannage Solutions (chimie) Sulfate de chrome Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Conductimetric titrations of freshly boiled, concentrated, one-third basic chromium sulphate tanning liquors (S02 reduced dichromate), showed that the average or predominant complex was probably a dimer, in which two chromium atoms are linked in ring formation with two OH groups, and two sulphate groups are bidendately bound to this complex. It was suggested that both of these sulphates formed part of the ring structure, but Slabbert considers this to be unlikely due to the fact that bond angles would be strained. En ligne : https://drive.google.com/file/d/1Dsil0lFMc5wMY9eD1qWAr5OA1S85hU_l/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34154 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
007131	-	Périodique	Bibliothèque principale	Documentaires	Disponible