1,721,004 research outputs found
New tanning agents
No full textNew tanning agents active in leather tanning and retanning, obtained from renewable materials
Tanning agents
No full textThe present invention refers to the use as tanning agents for animal pelts of known furan derivatives, which are not toxic and biodegradable, and to a tanning process economically sustainable and comprising a phase of treatment of the pelts directly with aqueous solutions comprising said furan derivatives, obtained by hydrolysis of a lignocellulosic biomass
Use of fleshings-derived collagen in chrome tanning process
Full text linkThe manufacturing process to transform hides into leather requires a series of chemical
and mechanical operations. Fleshings represent one of the most important byproduct of the leather
compartment. They are mainly constituted of raw collagen and through an alkaline hydrolysis a
collagenous solution is obtained. In this work, an experimental activity research was performed for
assessing the feasibility of the reuse of the collagen hydrolizate solution in the tanning phase. The
hydrolizate has been used in combination with chromium salts to obtain bovine upper leather up to
a dosage of 20% of solution (68% dry protein matter content) on the fleshed hide weight. Following
a laboratory scale screening of the optimal operating conditions, crust leathers have been obtained
on pilot scale. The final leather shows similar properties to those of the traditionally tanned leather
in terms of technical and mechanical properties. Furthermore, a dry tannage is feasible, thus
avoiding the production of effluents, and it is possible to adopt a retannage/dyeing/fatliquoring
characterized by a lower consumption of chemicals in comparison with the standard procedure. The
results obtained indicate the use of the collagen hydrolizate in the tanning phase as an interesting
route for valorisation of fleshings
Tannery wastewater sludge ash for the production of waterproofing membrane: a technical and environmental feasibility study
No full textSludge from tannery effluent treatment processes is a by-product of leather-making industry, in which chrome compounds are the most common used materials. The objective of this work was to investigate the effects and feasibility in the use of tannery sludge ash as a partial or total replacement of usual mineral filler such as in manufacture of waterproofing membranes. The effects of sludge ash on the morphology and mechanical properties of membranes were investigated. Leaching tests were carried out in order to guarantee that the fulfilment of “filler function” was done in respect with environmental criteria. Besides, a Life Cycle Assessment (LCA) analysis was performed in order to assess the environmental performances of the waterproofing membrane filled by tannery sludge ash in comparison with the conventionally filled membrane. The performances of the membranes and the results of environmental assessment indicate that tannery sludge ash may be used as total replacement of CaCO3 for waterproofing membranes
THERMOPLASTIC POLYMER COMPOSITION | [COMPOSITION POLYMÈRE THERMOPLASTIQUE]
No full textThe present invention relates in general to the field of thermoplastic polymeric materials, and more precisely it relates to novel thermoplastic; polymeric compositions defined better herein after that are useful for the manufacture, by hot melt extrusion, of biodegradable artefacts and packaging, compostable and having at the same time performances and costs comparable to those of the products obtained with the traditional non-biodegradable thermoplastic polymeric materials, such as the polyoleflns
Leather manufacturing by using treated municipal wastewaters
Full text linkLeather processing requires copious amounts of freshwater, approximately between 15 and 20 L per kg of raw hide. The possibility of reusing reclaimed municipal wastewaters in the leather production assumes a great significance, proving a sustainable solution to the conservation of the groundwater reserves. In the present work, a combination of a membrane bioreactor (MBR) and nanofiltration (NF) membrane processes was investigated for the municipal wastewater reclamation, and their performances were evaluated and designed to meet water quality criteria required by the wet stages of tanning process. The results showed that the municipal wastewaters treated by combing MBR and NF met the required quality criteria in terms of total/permanent hardness, Fe, Mn and ammonium contents. The quality of the leathers produced both on pilot and industrial scale using treated water did not show any significant difference in terms of physical and technical properties, and satisfied fully the tannery specifications
Studies on Mono and Divalent Cations Effects on Hair Immunization
No full textWithin the studies on the phenomenon of alkali-induced hair immunization, it has been observed that the hair immunization process arising from the action of dibasic alkalis takes place differently than immunization using monobasic alkalis. On the basis of these observations, our work investigated the influence of mono and divalent cations on the hair immunization mechanisms. In our experimental design, fresh salted bovine hides were exposed to mono and divalent alkalis and salts at different concentrations for various time periods. After treatment, the hides were exposed to reducing agents in order to verify the effectiveness of each cation in promoting immunization. We observed that immunization occurs with dibasic cations, but that both a minimum exposure time and a proper alkalinity are required. The appearance of inter and intra polypeptide chain links was investigated by comparing non-immunized and immunized hair using MIR and FIR spectroscopy, ICP chemical analysis and DSC. The chemical and the instrumental analyses indicate that the exposure of hair to divalent cations in alkaline medium, unlike the monovalent cations, induces the formation of cross-links in the keratin structure and promotes immunization. These investigations contribute to confirmation that the immunization process occurs only in the presence of divalent cations. Research work is in progress in order to further understand the nature and the mechanisms of these complex interaction
La metodologia LCA per la sostenibilità ambientale del processo conciario
No full textSecondo la definizione proposta dalla SETAC, la valutazione del ciclo di vita (dall’inglese Life Cycle Assessment, LCA) è un processo che permette di valutare i carchi ambientali associati ad un prodotto, processo o attività, identificando e quantificando i consumi di materia ed energia e le emissioni nell’ambiente. La metodologia si basa su un approccio sistematico secondo cui il prodotto, processo o servizio, è analizzato in ogni fase della sua vita, dall’estrazione e trasformazione delle materie prime, attraverso la produzione, il trasporto e l’utilizzo, fino al riciclo o allo smaltimento. Attraverso uno studio LCA è possibile individuare le fasi in cui si concentrano maggiormente le criticità ambientali di un processo produttivo e le informazioni necessarie per realizzare gli interventi di miglioramento. Si tratta pertanto di uno strumento adatto a perseguire iniziative di sviluppo sostenibile, permettendo di valutare, in un’ottica di bilancio complessivo del processo, gli impatti ambientali potenziali connessi all’introduzione di innovazioni tecnologiche o di processo in un ciclo produttivo. La metodologia LCA è stata quindi applicata al settore conciario per confrontare l’impatto ambientale della fase di depilazione tradizionale con un processo di depilazione innovativo, al fine di valutare se effettivamente le innovazioni introdotte implicano i benefici ambientali attesi
- …
