Made available in DSpace on 2014-10-09T12:53:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:31Z (GMT). No. of bitstreams: 0 / Tubos de cobre fabricados com o material ASTM C12200 (99,9%Cu-0,015-0,040%P) são utilizados mundialmente no transporte de água potável. A maior causa de vazamentos nestas tubulações é a corrosão por pite, que usualmente estão relacionadas com a qualidade da água. Estudos recentes mostraram que vazamentos em tubos de cobre usados para transporte de água de rede pública ocorreram em decorrência da corrosão por pite, o que se deu em virtude da presença do íon cloreto originado do tratamento para a desinfecção da água. Outro parâmetro que pode influenciar a corrosão por pite é a condição de acabamento interno dos tubos. Os óleos lubrificantes usados no processo de fabricação de tubos de cobre contêm carbono e este forma um filme deletério após o recozimento destes tubos. Este filme cria condições na superfície interna para a formação de pilhas de ação local. O objetivo deste trabalho é investigar se o teor de cloreto de sódio no meio aquoso, e o acabamento superficial da superfície interna de tubos de cobre utilizados comercialmente para transporte de água (ABNT/NBR-13206), têm influência na resistência à corrosão destes tubos. A resistência à corrosão foi investigada por meio de ensaios eletroquímicos em soluções naturalmente aeradas com várias concentrações de cloreto de sódio, a 25 oC. A superfície interna dos tubos foi observada, antes e após os ensaios eletroquímicos, por microscopia eletrônica de varredura (MEV). Os tipos de acabamentos superficiais estudados foram: desengraxamento, jateamento e acabamento do processo final de fabricação (sem tratamento). Foi também construído um circuito fechado para estudar o efeito do acabamento superficial na resistência à corrosão sob condições mais próximas das encontradas na prática. O efeito do tratamento de recozimento do tubo em atmosfera inerte, que causa a recristalização da microestrutura e eliminação dos resíduos de óleo lubrificante, também foi avaliado. Os resultados indicaram que o mecanismo de corrosão em soluções com teores de cloreto entre 0,06 mol L-1 e 0,12 mol L-1 correspondeu ao de ataque localizado, enquanto que para a concentração de 0,6 mol L-1 prevaleceu o ataque generalizado. Os resultados do estudo do efeito do acabamento superficial indicaram que os tratamentos que reduzem o teor de carbono na superfície são benéficos à resistência à corrosão, mas este não é o único fator que afeta a resistência à corrosão. Outras características superficiais resultantes do tratamento da superfície também devem ser consideradas. Por exemplo, embora o jateamento cause a diminuição do teor de carbono na superfície dos tubos, o aumento de rugosidade produzido por este acabamento pode resultar em uma menor resistência à corrosão. Os tratamentos superficiais que produziram superfície com maiores resistências à corrosão foram aqueles que também produziram superfícies com menores teores de carbono, a saber, desengraxe e recozimento. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

O presente estudo avaliou a influência do hipoclorito de sódio a 1% e 2,5% na qualidade do acabamento superficial e na resistência à corrosão de duas limas endodônticas: Race® e Hyflex® através de ensaio eletroquímico de polarização potenciodinâmica cíclica (EPPC) e imagens obtidas por microscopia eletrônica de varredura (MEV). Para o EPPC foram utilizados vinte limas de cada marca comercial (#25, conicidade 0.04 e 25 mm de comprimento). Dez dos vinte instrumentos foram individualmente fixados pelo cabo a uma ponta de fio de cobre 0,12 mm de 20 cm de comprimento e posicionado no interior de uma célula eletroquímica com 500 mL de solução de hipoclorito de sódio (NaClO) 1% (Fórmula&Ação) à temperatura ambiente controlada em 23 ºC (±2) até cobrir a parte ativa do instrumento. Os registros foram feitos com o potenciostato da PAR modelo 273A. O ensaio foi repetido nos mesmos padrões para as outras dez limas da mesma marca comercial com o NaClO 2,5%. Além do EPPC, as limas foram submetidas a exames e análises em MEV antes e depois do teste de corrosão para a obtenção de fotomicrografias dos 3 (três) mm finais de cada lima com o intuito de estabelecer parâmetros para a avaliação final. Das fotomicrografias obtidas, 72 foram escolhidas, inseridas no Power Point sem legenda original de identificação, numeradas aleatoriamente para avaliação e projetadas num monitor para 06 avaliadores orientados e calibrados. Os dados obtidos foram tabulados e submetidos aos testes estatísticos pertinentes (Friedman, Wilcoxon e Mann-Whitney). A lima Hyflex® apresentou uma quantidade maior de alterações superficiais (ranhuras, manchas e materiais depositados) antes e depois do ensaio sendo mais suscetível à corrosão. Race® apresentou uma superfície mais polida e regular. Em relação a concentração do NaClO, percebeu-se que os defeitos presentes se tornavam mais evidentes para a concentração maior (2,5%). Nas duas concentrações os itens que apresentaram diferença significativa foram bordas, ranhuras, microcavidades, rebarbas e material depositado. Concluiuse que o acabamento superficial e a concentração da solução de NaClO influenciam a resistência à corrosão dos instrumentos de NiTi. A lima Race® apresentou menor corrosão e melhor acabamento de superfície do que a lima Hyflex® nas condições experimentais testadas. / The present paper evaluated the influence of 1% and 2.5% sodium hypochlorite in the quality of the surface finishing and resistance to corrosion of two endodontic files: Race® and Hyflex® by electrochemical test of cyclic power dynamics polarization (EPPC) and images obtained by scanning electronic microscopy (SEM). Twenty files of each commercial brand (#25, 0.04 taper and 25 mm length) were used in EPPC. Ten from the twenty instruments were individually fixed by the handle to a copper wire tip (0.12 mm diameter and 20 cm length) and placed in the interior of an electrochemical cell with 500 mL sodium hypochlorite solution (NaCIO) 1% (Fórmula e Ação) at the environment temperature controlled in 23ºC (±2) until covering the active part of the instrument. Recordings were made with a PAR potentiostat model 273A. The test was repeated in the same pattern to the other ten files from the same commercial brand with NaClO 2.5%. Besides EPPC, the files were submitted to the scanning electronic microscopy (SEM) test before and after the corrosion test to obtain photomicrographs of the final 3 mm of each file in order to establish the parameters for final evaluation. From the obtained photomicrographs, 72 were chosen and inserted in the Power Point without the original identification legend, randomly numbered for evaluation and projected on the screen to the 06 guided and calibrated evaluators. Data obtained were tabbed and submitted to the relevant statistical tests (Friedman, Wilcoxon and Mann-Whitney). The Hyflex® file showed a higher amount of surface alterations (grooves, stains and deposited materials) before and after the test, being more susceptible to corrosion. Race® showed a more polished and regular surface. As to the NaClO concentration, it was seen that the present defects became more evident in the higher concentration (2.5%). In the two concentrations, the items that presented significant differences were edges, grooves, micro cavities, margins and deposited materials. Conclusion was that surface finishing and the concentration of the NaClO solution influenced the resistance to corrosion of NiTi instruments. The Race® file showed the least corrosion and the best surface finishing compared to the Hyflex® file under the tested experimental conditions.

Orientador: Anselmo Eduardo Diniz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T18:33:44Z (GMT). No. of bitstreams: 1 Aguiar_MarceloMendesde_M.pdf: 3795090 bytes, checksum: a76ee2a93e8e7595881459d7a6d71b50 (MD5) Previous issue date: 2012 / Resumo: Normalmente, a utilização de aços ferramenta endurecidos, juntamente com as formas complexas típicas das peças utilizadas na área de moldes e matrizes, oferecem dificuldade na usinagem por fresamento, principalmente nas operações de acabamento que exijam o uso de ferramentas longas. A técnica de fresamento HSM (High Speed Machining - usinagem em altas velocidades, ou ainda High Speed Milling - fresamento em altas velocidades) tem se tornado uma alternativa para realizar este tipo de usinagem, reduzindo, ou às vezes até eliminando operações de eletro-erosão e polimento. Tipicamente, as fresas de pastilhas de metal duro intercambiáveis tem sido usadas em operações de desbaste e semi-acabamento, enquanto nas operações de acabamento ou em usinagem de geometrias que exijam ferramentas com pequenos diâmetros ainda predomina o uso de fresas inteiriças. O objetivo principal deste estudo é avaliar a influência de cinco variáveis de processo de fresamento com alta velocidade de corte, sobre o acabamento da superfície usinada. A influência do desgaste das ferramentas sobre o acabamento superficial, ao longo de 400 minutos de usinagem, também foi avaliado, além de uma comparação entre ferramentas inteiriças de metal duro e ferramentas de pastilha intercambiável montada em corpo de metal duro, a fim de avaliar a viabilidade técnica do uso deste segundo tipo de ferramenta, em substituição às tradicionais fresas inteiriças utilizadas em operações de acabamento. Na maioria dos experimentos realizados, pequenos valores de rugosidade foram mantidos, demonstrando que operações de acabamento em aço ABNT H13 IM com dureza de 50 HRC é possível com vida longa de ferramenta, mesmo utilizando-se valor de 500 m/min para velocidade de corte. Além disto, a análise da influência das variáveis de processo utilizadas neste trabalho mostrou que é possível, sob algumas condições, utilizar tanto ferramentas inteiriças, quanto de pastilha intercambiável montada em corpo de metal duro em operações de acabamento / Abstract: Typically, the use of hardened tool steels, along with complex shapes typical of the parts used in the field of molds and dies, offer difficulty in machining by milling, mainly in finishing operations that demand the use of long tool. The HSM (High Speed Machining or High Speed Milling) has become a possible alternative for making this type of machining, reducing, or sometimes eliminating electric discharge machining and polishing operations. Usually, indexable carbide insert mills has been used for roughing and semi-finishing, while in finishing operations or when the machining geometries that require tools with small diameters the integral tools are used yet. The main objective of this study is to evaluate the influence of five process variables, with high cutting speed, on the finish of the machined surface. The influence of tool wear on surface finish through 400 minutes of milling was also evaluated, as well as a comparison between integral carbide mills and indexable insert mounted at cemented carbide toolholder endmills, in order to evaluate the technical feasibility of using this second type of tool, replacing the traditional integral carbide endmills used in finishing operations. In most experiments, small roughness values were maintained, showing that finishing operations on AISI H13 IM with a hardness of 50 HRC is possible with long tool life, even using the cutting speed of 500 m/min. Furthermore, the analysis of the influence of process variables used in this study showed that is possible, under some conditions, the use either integral carbide tools, or indexable insert mounted at cemented carbide toolholder endmills on finishing operations / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Made available in DSpace on 2014-08-20T14:38:50Z (GMT). No. of bitstreams: 1 Tese_Clovis_Jose_Cardoso_de_Avila.pdf: 2746145 bytes, checksum: 62c7ab08eaaea53ed524a1d6314c3fd7 (MD5) Previous issue date: 2010-05-30 / The study was conducted in two distinct properties located in the region of Serra do Sudeste, Rio Grande do Sul, Brazil: counties of, Pedras Altas and Arroio Grande. The overall objective was to evaluate the possibilities of increased production of lamb meat quality by using alternative methods to increase productivity and the effect of three finishing systems and sex on growth and development of lambs. In the first study 74 sheep were used from the cross of Corriedale and Texel rams and three Poll Dorset breed. The animals were kept on ryegrass pasture and native grassland, and supplemented daily with a mixture of soybean hulls and corn in amounts determined according to the availability of forage and the needs of each category. The sheep were subjected to the male effect and exposed to artificial reduction of photoperiod and later synchronization, needed in times (December and August). Fixed mating season was and response to the rate of estrus. The rates of estrus observed in this study show no significant difference (P <0.05) between the periods studied in the first service. However following the a second mating of sheep, differences were observed, where at the time of June a lower rate of expression of estrus (80%) was obtained. It is concluded that the use of management with the control of photoperiod in times of mating unconventional causes estrus rates over time traditionally used. In the second stage were used 90 x Corriedale lambs Texel, and 45 non-castrated males and 45 females divided into three finishing systems lamb with mother grazing (CMPN); lamb weaned, grazing (CDPN), lambs weaned, grazing supplemented with soybean hulls to 1% body weight (CDPNS). The slaughter criterion was 2.0 to 3.0 corporal condition. The effect of sex was higher in males for Initial Weight, GPTotal, GmdTotal, weight at 100 days, GP 70-100, Gmd70-100, weight at 120 days, anterior height, back Height, body weight, HCW, skin, full green guts, legs, head, heart, lung + trachea., liver vesicle., bladder and kidneys, for the female sex was higher for internal fat and fat-renal pelvic in percentages. The treatment effect was manifested to GmdTotal, GP 70-100, Gmd70-100, GP 100-120, 100-120 ADG, heart, internal fat and pelvic renal fat and percentages for HCW and full green guts. / O estudo foi realizado em duas propriedades distintas situadas na região da Serra do Sudeste, no Rio Grande do Sul, no município de Pedras Altas e no município de Arroio Grande. O objetivo geral foi avaliar as possibilidades de aumento de produção de carne ovina de qualidade, utilizando métodos alternativos de incremento de produtividade e o efeito de três sistemas de terminação e sexo no crescimento e desenvolvimento de cordeiros. Na primeira parte foram utilizando 74 ovelhas provenientes do cruzamento das raças Corriedale e Texel e três carneiros da raça Poll Dorset. Os animais foram mantidos em pastagem de azevém e campo nativo, além de serem suplementadas diariamente com uma mistura de casquinha de soja e milho em quantidades determinadas conforme a disponibilidade de forrageira e as necessidades de cada categoria. As ovelhas foram submetidas ao efeito macho e expostas à redução artificial do fotoperíodo e posterior sincronização, nas épocas necessárias (dezembro e agosto). Foi utilizado como efeito fixo a época de acasalamento e como variável resposta a taxa de estro. As taxas de estro observadas neste estudo mostram que não houve diferença significativa (P<0,05) entre as épocas estudadas no primeiro serviço, no entanto após o repasse dos carneiros, foi observada diferença, onde na época de junho foi obtida menor taxa de manifestação de estro (80%). Conclui-se que o uso do manejo com o controle do fotoperíodo nas épocas de acasalamento não convencionais provoca taxas de estro superiores à época tradicionalmente utilizada. No segundo momento foram utilizados 90 cordeiros Texel x Corriedale , sendo 45 machos não castrados e 45 fêmeas separados em três sistemas de terminação cordeiro com a mãe, mantidos em pastagem (CMPN); cordeiro desmamado, mantidos em pastagem (CDPN); cordeiro desmamado, mantidos em pastagem com suplementação com casca do grão de soja a 1% peso corporal (CDPNS). O critério de abate foi à condição corporal 2,0 - 3,0. O efeito do sexo se superior nos machos para Peso Inicial, GPTotal, GmdTotal, Peso 100 dias, GP70-100, Gmd70-100, Peso 120 dias, Altura do Anterior, Altura do Posterior, Peso corporal, PCQ, Pele, Vísceras Verdes Cheias, Patas, Cabeça, Coração, Pulmão+traq., Fígado+Vesic., Bexiga e Rins, para as fêmeas o sexo se manifestou superior para gordura interna e Gordura Pélvico-renal em valores percentuais. O efeito do tratamento se manifestou para GmdTotal, GP70-100, Gmd70-100, GP 100-120, Gmd 100-120, Coração, Gordura interna e Gordura Pélvico-renal e para valores percentuais para PCQ e V.Verdes Cheias.

Doctor of Philosophy / Department of Animal Sciences and Industry / Michael D. Tokach / Eleven experiments using 5,434 growing-finishing pigs were performed in addition to the development of a model to predict dietary NE that yields the greatest economic benefit. Two experiments were conducted to determine the effect of dietary phytogenics on growth and carcass performance of growing-finishing pigs. The addition of the combination of two phytogenics products (EOM 1+2) to diets improved ADFI, HCW, and carcass ADG. However, there was no evidence for treatment differences for growth or carcass performance in a second study. Two experiments were conducted to determine the effects of feeding high SID Trp:Lys ratios with and without Ractopamine HCl (RAC) on growth and carcass characteristics of finishing pigs. In Exp. 1, whereas increasing SID Trp:Lys ratio above 20% improved growth and carcass performance when diets contained RAC, pigs fed SID Trp:Lys ratios above 20% in diets without RAC had reduced growth and carcass performance. Contrary in Exp. 2, pigs fed increasing SID Trp:Lys in diet containing RAC did not provide further performance benefits. Three experiments were conducted to determine the optimum dietary SID Lys and CP concentrations in finishing pigs over 100 kg. The SID Lys requirement to obtain 100% of maximum response was 0.55 to 0.63% depending on the response variable. Growth and carcass performance was maximized in diets containing at least 12% dietary CP. Four experiments were conducted to determine the effects of SBM concentration and whether dEB, choline, or K are the reasons that performance is reduced when pigs over 100 kg BW are fed low CP diets. Performance was reduced as SBM concentration was reduced in the diet. Choline, K, and dEB do not appear to be the reason that performance is reduced when SBM concentration is decreased in low CP diets fed to pigs over 100 kg BW. A Microsoft Excel®-based model to predict the value of dietary NE that yields the greatest economic return to the production system was developed. Furthermore, a meta-analysis was conducted to incorporate the impact of NDF on carcass yield in the model.

The textile industry in South Africa is a significant contributor to the chemical load that public wastewater treatment plants have to process, and the discharge of toxic substances, especially to the aquatic environment. In order to address this issue at factory level, the processes at a textile plant, JMV Textiles were chosen for investigation into the possibilities of minimization of discharges of harmful substances into the environment. The study followed the principles of cleaner production, and the processes that were investigated and revised were: The conventional peroxide bleaching process employed a peroxide stabilizer that did not biodegrade easily. The bleaching process was changed, so that the prevailing conditions in the fabric and dyebath facilitated bleaching without the addition of peroxide stabilizer, and also reduced the alkali and energy requirements. Polyester‐viscose fabric was pretreated by bleaching with hydrogen peroxide, which seemed to be unnecessarily rigorous, because polyester and viscose, unlike natural fibres, are relatively clean and have good whiteness in comparison with natural fibres. The proposed alternate pretreatment was a scour with detergent and alkali. The pretreatment for all polyester‐cotton fabrics was also a hydrogen peroxide bleach. Due to the ability of medium and dark shades to mask the natural tint of cotton fibres, a simpler alternate pretreatment, consisting of an alkaline scour with sequestering agent, was trialled. An unacceptable proportion of the dyeings on polyester was rejected for dye‐stains and dye‐marks. A possible solution exploited the properties of using the finishing auxiliary chemical to alleviate dye‐stains and dye‐marks during the dyeing stage, instead of using the chemical after dyeing. The highly toxic carrier that was used to facilitate level dyeing of polyester fibres that had unacceptable variation in their dyeing properties, was replaced by a less toxic carrier. The formulation for dyeing polyester was simplified to eliminate the auxiliary chemicals that were not essential to the dyeing process. Pale reactive dyed shades on cellulose and polyester‐cellulose were washed off only with hot water instead of detergent. The revised procedures consequential to the study, offered significant environmental benefits by reducing the concentration and volume of effluent produced, substituting a highly toxic carrier with a less toxic one and saving energy and water. Implementation of the suggested changes also offered financial benefits. The management of the factory, however, accepted and implemented some changes, but wanted further investigations for others and a phased approach to the other suggested changes.

O objetivo deste trabalho foi avaliar o temperamento durante o período de confinamento através das análises das correlações entre três indicadores de temperamento (Escore de Reatividade, Velocidade de Fuga e Avaliação Qualitativa de Comportamento). Foram utilizados 124 bovinos machos inteiros, filhos de cruzamento de touros Angus e vacas Nelore, com peso vivo inicial médio de 286 kg &plusmn;14,2 e com idade média de 17 &plusmn;1 meses, alojados em currais de confinamento, com área de 25,8 m2 por animal, e disponibilidade de 6 m2 por animal de sombreamento artificial. O confinamento teve duração de 130 dias (18 dias de adaptação + 112 dias de experimento). Foi registrado o temperamento dos garrotes, por meio dos testes de Escore de Reatividade (ER), Velocidade de Fuga (VF) e Avaliação Qualitativa do Comportamento (QBA), durante o manejo de pesagem a cada 28 dias no tronco de contenção. Os dados de QBA foram analisados por duas variâncias distintas após transformação em arco seno raiz quando não normalizados, uma com efeito fixo de categoria de VF (lento, mediano, rápido) e outra com efeito fixo de ER, sempre considerando os efeitos de animais como medida repetida no tempo. Correlações de Spearman entre todos os parâmetros foram realizadas. O escore de reatividade na balança (ER) apresentou correlações positivas com as categorias de QBA \"atividade motora\", \"amedrontado\" e \"agitado\", enquanto que, para as categorias \"relaxamento\" e \"calmo\" houveram correlações negativas (r = -0,54 e r = -0,54). A velocidade de fuga apresentou correlação positiva (r = 0,57) com o escore de reatividade. A concentração de cortisol sérico apresentou correlação positiva com as categorias \"atividade motora\" (r = 0,42), \"amedrontado\" (r = 0,46) e, \"agitado\" (r = 0,50) e correlação negativa com \"relaxamento\" e \"calmo\", como esperado. Em relação ao escore de reatividade, houve correlação positiva com os níveis séricos de cortisol (r = 0,38). Houve diferença significativa entre os parâmetros de QBA, VF e cortisol nas classes de escore de reatividade, sendo as maiores médias encontradas na classe 4, para as categorias de QBA \"atividade motora\", \"amedrontado\" e \"agitado\", com médias de 3,46; 5,30 e 5,16, respectivamente, e de 2,16 para VF, e 4,17 para cortisol. Os três indicadores de temperamento estudados decresceram durante o período de confinamento. É possível concluir que as avaliações qualitativas de comportamento (QBA) se mostraram eficientes para um entendimento da relação entre os indicadores de temperamento (ER e VF) e os níveis de estresse (cortisol sérico). Os animais confinados apresentaram melhora no temperamento durante o período de confinamento, devido a um possível processo de habituação, através do manejo no tronco ou do convívio direto com os humanos envolvidos no manejo diário. / This study aimed to evaluate the temperament during the confinement period by analyzing the correlations between three temperament indicators (Reactivity Score, Flight Speed and Qualitative Behavior Assessment). A total of 124 male steers were used, crossbred Angus bulls and Nellore cows, with mean initial live weight of 286 kg &plusmn;14.2 and mean age of 17 &plusmn;1 months housed in confinement pens with an area of 25.8 m2 per animal, and availability of 6 m2 of artificial shading per animal. The confinement lasted for 130 days (18 days of adaptation + 112 days of experiment). It was recorded temperament of steers by means of Reactivity Score (RS), Flight Speed (FS) and Qualitative Behavioral Assessment (QBA) during weighing handling every 28 days in the Squeeze shut. The QBA data were analyzed by two distinct variances after transformation in a sine root arc when not normalized, one with fixed effect of FS category (slow, medium, fast) and another with fixed effect of RS, always considering the effects of animals as repeated measure in time. Spearman correlations among all parameters were performed. The reactivity score during weighing showed a positive correlation with the categories of QBA \"motor activity\", \"frightened\" and \"agitated\", whereas for the \"relaxation\" and \"calm\" categories there were negative correlations (r = -0.54 e r = -0.54). The flight speed showed a positive correlation (r = 0.57) with the reactivity score. Serum cortisol concentration was positively correlated with \"motor activity\" (r = 0.42), \"frightened\" (r = 0.46) and \"agitated\" (r = 0.50) and negatively correlated with \"relaxation\" and \"calm\" as expected. Regarding the reactivity score, there was a positive correlation with serum cortisol levels (r = 0.38). There was a significant difference between the QBA, FS and cortisol parameters in the reactivity score classes, with the highest averages found in class 4, for the QBA categories \"motor activity\", \"frightened\" and \"agitated\", with averages of 3.46; 5.30 and 5.16, respectively, and 2.16 for FS, and 4.17 for cortisol. The three temperament indicators studied decreased during the confinement period. It is possible to conclude that the qualitative evaluations of behavior (QBA) were efficient for an understanding of the relationship between the temperament indicators (RS and FS) and stress levels (serum cortisol). Confined animals presented improvement in temperament during the confinement period due to a possible habituation process, through trunk management or direct contact with the humans involved in the daily management.

Content: Air temperature and humidity are fundamental in the milling operation. There is a complicated correlation between air conditions and leather moisture that is practically impossible to predict in industrial process. Many important characteristics like softness, grain, pebble, yield depend on leather moisture. This patented system is the latest improvement in milling drums technology that keeps the leather cooler and allows a precise and optimal humidity control. Designed for soft, tight-grained leathers, especially from organic tannages and opened to a wide range of new operating conditions impossible with traditional machinery. The original new design makes the milling drum completely independent from the outside environment with many advantages: consistency over seasons, shorter transition time, energy savings. The original design is recognized by international patent, laboratory results on leather will be displayed during the presentation. Take-Away: The original new Cold Milling technology design makes the milling drum completely independent from the outside environment with many advantages: consistency over seasons, shorter transition time, energy savings. Nappa leather and all tight-grained leathers, especially organic tannaed, are beneficiary of this new technology.

Content: ZnO nanoparticles were developed by 1:2 ratios of Zinc sulphate heptahydrate and Sodium hydroxide by using precipitation method. The structure, morphology of ZnO nanoparticles were investigated by using XRay Diffraction, Scanning Electron Microscopy and Transmission electron Microscopy. X-Ray Diffraction confirms the formation and average crystallite size of ZnO nanoparticles. Scanning Electron Microscopy studies shows the ZnO nanoparticles were in spherical in structure. These ZnO nanoparticles were used in different ratios along with conventional finishing formulations and coated on the leather surface. The performance properties such as water fastness, rub fastness and flexing resistance were evaluated. Application of ZnO nanoparticles in leather finishing showed significant improvement in overall performance properties than conventional finishing formulations. XRD confirms the formation of ZnO nanoparticles (wurtzite structure) at 36.67° (101) plane and the particles size was in the range of 43 nm. SEM image shows that the particles are in the spherical structure wheras EDAX investigate the stoichiometry and chemical purity of the samples to confirm the presence of zinc and oxygen. Optimum quantity up to 2-5 g/L of the season of ZnO nanoparticle is desirable for upgrading the value of leathers by improving color fastness to water, rub fastness and flexing resistance (wet & dry) properties significantly in cationic (wet), NC lacquer emulsions and PU top coat dispersions in finishing formulations. Take-Away: Optimum quantity up to 2-5 g/L of the season of ZnO nanoparticle is desirable for upgrading the value of leathers by improving color fastness to water, rub fastness and flexing resistance (wet & dry) properties significantly in cationic (wet), NC lacquer emulsions and PU top coat dispersions in finishing formulations.

Content: Consumers perceive leather as a durable and natural product. To support this positive image, car manufacturers have set demanding performance profiles addressing wear, emissions and sustainable manufacture. Poor performance of auto leather becomes visible as the polymeric finishing coat wears off or cracks over time. Therefore ageing property is seen as a representative key performance parameter and is determined by checking how flexible and strong a polymer coating remains after leather has been exposed to light, heat and humidity for a given time. Ageing of leather is complex to determine and depends on various parameters and requires a full system approach . In a first step different type of crusts (wet-blue, wet-white) were prepared and finished with a standard polyurethane coating. It turned out that the selection of the right fat liquors and tanning agents as well as the presence of vegetable tannins play an important role. On top of this the effective use of proper protective chemicals like anti-oxidants is needed. In a second approach the polymer coating itself was studied and optimized with regard to aged flexing and abrasion. Parameters like polymer type, crosslinking, application technology, coating thickness and impact of additives were investigated and tested when applied on the best crust leathers selected from part 1 of this work. Results show that not only is the right selection of polymers critical but also so is the way the coat is being applied . Furthermore coating thickness greatly defines wear (abrasion), lightfastness and ageing properties. Additives like dulling agents, levelers, feel agents, waxes ,fillers although needed can weaken the integrity of the polymer matrix and consequently reduce physical and chemical fastness properties. This may also apply to a certain extent to protective additives such as anti-oxidants and UV stabilizers, but when used properly their advantages outweigh the potential disadvantages. As to application, special emphasis is given to transfer coating technology which can provide advantages in application and quality consistency but also with regards to fastness properties such as wear and ageing. Take-Away: - crust leather has a critical impact on performance of finishing coat of automotive leathers and requires careful selction of products and use of protective chemical - polymer selection and use of protective chemical play an important role for achieving good aged flexing performance - type of application of finishing coat on auto leather further determines the performance of coating