A steady-state mathematical model for the stripping section of an industrial EPDM rubber production process was developed for a three-tank process, and two four-tank processes. The experiments that were conducted to determine model parameters such as equivalent radius for EPDM particles, as well as solubility and diffusivity parameters for hexane and ENB in EPDM polymer are described. A single-particle multiple-tank model was developed first, and a process model that accounts for the residence-time distribution of crumb particles was developed second. Plant data as well as input data from an existing steady-state model was used to determine estimates for the tuning parameters used in the multiple-particle, multiple-tank model. Using plant data to assess the model’s predictive accuracy, the resulting three-tank and four-tank process B models provide accurate model predictions with a typical error of 0.35 parts per hundred resin (phr) and 0.12 phr. The four-tank process A model provides less-accurate model predictions for residual crumb concentrations in the second tank and has an overall typical error of 1.05 phr. Additional plant data from the three- and four-tank processes would increase the estimability of the parameter values for parameter ranking and estimations steps and thus, yield increased model predictive accuracy. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-10-23 21:06:05.509

The steady growth of the rubber industry requires attention regarding the waste management and the methods applied in recycling and in the reclaiming processes. The ok in this thesis responds to the demand for an efficient recycle method for EPDM rubber waste. A solvent free chemical activation method to recycle EPDM rubber waste which provides high-quality recycled products, despite of the high amount of recycled particles used as a substitute of the raw material, was developed. The process needed to be both environmentally sustainable and applicable on an industrial scale without requiring special equipment. The final aim of this project was to use the activated particles in the production of seals and sealing systems on an industrial scale. In order to achieve this, the recycling of EPDM rubber waste particles by means of chemical activation using low molecular weight polymers (liquid polymers) was investigated. These liquid polymers are highly compatible with the waste rubber particles from the EPDM rubber and also suitable for sulphur vulcanisation. In comparison with other methods used for recycling of rubber and when considering environmental and economic aspects, chemical activation at the surface particle using low molecular weight polymers offers great recycling potential. In order to demonstrate the potential of the activated particles as a substitute for the raw material, aspects were investigated including: (1) characterization of the EPDM rubber waste particles; (2) optimization of the ratio between the waste rubber particles and the low molecular weight polymers; (3) investigation of the influence of various amounts of curing system; (4) study of the effect of the diene and ethylene percentage contained by the low molecular weight polymer used for activation of the particles; (5) investigation of the influence of the amount of activated particles used as substitute of the raw material; (6) study of the type of curing system used and (7) application of the process on an industrial scale.

The following report conducted with the collaboration of the University of Halmstad and HGFrubber company (Halmstad).The focus on the project is eliminating the dust particles from the inner surface of the EPDM basedrubber module.As a part of improving knowledge about the quality and surface finishing and understanding thematerial’s characteristics. This project initiated in February 2018 and end date was set to August2018.The methodology used in this project is based on the Six-Sigma tools which is widely appreciatedglobally to obtain the Zero-defect production.The implementations of this method and other tools are efficient and beneficial to reduce thedefects in the production without compromising the initial quality of the product.This thesis resulted in a quality improvement approach for eliminating the dust using methods suchas Six-Sigma and 5 why’s.

Made available in DSpace on 2016-12-08T15:56:17Z (GMT). No. of bitstreams: 1 Denilso Palaoro.pdf: 3446834 bytes, checksum: a842ffb16a48a459dc2b2e44efa303af (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The rubber industry has a great role in many areas of the economy, such as automotive, construction, footwear industry, hospital, etc. Rubber products are produced from complex mixtures of different raw materials, both natural and synthetic sources. From an industrial point of view, a major difficulty is to develop a formulation that meets the particular product requirements. This work seeks to develop an experimental methodology to obtain EPDM rubber compounds, using experimental design techniques coupled with computer numerical optimisation. A fractional factorial design was used to design and analyse the experiments, with factors the contents of calcium carbonate, paraffinic oil and vulcanizing accelerator (weight fractions). Twelve properties were measured (six of original samples, three of heat aged and three of processing). Statistical analyses enabled to find regression models for the properties and the cost of the formulation. A computer program was developed to minimise the cost function, subject to constraints on the properties. The results showed that it was possible to obtain formulations of EPDM rubber compounds which can be optimized at low cost, for example, of US$ 2.02/kg a 2.43/kg, for use in hoses and pads at different manufacturing processes such as compression moulding, transfer or injection. Selected compositions were analysed by FTIR, SEM and TGA, regards to their chemical and structural characteristics. Compositions with low vulcanization accelerator contents contribute to form cross-links with many sulphur- sulphur between the carbon chains which can damage mechanical properties in the original cured and aged samples. Using higher accelerator content, better properties are achieved probably due to lower content of the same sulphur- sulphur cross-links between polymer chains. The EPDM compounds studied may be used in cushions, hoses products which can withstand to hot air environments. Thus, the present study provides an experimental and scientific technique that allows developing rubber compounds with increased efficiency and reliability in research and development, taking into account the cost of the material. / A indústria da borracha possui um papel significativo em diversas áreas da economia, tais como: indústria automobilística, construção civil, indústria calçadista, hospitalar, etc. Artefatos de borracha são produzidos a partir de misturas complexas de diversas matérias-primas, naturais e sintéticas. Na indústria, uma grande dificuldade é desenvolver uma formulação que atenda aos requisitos de determinado produto. Assim, neste trabalho, busca se desenvolver uma metodologia experimental para obtenção de compostos de borracha de etileno propileno dieno (EPDM), utilizando-se técnicas de planejamento de experimentos aliado com otimização numérica computacional. Foi utilizado um planejamento fatorial fracionado 33-1 (três níveis e três fatores), sendo os fatores: teor de carbonato de cálcio, teor de óleo parafínico e teor de acelerador de vulcanização. Foram medidas no total, 12 propriedades (seis originais, três envelhecidas e três propriedades de processos). A partir de estudos estatísticos foram obtidos modelos de regressão para as propriedades e para o custo da formulação. Um programa computacional foi desenvolvido para minimizar a função custo, sujeita às restrições nas propriedades. Os resultados mostraram que foi possível obter formulações de compostos de borracha EPDM otimizadas a um custo variando entre US$ 2,02/kg a 2,43/kg, para aplicação em mangueiras e coxins e em processos de transformação diversos, tais como, moldagem por compressão, transferência ou injeção. Composições selecionadas foram escolhidas e analisadas, por meio de FTIR, MEV e TGA, quanto às suas características químicas e estruturais. Composições com baixos teores de acelerador de vulcanização contribuem para formar ligações cruzadas com cerca de 4 a 7 átomos de enxofre entre as cadeias carbônicas, prejudicando as propriedades mecânicas no vulcanizado original e envelhecido. Com um teor maior de acelerador, melhores propriedades são obtidas, tendo em vista que um número elevado de ligações cruzadas com uma quantidade de átomos de enxofre inferior a 4 na cadeia são formadas. Os compostos de EPDM estudados podem ser utilizados em produtos de coxins e mangueiras para aplicações resistentes ao calor. Assim, esta pesquisa apresenta uma metodologia experimental, para a pesquisa e desenvolvimento de compostos de borracha EPDM, levando em conta o custo do material e restrições nas propriedades.

L'objectif de cette thèse est l'étude des conséquences de la thermo-oxydation sur la structure chimique et le comportement mécanique d'un Ethylène Propylène Diène Monomère (EPDM). Afin de déterminer les modifications à différentes échelles structurales, quatre formulations modèles sont étudiées : la gomme pure, les matrices vulcanisées stabilisée et non stabilisée et l'élastomère industriel. L'ensemble des échantillons est vieilli entre 70 et 170°C dans l'air ou sous vide puis caractérisé par divers outils analytiques. La thermogravimétrie donne accès aux variations de masse résultant de l'incorporation d'oxygène et l'émission de composés volatils. L'analyse infrarouge permet de suivre les évolutions des espèces chimiques. Les essais de gonflement, de chromatographie et de spectrométrie mécanique permettent de calculer les nombres de coupures de chaînes et d'actes de réticulation à chaque instant. Sur la base de ces résultats, un modèle cinétique général de thermo-oxydation de la matrice EPDM est proposé et en partie validé. Les conséquences du vieillissement thermique sur le comportement mécanique de l'élastomère industriel sont mises en évidence par des essais de traction uniaxiale et de multi-relaxation à température ambiante et vitesse de déformation initiale de 10-3 s-1. L'impact du vieillissement thermique sur les propriétés ultimes et les réponses à l'équilibre et hors équilibre est examiné. Un critère prédictif de rupture basé sur la mécanique de la rupture est proposé. Enfin, le couplage vieillissement thermique - contrainte mécanique est étudié par des essais relaxation de contraintes continues entre 130 et 170°C dans l'air. Les modifications de la microstructure pendant le vieillissement thermique sont intégrées dans les équations constitutives du modèle mécanique macroscopique afin de proposer un outil de prédiction du comportement à long terme de l'élastomère industriel. La simulation numérique montre une bonne adéquation avec les résultats expérimentaux. / The aim of this work is to study the consequences of the thermal oxidation on the chemical structure and mechanical behavior of an Ethylene-Propylene-Diene Monomer (EPDM). In order to determine the structural changes at different scales, four model formulations have been considered: free additive gum, stabilized and unstabilized vulcanized matrix and industrial rubber. All samples were aged between 70 and 170°C in air or vacuum and characterized by several analytical tools. Thermogravimetry gives access to weight variations due to oxygen grafting and volatile compounds release. Infrared analysis is used to follow chemical species evolutions. Swelling tests, chromatographic and mechanical spectrometry tests allow calculating the number of chain scission and cross-linking events at any time. Based on these results, a general kinetic model is proposed and partially validated for EPDM matrix thermal oxidation. The consequences of thermal ageing on the mechanical behavior of the industrial rubber are pointed out by monotonic tensile and stress relaxation tests at room temperature and a 10-3 s-1- initial strain rate. The impact of thermal ageing on ultimate properties and equilibrium and non-equilibrium response are examined. Finally, the coupling between thermal ageing and mechanical stress is studied by continuous stress relaxation tests between 130 et 170°C in air. The microstructural modifications during thermal ageing are introduced into the constitutive equations of the macroscopic mechanical model in order to propose a predictif tool of the long time behavior of the industrial rubber. The numerical simulation is in good agreement with experimental results.