Desenvolvimento de têxteis técnicos para reforço de compósitos poliméricos

Materials denominated technical textiles can be defined as structures designed and developed with function to fulfill specific functional requirements of various industrial sectors as are the cases of the automotive and aerospace industries. In this aspect the technical textiles are distinguished from conventional textile materials, in which the aesthetic and of comfort needs are of primordial importance. Based on these considerations, the subject of this dissertation was established having as its main focus the study of development of textile structures from aramid and glass fibers and acting in order to develop the manufacture of composite materials that combine properties of two different structures, manufactured in an identical operation, where each structure contributes to improving the properties of the resulting composite material. Therefore were created in laboratory scale, textile structures with low weight and different composition: aramid (100%), glass (100%) and aramid /glass (65/35%), in order to use them as a reinforcing element in composite materials with polyester matrix. These composites were tested in tension and its fracture surface, evaluated by MEV. Based on the analysis of mechanical properties of the developed composites, the efficiency of the structures prepared as reinforcing element were testified by reason of that the resistance values of the composites are far superior to the polyester matrix. It was also observed that hybridization in tissue structure was efficient, since the best results obtained were for hybrid composites, where strength to the rupture was similar to the steel 1020, reaching values on the order of 340 MPa

Fabricação de eco-composito com a fibra de lã canina

The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. The fibers were characterized and made matting (non-woven). The phases of the project were consisted to develop methods and to convert these fibers (booster) blended with polyester resin (matrix) in different proportions (10%, 20% and 30%) at the composite. Were studied fiber characteristics, mechanical properties of the composites, water absorption and scanning electron microscopy. Initially, the fibers were treated with solution of sodium hydroxide of 0.05 mols, and then taken to matting preparing at the textile engineering laboratory - UFRN. The composites were made by compression molding, using an orthophthalic polyester resin as matrix and 1% MEK (methyl ethyl ketone peroxide) as initiator (catalyst). To evaluate the mechanical tests (tensile and flexural) and water absorption were made twelve specimens with dimensions 150x25x3 mm were cut randomly. According to the standard method, tensile tests (ASTM 3039) bending tests (ASTM D790) were performed at the mechanical testing of metals at laboratory UFRN. The results of these tests showed that the composite reinforced with 30% had a better behavior when exposed to tension charge; while on the three points bending test showed that the composite reinforced with 10% had a better behavior. In the water absorption test it was possible to see that the highest absorption happened on the composite reinforced with 30%. In the micrographs, it was possible to see the regions of rupture and behavior of the composite (booster / matrix)

Compósito Polimérico Híbrido: Comportamento Mecãnico, Descotinuidade Geométrica e Resistência Residual

The growing demand in the use of hybrid composite materials makes it essential a better understanding of their behavior face of various design conditions, such as the presence of geometric discontinuities in the cross section of structural elements. This way, the purpose of this dissertation is a study of the mechanical response (strength and stiffness), modes (characteristics) of fracture and Residual Strength of an hybrid polymeric composite with and without a geometric discontinuity in its longitudinal section (with a reduction in the cross section) loaded by uniaxial tension. This geometric discontinuity is characterized by central holes of different diameters. The hybrid composite was fabricated as laminate (plate) and consisting of ortho-tereftalic polyester matrix reinforced by 04 outer layers of Jute fibers bidirectional fabrics and 01 central layer of E-glass bidirectional fabric. The laminate was industrially manufactured (Tecniplas Nordeste Indústria e Comércio Ltda.), obtained by the hand lay-up technique. Initially, a study of the volumetric density of the laminate was made in order to verify its use in lightweight structures. Also were performed comparative studies on the mechanical properties and fracture modes under the conditions of the specimens without the central hole and with the different holes. For evaluating the possible influence of the holes in the structural stability of the laminate, the Residual Strength of the composite was determined for each case of variation in hole diameter. As a complementary study, analyses of the macroscopic final fracture characteristic of the laminates were developed. The presence of the central hole of any sizes, negatively changed the ultimate tensile strength. Regarding the elastic modulus, moreover, the difference found between the specimens was within the range of tests displacement, showing the laminate stability related to the stiffness

Influência da umidade nas propriedades mecânicas dos compósitos poliméricos híbridos (sisal/ vidro)

This study aims to evaluate the mechanical properties of polymer matrix composites reinforced with sisal fabric bidirectional tissue (Agave sisalana,) and E-glass fibers, containing the following configuration: a polymer matrix hybrid composite (Polyester Resin orthophalic) reinforced with three (3) layers of glass fibers and alternating-2 (two) layers of bidirectional sisal fabric, and finally a composite of polymer matrix reinforced with five (5) layers of glass fiber mat-type E. For this purpose as first step, the preparation of by sisal, since they are not on the market. The composites were made by manual lamination (Hand lay-up) and evaluated for tensile properties and three point bending both in the dry, and wet conditions aswele as immersed in oil. Macroscopic and microscopic characteristics of the materialsweve awalysed, after the completion of the mechanical tests. After the studies, it was proven that the sisal fiber decreases the tensile stiffness of the material above 50% for both situations studied the tensile strength of the material decreases by approximately 40% for the cases mentioned, and when compared to the specific strength stiffness values drop to 14.6% and 29.02% respectively for the dry state only. Constants for bending the values were are to approximately 50% to 25% for strength and stiffness of the material for the cases dry, wet and immersed in oil. Under the influence of tension fluids do not interfere in the stiffness of the material for the bending tests, the same does not occur with the resistance, and these values are modified only in the cases stiffness and flexural strength

Avaliação da estrutura de tecidos técnicos como elemento reforçante em compósitos poliméricos sistema poliéster isoftálico

Materials known as technical textiles can be defined as structures designed and developed to meet specific functional requirements of various industry sectors, which is the case in automotive and aerospace industries, and other specific applications. Therefore, the purpose of this work presents the development and manufacture of polymer composite with isophthalic polyester resin. The reinforcement of the composite structure is a technical textile fabric made from high performance fibers, aramid (Kevlar 49) and glass fiber E. The fabrics are manufactured by the same method, with the aim of improving the tensile strength of the resulting polymer composite material. The fabrics, we developed some low grammage technical textile structures in laboratory scale and differentiated-composition type aramid (100%), hybrid 1 aramid fiber / glass (65/35%) and hybrid 2 aramid fiber / glass (85/15% ) for use as a reinforcing element in composite materials with unsaturated isophthalic polyester matrix. The polymer composites produced were tested in uniaxial tensile fracture surface and it´s evaluated by SEM. The purpose of this work characterize the performance of polymer composites prepared, identifying changes and based on resistance to strain corresponding to the mechanical behavior. The objectives are to verify the capability of using this reinforcement structure, along with the use of high performance fibers and resin in terms of workability and mechanical strength; verify the adherence of the fiber to the matrix and the fracture surface by electron microscopy scanning and determination of tensile strength by tensile test. The results indicate that, in a comparative study to the response of uniaxial tensile test for tensile strength of the composites and the efficiency of the low percentage of reinforcement element, being a technical textile fabric structure that features characteristic of lightness and low weight added in polymer composites

Tubulações de PRFV com adição de areia quartzosa visando sua aplicação na indústria do petróleo

Fillers are often added in composites to enhance performance and/or to reduce cost. Fiberglass pipes must meet performance requirements and industrial sand is frequently added for the pipe to be cost competitive. The sand is added to increase pipe wall thickness, thus increase pipe stiffness. The main goal of the present work is to conduct an experimental investigation between pipes fabricated with and without de addition of sand, to be used in the petroleum industry. Pipes were built using E-glass fibers, polyester resin and siliceous sand. The fabrication process used hand lay up and filament winding and was divided in two different parts: the liner and the structural wall. All tested pipes had the same liner, but different structural wall composition, which is the layer where siliceous sand may be added or not. The comparative investigation was developed considering the results of longitudinal tensile tests, hoop tensile tests, hydrostatic pressure leak tests and parallel-plate loading stiffness tests. SEM was used to analyze if the sand caused any damage to the glass fibers, during the fabrication process, because of the fiber-sand contact. The procedure was also used to verify the composite conditions after the hydrostatic pressure leak test. The results proved that the addition of siliceous sand reduced the leak pressure in about 17 %. In the other hand, this loss in pressure was compensated by a stiffness increment of more than 380 %. MEV analyses show that it is possible to find damage on the fiber-sand contact, but on a very small amount. On most cases, the contact occurs without damage evidences. In summary, the addition of sand filler represented a 27.8 % of cost reduction, when compared to a pipe designed with glass fiber and resin only. This cost reduction combined to the good mechanical tests results make siliceous sand filler suitable for fiberglass pressure pipes

Avaliação mecânica e microestrutural de compósitos de poliéster com adição de cargas minerais e resíduos industriais

With the current growth in consumption of industrialized products and the resulting increase in garbage production, their adequate disposal has become one of the greatest challenges of modern society. The use of industrial solid residues as fillers in composite materials is an idea that emerges aiming at investigating alternatives for reusing these residues, and, at the same time, developing materials with superior properties. In this work, the influence of the addition of sand, diatomite, and industrial residues of polyester and EVA (ethylene vinyl acetate), on the mechanical properties of polymer matrix composites, was studied. The main objective was to evaluate the mechanical properties of the materials with the addition of recycled residue fillers, and compare to those of the pure polyester resin. Composite specimens were fabricated and tested for the evaluation of the flexural properties and Charpy impact resistance. After the mechanical tests, the fracture surface of the specimens was analyzed by scanning electron microscopy (SEM). The results indicate that some of the composites with fillers presented greater Young s modulus than the pure resin; in particular composites made with sand and diatomite, where the increase in modulus was about 168 %. The composites with polyester and EVA presented Young s modulus lower than the resin. Both strength and maximum strain were reduced when fillers were added. The impact resistance was reduced in all composites with fillers when compared to the pure resin, with the exception of the composites with EVA, where an increase of about 6 % was observed. Based on the mechanical tests, microscopy analyses and the compatibility of fillers with the polyester resin, the use of industrial solid residues in composites may be viable, considering that for each type of filler there will be a specific application

Estudo da incorporação de resíduo industrial polimérico ao CAP

This work presents the incorporation of an industrial polymeric waste into a petroleum asphalt cement with penetration grade 50-60 (CAP 50-60). The main goal of this research is the development of a polymer-modified asphalt, with improvements in its physical properties, in order to obtain a more resistant material to the traffic loads. Furthermore, the use of this polymeric waste will result in economic and environmental benefits. The CAP 50-60 used in this research was kindly supplied by LUBNOR Lubrificantes e Derivados de Petróleo do Nordeste (produced in Fazenda Belém Aracati - Ceará) and the industrial polymeric waste was provided by a button manufacturer industry, located in Rio Grande do Norte state. This polymeric waste represents an environmental problem due to its difficulty in recycling and disposal, being necessary the payment by the industry to a landfill. The difficulty in its reuse is for being this material a termofixed polymer, as a result, the button chips resulting from the molding process cannot be employed for the same purpose. The first step in this research was the characterization of the polymeric waste, using Differential Scanning Calorimetry (DSC) Infrared spectroscopy (IR spectroscopy), and Thermogravimetric analysis (TGA). Based on the results, the material was classified as unsaturated polyester. After, laboratory experiments were accomplished seeking to incorporate the polymeric waste into the asphalt binder according to a 23 experimental factorial design, using as main factors: the polymer content (2%, 7% and 14%), the temperature of the mixture (140 and 180 oC) and the reaction time (20 and 60 minutes). The characterization of the polymer-modified asphalt was accomplished by traditional tests, such as: penetration, ring and ball softening point, viscosity, ductility and flash point temperature. The obtained results demonstrated that the addition of the polymeric waste into the asphalt binder modified some of its physical properties. However, this addition can be considered as a feasible alternative for the use of the polymeric waste, which is a serious environmental and technological problem.

Caracterização de Efluente Têxtil e Proposta de Tratamento

Textile industry deals with a high diversity of processes and generation of wastewaters with a high content of pollutant material. Before being disposed of in water bodies, a pre-treatment of the effluent is carried out, which is sometimes ineffective. In order to be properly treated, physical and chemical properties of the effluent must be known, as well as the pollutant agents that might be present in it. This has turned out to be a great problem in the textile industry, for there is a variety of processes and the pollutant load is very diversified. The characterization of the effluent allows the identification of most critical points and, as a consequence, the most appropriate treatment procedure to be employed, may be chosen. This study presents the results obtained after characterizing the effluent of a textile industry that comprises knitting, dyeing and apparel sections, processing mainly polyester/cotton articles. In this work, twenty samples of the effluent were collected, and related to the changes in production. From the results, a statistical evaluation was applied, determined in function of the rate of flow. The following properties and pollutants agents were quantitatively analysed: temperature; pH; sulfides; chlorine; alcalinity; chlorides; cianides; phenols; color; COD (Chemical Oxygen Demand); TOC (Total Organic Carbon); oil and grease; total, fixed and volatile solids; dissolved, fixed and volatile solids; suspended, fixed and volatile solids; setteable solids and heavy metals such as cadmium, copper, lead, chromium, tin, iron, zinc and nickel. Analyses were carried out according to ABNT NBR 13402 norm, based upon Standard Methods for the Examination of Water and Wastewater. As a consequence, a global treatment proposal is presented, involving clean production practices as contaminant load reducer, followed by conventional (biological) treatment

A produção das perdas dentárias: narrativas de usuários do SUS

For a complete comprehension of the effect of tooth loss is necessary to listen to the patients that have it. This study, of qualitative approach, investigate, in the dental history of users of SUS, listening to his/her experiences with the services of dental care, the reason that lead his/her to dental lost and the repercussion of this in his/her life. The collect of data was made by narrative interview, obeying to a pre-defined schema. The subjects interviewed were six (three of urban zone and three of rural zone), all of them were users of Family Health Units. The criterions of inclusion were the followings: the presence of tooth lost (total lost in both dental arch or in one of them, or partial lost in at least six elements in one of the arches); age between 25 and 59; male or female; to live in municipal district of São Tomé/RN or Natal/RN. Based on previous interviews was elaborated the odontological history of each patient. Such narratives, systemized in odontological history, were analyzed taking as base the studies of Souza71 and the proposal of Schutze, suggested for Jovchelovitch, Bauer34. The results show that toothache was the main reason for the search of odontological care. The patients confront the ache with home-made medicaments, allopathic ones, and searching for dental care. The searching for exodontics was stimulated for geographic access difficulties or for repressed demand, which as a result produced the aggravation of the lesions and the discredit in restoration s treatment. The self-care practice of tooth-brush with juá or toothpaste and the controlled ingestion of sugar was not sufficient to avoid dental lost. Guilty sentiments were identified in relation with lack of care with teeth. The acceptance of dental lost as a natural factor is an important motivation in lack of pain and in the belief that it was a simple part of life in old age. Life with dental prosthesis makes clear the difference between which was natural and which was unnatural, and difficulties with the prosthesis appeared. The limitation of the prosthesis in its functional aspect can be compensated by esthetic restitution, making possible smiling expression. Starting with this study and considering the high number of dental lost, mainly in low-rent population, which live with toothless limitations or bad-quality prosthesis which do not rehabilitate adequately, we suggested the realization of qualitative researches which include, also, another actors in heath care services such as professionals and administrators

Avaliação da desadaptação das selas de próteses parciais removíveis após 1 a 5 anos de uso

The non-adaptation of the removable partial prosthesis (RPP) base to fibromucosal tissue is caused by resorption of residual ridges (RRR). The onset of bone resorption, which occurs after tooth extraction and continues throughout life, is accelerated by local or systemic factors. Aim: Assess the degree of non-adaptation of removable partial prosthesis saddles and the factors that influence it. Methodology: A sectional study was conducted with 81 patients using RPP who had their prostheses installed between 2003 and 2007 (1 to 5 years of use) at the Faculty of Dentistry of the Universidade Federal do Rio Grande do Norte (UFRN). After anamnese and clinical examination, a cast was made with polyether-based material, using the base of the prosthesis to make the impression. The base of the saddle was loaded with the casting material and positioned in the mouth, applying pressure on the supports. After polymerization, the material was removed from the saddle and measurements were taken at 3 different points using a pachymeter. Results: The non-adaptation of the saddle increased significantly with years of use (p = 0.005). The tooth-tissue supported prostheses obtained higher mean non-adaptation values than those of tooth supported prostheses (p < 0.001). Flaccid mucosa showed the worst non-adaptation results, which were statistically different from resilient mucosa (p < 0.001). The greater the extension of the saddle, the greater the non-adaptation (p < 0.001). The natural tooth antagonistic arch yielded better results than did RPP and total prosthesis (p < 0.001). Saddle non-adaptation at the free end was less near the pillar tooth and greater in the more posterior region (p < 0.001). When adaptation of the supports to the niches was poor, greater saddle non-adaptation occurred than when it was good or fair (p < 0.001). Saddles located in the posterior region of the arch had greater non-adaptation than those in the anterior region (p = 0.023). Conclusion: The mean non-adaptation of the saddle to the residual ridges was 0.27 mm. It can be concluded that, even with the use of RPP, bone height reduction was slight within the 1-5-year period of use. The following are factors that influence adaptation of the RPP saddle base: years of use, age, force transmission path to the alveolar bone, location of the toothless area, antagonistic arch, type of mucosa, adaptation of supports to the niche and extension of the saddle

Avaliação clínica e comparativa da oclusão balanceada bilateral e desoclusão com guia canino sobre a função mastigatória de usuários de prótese total removível

The maintenance of masticatory function is especially important for patients who wear complete dentures due to the limitations of this type of prosthesis. Thus, the bilateral balanced occlusion (BBO) is used to achieve, besides other advantages, greater masticatory efficiency. However, analyzing critically the literature, it is observed that there is not enough scientific evidence that support the BBO as the most appropriate occlusal concept in complete dentures. This way, the purpose of the present study was to verify if complete dentures wearers with BBO present better masticatory efficiency and capacity than those with canine guidance (CG). A double-blind controlled crossover clinical trial was conducted. The sample was made of 24 completely edentulous patients. The subjects wore sets of complete dentures with both occlusal concepts for equal periods of 3 months. Objective data were collected through the masticatory efficiency test, performed by the colorimetric method, in which capsules of a synthetic material enclosing fuchsine- containing granules were used. Subjective data were recorded by patient´s ratings of their chewing function, which is the masticatory ability. No significant statistical difference was found for masticatory efficiency (p=0,0952) and masticatory ability (x2=0,5711/ p=0,4498) between the two occlusal concepts studied, as well as there was no correlation between these two variables (p=0,2985). Based on these results, it seems reasonable to use CG for the setup of complete dentures, since it is an easier and quicker technical procedure, until that future researches can come to complement this question

Caracterização do processo de trabalho do cirurgiãodentista na estratégia de saúde da família do município de Parnamirim-RN

Family Health Strategy (FHS), founded in 1994 has appeared to play a strategic role in the SUS construction and consolidation. It has reaffirmed its Principles and Guidelines and has elected family as core of attention. The principle that has guided the work concerns the quality of the relationship between professional and family. Thus, the FHS has the family as a subject of health-disease process, and relations with its own characteristics and can be partners in building their health and improvement of quality of life of its members and the entire community. This study aims to characterize the surgeon-dentist (SD) working process in the family health strategy, from the knowledge of the SD integration with other team members; organization of services; development of shares, changes perceived by SDs, as well as knowing the surgeon-dentist profile who is part of this strategy. The collecting tool used was a semi-structured questionnaire, in which participated 30 professionals. As for profile, most professionals were women, completed the graduation in public university and did not have any training to work by joining the FHS. Almost all have other public or private working ties. They often carry out activities with students, and occasionally do home visits. In relation to team work, in activities such as home visits, school health, community activities, among others, they sometimes seek the cooperation of other members. The way of accessing for users in the most part has occurred through the schedule. The most frequently activities made to the Centro Especialidades Odontológicas (CEO), are in Endodontics and Prosthesis. The majority of them participate in team meetings, but they do not have frequency set to happen. As for the planning and programming of activities to be conducted, most said that individually develops them. Concerning the performance of their duties, most reported being satisfied, but that improvements could happen. Besides, they reported improvements in dental care following the inclusion of SD in the FHS in various aspects, such as access, organization, humanization, care and oral disease prevention. The professionals had poor integration with other team members, in addition to have a profile to more individualistic work, a fact seized by way of development and planning of actions. They work the actions in individual and curative way, in detriment promotion and collective ones. They work humanization, definition of territory and adscript population. Thus, it is concluded that the working process developed by SDs, includes the part which is advocated by FHS. This points out to a greater undertaking of this process aiming to detect the weakness met in order to reach the potential that the FHS represents in organization of basic attention

Centros de especialidades odontológicas: avaliação da atenção de média complexidade na rede pública da Grande Natal

The Specialized Dental Care Centers (CEO) were developed to provide specialized dental care to the population, given the accumulated needs of health since the past. They must operate as units of reference for the Oral Health Team of the Primary Care, complementing the dental procedures performed at this level of attention. This study aims to assess the performance of CEOs of the Grande Natal Health Region as a strategy of Secondary Care consolidation in oral health through users, dentists and managers. For this to try to identify factors about access, hosting and satisfaction with the service, the actions developed in these centers, integration between the CEOs and the Basic Health Units (UBS), considering the reference and counter reference. Data were collected through semi-structured interview, conducted in four CEOs, among 253 users, 31 dentists and 4 managers. It was submitted to descriptive statistical analysis and to content analysis by software ALCESTE 4.5. The results revealed that the specialties of prosthesis, endodontics and surgery were the most sought by 38.2%, 23.7% and 21.7% of respondents, respectively. It was noticed that among users aged 18 to 30 years-old the greatest demand is for the specialty of endodontics (44.4%) and over 50 years for prosthesis (76.4%). There is a weakness in the reference and counter reference between UBS and CEO, because part of users goes directly to the centers without going before to the Primary Care and the majority does not want to return to the dentist of Health Unit. Satisfaction with care was reported by 90.9% of users, because they resolved the problems needed and were welcomed by the team. But the delay in care was the main factor for not satisfaction. For most dentists, some users could solve their problems completely in Primary Care, which shows the existence of unnecessary referrals to the CEOs, however they consider the existence of limiting factors in UBS that compromise the service. Most dentists revealed that some users do not get to CEOs with the basic dental treatment done, and some of them do not counter reference users. It can be concluded that the studied CEOs are being resolutive for those who access them, offering necessary care for the population, and if they don t account with this service, will encounter obstacles to resolution of problems, ranging seek care service in particular, in another public sector, or even giving up treatment. However, it is perceived the need of professionals training to understand the importance of the reference and counter reference, to that they can better serve and guide users. It is also important that cities offer better conditions to UBS and CEOs, so they can work together, with complementary actions of oral health, seeking full care, aiming for better resolution to the users' health problems

Satisfação dos usuários e qualidade dos tratamentos protéticos realizados nos centros de especialidades odontológicas da grande Natal RN

Aim: To evaluate user satisfaction and quality of prosthetic treatments performed in specialized dental clinics (CEOs) of Natal Metropolitan Region - RN. Methods: Cross-sectional study with subjects who underwent prosthetic CEOs in the cities of Natal, Macaíba, Parnamirim and Sao Goncalo do Amarante in the period 2007 to 2009. Data collection was performed by questionnaire, clinical examination of the oral cavity and examination of fabricated denture. This analysis involved the following aspects: retention, stability, aesthetics and prosthesis fixation. The variables are presented by means of absolute numbers and proportions. The determination of the association between the independent and dependent variables was conducted by the association of Chi-square test and Fisher exact test. Results: A total of 149 users, totaling 233 conventional dentures (148 upper and 85 lower). Most patients (56.4%) were rehabilitated with conventional complete dentures. The technical quality of the denture was regarded as satisfactory in the majority (52.7%), whereas the inferior dentures were rated as unsatisfactory in 90.5% of cases. Satisfaction with the prosthesis was 69.1% (N = 103). The average time to begin treatment was 3 months to receive while the prosthesis was 4 months old. The presence of injury from the upper prosthesis occurred in 21.5% of cases (N = 32), candidiasis being the most frequent (N = 18). The technical quality of the upper prosthesis (p=0,041), as well as retention (p=0,002) and stability (p<0,001) were significantly associated with user satisfaction. Conclusions: The specialized Dental clinics has been fulfilling its role of providing treatment of intermediate complexity for low-income population with the majority of satisfield patients, even when their dentures have problems of technical quality