Natural and synthetic fibres improving tensile strength and elongation of paper products

The theory part of the Master’s thesis introduces fibres with high tensile strength and elongation used in the production of paper or board. Strong speciality papers are made of bleached softwood long fibre pulp. The aim of the thesis is to find new fibres suitable for paper making to increase either tensile strength, elongation or both properties. The study introduces how fibres bond and what kind of fibres give the strongest bonds into fibre matrix. The fibres that are used the in manufacturing of non-wovens are long and elastic. They are longer than softwood cellulose fibres. The end applications of non-wovens and speciality papers are often the same, for instance, wet napkins or filter media. The study finds out which fibres are used in non-wovens and whether the same fibres could be added to cellulose pulp as armature fibres, what it would require for these fibres to be blended in cellulose, how they would bind with cellulose and whether some binding agents or thermal bonding, such as hot calendaring would be necessary. The following fibres are presented: viscose, polyester, nylon, polyethylene, polypropylene and bicomponent fibres. In the empiric part of the study the most suitable new fibres are selected for making hand sheets in laboratory. Test fibres are blended with long fibre cellulose. The test fibres are viscose (Tencel), polypropylene and polyethylene. Based on the technical values measured in the sheets, the study proposes how to continue trials on paper machine with viscose, polyester, bicomponent and polypropylene fibres.

Eucalyptus pulp fibres as alternative reinforcement to engineered cement-based composites

This paper evaluates the advantages of using hardwood short fibre pulp (eucalyptus) as alternative to softwood long fibre pulp (pinus) and polymer fibres, traditionally used in reinforcement of cement-based materials. The effects of cellulose fibre length on microstructure and on mechanical performance of fibre-cement composites were evaluated before and after accelerated ageing cycles. Hardwood pulp fibres were better dispersed in the cement matrix and provided higher number of fibres per unitary weight or volume, in relation to softwood long fibre pulp. The short reinforcing elements lead to an effective crack bridging of the fragile matrix, which contributes to the improvement of the mechanical performance of the composite after ageing. These promising results show the potential of eucalyptus short fibres for reducing costs by both the partial replacement of expensive synthetic fibres in air curing process and the energy savings during pulp refining. (C) 2009 Elsevier B.V. All rights reserved.

Enzymatic biofinishes for synthetic textiles

Fundação para a Ciência e a Tecnologia, Grant SFRH/BPD/46515/2008. Jiajia Fu acknowledges the support of Jiangsu Provincial Natural Science Foundation of China (No. BK2012112) and the National Natural Science Foundation of China under Grant No. 3120113

Vaatetus- ja tekstiilimateriaalien ekologinen elinjakson hallinta Talousvarikon toiminnoissa

Tämän case -tutkimuksen tarkoituksena on kartoittaa tekstiili- ja vaatetusmateriaalien ekologista elinjakson hallintaa Talousvarikon toiminnoissa ja tutkimalla mahdollisuuksia soveltaa saatuja tuloksia. Talousvarikko on Puolustusvoimien Materiaalilaitoksen alainen järjestelmävastuuvarikko, jonka tehtävänä on varusmiesten ja kadettien vaatetuksen hankinta- ja ylläpitotoiminnot. Talousvarikko jakautuu neljälle paikkakunnalle. Hämeenlinnassa on hankinta-, hallinto- ja materiaaliosasto. Säkylässä, Mikkelissä ja Sodankylässä ovat vaatetuskorjaamot. Tekstiilimateriaalien elinkaariajattelussa tarkastellaan raaka-aineiden jaottelua ja maailman kuitutuotantoa. Tekstiilikuidut jaotellaan luonnon- ja tekokuituihin. Luonnonkuidut ovat pääosin luonnon raaka-aineita ja tekokuidut ovat synteettisesti valmistettuja. Tekstiilikuitujen- ja materiaalien vaikutus ekologiseen elinjakson hallinnan vaiheisiin on riippuvainen raaka-aineidenalkuperästä. Vaatetus- ja tekstiilimateriaalin elinkaari muodostuu tuotekehityksestä, hankinnasta, valmistuksesta, käytöstä, huollosta ja hylkäyksestä. Ekologista elinjakson hallintaa tarkastellaan materiaalivirta- ja elinkaarianalyysien kautta. Elinkaarianalyysin tarkastelu painottuu vaikutusluokkien arvottamiseen ja materiaalivirta-analyysissä tarkastellaan ainevirtoja ja sitä kautta jätteiden määrän vähentämistä. Joutsenmerkin valintakriteerien pohjana on aina tuotteiden elinkaarianalyysi. Joutsenmerkin valintakriteerien soveltaminen Talousvarikon toimintoihin vaatetus- ja tekstiilimateriaalin elinkaaren jokaisessa vaiheessa antaa mahdollisuuden lisätä ekologista elinkaaren hallintaa Talousvarikon toiminnoissa. Ympäristönäkökohtien huomioiminen tuotekehityksessä ja hankinnoissa antaa mahdollisuuden tehdä tilauksia / sopimuksia yhteiskuntavastuullisilta yrityksiltä huomioiden valmistuksen yhdeksi osaksi hankinta ja logistiikka pääprosessia.

Tailored Ion Imprinted Polymer Materials for the Preconcentrative Separation of Noble Metals

Tailored ion imprinted polymer materials for the preconcentrative separation of noble metals. This study deals with the synthesis, separation,characterization and analytical application of the noble metals especially palladium and platinum. Platinum group metals(PGM) are currently receiving world wide attention. This group include Palladium(Pt),rhodium(Rh), ruthenium(Ru), iridium(Ir) and osmium(Os).PGM are used as catalysts for a wide variety of hydrogenation, oxidation, isomerization,cyclization,dehydrogenation and dehalogenation reactions.The corrosion resistance of PGM enables them to use in jewellery,electrical and glass industries,extrusion of synthetic fibres,manufacture of laboratory utensils,dental and medical devices. This study clearly establishes selective recovery of platinum from other noble and transition elements.

Short Isora Fibre Reinforced Natural Rubber Composites

The present study deals with the short isora fibre reinforced natural rubber composites. In recent years there has been a tremendous advancement in the field of science and technology of short fibre reinforced polymer composites. The low density, high strength, high stiffness to weight ratio, excellent durability and design flexibility are the primary reasons for their use in many diversified fields such as air crafts, automobiles, marine industry etc. Compared to the various natural and synthetic fibres used as reinforcement for elastomer composites isora fibre is superior in many aspects. `Isora' is a natural lignocellulosic fibre which is easily available in South India especially in Kerala. The fibre is separated from the bark of the Helicteres isora plant by retting process. This fibre has excellent mechanical properties and is easily amenable to physical and chemical modifications. The study shows that composites with poor interfacial bonding tend to dissipate more energy than that with to interfacial bonding. The mechanical loss also can be related to interfacial bonding. The effect of chemical treatment of isora fibre on damping was also studied. Both in the low and high temperature region which indicates that this composite posseses low damping and hence good interfacial bonding characteristics. Hence these composites are better candidates for high damping applications. Composites with longitudinally oriented fibres showed high storage modulus than transversely oriented ones due to the effective stress transfer between fibre and matrix.

Isora Fibre Reinforced Polyester and Epoxy Composites

The aim of this investigation is to study the effectiveness of isora fibre as reinforcement material in short and long forms, for unsaturated polyester and epoxy resins.Studies on the optimization of fibre length and fibre loading of randomly oriented isora-polyester composite are described.The salient features of the alkali treatment of short isora fibre on the properties of randomly oriented isora-polyester composite are outlined in this thesis.The effect of surface modification of the hydrophilic isora fibre by different chemical treatments on the properties of randomly oriented isora-polyester composite is outlined.The properties of oriented and randomly oriented isora fibre reinforced epoxy composites with special reference to the effect of fibre loading are reported and also the dynamic mechanical properties ofthe oriented and randomly oriented isora-polyester and isora-epoxy composites are presented and the water absorption kinetics of oriented and randomly oriented isora-polyester composites and oriented isoraepoxy composites are given. The effect of hot air oven aging on the tensile and flexural properties of oriented isora-polyester and isora-epoxy composites are also reported in this thesis.

Materials for Fish Nets-Their Properties, Selection and Preservation

The properties of synthetic fibres vary with thc inherent physical characteristics of the basic raw materials used mode of preparation of yarns and method of construction of twines. Since the synthetic fibres as maufactured from polymers which are synthesized from simple chemical units, the qualities of man-made fibres can he influenced by the process of manufacture and certain modifications can even be introduced at the processing stage to meet any specific requirement to a certain extent. Hence, an elaborate study of the properties of fish not twines produced has been taken up with a view to determining their suitability for various types of fishing gear with particular reference to conditions prevailing in India.

Influence Of Additives On The Drain Down Characteristics Of Stone Matrix Asphalt Mixtures

In Kerala highways, where traditional dense graded mixtures are used for the surface courses, major distress is due to moisture induced damages. Development of stabilized Stone Matrix Asphalt (SMA) mixtures for improved pavement performance has been the focus of research all over the world for the past few decades. Many successful attempts are made to stabilize SMA mixtures with synthetic fibres and polymers. India, being an agricultural economy produces fairly huge quantity of natural fibres such as coconut, sisal, banana, sugar cane, jute etc.. Now- a -days the disposal of waste plastics is a major concern for an eco- friendly sustainable environment. This paper focuses on the influence of additives like coir, sisal, banana fibres (natural fibres), waste plastics (waste material) and polypropylene (polymer) on the drain down characteristics of SMA mixtures. A preliminary investigation is conducted to characterize the materials used in this study. Drain down sensitivity tests are conducted to study the bleeding phenomena and drain down of SMA mixtures. Based on the drain down characteristics of the various stabilized mixtures it is inferred that the optimum fibre content is 0.3% by weight of mixture for all fibre mixtures irrespective of the type of fibre. For waste plastics and polypropylene stabilized SMA mixtures, the optimum additive contents are respectively 7% and 5% by weight of mixture. Due to the absorptive nature of fibres, fibre stabilizers are found to be more effective in reducing the drain down of the SMA mixture. The drain values for the waste plastics mix is within the required specification range. The coir fibre additive is the best among the fibres investigated. Sisal and banana fibre mixtures showed almost the same characteristics on stabilization.

Compósitos híbridos: desenvolvimento de configuração e efeitos de umidificação

The advantage in using vegetable fibres in place of synthetic fibres such as glass fibre, for reinforcements in composites are: biodegradability, low cost, low density, good tenacity, good thermal properties, low energy content and reduced use of instruments for its treatment or processing. Even though, problems related to low mechanical performance of some of the natural fibres, has caused difficulty in their direct application in structural elements. The use of alternative materials like hybrid composites has been encouraged, thus trying to better the structural performance of the composites with natural fibres. This work presents a comparative study of the strength and stiffness of hybrid composites with orthopthalic polyester matrix reinforced with E-fibre glass, jute and curauá. The experimental part includes uniaxial tension and three point bending tests to determine the mechanical properties of the final product. The hybrid composite was manufactured in a local industry and was in the form of laminates. All the samples were projected to withstand the possible structural applications as reservoirs and pipes. CH (laminated hybrid composite with glass and curauá fibres). The results obtained show clearly the influence of the hybridization in all the types tested and indicate a good mechanical performance of the composite with glass/curauá fibres in relation to the composite with glass fibres. Aspects in relation to the interfaces glass/curauá composites besides the fracture characteristics for all loading types were also analysed

Desempenho mecânico de compósitos híbridos de fibras naturais e poliéster não saturado

With the objective to promote sustainable development, the fibres found in nature in abundance, which are biodegradable, of low cost in comparison to synthetic fibres are being used in the manufacture of composites. The mechanical behavior of the curauá and pineapple leaf fibre (PALF) composites in different proportions, 25% x 75% (P1), 50% x 50% (P2) e 75% x 25% (P3) were respectively studied, being initially treated with a 2% aqueous solution of sodium hydroxide. Mechanical analyses indicated that with respect to studies of traction, for the combination of P1 and P3, better results of 22.17 MPa and 16.98 MPa, were obtained respectively, which are higher than that of the combination P2. The results of the same pattern were obtained for analysis of bending resistance where P1 is 1.21% and P3 represents 0.96%. In the case of resistance to bending, best results were obtained for the combination P1 at 49.07 MPa. However, when Young's modulus values were calculated, the values were different to the pattern of the results of other tests, where the combination P2 with the value of 4.06 GPa is greater than the other combinations. This shows that the PALF had a greater influence in relation to curauá fibre. The analysis of the results generally shows that in combinations of two vegetable fibers of cellulosic origin, the fiber which shows higher percentage (75%) is the best option than to the composition of 50%/50%. In the meantime, according to the results obtained in this study, in the case where the application should withstand bending loads, the better composition would be 50%/50%