Insights into the Bead Fusion Mechanism of Expanded Polybutylene Terephthalate (E-PBT)

Expandable polystyrene (EPS) and expanded polypropylene (EPP) dominate the bead foam market. As the low thermal performance of EPS and EPP limits application at elevated temperatures novel solutions such as expanded polybutylene terephthalate (E-PBT) are gaining importance. To produce parts, individual beads are typically molded by hot steam. While molding of EPP is well-understood and related to two distinct melting temperatures, the mechanisms of E-PBT are different. E-PBT shows only one melting peak and can surprisingly only be molded when adding chain extender (CE). This publication therefore aims to understand the impact of thermal properties of E-PBT on its molding behavior. Detailed differential scanning calorimetry was performed on neat and chain extended E-PBT. The crystallinity of the outer layer and center of the bead was similar. Thus, a former hypothesis that a completely amorphous bead layer enables molding, was discarded. However, the incorporation of CE remarkably reduces the crystallization and re-crystallization rate. As a consequence, the time available for interdiffusion of chains across neighboring beads increases and facilitates crystallization across the bead interface. For E-PBT bead foams, it is concluded that sufficient time for polymer interdiffusion during molding is crucial and requires adjusted crystallization kinetics

National Educators' Workshop: Update 1989 Standard Experiments in Engineering Materials Science and Technology

Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 89, held October 17 to 19, 1989 at the National Aeronautics and Space Administration, Hampton, Virginia. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community

The Plastics Collection Reference Packet

This reference packet is an informational tool to support further research into the history of plastics—whether interested in companies, individuals within the plastics industry\u27s history, historical plastics materials, essays, and more. All content featured within this packet was previously published on the former plastics.syr.edu website as part of a Syracuse University Libraries and Special Collections Research Center (SCRC) partnership established in 2007 with the Plastics Pioneers Association (PPA)—an association of plastics industry professionals interested in preserving the plastics industry\u27s past

Re-use of adhesive and sealant residues from automobile industry

Orientadora: Profa. Dra. . Margarete Casagrande Lass ErbeCoorientador: Prof. Dipl.-Ing. Matthias RapfDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Mestrado Profissional em Meio Ambiente Urbano e Industrial, em parceria com o Serviço Nacional de Aprendizagem Industrial e a Universität Stuttgart. Defesa: Curitiba, 01/08/2018Inclui referências: p.74-80Resumo: O aumento do consumo de adesivos e selantes na indústria automobilística pode resultar em projetos mais ecológicos, seguindo a política de design mais leve, mas que tem a possibilidade de sobrecarregar o ambiente se houver quaisquer resíduos da aplicação e/ou limpeza. No entanto, ao escolher o plano correto de gerenciamento de resíduos, pode-se reduzir os efeitos adversos do lixo no meio ambiente, economizar recursos naturais e reduzir os custos. No presente estudo, respeitando à política de hierarquia de resíduos, optou-se por avaliar se é possível reutilizar os resíduos de adesivos e selantes não curados gerados por uma indústria automobilística localizada em Curitiba, Brasil, em outros destinos para qualquer produção de bens. Atualmente, a indústria automobilística envia seus resíduos para recuperação de energia em fornos de cimento (coprocessamento). Entretanto, encontrar uma opção de reutilização apresenta vantagens para a proteção ambiental e de recursos. Cumprindo esse objetivo, dois resíduos foram escolhidos para os estudos. Os resíduos foram classificados para avaliar se eram perigosos ou não e caracterizados por meio de análises físico-químicas. A base polimérica foi definida com o auxílio da espectroscopia FTIR. Na etapa seguinte, realizou-se uma pesquisa sobre diversos produtos poliméricos e seu processo de produção, a fim de encontrar destinos que tenham insumos brutos similares, com ingredientes significativos dentro dos resíduos estudados, além de verificar se os resíduos estariam totalmente curados após reutilizados no destino sugerido. Este último fator foi considerado como uma garantia para eliminar possíveis riscos à saúde ou ao meio ambiente que a reutilização dos resíduos poderiam causar. Foi recomendado o reaproveitamento dos resíduos estudados para a produção de produtos como pneus, principalmente pneus poliméricos sólidos; gaxetas de borracha para perfis de portas e janelas; esteiras e pisos; correias transportadoras; correias de transmissão e elevador; revestimento industrial; amortecedores e compósito com matriz polimérica. Palavras-chave: gerenciamento de resíduos, hierarquia de resíduos, reutilização, resíduos de adesivo, resíduos de selantes.Abstract: Increasing adhesive and sealant consumption in the automobile industry could result in environmentally friendlier designs by following the lightweight design policy, but it has the possibility to burden the environment if there are residues left over from the application and any cleaning. However, by choosing the right waste management plan, one can reduce the waste's adverse effects on the environment, save the resource and cut down on costs. In the present study, concerning the waste hierarchy policy, it was decided to assess, if it is possible to reuse the uncured adhesive and sealants residues generated by an automobile industry located in Curitiba, Brazil in other destinations for any goods production. At present, the automobile industry sends its residues for energy recovery in cement kilns (co-processing), however considering the waste hierarchy, finding a reuse option is more valuable regarding environmental and resource protection. To fulfill this goal, two residues were chosen for further studies. The physicochemical characteristics of the residues were analyzed to classify the residues and find out their possible hazards. The polymeric base of the residues was defined with the help of FTIR spectroscopy. In the next step, a bibliographic research about various polymeric goods and their production process was done in order to find destinations which have similar raw input materials as the significant ingredients within the studied residues, in addition to the existence of a possibility for the residues to become fully cured after being reused in the suggested destination. The latter factor was considered as a guarantee to eliminate any possible health or environmental risk that reusing the residues may cause. Reuse of the studied residues for production of products such as Tires, especially solid polymeric tires; rubber gaskets for door and window profiles; matting and flooring; conveyor belts; transmission and elevator belts; industrial lining; dampeners, and polymer matrix composite was recommended. Keywords: waste management, waste hierarchy, reuse, adhesive residue, sealant residue.ZUSAMMENFASSUNG Zunehmender Klebstoff- und Dichtstoffverbrauch in der Automobilindustrie könnte zu umweltfreundlicheren Designs führen, indem die Leichtbaupolitik befolgt wird, aber es hat die Möglichkeit, die Umwelt zu belasten, wenn Rückstände von der Anwendung und Reinigung zurückbleiben. Durch die Wahl des richtigen Abfallwirtschaftsplans können jedoch die negativen Auswirkungen des Abfalls auf die Umwelt verringert, die Ressourcen geschont und die Kosten reduziert werden. In der vorliegenden Arbeit wurde in Bezug auf die Politik der Abfallhierarchie entschieden, ob es möglich ist, die ungehärteten Kleb- und Dichtstoffrückstände, die von einer Automobilindustrie in Curitiba, Brasilien, an anderen Bestimmungsorten für die Herstellung von Waren erzeugt werden, wiederzuverwenden. Gegenwärtig schickt die Automobilindustrie ihre Rückstände zur Energierückgewinnung in Zementöfen als Erzatsbrennstoffe, aber unter Berücksichtigung der Abfallhierarchie ist es für den Umwelt- und Ressourcenschutz wertvoller, eine Wiederverwendungsoption zu finden. Um dieses Ziel zu erreichen, wurden zwei Rückstände für weitere Studien ausgewählt. Die physikochemischen Eigenschaften der Rückstände wurden analysiert, um die Rückstände zu klassifizieren und ihre möglichen Gefahren herauszufinden. Die polymere Base der Rückstände wurde mit Hilfe der FTIR-Spektroskopie definiert. Im nächsten Schritt wurde eine bibliographische Untersuchung über verschiedene polymere Güter und ihren Herstellungsprozess durchgeführt, um Optionen zu finden, die ähnliche Rohmaterialien wie die signifikanten Inhaltsstoffe innerhalb der untersuchten Rückstände aufweisen, zusätzlich zu der Möglichkeit für die Rückstände werden nach der Wiederverwendung im vorgeschlagenen Ziel vollständig geheilt. Der letztgenannte Faktor wurde als Garantie dafür angesehen, dass alle möglichen Gesundheits- oder Umweltrisiken ausgeschlossen werden, die durch die Wiederverwendung der Rückstände entstehen können. Wiederverwendung der untersuchten Rückstände zur Herstellung von Produkten wie Reifen, insbesondere festen Polymerreifen; Gummidichtungen für Tür- und Fensterprofile; Matten und Bodenbeläge; Förderbänder; Getriebe- und Elevatorriemen; Industrielles Futter; Dämpfer und Polymer Matrix Composite wurde empfohlen. Schlüsselwörter: Abfallwirtschaft, Abfallhierarchie, Wiederverwendung, Kleberrückstande, Dichtungsmittelrückstande

CHARACTERIZATION OF A CARDBOARD RECYCLING FACILITY\u27S PLASTIC WASTE FOR BENEFICIAL USE

An issue with old cardboard container (OCC) recycling is the generation of a plastic waste that currently either gets land-filled or burned. A Wandel screen, a common process unit, generates 35% of overall rejects that contain 75% of the facility\u27s total plastic output. Plastic-rich Wandel wastes have not been well characterized. This study evaluated the plastic waste stream for engineering new, second-life products. Wandel wastes were composed typically of hot melt adhesives (37%), polypropylene (32%), polyethylene (17%), and polystyrene (9%). Proportions varied 10% or less in each polymer category. The plastic waste was compounded, milled and injection molded into test specimens. Differential scanning calorimetry (DSC) analysis showed that the polymers exist generally in separate phases. Thermal gravimetric analysis (TGA) determined that the onset degradation (405°C) of the mixed stream is an average of its components. In tensile tests, the mixed plastic waste stream performed comparably to its starting materials (tape, hot melt glue, thin film, etc.) with a modulus of 9.6 MPa, ultimate strength of 8.7 MPa, and toughness of 52.6 J. After initial characterization, the material was compounded with wood flour (WF), cement, ash and maleated polyethylene (MAPE). WF and MAPE increased the tensile modulus by 65%, ash and cement increased moduli by 49% and 39%. All additives decreased error in breakage indicating an increase in internal compatibilization. MAPE decreased crystallinity and compatibilized both mixed polymers and additives. Samples were characterized by DSC and TGA. Additives decreased phase separation. TGA analysis showed wood flour, ash, cement and MAPE thermally stabilized the plastics. These improvements make this mixed plastic waste more attractive for reuse

Parts, Materials, and Processes Experience Summary

The ALERT program, a system for communicating common problems with parts, materials, and processes, is condensed and catalogued. Expanded information on selected topics is provided by relating the problem area (failure) to the cause, the investigations and findings, the suggestions for avoidance (inspections, screening tests, proper part applications), and failure analysis procedures. The basic objective of ALERT is the avoidance of the recurrence of parts, materials, and processed problems, thus improving the reliability of equipment produced for and used by the government

Novel Methods to Construct Microchannel Networks with Complex Topologies

Microfluidic technology is a useful tool to help answer unsolved problems in multidisciplinary fields, including molecular biology, clinical pathology and the pharmaceutical industry.Current microfluidic based devices with diverse structures have been constructed via extensively used soft lithography orphotolithography fabrication methods. A layer-by-layer stacking of 2D planar microchannel arrays can achieve limited degrees of three dimensionality. However, assembly of large-scale multi-tiered structures is tedious, and the inherently planar nature of the individual layers restricts the network’s topological complexity. In order to overcome the limitations of existing microfabrication methodswe demonstrate several novel methods that enable microvasculature networks: electrostatic discharge,global channel deformation and enzymatic sculpting to fabricate complex surface topologies. These methods enable construction of networks of branched microchannels arranged in a tree-like architecture with diameters ranging from approximately 10 μm to 1 mm. Interconnected networks with multiple fluidic access points can be straightforwardly constructed, and quantification of their branching characteristics reveals remarkable similarity to naturally occurring vasculature. In addition, by harnessing enzymatic micromachining we are able to construct nanochannels, microchannels containing embedded features templated by the substrate’s crystalline morphology, and an irregular cross section of microchannel capable of performing isolation and enrichment of cells from whole blood with throughput 1 – 2 orders of magnitude faster than currently possible. These techniques can play a key role in developing an organ-sized engineered tissue scaffolds and high-throughput continuous flow separations

Natural Fiber Based Composites

Entitled “Natural Fiber-Based Composites”, this Special Issue has the objective to give an inventory of the latest research in the area of composites reinforced with natural fibers. Fibers of renewable origin have many advantages. They are abundant and cheap, they have a reduced impact on the environment, and they are also independent from fossil resources. Their ability to mechanically reinforce thermoplastic matrices is well known, as their natural heat insulation ability. In the last twenty years, the use of cellulosic and lignocellulosic agricultural by-products for composite applications has been of great interest, especially for reinforcing matrices. The matrices can themselves be of renewable origin (e.g., proteins, starch, polylactic acid, polyhydroxyalkanoates, polyamides, etc.), thus contributing to the development of 100% bio-based composites with a controlled end of life. This Special Issue’s objective is to give an inventory of the latest research in this area of composites reinforced with natural fibers, focusing in particular on the preparation and molding processes of such materials (e.g., extrusion, injection-molding, hot pressing, etc.) and their characterization. It contains one review and nineteen research reports authored by researchers from four continents and sixteen countries, namely, Brazil, China, France, Italy, Japan, Malaysia, Mexico, Pakistan, Poland, Qatar, Serbia, Slovenia, Spain, Sweden, Tunisia, and Vietnam. It provides an update on current research in the field of natural fiber based composite materials. All these contributions will be a source of inspiration for the development of new composites, especially for producers of natural fibers, polymer matrices of renewable origin and composite materials. Generally speaking, these new materials are environmentally friendly and will undoubtedly find numerous applications in the years to come in many sectors. Dr. Philippe Evon Guest Edito