Moulding

The objective of this study was to investigate the effects of material compositions on the mechanical properties of wood–plastic composites (WPCs) manufactured by injection molding. Using a ratio of wood flour/plastic matrix/MAPP (maleic anhydride polypropylene)/zinc stearate of 47:47:3:3, the tensile strength and modulus of rupture (MOR) of WPCs manufactured with LDPE (low-density polyethylene) and PP (polypropylene) were found to be larger than those of LDPE and PP themselves. However, contrasting findings were obtained when the polymer matrix was ABS (acrylonitrile-butadiene-styrene). In comparison to the mechanical properties of RPP (recycled polypropylene) itself, the MOR increased and the tensile strength decreased for WPCs manufactured with RPP.The tensile strength, MOR, and storage modulus of WPCs made from PP mixed with 47% wood flours (<180 μm) and 3–4.5% MAPP were larger than those of the other WPCs manufactured in this study. However, the polymer damping peaks showed a contrary result.

“Neri” “karıştırmak, birleştirmek” ve “Komi” “içine basmak” anlamındaki kelimelerden türetilmiş olan Japonca kökenli Nerikomi, renklendirilmiş çamur katmanlarının istiflenerek ya da sıkıştırılarak birleştirilip kalıba basma yöntemiyle şekillendirilmesini esas alan bir dekor tekniğidir.

The Japanese art technique Nerikomi, which is derived from the words "Neri" (to mix, to combine) and "Komi" (to press into), is a decorating technique that consists of combining colored clay layers by stacking or compressing, and shaping by molding.

Traditional chocolate manufacturing relies largely on the experience and skill of the chocolatier. Nowadays, with the replacement of manual processes with automated equipments, it is increasingly important to apply right processing conditions and controlling parameters, such as the time, the temperature, the moisture content, the relative humidity of the surrounding air, etc. This study investigated the influences of these factors during the moulding and cooling stage of chocolate manufacturing process on the ease of demoulding. Adhesion of chocolate to the polycarbonate mould surface was used as a measure for the demoulding properties, and was determined as the force required to separate a flat mould surface from the solidified chocolate sample. The results demonstrated that processing parameters, like temperature, contact time, and the relative humidity of the surrounding environment, have a significant impact on chocolate crystallization and solidification processes and on the adhesion of chocolate to a mould surface. Experimental findings from this work confirmed observations made during commercial chocolate manufacturing.

A new method of constructing open spandrel arch bridge has been developed for span ranges from 12m to 27m using precast concrete techniques. The buildability of this new system has been proven in a pilot project featuring simple precasting method, handling process, installation sequence with manageable units, and practical jointing means with “self-propping” construction techniques. This revolutionary arch bridge construction with simplified processes has resulted in substantial labour and material costs saving.  It has also been proven to be an economically viable alternative to conventional bridge solution. Nonetheless, stocks of steel moulds catering for the full spectrum of span ranges have remained a costly logistic issue with many operational difficulties. The problem may become more acute especially for bridge market of relatively lower volume but with many geometrical variations. This paper presents a systematic approach to standardise the design and development process with great emphasis on the practical aspects of precasting and moulding requirements. Three sets of moulds for two types of geometrical framing, called M-Series and K-Series Open Spandrel Arch Bridge have been developed to cater for the targeted span segment with due considerations on the functionality and applicability.

Over the past three decades, Orally Disintegrating Tablet (ODT) has gained much attention as a preferred alternative to conventional oral dosage form such as tablet and capsules. These dosage forms are placed in the mouth, allowed to disperse in the saliva, to produce a suspension which can be easily swallowed by the patient. In addition, patients suffering from dysphagia, motion sickness, repeated emesis and mental disorders prefer these medications because they cannot swallow large quantity of water. Further, drugs exhibiting satisfactory absorption from the oral mucosa or intended for immediate pharmacological action can be advantageously formulated in these dosage forms. Fast dissolving tablets are solid dosage forms containing drugs that disintegrate in the oral cavity within less than one minute leaving an easy-to-swallow residue.

The two bronze statues found off the coast of Riace (Statue A and Statue B) are among the few complete bronze Greek originals dating back to the 5th century . As the casting cores were expected to impair the conservation of the inner bronze surfaces, the core residues were removed by micro-excavation, revealing that both statues were built with a peculiar slab manufacturing technique. This paper describes the results of petrographical, chemical and palaeontological analyses conducted on the cores. There are structural and compositional differences in the materials used for the two statues. The bulk of the material used to manufacture each core appears to be very homogeneous in both cases. Nonetheless, modelled features of the casting cores with different petrographic and chemical composition were identified in both statues. A preliminary attempt was made to restrict the possible areas of provenance of the bulk material used for the cores, by matching petrographical information with the geology of southern Italy and Greece. The statues appear to have been manufactured in Greece; some areas, including the plain of Argos, in the north-eastern Peloponnesus, are more likely candidates than others.

injection moulding is the most common manufacturing method for production of high volume plastic parts. Although theoretically simple, the existence of strong non-linearities and the unpredictability inherent to the raw material used, transforms it into a quite complex process. The development of a process model, based on the analysis of the mathematical relationships between the variables, although possible, would be extremely difficult. Artificial Neural Networks, ANN. due to their capabilities and simplicity, are an attractive approach. Several training algorithms are presented in the paper, from which resilient backpropagation has been used to train a neural network capable of modelling the process behaviour. Because of the complexity involved, due to the large number of available variables, Principal Component Analysis, PCA, has been applied to reduce the dimensionality of the model to be learned by the neural networks.

Cet article décrit les stucs sculptés et les pigments colorés utilisés à l&#x27;Alhambra de Grenade (Espagne). On décrit en détail la nature, la structure, et la détérioration de ces matériaux, ainsi que les techniques de fabrication des stucs et de peinture employées. La technique de ...

The AIM TM process has been used to successfully produce short runs of injection moulded parts. One of the main drawbacks w of the process is the tendency of the tools to be damaged during part ejection Jacobs PF. Recent advances in rapid tooling from stereolithography. Proceedings of the 2nd National Conference on Rapid Prototyping and Tooling Research. Buckinghamshire x TM College 1996, ISBN: 085298 982 2 . At De Montfort University a successful AIM moulding cycle has been developed in which simple shapes from polypropylene are produced and the ejection forces required are measured. Two different ejection methods are used; one uses conventional ejector pins and the other uses a conformal ejector pad. The tool surface roughness is measured before and after moulding to observe any changes caused by ejection. Results show that ejector pins require a lower ejection force than a conformal ejector pad and this may contribute to longer tool life for the AIM TM process. Possible reasons for the results are discussed along with recommendations for further work. ᮊ

Presentation de l&#39;experience de modelisation en trois dimensions effectuee a l&#39;aide d&#39;un emetteur laser et de capteurs optiques (camera CCD) pour realiser un enregistrement informatise de haute precision de deux tombes campaniformes extremement fragiles mises au jour a Altwies - Op dem Boesch (Grand-Duche de Luxembourg). Reflexions autour de l&#39;emploi et de la methodologie de ce type de technologie et implications dans les metiers du Patrimoine culturel, en particulier dans le domaine de la duplication de structures archeologiques. La prise d&#39;empreinte virtuelle sans contact s&#39;inscrit en complement des techniques traditionnelles de moulage.

Foundry shop is an important section in industries. In foundry manufacturing of major pieces is done, which supplies to another industries such as automotive, naval, aeronautic, weapon and agricultural industries. Many of these pieces play key roles in final product as these are used in automotive engine, aero plane components or wind energy castings. Sand is the principal moulding material in the foundry as it is using for all types of castings. This machine designs an idea of testing tensile strength of sand which is using for castings in foundries with the help of load cell. This system defines the sand whether it is good or bad for castings. We cannot check tensile strength of each grain of sand so; we form brick of that sand and then check tensile strength of that sand brick. Sand brick is placed in between load cell and DC motor. DC motor continuously applies force on that brick till it breaks and at other side simultaneously load cell converts that force into electrical signal and analog -to-digital converter converts that into digital and it displays on LCD. Force at which point brick breaks motor automatically stops that is the maximum tensile strength of that sand.

Warpage of micro-electronics caused by the curing process and thermal cycling is of major importance in electronic packaging. Industry is availed by good methods to be able to predict warpage accurately. The main difficulty for prediction of warpage is caused by the complicated material behavior of molding compound. It turns out that the mechanical behavior of molding compound is dependent on time, temperature and degree of conversion. Since molding compound is available in large variabilities, for each type the model parameters should be established experimentally.

A new procedure for the production of infrared lenses and prisms based on As2S3 chalcogeniude glass has been devised. Infrared components are obtained with the size in the range 100-1500 micrometers. The procedure allows for getting various curvature radii of the micrometer lenses, ranging from planno-convex to spherical ones.

We report on different optical coupling concepts between resonant-cavity light-emitting diodes and plastic optical fiber for the automotive according to the Multimedia Oriented Systems Transport standard. We present five different candidate optical coupling schemes. Two coupling schemes were investigated in depth regarding manufacturing and assembly tolerances using a Monte Carlo simulation method: a system using a ball lens and another made by clear molding. We select the best suited system according to manufacturing and assembly capabilities as well as its suitability for automotive applications.

When packaging multimode lasers into low-cost modules, passive fiber alignment would be extremely advantageous especially if the fiber alignment structures could be manufactured by using injection-molding technique. Injection molding as large-volume manufacturing technique allows for the reduction of the unit price of molded parts provided that the number of parts molded by using a single molding tool is large. In this paper, we compare active and passive fiber alignment techniques. The constructions and packaging procedures of two modules packaged by using active and passive alignment techniques are shown. Using a sleeve construction, a multimode laser with a 230 pm x 2 pm emitting area was actively pigtailed with a 100/140-pm multimode fiber. In the other example, a multimode laser with a 300 pm x -1 pm emitting area was passively pigtailed with a 200/230-pm multimode fiber by the use of an alignment structure, which was precision-machined using LIGA technique. The study results the applicability analysis of the passive alignment technique for low-cost fiber pigtailing.

Commercial FEM software codes do not directly support the cure dependency of polymers behavior. In electronics packaging, for example, cure shrinkage of the molding compound is consequently treated as a surplus to thermal contraction and its changes in visco-elastic behavior during curing are usually ignored. This give rise to inaccurate results and may cause difficulties even in recognizing factors important for further optimization.

A photonic crystal biosensor incorporating a nanomolded porous dielectric is fabricated for the first time on a flexible polysulfone substrate. The plastic substrate necessitates several changes to the fabrication procedure, including reduced processing temperatures. The resulting structure shows excellent response uniformity across a large area in the steady state as well as for perturbations of the bulk and near-surface dielectric permittivity. Kinetic binding data for a representative biomolecular assay demonstrate robust sensor operation.

Traditional chocolate manufacturing relies largely on the experience and skill of the chocolatier. Nowadays, with the replacement of manual processes with automated equipments, it is increasingly important to apply right processing conditions and controlling parameters, such as the time, the temperature, the moisture content, the relative humidity of the surrounding air, etc. This study investigated the influences of these factors during the moulding and cooling stage of chocolate manufacturing process on the ease of demoulding. Adhesion of chocolate to the polycarbonate mould surface was used as a measure for the demoulding properties, and was determined as the force required to separate a flat mould surface from the solidified chocolate sample. The results demonstrated that processing parameters, like temperature, contact time, and the relative humidity of the surrounding environment, have a significant impact on chocolate crystallization and solidification processes and on the adhesion of chocolate to a mould surface. Experimental findings from this work confirmed observations made during commercial chocolate manufacturing.

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The article reviews data on a process of sand casting that was filmed in Morocco more than ten years ago. It starts from the twin assertion that historical traces of sand casting are rare and that this technique does not lend itself easily to technological analysis which is commun in french visual anthropology (because of a constant change in state of its two principal materials and the functional ambiguity of some of its technical components). Sand casting is thus approached as the result of mainly plastic transformations. Since it allows to free oneself from ambiguous categories such as tool, object and matter, plasticity invites to consider the technical process as the product of successive encounters between “plasm” and “plast” bodies, between “formed beings” and “forming beings”. The process of production is then no longer conceived as the transformation of a material in its natural state into a constructed object, but as a permanent process of taking/giving/destroying forms. Thinking in terms of plasticity is particularly suited to understand the logics operating in this moroccan process of sand casting, a technique characterized by the cyclicality and categorial instability of its components.

A method is proposed to realize cavity resonator filters for cellular frequencies in surface-mount technology. The cavity resonators can be produced by molding techniques and subsequently soldered onto a circuit board, where a stripline structure in the circuit board makes the coupling between the resonators. The molded parts for all resonators of a given filter can be identical. Means are

This review gives an overview of the progress made in recent years in the development of low-cost parallel patterning techniques for ceramic materials, silica, and organic-inorganic silsesquioxane-based hybrids from wet-chemical solutions and suspensions on the micrometer and nanometer-scale. The emphasis of the discussion is placed on the application of soft-lithographic methods, but photolithography-aided patterning methods for oxide film growth are also discussed. In general, moulding-based patterning approaches and surface modification-based patterning approaches can be distinguished. Lateral resolutions well below 100 nm have been accomplished with some of these methods, but the fabrication of high-aspect ratio patterns remains a challenge.

Established design and fabrication guidelines exist for achieving a variety of motions with soft actuators such as bending, contraction, extension, and twisting. These guidelines typically involve multi-step molding of composite materials (elastomers, paper, fiber, etc.) along with specially designed geometry. In this paper we present the design and fabrication of a robust, fiber-reinforced soft bending actuator where its bend radius and bending axis can be mechanically-programed with a flexible, selectively-placed conformal covering that acts to mechanically constrain motion. Several soft actuators were fabricated and their displacement and force capabilities were measured experimentally and compared to demonstrate the utility of this approach. Finally, a prototype two-digit endeffector was designed and programmed with the conformal covering to shape match a rectangular object. We demonstrated improved gripping force compared to a pure bending actuator. We envision this approach enabling rapid customization of soft actuator function for grasping applications where the geometry of the task is known a priori.

Polymeric large-core (47 µm × 41 µm) optical waveguides for optical interconnects have been fabricated by using a rubber molding process. For low-cost low-loss large-core waveguides, our newly developed thick-photoresist patterning process is used for a master fabrication. Also a low-loss thermocurable polymer, perfluorocyclobutane (PFCB), is used in fabricating optical waveguides by rubber molding for the first time. The propagation loss is measured to be 0.4 dB/cm at the wavelength of 1.3 µm, and 0.7 dB/cm at the wavelength of 1.55 µm.

ABSTRACT In high-voltage integrated circuits (HV-ICs) operating at high temperatures, the high electric field spreading out from the high-voltage bond-pad can induce charge transport phenomena in the encapsulation material. A new TCAD-based approach is proposed which is suitable for investigating the role played by the propagation of charge within the plastic mold over the surface of high-voltage circuits. Simulations are compared with experimental data carried out using a dedicated test chip. The proposed approach is able to predict the features of the leakage current curves measured on different sensors during a complete charging transient.

A measuring system and a mathematical model are developed to study thermal transfer within polymers during the injection moulding phase. Temperature measurements within moulded parts reveal several "rise in the temperature" events at the surface of the part during the moulding cycle. These thermal singularities are related to the evolution of the parameters of implementation and depend on the nature of moulded polymer. The modelling of heat exchange makes it possible to integrate the evolution of the thermal contact between polymer and the mould as well as crystallization in the case of PP. The comparison between temperature experimental and theoretical results makes it possible to determine the characteristics of the process at the origin of these heating events.

Three different treatment processes for the reclamation of bentonite bonded moulding sands, made up of silica sand, coal dust, and clay, are considered in this work. The studied processes are the following: two kinds of wet mechanical regeneration, performed by the Safond and ...

Transdermal drug delivery through microneedles is a minimally invasive procedure causing little or no pain, and is a potentially attractive alternative to intramuscular and subdermal drug delivery methods. This paper demonstrates the fabrication of a hollow microneedle array using a polymer-based process combining UV photolithography and replica molding techniques. The key characteristic of the proposed fabrication process is to define a hollow lumen for microfluidic access via photopatterning, allowing a batch process as well as high throughput. A hollow SU-8 microneedle array, consisting of 825 mum tall and 400 mum wide microneedles with 15-25 mum tip diameters and 120 mum diameter hollow lumens was designed, fabricated and characterized.

The hardness, planing, and moulding properties of tamarack wood from natural forests were evaluated on kiln-dried specimens following three types of drying schedules: high temperature, elevated temperature, and conventional. Hardness tests were conducted according to the ASTM D143 standard. Planing and moulding properties were evaluated according to the ASTM D1666-87 standard. Wood specimens were machined at 7 percent moisture content, and the resulting surface quality was visually graded on a scale of 1 to 5 (excellent or defect-free to very poor). The maximum depth of torn grain produced by planing was also measured for eight cutting conditions. Hardness was positively related to wood density. Machining and hardness properties appeared not to be affected differently by the drying process. Tamarack wood performed well in the planing and moulding processes. The best planing condition was obtained when using a 10°rake angle and 20 knife marks per 25.4 mm cutting length. The global analysis of properties indicated that tamarack wood is suitable for the fabrication of flooring products.

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We report a novel surface-energy patterning phenomenon, in which a novel polymer composition inherits the surface energy of the medium it is in contact with during polymerization. This surface property mimicking process occurs via spontaneous selective molecular alignment of hydrophilic and hydrophobic monomers mixed into an off-stoichiometry thiol-ene (OSTE) formulation. This single-step method for simultaneous structuring and surface energy micropatterning of polymer structures is potentially more robust and lower cost than state-of-the-art processes requiring post-processing surface modification steps. We further demonstrate the selfassembly of a liquid droplet array on the replicated polymer surfaces.

A critical point in the continuous steel casting process exists in the meniscus zone of the cooled mould, i.e., the region in which the steel stream flowing out of the tundish nozzle starts to solidify. This is a critical point because of the sticking that occurs between the solid shell of steel and the mould. In this work, a new system for the ultrasonic lubrication of the continuous steel casting is proposed and experimentally tested. The basic idea is to excite one of the mould's natural vibration modes by means of a distributed ultrasonic source. This source is composed of an array of power emitters, with each of them placed upon an antinode of the mould. An experimental characterization of the vibrational behavior of a square mould was first carried out. The most active resonance modes of the mould were detected with an experimental technique based on a simple impedance measurement. The modal shape of the selected mode, and hence the position of antinodes, was obtained by means of interferometer measurements. Additional experimental investigations were performed by exciting mould vibrations with up to four piezoceramic disks placed on different sets of antinodes. Some positioning criteria to maximize the superposition effect were derived. Measurements were obtained through excitation of the mould with up to four Langevin-type power emitters, designed and manufactured to work at the mould's selected resonance frequency. These measurements have shown that, by increasing the number of emitters, the ultrasonic power transmitted to the mould and, consequently, the maximum available displacement, increases. Other practical advantages of the proposed system are highlighted and discussed.

A flow controller for refrigerant expansion is reported. Devices are fabricated using a micromolding technique that is developed for thick nickel electrodeposition. The device consists of a short-tube restrictor with an integrated normally open valve, which, when actuated, presents a controllable blockage into the flow passage to obstruct the flow. Fabricated devices are evaluated with compressed air, with up to 22% reduction in mass flow rate at maximum actuation of the restrictor. The devices are also evaluated in an R134a vapor compression system of 1.5-2 kW, with the ability to control mass flow that is found to be greatly influenced by the vapor compression cycle's operational parameters. After the inlet pressure, the level of subcooling proved to be the most important parameter. For a cycle operating between 29 • C and 4 • C, saturation temperatures in the condenser and evaporator, respectively, actuation of the device reduced the refrigerant mass flow rate by 3.5% with 0.6 • C subcooling and up to 10.8% with 5 • C subcooling.

Warpage of micro-electronics caused by the curing process and thermal cycling is of major importance in electronic packaging. Industry is availed by good methods to be able to predict warpage accurately. The main difficulty for prediction of warpage is caused by the complicated material behavior of molding compound. It turns out that the mechanical behavior of molding compound is dependent on time, temperature and degree of conversion. Since molding compound is available in large variabilities, for each type the model parameters should be established experimentally.

Thick rubber part moulding is a process, during which coupling between heat and chemical kinetic equations is strong. Automatic tooling control, therefore, is the guarantee of achieving proper curing within the mould. This article initially presents a detailed method for curing optimization. With this aim in view, the optimum temperature cycle for the desired curing state is examined. The use, here, of the conjugate gradient method implies to determine the solution of both adjoin and sensitivity equations. A sensitivity study is also conducted in order to improve the kinetic model. Finally, some optimization examples are discussed.

Nanofabrication is the core task performed and constantly further developed by todays and future semiconductor industry. Optimization of throughput and minimizing process cost and complexity thus increasing fabrication reliability constitute the main challenges within this development. Printing techniques play a crucial role in nanofabrication since they are offering the capability of large area patterning while simultaneously holding overall process time

The paper is concerned with the problem of regulating the molten metal level in the mold of a continuous casting plant despite the continual perturbations caused by mold shaking and the occasional perturbations due to the sudden uncloggings of the nozzle through which the liquid is poured into the mold. To deal with both kinds of perturbations, two distinct controllers