Blow molding

Blow molding (or moulding) is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins with softening plastic by heating a preform or parison. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can enter. The plastic workpiece is then clamped into a mold and air is blown into it. The air pressure inflates the plastic which conforms to the mold. Once the plastic has cooled and hardened the mold opens and the part is ejected. Water channels within the mold assist cooling. History The process principle comes from the idea of glassblowing. Enoch Ferngren and William Kopitke produced a blow molding machine and sold it to Hartford Empire Company in 1938. This was the beginning of the commercial blo

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Correlation between sizing formulation and compressive behaviour of concentrated glass bundle suspensions

Emmanuelle Comte, Jan-Anders Månson, Véronique Michaud

The correlation between sizing formulation, bundle mechanical characteristics, and bundle-matrix static and dynamic interactions are investigated. Two glass-fiber sizing formulations are considered, one containing polyvinyl acetate (PVAc) and the other polyester/PVAc, as conventionally used in sheet molding compounds (SMC). Axial compression tests are conducted on dry two-dimensional (2D) random suspensions. The forced packing is governed by the bending of fiber bundle segments between bundle-bundle contact points. Benchmarking of the experimental curves with a modified theoretical model provides an estimation of the fiber bundle bending rigidity under forced packing conditions. This value is found to depend on the bundle sizing as well as on the interaction with solvents present in the matrix as is the case for SMC. Free flow and molding experiments are performed on planar SMC sheets using the two different fiber bundles as reinforcements. The results confirm the dependence of the molding energy and the SMC rheology on the bundles chemical and mechanical characteristics.

2005

Photo-polymer microchannel technologies and applications

Marc Olivier Heuschkel, Philippe Renaud, Albert van den Berg, Harald Van Lintel

A set of new technologies to fabricate microchannels using photosensitive polymer materials is presented. They are based on the use of polymers, hereafter called photopolymers, that are cured with UV light under a mask exposure. The basic material is ail epoxy-based photopolymer which can be patterned in thick layers with high aspect ratio.-Several process variations for making multilayered channel network are described and discussed. a) a process based on the refill of channels with a non-sensitive polymer, b) a process based on interlevel masking and c) a new process involving the lamination of dry films. With all three processes, multilevel channel networks have been fabricated with minimum channel width and height of about 25 micrometers. The photopolymer channel technology offers: a good alternative to other technologies such as glass and silicon micromachining or plastic molding when multilevel crossing microchannels are needed. Moreover, the photoplastic channel technology is a relatively low cost technology that could be applied, in some cases, to disposable fluidic chips.

2000

Screening method for the onset of bonding of molten polyamide resin layers to continuous fiber reinforced laminate sheets

Martyn Douglas Wakeman

Thermoplastic polymer composites (TPC) with multiple fabric layers of continuous fiber reinforcement are laminate sheets designed to be thermally stamped and overmolded leading to low cycle times and thus high volume composite parts. Injection over-molding is one way to combine the high processability of thermoplastic melts with the less processable TPC sheets, for complex part making. To simulate the adhesion development during processes like over-molding, a non-isothermal screening method for bonding molten polyamide (PA) to a solid TPC surface has been developed and applied to evaluate differences in the threshold temperatures for good bond formation as a function of TPC matrix composition. Pure PA66 and aromatic high temperature nylons (PPA) in addition to miscible PPA blends comprising different ratios of PA66, were used as TPC matrices, and retain most of the very high melting point of 100% PPA. We have devised experiments to address two critical aspects: The first is to develop a screening test that probes very short timescales relevant to practical part making. The second is to investigate various miscible semi-crystalline blend ratios as matrices for the TPC where both blend species are crystalline. This allows us to explore a practical improvement of a lower required bonding temperature without substantially decreasing the high melting point of the PPA. DSC was also used to correlate the various blend melting transitions with the temperature required for the onset of bonding. The interfaces are shown to develop high strength partly because of substantial surface melting of certain blend components of the initially solid TPC, and this quickly allows interpenetration and inter-diffusion across the interface, which then crystallizes and strengthens during cooling.

2016

MICRO-301: Manufacturing technologies

This course gives an introduction to production methods and manufacturing technologies used in microengineering. The focus is given on the understanding of physical phenomena underlying the processes, the relation between materials, manufacturing processes and design, as well as economical aspects.

MSE-340: Polymer composites + Laboratory Work

Les propriétés mécaniques et physiques des composites anisotropes ainsi que leurs outils de calcul sont présentés. Les constituants, les mises en oeuvre et les relations microstructure-procédé-propriété sont décrits pour les composites polymères utilisés dans le transport, le sport et l'énergie.

MSE-360: Polymer science + TP

Introduction à la physique des polymères et aux liens entre structures chimiques et propriétés macroscopiques, avec accent sur la morphologie et le comportement thermomécanique. Méthodes de mise en œuvre, fournissant les bases nécessaires à la sélection des polymères dans un contexte industriel.

Plastic

Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into sol

Glass

Glass is a non-crystalline solid that is often transparent, brittle and chemically inert. It has widespread practical, technological, and decorative use in, for example, window panes, tableware, and

Polymer

A polymer (ˈpɒlᵻmər; Greek poly-, "many" + -mer, "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad