Thin walled articles

However, even at relatively low SAN levels, the blends can become hazy or opaque. Transparent compositions can be obtained by using a poly(siloxane)/PC copolymer instead of pure PC (25). Thin-walled articles can be successfully fabricated from such a composition. The SAN should not contain more than 25% of AN. 

Clay mostly already contains organic components which affect the plasticity in a positive way. The fine ceramics industry makes use of this fact in order to make masses more plastic, especially in the manufacture of thin-walled articles. 

Drying is carried out in rocking, box and tunnel driers often utilizing the combustion heat from kilns. Rapid drying (ca. 10 min) with IR irradiation has recently been introduced for thin-walled articles (crockery). This compares with drying times for large format articles of up to 24 h and more (e.g. sanitary ware). 

More recently,thin walled articles have been fabricated by blow-molding composites of liquid crystal polymer (LCP) and expanded porous polydetrafluoroethylene sheetingl l material. Container application examples include food and pharmaceuticals, automotive gas tanks, bottles, and other vessels. Unlike most other thermoplastic polymers, thermotropic LCP forms high-viscosity melts that have thixotropic characteristics. Applying shear force to the melt substantially alters the melt viscosity of LCP and the orientation of its polymer domains. These attributes are useful to... 

Because of the relatively low temperature of decomposition, DTA can be used to make foams with a uniform cellular structure without deterioration of the polymer. The disadvantages of DTA are, however, poor dispersive abihty in mixtures and sensitivity to moisture. Nevertheless, DTA is used in foaming PVC (especially for thin walled articles), polyurethane, polystyrene, polyamides, and siloxane rubbers. 

Main fields of application cable wire, thin-wall articles, plastisols ... 

Injection thin-wall articles, engineering components Extrusion bristles, packaging, tapes, fiber, wire, film, sheet, tubes, profiles, sheathing... 

The good flow properties of these alloys have made them ideal for a wide range of injection moulding applications, such as thin-wall articles, within the E E and TT sectors. Until the last few years, these very properties, including the plasticising effect of the FRs used, prevented adequate melt stability from being achieved and so precluded their use in extrusion. 

Cylindrical ejector pins are most commonly used. However, rectangular pins or blade ejectors could be used in constricted areas. A stripper plate acts on the entire wall of the part and so distributes the ejection force. Air assisted ejection of thin walled articles could be used. 

A micro-grinding of the semicrystalline polymers seems to be the most suitable solution to produce thin wall articles with improved aesthetics and mechanical properties. 

Bulky, complex shapes and thin-walled articles can be produced in this way. Reaction times of a few seconds are possible, and mold residence times of one or two minutes have been achieved. RIM consumes less energy and uses less expensive equipment than conventional injection-molding processes. The process is used to make fascias, bumpers, and other flexible automotive parts. Fillers may be incorporated in the components to lower cost and increase rigidity. This fabrication technique is discussed further in the section on Fabrication of Plastics under Injection Molding. ... 

TYPICAL FORMULATIONS Disposable, thin-walled articles " ... 

In another guise, the dipping technique can be used to produce flexible, thin-walled articles from natural or synthetic polymers. The various types of synthetic polymer used for dipping are discussed in the next section. In the dipping process, a suitable shape, called in the industry a mold , form or former , is dipped with an appropriate dwell time into a liquid containing the polymer. The coated former is then heated to dry and cure the polymer as necessary. Finally, the article is removed from the former, whose shape it retains. The dipping process therefore provides the means to make seamless thin-walled items with predetermined, perhaps complex, shapes. 

The basic concept of producing a coating or a thin-walled article by the dipping process is straightforward. A former of the desired shape is dipped into a liquid mix... 

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