Core rod

Most PET botties are produced by injection blow mol ding (71) the resin over a steel-core rod. The neck of the bottie is formed with the proper shape to receive closures and resin is provided around the temperature-conditioned rod for the blowing step. The rod with the resin is indexed to the mold, and the resin is blown away from the rod against the mold walls, where it cools to form the transparent bottie. The finished bottie is ejected and the rod is moved again to the injection-molding station. This process is favored for single cylindrical botties, but cannot be used for more complex shapes such as botties with handles. 

Injection The injection blow moulding machine is based on an extruder barrel and screw assembly which melts the polymer. The molten polymer is fed into a manifold where it is injected through nozzles into a hollow, heated preform mould. The preform mould forms the external shape and is clamped around a mandrel (the core rod) which forms the internal shape of the preform. The preform consists of a fully formed bottle/jar neck with a thick tube of polymer attached, which will form the body. 

Blowing The preform mould opens and the core rod is rotated and clamped into the hollow, chilled blow mould. The core rod opens and allows compressed air into the perform, which inflates into the finished article shape. 

Ejection After a cooling period the blow mould opens and the core rod is rotated to the ejection position. The finished article is stripped off the core rod and leak-tested prior to packing. The preform and blow mould can have many cavities, typically three to sixteen depending on the article size and the required output. There are three sets of core rods, which allow concurrent preform injection, blow moulding and ejection. 

Figure 7.7 Direct melting process of making optical glass fiber. Qadding and core rods are melted in a double crucible and wound on a drum.

Linear variable differential transformer (LVDT, Fig. 2) is a device that produces voltage proportional to the position of a core rod inside a cylinder body. It measures displacement or a position of an object relative to some predefined zero location. On tablet presses, LVDTs are used to measure punch displacement and in-die thickness. They generally have very high precision and accuracy, but there are numerous practical concerns regarding improper mounting or maintenance of such transducers on tablet presses. 

One level of relatively thin tablets or parts with any contour (class I of P/M Figure 187 2) an be pressed with a single punch and force may be applied from one side. The maximum dimension A (Figure 187) depends on the particulate feed and the shape of the compact. Thicker parts (class II of P/M Figure 188), while still requiring only simple tooling, must be pressed from two directions. Holes are obtained by the installation of mandrels or core rods. 

Also mandril. A metal bar that serves as a core around which material may be bent, cast, forged, molded, or otherwise shaped. (See also core rod.)... 

POM - rubberized tough skin semi-crystalline and rubber sheets core rod shaped rubber particles aligned in flow direction Percorini, 1990... 

A schematic of a commercial TMA instrument is shown in Fig. 16.33. The instrument consists of a dimensionally stable (with ternperamre) sample holder and measuring probe, a programmable furnace, a linear variable displacement transducer (LVDT) to measure the change in length, a means of applying force (load) to the sample via the probe (core rod, push rod), and a temperature sensor (usually a thermocouple). 

An alternative approach is to cool the parison completely after the injection molding step, and remove it from the core rod. The parison can then be stored or shipped elsewhere before blow molding. In this case, it is necessary to reheat the parison to the desired temperature before the blow-molding step. This approach is seldom used for ordinary injection blow molding, but is not uncommon for stretch blow molding, which is discussed in Section 12.4. 

CVD method using SBA-15 rods as templates (see Figure 4.12). When rod-like mesoporous silica templates synthesised at temperatures lower than 70 °C were used, hollow mesoporous nanotubules were obtained rather than solid core rods (Figure 4.12). ... 

There are several different IBM methods available, with different means of transporting the core rods from one station to another. These methods include the shuttle, two-parison rotary, axial movement, and rotary with three or more stations used in conventional IM clamping units. A variation of IBM is displacement BM or dip molding. A premeasured amount of hot melt is deposited into a cupel, the shape of a preform. A core rod is inserted... 

The first examples of end-to-end connected bent-core—rod couples and rod—bent-core—rod trimesogens incorporating a bent 3,5-diphenyl-l,2,4-oxadiazole core (Figure 12) have been synthesized and their LC phase behaviors studied (2012BJO472). AH compounds form nematic phases over wide temperature ranges, in some cases accompanied by additional nontHted (CybA) or tilted (SmC) mesophases at lower temperatures. 

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