Gauge Control

Orientation, stretching the film to produce some molecular realignment in the direction of the stretch, is often used to modify cast film properties. Orientation tends to increase crystallinity, barrier properties, and strength in the stretched direction(s), while decreasing strength in the direction(s) perpendicular to the orientation. 

Two-step orientation is widely used to make oriented PET and PP film. First the film is drawn in length, and then it is drawn in width. In one-step orientation, the film is stretched simultaneously in the length and width directions. Both processes are known as tentering (Fig. 7.6). 

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Digital Ionization gauge control monitors vacuum performance and provides necessary vacuum interlocks. 

Coextrusion can be performed with flat, tubular, and different shaped dies. The simplest application is to nest mandrels and support them with spiders or supply the plastic through circular manifolds and/or multiple ports. Up to 8-layer spiral mandrel blown film dies have been built that require eight separate spiral flow passages with the attendant problem of structural rigidity, interlayer temperature control, gauge control, and cleaning. Many techniques are available for coextrusion, some of them patented and available under license (Chapter 5). 

A screen changer is located between the extruder and die to remove any dirt or foreign particles. Gear pumps located between the extruder and die reduce power consumption and provide a more uniform rate of polymer delivery to the die, providing improved gauge control [3]. 

Fig. 5 Experimental setup for diffusion measurements in zeolites. Schematic arrangement around the IR flow-through cell (6), which for macro-FTIR measurements may be that described in Vol. 4, Chap. 1, p 42 of this series (see also [23]) or for micro-FTIR measurements the cell represented in Fig. 4b. Detailed explanation of main parts (1) ionization gauge (2) ionization gauge controller (3) baratron (4) pressure controller (5) magnetic valve (6) IR flow cell with sample (7) temperature controller (8) mass flow controllers (9) thermostatted saturators (10) four-way valves...

Table 9.12 shows how polybutadiene microstructure and macrostructure (i.e., molecular weight, Mw, Mn, polydispersity, and branching) can affect the processability of a polymer (Kumar et al 1996). A study with both cobalt- and neodenium-catalyzed polybutadiene showed the relationship between polydispersity or molecular weight distribution and increases in stress relaxation. Increases in stress relaxation, as measured by the Mooney viscometer, will infer greater difficulty in compound processing, gauge control, nerve, and extrudate or calendered sheet shrinkage (Waddell et al 2004). 

An SPE column is assembled by packing polymer particles (100 mg) between two Teflon frits in a 6-mL glass cartridge. The column is mounted on a BAKER spe -12G Column Processor (containing a 12-port vacuum manifold and a vacuum gauge controller) from J.TBaker (Deventer, Holland). Prior to sample application, the column is equilibrated by passing 5 mL of toluene at approximately 2 mL min flow rate, by applying an appropriate vacuum to the manifold. 

Transverse Gauging Control Debuts for Blown Film, Windmoeller and Hoelscher, PM E, p. 9, Jan. 1989. 

Flow control valve and pressure gauge Control of ammonia flow for optimum concentration In feed gas Safety issues if ammonia concentration in feed gas is high Online gas analyser to be provided... 

A complete mass spectrometer normally contains an ion source, a mass filter, and one or more ion detectors. In addition, the system will require a vacuum chamber, a method of sample introduction, vacuum pumps (usually a roughing pump and a main pump), a vacuum gauge, control electronics, and a data acquisition, display, and storage system. 

High output lines often employ automatic gauge control. One type of system utilizes a series of small heaters located around the circumference of the die lips. A downstream thickness measurement is reported back through a controller that decides whether to... 

Thus, film tends to be thicker on one side of the die. In addition, gauge control is poor, and so the die is seldom used in production lines. 

Autoprofile, Gauge control, Battenfeld Gloucester Engineering Co. Inc. 

The roller die (B.F. Goodrich, 1933) is a combination of a standard sheet die and a calender. It allows high throughput by reducing the diehead pressure it reduces air entrapment and provides good gauge control. 

As well as improved output, processors gain extended use of equipment and greater flexibility in speed, temperature, pressure, and gauge control, with a wider choice of blend ratios. There is less downtime for cleaning die apertures and start-up is also easier. The latest types can also be mixed into many pigmented masterbatches with less interaction. 

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