Mandrel hollow

The process of rolled ring forging is used in the manufacture of seamless rings. A hollow cylindrical billet is rotated between a mandrel and pressure roll to reduce its thickness and increase its diameter. 

In filament winding the fiber is wound to form a desired pattern, usually but not necessarily hollow and cylindrical. The fiber is passed through the resin and then spun onto a mandrel. After the desired number of layers of fiber is added, it is cured. Prepregs can be filament wound. With the advent of new machinery, complex shapes and designs of the filament can be readily wound. 

For pultrusion of hollow cross-sections, cantilever mandrels that are mounted in front of the die (i.e., upstream ) are used. In the transverse direction, the mandrel (which may be heated) is oriented solely by the amount of reinforcement around it. The fact that it is difficult to produce perfectly concentric pipes and hollow sections with well-defined wall thicknesses underscores the significance of predie reinforcement guidance and positioning. 

A unique and considerably more elaborate multiaxial test employs a thick-walled hollow sphere test specimen which may be pressurized internally or externally with a nearly incompressible liquid. Figure 20 illustrates the essential features of the test device as described by Bennet and Anderson (5). The specimen is prepared by casting propellant in a mold fitted with a sand-poly (vinyl alcohol) mandrel inside the sphere which may be removed easily after curing. A constant displacement rate instrument drives the piston to pressurize the chamber and apply large deformations. The piston s total displacement volume is transferred to... 

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. 

FIG. 1.2. Tube drawing by machine. Tlie Danner Process. The molten glass from the continuous furnace flows on to the hollow rotating mandrel and is drawn off as a Uibe. 

The twin problems of (1) ensuring transverse flow uniformly along the length of fibers and (2) ensuring even flow distribution on shell side were solved largely by adopting the concept of hollow fibers in fabric array form that was wound around a central hollow mandrel with porous wall. The shell side fluid could be introduced in the membrane contactor through the central distribution mandrel. It could then flow radially outward, in a direction transverse to hollow fiber axes. The central... 

Figure 15.6 A hollow die, or a spider die with a fixed mandrel as an integrate part of the die to make the tongue-and-groove profile (see Fig. 15.2).

Paraplast [Hexed] l iganic powders used to cast mandrels or cores used in prod, of hollow [dastic articles. 

Figure 5.16 shows the principal steps for isos-tatically molding a simple solid cylinder. The mold cavity is formed inside an elastomeric membrane shaped like a hollow cylinder. In this case, it does not include any mandrels and is completely filled with the powder. The elastomeric bag is closed, sealed and placed inside a pressure vessel. The vessel containing a fluid is sealed, pressurized and held for a dwell period during which the powder is compacted by the action of a pressurized fluid. At the end of the dwell time, the vessel is depressurized and the mold is removed and disassembled for the removal of the preform. 

The ram extruder for this process is a special unit and can be either horizontally or vertically oriented, which refers to the direction of the ram movement. The extmder consists of a heated barrel where the preform is loaded, and a hydraulic or screw-driven ram. The conductor is drawn by a power system through a hollow mandrel located at the center of the barrel. The mandrel terminates in a wire guide tube. 

As noted, the part must be fully supported because of the high forces of FSW. This can be accomplished by having backing support behind the part. The backing can be a fixture itself, or a rib, or some other feature within the part itself. This means that special considerations must be given for open or hollow sections. Open or hollow sections can be welded if the weld is on a rib or other feature in the part, or if a mandrel is built to support the part. 

The primary piece of equipment for the installation is a tower and mandrel system developed by Nilex, Inc. and DuPont. The Nilex rig, shown in Figure 30.2, consists of a square metal hollow tube, or mandrel, mounted vertically on a tower... 

Catalysts of metal modified amorphous silica are made from the powders by compacting the powder under pressiure. The powder may be evenly flowed into a steel mold or die and compacted with a plunger. Hydrostatic compaction around a mandrel in a mbber mold which is squeezed by hydrostatic pressure can be employed for making cylindrical, hollow objects. Powders can be roll-formed into sheets or bars or can be extruded through a die to form rods. 

FW technology is also being used for production of blanks for high performance products outside the hollow cylinder geometry. Springs for motor vehicle suspension elements are produced by filament winding and then cut, while a carbon/epoxy I-beam has also been produced on a small machine, producing a tube on a cylindrical mandrel... 

A matched set of tapered rectangular winding mandrels for the spars was designed from glass fiber, based on the similarity of its linear coefficient of thermal expansion (GTE) characteristics with the GTE characteristics of carbon. One kit of five mandrels was fabricated for the vertical stabilizer, and a second kit of four mandrels was made for the horizontal stabilizer. For the small, square tubing used as core, a cable braider was used to wind prepreg tape over long, hollow mandrels made with extruded PVG and silicon rubber. 

Filament winding of a 14.6-cm (5.75-in.)-ID by 25.4-cm (lO.O-in.)-long by 0.15-cm (0.060-in.)-thick, hoop-wound test cylinder was accomplished on a McClean-Anderson W-1 winding machine. The cylinder was wound on a hollow steel mandrel capable of being internally heated or cooled. The winding conditions were ... 

A metal-forming process used for production of hollow, rotationally symmetric sheet metal components. To produce a component with a given shape and thickness distribution, the sheet is clamped to a rotating rigid mandrel and formed by a roller tracing the shape of the mandrel at a fixed distance. 

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