Extrusion


A Technique of Ultrasonic Testing without Dead Zone for Coarse-Grained TC4 Extrusion Pipe. - The Development of Single Crystal Creeping Wave Prohe.  [c.806]

Fig. 7 The longitudinal microstructure( x 100) of coarse-grained TC4(Ti-6Al-4V)P extrusion pipe of artificial reference test pipe Fig. 7 The longitudinal microstructure( x 100) of coarse-grained TC4(Ti-6Al-4V)P extrusion pipe of artificial reference test pipe
Fig. 8 The transversal microstructure (x 100) of TQP extrusion pipe of artificial reference test pipe Fig. 8 The transversal microstructure (x 100) of TQP extrusion pipe of artificial reference test pipe
UT for Plastic Pipe extrusion. State of the art, 20 chapters inch 30 Fig.,  [c.977]

The method consists essentially in allowing a solution of the substance in a suitable solvent to pass slowly down a long column containing the adsorbent material. The tenacity with which this material adsorbs the various components of the mixture may vary considerably, with the result that a sharp separation of the components into coloured zones or bands may result. At this stage, the passage of the solvent may be stopped and the individual zones removed either by careful extrusion of the adsorbent material or by cutting the tube in sections corresponding with the zones. It is usually more convenient to elute the components, i.e.y by the further passage of the pure solvent  [c.48]

Finite element modelling of flow distribution in an extrusion die  [c.173]

We consider a co-extrusion die consisting of an outer circular distribution channel of rectangular cross-section, connected to an extrusion slot, which is a slowly tapering narrow passage between two flat, non-parallel plates. The polymer melt is fed through an inlet into the distribution channel and flows into  [c.173]

Figure 5.20 (a) The predicted non-uniform exit flow distribution in a co-extrusion die.  [c.176]

Industrial polymer processing encompasses a wide range of operations such as extrusion, coating, mixing, moulding, etc. for a multiplicity of materials carried out under various operating conditions. The design and organization of each process should therefore be based on a detailed quantitative analysis of its specific features and conditions. The common - and probably the most important part in the majority of these analyses is, however, the simulation of a non-isothermal, non-Newtonian fluid deformation and flow process.  [c.287]

The method consists essentially in allowing a solution of the substance in a suitable solvent to pass slowly down a long column containing the adsorbent material. The tenacity with which this material adsorbs the various components of the mixture may vary considerably, with the result that a sharp separation of the components into coloured zones or bands may result. At this stage, the passage of the solvent may be stopped and the individual zones removed either by careful extrusion of the adsorbent material or by cutting the tube in sections corresponding with the zones. It is usually more convenient to elute the components, i.e., by the further passage of the pure solvent  [c.48]

In this paper, a technique is introduced that by using a single crystal creeping wave probe, the ultrasonic testing without dead zone can be realized for coarse-grained TC4P extrusion pipes, and the principles, characteristics and properties etc. of the newly-developed 5MHz single crystal creeping wave probe are fiilly studied and described.  [c.806]

Because these pipes are key components used for airplanes, their ultrasonic testing quality must be guranteed. Therefore, the author has conducted studies about the flaw detection methods for coarse-grained TC4P extrusion pipes.  [c.806]

It is known to all that although an ordinary one-transmitting-and-the-other-receiving double crystal probe has a smaller upside-dead zone, it still has a upside-dead zone of 2 - 3 mm, and its superiority of ultrasonic testing for coarse-grained materials is not obvious. As to a one-transmitting-and-the-other-receiving double crystal. Creeping wave probe, although its ultrasonic testing for coarse-grained materials is more effective It generally has a upside-dead zone of 2 3mm. Now the author has used the advantage that the ultrasonic testing of a one-transmitting-and-the-other-receiving double crystal creeping wave probe is suitable for coarse-grained materials, has solved the noise confusing problem of creeping wave probe and has developed a 5MHz single crystal creeping probe which can transimt and receive by itself Experimental results show that this probe has achieved a satisfactory result to the realization of the ultrasonic testing without dead zone for the coarse-grained TC P extrusion pipes.  [c.807]

Figures 9 and 10 show the tested echo s wave form of artificial d>0.8mm FBH of coarsegrained TC4P extrusion pipe ((j)162 x 30 1028mm) by using 5MHz single crystal creeping wave probe.  [c.809]

Figures 11 and 12 show the tested echo s wave forms of artificial 0.8mm FBH of coarsegrained TC4P extrusion pipe ((j)158 x 19 - 1020mm) by using 5MHz single crystal creeping wave probe.  [c.809]

In these problems, flow geometry is not known a priori and some sections of the domain boundary may change with flow. This situation arises in a variety of polymer processes such as injection moulding and mixing in partially filled chambers. Free surface flow regimes are also encountered in extrusion and wire coating operations where die swell is a common phenomenon. Various techniques for the modelling of free boundary flow regimes have been developed in the last two decades. Some of these methods are process specific, or they were developed in conjunction with particular numerical schemes and cannot be regarded as general simulation tools.  [c.101]

Boundary conditions for the solution of Equation (5.50) are zero pre.ssure on the exit and zero normal pressure gradient at the inlet. The exit condition can be imposed directly to impose the inlet conditions a layer of virtual elements is attached to the outer edges of the elements at the inlet section. A suitable value for the source term in Equation (5.50) is chosen in these elements. The source tern in all other elements is set to zero. All of the boundary line integrals, appearing after the application of Green s theorem to the discretized model equation, are also set to zero. The described bomrdary conditions ensure, respectively, that melt leaving the extrusion slot at the exit is flowing in the radial direction, and there is no fluid flow from the outer edges of the virtual elements.  [c.175]

A series of simulations has been carried out, varying the parameters a and h in Equation (5.54), this is equivalent to altering the extrusion slot height and taper. The results of successive simulations are compared until a die geometry that yields uniform exit flow is obtained. In Figures 5.20a and 5.20b the exit flow uniformity, indicated by the length of the predicted velocity vectors, for sets of a 0.0011 h = -0.0005) and ([c.175]

Nassehi, V. and Pittman,. 1. F. T., 1989. Finite element modelling of flow distribution in an extrusion die. In Bush, A. W., Lewis, B.A. and Warren, M.D. (eds), Flow Modelling in Industrial Processes, Chapter 8, Ellis Horwood, Chichester.  [c.189]

Diallylsulfonium salts undergo intramolecular allylic rearrangement with strong bases to yield 1,5-dienes after reductive desulfurization. The straight-chain 1,5-dienes may be obtained by double sulfur extrusion with concomitant allylic rearrangements from diallyl disulfides. The first step is achieved with phosphines or phosphites, the second with benzyne. This procedure is especially suitable for the synthesis of acid sensitive olefins and has been used in oligoisoprene synthesis (G.M. Blackburn, 1969).  [c.39]

Fully conjugated cyclopolyynes, so-called cyciocarbons, constitute another class of carbon modifications besides diamond, graphite, and the recently discovered fullerenes (see section 5.6). Syntheses of these unstable rings might be possible by mild elimination, extrusion, or  [c.338]


See pages that mention the term Extrusion : [c.13]    [c.67]    [c.178]    [c.206]    [c.245]    [c.317]    [c.806]    [c.811]    [c.2762]    [c.173]    [c.174]    [c.176]    [c.78]    [c.334]   
See chapters in:

Plastics engineering Изд.3  -> Extrusion


Engineering materials Ч.2 (1999) -- [ c.258 ]

Plastics materials (1999) -- [ c.48 , c.49 , c.158 ]

Plastics engineering Изд.3 (2002) -- [ c.246 , c.377 ]