Grooved mandrel

The most expensive method is to roll the pipe/tubing on a grooved mandrel. This is utilized for veiy small Dc-to-d ratios, usually followed by some form of heat treatment while still on the mandrel. Grooved mandrels create a verx high-tolerance product and help to prevent flattening to some extent. 

Stainless steel coils may recjuire solution annealing after forming to prevent springback" and alleviate high residual stresses. Solution heat treatment can be performed in a fixture or with the grooved mandrel to ensure dimensional stability. 

Applications for grooved mandrel are very expensive due to the cost of the machining of the mandrel. Mandrels that are solution heat treated with the coil are tvqncally good for only one or hvo heat treatments due to the severe quench. Thus the cost of the mandrel must be included in the cost of the coil. 

Grooves Mandrel is coated with material Clean mandrel... 

Bellows Nickel bellows can be made by electrodeposition onto a grooved cylinder. In this case, the nickel coating cannot be slid off, and so the substrate must be removed destructively. The grooved cylinders or mandrels are frequently of aluminium alloy which is dissolved away in caustic alkali when the nickel deposition is completed. Uses include pressure switches, flexible couplings, and pressure transducers . 

Discs Discs of nickel electroformed on to mandrels bearing grooves modulated with recorded sound have been used for many years for stamping sound recording discs. This process has been adapted and refined for the manufacture of digital records, including video discs . Video disc stampers must be hard, stress-free, and flat to within 0.1 m results of a short investigation directed towards these requirements have been reported ". 

A method of preparing a metal sieve cloth holder has been described in which parallel grooves were cut on a metal mandrel [34]. These were... 

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).

The incoming polymer melt stream is divided into separate feed ports. Each feed port feeds the polymer into a spiral groove machined into the mandrel. The cross-sectional area of the groove decreases with distance, while the gap between the mandrel and the die increases towards the die exit. This multiplicity of flow chan-... 

The design of nozzle (Figure 4.52b) features copper/beryllium tips that may be removed from the body, which means a special technique for installation in the mould and removal is needed. The tips (2) with auxiliary installation pins (4) should be located in the insulation chamber, and the nozzle body (1) is then placed on them. With the aid of nuts on the mandrels (4), the tips should be tightened up until they go into the grooves and onto the nozzle body pegs. Then the pin (4) should be unscrewed and the screws (3) introduced to replace it. 

Spiral-Mandrel Die n The most popular die design for extrusion of blown film, in which the melt, fed into a manifold at the bottom of the die, flows up to the die lip via multiple spiral grooves. The design is capable of handling a range of resins, provides even distribution to the lip, thus helping to minimize circumferential variations in film thickness, and has relatively low pressure drop. 

Fig. 6 A 0.5 -inch-long grooved cobalt mandrel is inserted into tubing, which is sealed on both ends with medical adhesive. The grooves are intended to simulate the spaces between pacemaker lead conductor coils. A 1-mm-diameter hole is made in one end to assure ingress of exudate/transudate. Samples are tied together in strings, identified with a colored glass bead, and implanted in the subcutis of rabbits as shown in Fig. 3. After optical microscopic examination, the samples may be analyzed by FTIR, HPLC molecular weight, SEM, and other suitable techniques...

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