Mandrel securing

The next operation is to coil one of these slabs around a mandrel in a spiral form, and weld it securely under the blows of liaud-hamxners. It is now a gun-bairel in the ro igh. 

The design most commonly nsed today is the multimanifold spiral mandrel tubular-blown film die (Fig. la). This die consists of several concentric manifolds, one within the other. The manifolds are supported and secured through the base of the die. Each manifold consists of a flow channel that spirals around the mandrel. 

Do arbors and mandrels have firm and secure bearings, and are they free from play ... 

Fig. 3 shows the design of a modern lead pipe press. It has a bottom cylinder platen a which is positively connected to the top counterplaten c by means of four columns 6. The plunger d runs in a bronze bush in the cylinder and travels over a mandrel-bar holder e which is rigidly secured in the base of the cylinder. Sealing of the plunger in the cylinder and on... 

A straight or tapered fine thread is provided in the mandrel-holder to secure the mandrel. The tapered thread which permits of changing the mandrel rapidly, has not found a wide application as the mandrel tends to loosen easily. 

Puncture resistance of the thermoformed cavities can be characterized in two locations, bottom and comer. The cavity bottom is the center of the tray. The comer is the one opposite of the peel tab. To maintain consistent test geometry with flat film, the formed cavity is mounted and secured on mandrel. The mandrel is moimded on a fixture in such a way to present the outer smface of the comer perpendicular to the puncture probe. 

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