Ram force

Second, if the air sample captured by the instrument inlet is slowed appreciably from the 200-m/s air speed, then the temperature of the gas will rise —20 °C and the pressure will be increased as much as 50% by ram force. For measurements of volatile particles, such a temperature rise may... 

Before testing, the samples were compression molded, usually at 10°F above the milling temperature, using a cycle with a five-minute preheat and three minutes at a pressure of 40,000 pounds ram force. Specimens were then transferred to a cooling press and cooled under pressure. 

Fig. 5 A graph of ram force as a function of length-to-radius ratio, depicting conditions under which surface defects occur when extruding microcrystalline cellulose-lactose-water (5 5 6). Die diameter = 1.5 mm ram speed cm/min ...

A capillary rheometer (Fig. 6.8) is similar to a melt indexer. The main difference is that instead of by gravity, the piston is driven by a variable speed motor. Also, a load cell in-line with the piston measures ram force in real time. This configuration allows tests to be run at a controlled shear rate, and even to vary the rate over a large range during a single test run. The piston force and the orifice geometry provide the data necessary... 

Tests were conducted using three combinations of plaque temperature and ram forces to simulate a range of field conditions. 

This process. Fig. 16.7, is used for the majority of extruded products. A heated billet is positioned in the container with a dummy block placed behind it. The container is moved forward against a stationary die and the ram pushes the metal through the die. After extrusion, the container is moved back and a shear descends to cut off the butt end of the billet at the die face. The process is repeated with a new billet. As the outside of the billet moves along the container liner during extrusion, high frictional forces have to be overcome, requiring the use of high ram forces. 

Transfer moulding differs from eompression moulding in that the rubber is transferred through a hole into the mould cavity. In its simplest form a transfer mould consists of a ram in a cyhnder fed with preheated slugs, and a mould cavity. A piece of the unvulcanized rubber is placed in the cylinder and covered by the ram. When the press is closed the ram forces the rubber through a hole into the actual mould cavity. This allows shorter cure times because of the heat generated as the rubber is forced to flow through the hole. 

Ram Force. The total load applied by a ram, and numerically equal to the product of the line pressure and the cross-sectional area of the ram. It is normally expressed in tons. 

The ram pressure is the total force exerted on the ram, divided by the area of the ram. For a hydraulically operated compactor, the total ram force is the product of the hydraulic pressure and the hydranlic cylinder area. 

Plunger plon-jori n (1611) The part of a transfer-press or old-style injection machine that applies pressure on the unmelted plastic material to push it into the chamber, which in turn displaces the plastic melt in front of it, forcing it through the nozzle and into the mold. See also Ram, Force Plug, and Pot Plunger. 

The tooling is illustrated in Fig. 15 and consists of a die-block a and two rams h acting opposite to each other The rams force the lead through an annulus formed by the mandrel c and the die d. The lead pipe e thus being formed fits round the cable core, which is indicated by a dash-dot line, and draws it through the hollow mandrel. The sheathed cable core... 

Calculation of the extrusion force, i. e. of the necessary ram force, at close approximation is only possible in few, particularly simple cases, because it depends on a variety of factors that can only be evaluated in an imperfect manner. These factors include the resistance to deformation of the alloy to be extruded, in dependence of the temperature and speed at which the work is performed, the resistances caused by the varying flow phenomena in the billet, the frictional resistance on the tools, the extrusion ratio, the shape of the section, etc. The latter factor alone may essentially increase the required force, if the section is of intrical shape as compared with round rods of identical cross-sectional area (see Fig. 107). 

Extrusion high pressure ram forces powder through an orifice determining the section profile. Injection molding fine powder coated with thermoplastic injected into dies. Relatively complex shapes with thin walls achievable. 

In A1 extrusion, a hydraulic ram forces a preheated billet against a die and squeezes the metal through the die opening. Control of temperature and speed are important to avoid... 

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