Punched sheet method

Punching sheet metal, especially thicker and tougher materials such as stainless-steel alloys, is inherently noisy. As noted in Section I.E and as shown in Fig. 8, noise is drastically reduced through the use of shear face punches. In addition, the fully controllable hydraulic ram offers yet another method to reduce audible noise slowing the speed of the punch as it strikes the workpiece. Although productivity in terms of strokes per minute is reduced, this trade-off may be necessary in some applications and in some fabricating environments where loud noise is at issue. 

Tile is manufactured in several ways. In each method, a continuous sheet is formed gauge refinement and planishing are carried out in subsequent calendering steps. Stresses that could lead to poor dimensional stability are avoided. The efforts to prevent stresses are governed by formulation, stock and roll temperatures, conveyor speeds, etc. After the final calendering, a resin—polymer—wax finish is applied to the surface of the sheet which is then buffed before it moves to the punch press. Frame scrap and tile rejected because of defects are returned to the mixers and recycled. 

The film for the Debye method is a narrow strip punched with one or two holes. Devices are available for cutting strip of the proper size from sheet film and punching properly located holes alternately, one can buy a roll of 35-mm film, which has the correct width for many Debye cameras, and punch and cut it to the right length. 

Fig. 6.9-18 Diagrams of the two methods used to compact aluminum swarf a) punch-and-die, b) roller press. 1, anvil (removable for ejection of compact 2, die 3, punch (rein-procating) 4, feed 5, Compact 6, rollers 7, force (screw) feeder 8, Compacted sheet (product).

Different methods can be applied to impose a bending moment on a sheet metal blank (Lange 1985). The most common techniques consist of positioning the sheet to be formed with the bend line coinciding with the centre line of a V-die and pressing a punch tool in the orthogonal direction (Fig. 1 right). The force... 

Blanking (die cutting). The cutting of flat sheet stock to shape by striking it sharply with a punch while it is supported on a mating die. Punch presses are often used for the operation. An alternate method is to make the cut with a thin, sharp-edged, shaped steel blade called a steel-rule die. See also die cutting. 

Non-woven fabrics are formed directly from short fibers that are assembled in sheets. The fibers are connected together to enhance the handlability of such sheet of otherwise loose fibers. Rows of needles are sometimes used to punch through the sheet of fibers and reorient some of the fibers to achieve mechanical adhesion between the fibers (needle punched fabrics). This process, although very successful with polymer fibers such as para-aramids, has less success with brittle ceramic fibers such as glass and carbon because fibers can easily break. Another method used to connect the short fibers is by using an adhesive to glue the short fibers to one another. In the case of short fiber composites, this glue will typically have a chemical affinity to the resins. 

In this test method, fiat sheet samples of filter media from commercially available filter masks are punch from the mask (Figure 6.28). These flat sheets are inserted into commercially available filter housings for testing under a variety of conditions. 

Zinc is rolled into a sheet, formed into a cylinder, and, with the use of a punched-out zinc disk for the bottom, soldered together. This method is obsolete except for the most primitive of assemblies. Last use of this method in the U.S. was during the 1980s in 6 inch cells. 

Zinc is impact extruded from a thick, flat calot. This is now the method of choice. Used globally, this method reshapes the zinc by forcing it to flow under pressure, from the calot shape into the can shape. Calots are either cast from molten zinc alloy or punched from a zinc sheet of the desired alloy. 

Punching n A method of producing components, particularly electrical parts, from flat sheets of rigid or laminated plastics hy cutting out shapes with a matched punch and die in a punch press. 

With the first two methods, the trim die is notched to allow the products to remain attached to the sheet until it is moved to the product removal station. Products are usually directly punched from the sheet to a collection table in in-line trimming. 

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