Shear cutting

At the gob feeder, the forming operation begias. The gob feeder deUvers a glass gob shaped such that it enters the blank mold without excessive mold contact, distortion, or reshaping of the glass. Shears cut off a gob of glass. The gob is fed to either a blow and blow, press and blow, or press-only forming operation to produce a container. 

For most packaging applications, compression cutting or shear cutting are used. LDPE is most often compression cut because its low modulus leads to necking in a shear die, and therefore a ragged edge is formed. For HDPE, PP, PMMA, PS, nylons, and PET, shear cutting can be used very effectively. However, the same die will not work equally well for each material because of the differences in modulus. 

Universal coal cutter A type of coal cutting machine, which is designed to make horizontal cuts in a coal face at any point between the bottom and top or to make shearing cuts at any point between the two ribs of the place. The cutter bar can be twisted to make cuts at any angle to the horizontal or vertical. 

In each of the previously described lines, the straighteners/levelers have operated continuously. As a rule, when processing most material, if these units are allowed to stop, surface marking will result. The start/stop line is the only system that intentionally stops and starts the material with every shear cut as part of normal line operation. In addition to leveling the material, the leveler also feeds and measures the strip directly into the shear. Once cut, the finished part is conveyed to a stacker (Fig. 16). 

The leveler requires a substantial amount of horsepower to operate. Because the leveler is required to stop and start with every feed progression, its drive is subject to wear. In addition, because the material is actually stopped in the leveler momentarily each time the shear cuts, certain materials may retain objectionable surface imperfections as a result. 

After the operator has produced a square blank, the back gauge is used for stripping (Fig. 17). Before making a shear cut, be sure that the leading edge is straight... 

Low shear-cut production (large glass blocks and lenses and glass insulators... 

The mixing torque and apparent shear viscosity of the blends increased with increasing amounts of NR might be due to the natural characteristics of ADS that is produced from NR latex without shear cutting in the production process and it was dried at low temperature using the heat from sunshine. Therefore, ADS itself will have high Mooney viscosity in comparison with those other NR block types. 

Sheet should be cut to the desired length and stacked flat. Usually, a traveling power shear cuts the sheet automatically to the desired lengths. Roll temperatures have a decisive influence on the quality of the finished sheet. If the rolls are too hot, the sheet will not be cooled sufficiently for easy handling and will tend to curl in the transverse direction. If the rolls are too cold, the sheet will curl in the machine direction, resulting in a pitted surface. ... 

A) Shear cutting B) Crush cutting C) Log cutting D) Razor blade cutting a) Web b) Log... 

Shear cutting (Fig. 18 A) is effected between a rotating knife and a roller edge and results in tapes with smoothly cut edges. This method has the highest precision, but the width of the tape rolls cannot readily be changed. It is used for most rigid-film tapes and double-sided tapes. 

Figure 2.16 Graph of mixing versus number of shearing-cutting-turning stages.

Only in forming/punching molds with shear cutting, are small differences of the maximum 1.5 °C needed in order to prevent the cutting edge of framing (due to linear expansion of the two mold halves). 

Pressure Air Forming with Forming/Punching Mold with Shear Cutting... 

FIGURE 1.172 Pressure air forming with forming/punching mold with shear cutting (company pictures Fa. ILLIG)... 

Other than powered equipment, there are moving hazards within a warehouse that are overlooked at times but create serious exposures to pinching, shearing, cutting, or grinding actions. Areas to be considered can involve ... 

---