Pinch rollers

It then passes through a pair of guide rollers, pinch rollers no. 5, a shear, an edge guide unit (to align the width of the sheet) and a final alignment pinch roll no. 6 as shown. 

Fig. 2.13. Extrusion-lamination scheme for production of two-layered inhibited polymer film materials (1) unwinding machine (2) film base, (3) extruder with a slot head, (4) inhibited polymer composition, (5) pinch roller, (6) cooling shaft, (7) coiler...

The travel of the film through the blown film tower is aided by various guiding and sizing devices. The film turns from molten to semisolid at the frostline but is still easily deformed as it moves up the tower. However, the orientation of the film is generally complete at this point. When the film is cool enough, the bubble is collapsed by plates and rollers (pinch rollers), and then wound up with or without slitting, gusseting, or other treatment. Thus, the blown film process can produce tubular as well as flat film. 

The blown film take-up system for LCP film must be capable of handling stiff film so that creases and folds do not form in the film as the bubble is flattened and pulled through the pinch rollers in the blown film process, shown schematically in Figure 11.19. A desiccant dryer is used to remove moisture from the LCP resin. As with any polyester, even small amounts of moisture can cause reduction in molecular weight, decreased melt strength, and other conditions that will adversely affect the quality of the film. Most LCP manufacturers recommend drying to less than 50 ppm, or dew point of -40°C [18]. 

Immediately upon extrusion from the die, the film tube is expanded by internal air pressure, which is supplied by air fittings and controls in the center of the die. An air ring may be used on the die to control the cooling and stabilize the semi-molten LCP film tube. The driven pinch rollers are controlled so that the total take-up speed will produce stretching, or draw, in the machine direction. 

This method consists of preparing a gel by mixing the desired quantities of the catalyst powder, PTFE emulsion and toluene or xylene. This gel can be rolled in a pinch roller to obtain electrode sheets of desired thickness. 

The former mechanism feeds the wire into the heated extrusion head using a pinch rollers connected to stepper motors (Turner et al. 2014). 

Magnetic tape media are divided into two categories (Onodera et al., 1996a) i.e., particulate media where magnetic particles are dispersed in a polymer matrix with some additives and coated onto the polyethylene terephthalate (PET) substrate, and thin film media in which monolithic magnetic thin films are deposited onto the substrate in a vacuum, which is discussed in this chapter. For magnetic tape helical scan systems, the tap>e is driven by a pinch roller and a tension (0.2 - 0.5 N) is applied. 

To obtain a constant tape speed, a motor is used to turn a small metal cylinder, called a capstan, at constant speed. When the tape player is switched on, a roller presses the tape against the rotating capstan. The tape is pinched between the roller and capstan, forcing it to move toward the take-up reel at constant speed, as desired. 

Adhesive tapes are also extensively employed for protection of pipes with curvilinear and corrugated surfaces used in chemical industry, gas and oil held developments. The problem of lining convoluted pipes is solved [116] by rolling the tube over a roller base wrapped in a poljuner tape (Fig. 3.45a). Roller axes are arranged at a pitch equal to the distance between crimps of the pipe. For this purpose, pinch mechanisms can also be used [117] made as a sprocket and having a roller on each beam (Fig. 3.45 ). 

Fig. 3.45. Diagrams of devices for hning convoluted pipes (a) with a roller base, (b) with a sprocket pinch mechanism (1) pipe, (2) adhesive tape, (3) base, (4) drive, (5) roller, (6) shaft, (7) sprocket, (8) spindle...

Pinch-off n. (1) In blow molding, a raised edge around the cavity in the mold that seals off the part and separates the excess material as the mold closes around the parison. (2) In making tubular film, the paired rollers (pinch rolls) at the top of the tower that flatten the tube and confine the air in the bubble. 

Most machines use power transmission components to transfer power from a motor, engine or other prime mover to an element of a machine where a useful function occurs. Some common power transmission components are belts, pulleys, ropes, sheaves, chains, sprockets, gears, and friction rollers. Many of these components create pinch, nip, or shear points. 

Where objects suddenly come into view along a conveyor, workers may not anticipate their arrival. An object may create a pinch point danger. Audio and visual warning devices can alert people to the pending danger of oncoming materials. This problem sometimes occurs with enclosed chute and roller conveyors, especially those moving between floors. 

FIGURE 2-24 Principles of operation of a pinch valve, pinched by a roller. (Courtesy of Red Valve Company, Carnegie, PA, U.S.A.)... 

Folienextrudieren) squeeze roller (nip or pinch rolls) QuotientA/erhaltnis ratio, relation... 

E es on Task (29) — Focuses eyes on task in which hands are involved. Avoids pinch points, i.e., keeps hands out of equipment during runs, while changing rollers or signatures. Keeps hands out of the line of fire. ... 

Peristaltic pumps are usually used for process engineering applications. These pumps are occasionally used in cases where small amounts of low-viscosity adhesives have to be applied. The flexible tube is pinched by cams or rollers and the adhesive therein becomes trapped ( occluded ). Due to the rotation of the cams or rollers, the adhesive is transported from the inlet to the outlet of the pump. The benefit of peristaltic pumps is that the actual pump mechanism does not come into contact with the medium being pumped. 

Conveyors have moving parts. Various pinch points exist in those areas that help the conveyor move product. A drive chain on a sprocket may move the rollers of the conveyor, but left unguarded this hazard can cause very serious hand injuries. The guard must be designed and mounted to completely seal off the hazards. This includes a full enclosure guard that does more than just cover the front of the drive chain. An employee could easily place a hand on the partial... 

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