Flexible seal contamination

The flexible serew conveyor is another system with many advantages. Figure 3.10 shows the sehematie diagram of a conveyor and examples of its applieations. The only moving part of this eonveyor is a flexible spiral directly driven by an electric motor and rotating within an outer tube. The system is totally sealed which makes it dust-free and eliminates atmospheric contamination (e.g., humidity). The spiral s gentle action does not degrade the material. This conveyor can convey in any direction and with a variable speed... 

A standard oil seal consists of an outer circular metal disk with an inner flexible rubber which is affixed to the metal during vulcanization. The bonded seal has no loose parts to allow leakage of oil or ingress of any contaminants. This kind of seal is more accurate, and can easily be fitted into a smaller space. An example is shown in Figure 2.9. 

T. Herrmann, B. Lynch, Ultrasonic sealing of flexible pouches through contaminated sealing surfaces. ANTEC 2003, 2629 (2003). 

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