Operation Clean Sweep

Plastic pellets inadvertently lost from plastic production and warehouse facilities pose a threat to fish and wildlife. Therefore, the U.S. EPA (Environmental Protection Agency) has classified plastic pellets as significant materials. . The finding of even one pellet in a storm water run-off without a permit is now subject to federal regulatory action with the potential for substantial fines and penalties. As a result, the plastics industry has launched Operation Clean Sweep, an initiative to prevent the accidental release of pellets into the environment. Specific recommendations for handling polyolefins to prevent resin loss into the environment have been developed by the Society for the Plastics Industry (38). 

Operation Clean Sweep—Pellet Loss Prevention Program, SPI, Literature Sales Department, 1801 K St, NW 600, Washington, DC 20006-1301. 

Operation Clean Sweep (2007) American Chemistry Council, http //www.opcleansweep.org/overview/ (last accessed June 2013). 

The manufacturing process utilizes Operation Clean Sweep Practices to minimize pellet loss at plastic manufacturing operations. 

The material of interest is dissolved in a volatile solvent, spread on the surface and allowed to evaporate. As the sweep moves across, compressing the surface, the pressure is measured providing t versus the area per molecule, a. Care must be taken to ensure complete evaporation [1] and the film structure may depend on the nature of the spreading solvent [78]. When the trough area is used to calculate a, one must account for the area due to the meniscus [79]. Barnes and Sharp [80] have introduced a remotely operated barrier drive mechanism for cleaning the water surface while maintaining a closed environment. 

The sweep device rests on the edges of the trough and is used to clean the surface before the experiment and to compress the film once it is formed. For accurate work, it is preferable that the sweep is attached to support rods (as shown in Fig. 46) which can be moved along the trough by means of a screw drive. It is usually necessary to place the film balance inside an air thermostat, with provision for operation from the outside. 

The grille across the front floor of the BSC must not be blocked by equipment or supplies, or by the operator. You must raise your arms above the grill so that air sweeps around your arms rather than allowing your arms to lie upon the grille. As in the chemical hood, you must work as far as possible inside the hood, but at least 4 inches further in from the front grille. Equipment and materials inside the BSC can disturb the airflow and it is important to keep these to the minimum of what is necessary for a particular operation only. Equipment that can generate aerosols should be as far back in the BSC as possible so that these aerosols are captured by the hood. If aerosols are near the front of the cabinet they could escape. If a vacuum system is used, it must be HEPA filtered. It is important to keep your clean materials at least a foot from aerosol-producing operations. 

In copolymerizations, one monomer reacts at a different potential from the other, such that the copolymerization requires an oxidation potential yet higher to proceed appreciably. However, often potentials even higher than these are required, to minimize blocking of the electrode surface by a thin film of polymer which impedes further electrochemical reaction. The use of ultrasound can be understood in terms of the removal of this layer in a "sweeping clean" manner, thus allowing the true reactivity ratio of the monomers to operate throughout the electrolysis. 

The construction of chutes, valves and conveyors should be such that they are self-cleaning, if possible arranged so that one of the other components in the mix cleans out any residue for example in an operation where pellet rubber is used, this is ideal to follow a sulphur/accelerator feed down a chute to sweep it clean. Vulcanized rubber sheet makes an excellent material for the construction of chutes. 

Comments have been made previously about the design of bends. Current thinking is to avoid broad, sweeping bends to eliminate particle-wall abrasion. Instead of these bends, a common T with one end plugged is recommended. Solids willl build up on the closed end of the T and the solids will abrade against themselves. Cleaning of these Ts is an easy operation, as mentioned earlier. 

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