Shredding secondary

Found in cigarette mainstream smoke. D-limonene may be released to the environment as a fugitive emission during its production, use, or transport. Limonene has been measured in open burning emissions, and studies have shown that gas phase reactions between ozone and terpenes can be a significant source of secondary organic aerosols. The simultaneous occurrence of ozone and terpenes in an indoor environment is relatively common. Ozone is routinely transported from outdoors to indoors, and indoor sources include photocopiers, electrostatic precipitators, and ozone generators. Limonene has been found as a contaminant in washed and dried shredded polyethylene terephthalate (PET, flake) obtained from curbside collection. 

Secondary Shredding. The sizing of the feedstock and its proper metering significantly affect pellet mill performance, wear, and product quality. The primary shredded air classifier light fraction must be further decreased in size prior to densi-fication to reduce milling action on the material by the die and roller assemblies. Otherwise, there are increases in wear and power consumption and a decrease of pellet mill capacity. Also, smaller size feed leads to higher bulk densities and improved flow. 

Figure 3. Particle size distribution of secondary shred light fraction—Rosin-...

In the middle 60 s, the major Italian producers of secondary lead patented and operated an automated battery shredding facility. This technology, later modified to take into account the increasing use of polypropylene cases containing more electrolyte, was in use till late 70 s-early 80 s. Since then, the same producers have modified the existing shredding facility to adapt it to the new battery type (as mentioned, with a polypropylene case and more acid) and to comply with the more restrictive regulations. 

Finally, it would be useful to cite the Annual Buyer s Guide to Tire and Rubber Recycling Equipment [66], which contains contact details and brief product information for more than a hundred companies, most North American, including manufacturers of primary and secondary tire shredding eqnipment, knives, and granulating and pulverizing systems. 

The production of tire shreds or tire chips involves primary and secondary shredding... 

Zegler and Weinle [69] developed a process to make the secondary backing for new carpet from the shredded carpet waste. The carpet waste could contain nylon 6, nylon 6,6, polyvinyl chloride, vinyl copolymer, polypropylene, and polyethylene. The content of nylon was about 15-50 wt%. The chopped carpet waste was extruded at a temperature of 215°C, then calendared and bonded to a primary backing of the new carpet through an adhesive coating. 

In secondary fiber preparation, peripheral systems are very important for the runn-ability of the whole plant as well as for cost minimization and environmental issues. Peripheral plant components are the reject system, sludge treatment and water handling (see Fig. 4.56-4.60). Coarse rejects from the pulping section, heavy particle separation and hole screening are dewatered to a dry content of approximately 60%. If thermal treatment is involved for these rejects, metal components have to be removed and the particle size adapted to the burning process by means of shredding. 

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