Fragmented plastic particle size

Fragmentation is an important precursor to biodegradation as it increases the surface area of plastic available to microbes to interact with. However, the kinetics of fragmentation (as opposed to that of degradation) and the evolution of particle sizes during fragmentation of plastics outdoors are essentially unknown. 

Plastic samples were pulverized with a blender and then mortar and pedestal. ASTM D6691-09 allows for testing of plastic products in the form of him, foam, powder, or fragments of molded product. According to ASTM, powder samples should have a mean particle size of less than 25 mm. Our powder samples had a mean particle size less than 25 mm based on visual observahons. CO2 biogas was measured with a PASCO detector with computer-controlled equipment as shown in Figure E.l. The samples are kept in an oven and held at 30°C for 26 weeks according to ASTM standards. 

The material properties such as particle size and deformation mechanism (elasticity-plasticity and fragmentation) and compressibility have been identified as affecting the ability of a binder to create strong tablets [10-14]. 

A bi-exponential equation can represent compaction of powders, first, by filling the same or larger size voids rather than the initial smaller voids and, second, by filling the smaller voids (due to particle deformation), thus proceeding with elastic or plastic deformation or fragmentation. 

Creep rupture tests of plastic pipe, described in Chapter 14, are typical of whole-lifetime testing. It is difficult to manufacture plastic products without incorporating foreign particles, of size about 0.1mm, such as undispersed pigment or stabiliser, or metal wear fragments from extruder screws. The... 

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