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LDPE resin pellets

Amorphous HIPS resin pellets compact very little in the temperature range of 25 °C to about 75 °C, a temperature that is about 25 °C below Tg, as shown in Fig. 4.5. The HIPS resin compacts to a much higher degree for temperatures of 25 °C below Tg up to Tg. Like the LDPE resin, the bulk density at 25 °C and zero pressure was measured using the cell shown in Fig. 4.2 at 0.62 g/cmL At temperatures 25 °C below the Tg (100 °C), the bulk modulus of the resin is relatively high, and thus the pellets do not deform easily under pressure. At higher temperatures, how... [Pg.113]

The compression ratio for pellet feedstocks typically ranges from about 1.8 for PMMA resins [2] to 4.5 for LDPE resins [3], although many exceptions are practiced. Compression ratios for several common resins are reported by Giles, Wagner, and Mount [2]. If high levels of a low-density recycle stream are added back into the feed hopper, then the compression ratio and compression rate will need to be increased as follows ... [Pg.192]

Compression rates typically vary between 0.0025 and 0.0055 for pellet feedstocks. If the compression rate is too low, then the compaction rate of the solid feedstock may not be high enough to force the entrained gas out through the hopper. If the compression rate is too high, poor melting performance and solid bed breakup can occur. For example, LDPE resins can be melted very easily using a screw with a compression rate of 0.0055, while LLDPE resins perform best with a compression rate near 0.0030 [3, 4]. If an LLDPE is extruded using a screw with a compression rate of 0.0055, then solid bed breakup and solid polymer particles in the extrudate are likely to occur. [Pg.192]

Large diameter, melt-fed extruders are commonly used for the final devolatilization and pelletization of LDPE and PE copolymers in resin manufacturing plants. A full description of this type of extruder and process is provided in Section 15.3. Simulation of these processes is complicated by the multiple flights used in the design and the high H/W aspect ratios of the channels. The processes can be simulated from the feed hopper to discharge, however, since they are not required to convey solids and melt resin. This section will show the requirements and difficulties for simulating these processes. [Pg.279]

The market outlook for recycled plasdcs is strong. The recycled resin demand for the six previously mentioned plastics (HOPE, LDPE, PET. PP. PS and PVC) by the end of 1993 are expected to be 3.5 times that of 1990 levels. The price of sorted, baled plastic is currently in the range of 7 to 120/lb tind die price of sorted, cleaned and flaked plastic is 20 to 30 /lb. Pelletized recycled resin ranges from 20 to 450/lb. [Pg.6]

Based on preliminary results, the design of a plant for treatment of the film plastic wastes was completed in 1985. The facilities were designed to produce pellets from the film plastic wastes ready to run a production with substitution of the required percentage of LDPE virgin resin. The mass balance and implementation of the plant design can be seen in Figures 19 and 20, respectively. [Pg.81]


See other pages where LDPE resin pellets is mentioned: [Pg.113]    [Pg.102]    [Pg.113]    [Pg.102]    [Pg.160]    [Pg.175]    [Pg.377]    [Pg.657]    [Pg.661]    [Pg.664]    [Pg.152]    [Pg.21]    [Pg.2928]    [Pg.515]    [Pg.227]    [Pg.211]    [Pg.2890]    [Pg.546]    [Pg.646]    [Pg.890]    [Pg.895]   
See also in sourсe #XX -- [ Pg.102 ]




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Pelletized resins

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