Is there a difference between recycled plastics and new ones?
The properties of waste plastics are reduced in different degrees after regeneration, mainly due to photoaging, oxidation and thermal aging. The extent of performance degradation depends mainly on the number of years spent and the environment. The waste edge, molding processing factory production waste recycling materials, the performance decline is very small, can be used when the new material almost, life is short; the indoor use of recycled products, performance has little change; but in outdoor use, long period, poor environment (effects such as pressure, electric and chemical medium etc.) product performance is poor, even can not recover. Due to the thermal aging in the process of regeneration, the color of the recycled material is changed from shallow to deep. The following describes several commonly used plastic recycling properties change.
PS: after regeneration, the color becomes yellow, so the recycled polystyrene is usually painted. The degradation degree of recycled material is proportional to the number of times of regeneration, and the fracture strength has no obvious change when the amount of admixture is less than 60%, and the limit viscosity has no obvious change when the amount of admixture is less than 40%.
Polyethylene: the performance of polyethylene has decreased after regeneration, the color yellow. After several extrusion, the viscosity of HDPE decreases, and the viscosity of LDPE increases.Polypropylene: when regenerated at one time, the color is almost constant, and the melt index rises. More than two times the color increased, the melt index is still rising. After regeneration, breaking strength and elongation decreased, but no problems in use.
Polyvinyl chloride: more obvious discoloration after regeneration, once after the extrusion will have a light brown, and three times almost become opaque brown. The specific viscosity is unchanged at two times, and tends to decrease more than two times. Both hard and soft PVC shall be joined with stabilizers. In order to make the product shiny, ABS 1% - 3% can be added when recycled.
Other plastics: ABS regeneration after discoloration is more obvious, but the use of the amount of mixing does not exceed 20% to 30%, the performance has no obvious change.Nylon regeneration also exists discoloration and performance degradation problems, the amount of mixing to 20% below is appropriate. The elongation decreased and the elasticity tended to increase.
