Remelting recycled PET would turn yellow when granulated into new products, and there are many reasons. Ultraviolet radiation, residual contamination, and even additives can cause discoloration of PET renewable materials. Chemists around the world developed a formula to help businesses use new products in regenerative PET, to minimize the possibility to turn yellow. As a result, there are more lucrative profit.
But organic chemists said when talking about the impact of all these years paint, labels, light and other factors. But the study never really heard before reprocessing, and the true impact of ultraviolet radiation on their PET container regeneration.
Vice president of Plastics Technology Co., Ltd. (Plastic Technologies Inc., located in Holland, Ohio, USA) is working to do. “We attend meetings, and have been discussing how to do a better job of recycled materials and have caused a series of problems,” the chemists said, some things have been discussed for so many years. But a really good answer of turning yellow is still a problem.
“This study is to give you some more information about the possibility of the factor for PET turning yellow.” He said.PTI number of PET bottles will be placed on the roof, to accept up to a year of light and turning them from time to time, to ensure a uniform UV illumination. Some other bottles are on the interior, illuminated by fluorescent lights, the third group of bottles as the experimental control group, are stored, protected from light.
Schloss said, though his studies have shown that UV is the cause yellowing of recycled PET a reason, but compared to other factors, such as additives and residues, effects of ultraviolet how much? For this, is unclear.
At least the United States, most recycled materials manufacturers and plastics recyclers recycled PET products will no longer be placed outside, exposed to the sun. “At least not for a long time to put out.” Schloss said. “There may be some people doing it,” he adds, but in other countries, “stacked outside may still be a very common phenomenon.”
“I’m not saying this is the main reason for PET yellowing, but it really is a factor we have to consider, so if you have a choice, do not put the recovered PET was piled outside sunlight, most recyclers in the United States to do so, but they may not know the impact. “he said.