Dow Chemical Co. says its new compatibilizer allows reclaimers to get improved properties from PE-PP mixes, making it possible to move the material into higher-value applications.
And, in a separate innovation, plastics manufacturer Indorama Ventures has created a stronger virgin PET for blow molding, allowing packaging companies to use it instead of a recycling-unfriendly PETG to make certain types of containers.
Those were two of the innovations spotlighted in the first-ever Association of Plastic Recyclers (APR) Plastic Recycling Showcase. The event was part of the APR Technical Forum on Feb. 1, held in conjunction with Plastics Recycling 2016 in New Orleans.
“Here at APR we wanted to create the plastics recycling showcase to celebrate APR members that have recently achieved commercial first sale of a new product or a new technology that benefits the recycling industry in a tangible way,” said John Standish, APR’s technical director. “We want to promote these new technologies so that other companies who might adopt the new technologies do so as rapidly as possible.”
Five products and an educational effort were highlighted in the showcase. Click here to read Plastics Recycling Update’s coverage of all of the innovations.
The following offers more detail about the new polymers developed to improve plastics recycling:
Compatibilizing HDPE and PP
Dow’s Intune Olefin Block Copolymers (OBCs) compatibilize HDPE and PP and create a new polymer with physical properties on par with straight HDPE.
“When you think about those two materials they’re very much like oil and water: They don’t like to be together,” said Michael White, new business development manager in Dow’s elastomers division.
While PE has good toughness, processability, sealing and adhesion, PP has good stiffness, heat resistance, clarity and environmental stress crack resistance, he said. But, when you mix them, you lose some of those qualities.
“Intune is that bridge that brings them together and allows you to start doing some different things,” White said. “It’s an effective compatibilizer used at low levels that allows you to really bring these materials together and take advantage of the different attributes that they have. So now you can start getting stiffness with toughness with processability across a very broad range of compositions.”
Dow has “seen a lot of commercial pull” for Intune, he said.
Standish noted that the first commercial use “helps set the stage for growth and wider acceptance in the industry, making recycled PP and PE blends more valuable.”
Blow-moldable PET
Meanwhile, Bangkok-headquartered Indorama created and commercialized a PET resin that can create bottles currently made from PETG but is still compatible with the standard PET stream.
The company’s Polyclear EBM PET 5507 resin can be used to make clear, high-gloss containers with or without handles. It can be used for products as varied as liquor, household cleaners, automotive fluids and other chemicals.
Frank Embs, director of new business development for polymers and resins at Indorama, said the technology is now in production, though he did not disclose the customer.
Polyclear EBM PET 5507 is a true semi-crystalline PET polymer that exhibits high melt strength and slow crystallization to allow for processing on extrusion blow molding equipment adapted to handle PET, according to a product summary. Products made from it can carry the No. 1 resin code.
Embs said the plastic is fully recyclable and follows APR’s Critical Guidance for PET Bottles.
“We didn’t want to have an amorphous resin which withstands the melt processing conditions but then is not recyclable because it cannot crystallize and cannot be processed,” Embs said. “Therefore, we started out with PET and modified it in a way so it has high melt viscosity.”
It also has oxygen permeation qualities similar to standard PET, which is important to enhance shelf life for oxygen-sensitive products.
Correction: The location of Indorama’s headquarters has been corrected. The company is headquartered in Bangkok, not Singapore.