Getting an assist from additives

Features - Materials Science

A number of new additives help compounders and plastics processors boost recycled content in their products.

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August 6, 2018
Bruce Geiselman
Images: Vertellus

Suppliers of additives used NPE2018: The Plastics Show, held in Orlando, Florida, May 7-11, to showcase new additives that make it easier for compounders and plastics processors to boost recycled content in their products.

Vertellus

Vertellus, an Indianapolis-based manufacturer of specialty chemicals, announced the launch of two additives for recycled resins.

Vertellus introduced ZeMac Link NP, a patent pending additive that makes nylon compatible with recycled polyethylene terephthalate (rPET) during compounding. The technology enables manufacturers to reduce costs and boost sustainability. ZeMac Link NP is effective at very low levels and is therefore cost-effective, according to the company.

“As compounders and molders seek to cost-effectively improve material performance while boosting sustainable production processes, ZeMac Link NP provides an innovative and cost-effective solution for including recycled nylon and rPET materials with virgin nylon in various alloys,” Prasad Taranekar, Vertellus marketing manager, says.

Target applications for resins using the compatibilizer include:

  • office furniture;
  • fasteners, such as nuts and bolts;
  • hand tools and small appliances;
  • string trimmers and other outdoor power equipment;
  • textile bobbins; and
  • auto wheel covers and hubcaps.

The resulting blend of nylon with up to 30 percent rPET, from such items as water and soft drink bottles, has performance characteristics close to that of 100 percent virgin nylon, the company says. The rPET can come from low-cost postindustrial and postconsumer sources.

Blending PET with nylon has the added benefit of increasing the electrical insulating properties as compared with pure nylon. That can be a benefit, especially in manufacturing power tools and other electrical and electronic appliances.

Glass fiber, minerals and impact modifiers can be used along with ZeMac Link NP to further improve the properties of blended nylon and PET, according to Vertellus.

The second product Vertellus introduced is ZeMac Extend P, a chain extender additive for improving the properties of recycled polyesters, including PET.

ZeMac Extend P increases the molecular weight and intrinsic viscosity of virgin PET and rPET. Delivering improved melt viscosity and increasing melt strength, ZeMac Extend P reduces sagging of the extrudate, which results in faster production. It also counteracts hydrolytic degradation and improves impact strength. The result is a recycled polyester with performance similar to that of 100 percent virgin polyester, Vertellus says.

The additive promotes sustainability because it encourages the use of low-cost, postindustrial and postconsumer rPET.

Target applications include:

  • injection molding;
  • film, sheet, tape and profile extrusion;
  • bottle blow molding; and
  • strapping and foamed sheet extrusion.

Ashok Adur, global commercial development director of plastics for Vertellus, says the products chemically bind molecules that normally are not compatible.

ZeMac Link NP “chemically bonds polyester to nylon and with [ZeMac Extend P], two polyester chains are joined together with our additives,” he says.

Aesse Sales & Distribution

Blending PET with nylon has the added benefit of increasing the electrical insulating properties of the blended polymer.

Aesse, a Sheboygan, Wisconsin-based distributor of materials used in the plastics industry, introduced a new compatibilizer to the North American market.

In October 2017, Aesse signed an agreement to become the exclusive North American distributor for products from Fine-Blend, a Shanghai polymerization technology company.

Aesse introduced Fine-Blend SAG 008, a chain extender that allows the blending of numerous recycled plastics that normally are not compatible. The company says it made its first commercial sale of the product in the U.S. in May.

One of the primary uses for the additive is to blend PET from soda and water bottles with the polyolefins used to make bottle caps, which normally don’t blend well. However, contamination of PET with caps is a common problem.

Mike McCormack, Aesse business unit manager, says while PET bottle recyclers are a targeted customer for SAG 008, the product’s molecular structure assists in blending a variety of plastics.

SAG 008, an additive that uses a patented styrene acrylonitrile glycidyl methacrylate polymer, improves the thermal stability, molecular weight, intrinsic viscosity and melt strength of degraded polymers, including recycled polyamide, polybutylene terephthalate, PET and polycarbonate. At the same time, it makes other polymers such as acrylonitrile butadiene styrene, acrylonitrile styrene acrylate and modified polyphenylene oxide more compatible or easier to blend with previously incompatible polymers.

“This is kind of like a glue that binds the polyester chains and also binds the polyolefins to the polyesters,” McCormack says.

Aesse recommends blending SAG 008 with recycled plastics at concentrations ranging from 0.5 percent to 5 percent.

The company distributes a range of materials used across the plastics industry, including flame retardants, coupling agents, impact modifiers, lubricants, anti-scratch products and compatibilizers. It has distribution agreements with numerous worldwide companies, the latest of which is Fine-Blend.

Struktol

Hubcaps and auto wheel covers are target applications for resins using one of the new Vertellus compatibilizers.

Struktol, Stow, Ohio, announced a pair of new additives and upgrades to an established product for controlling odors in recycled and virgin plastics.

The products are targeted at automotive, packaging and recycling applications.

Odor-control products range from simple odor masks, which disguise an offensive odor, to complex odor neutralizers that can absorb odors and deactivate specific odor-causing compounds. The products Struktol highlighted take the second neutralizing approach.

“If you are using a recycled compound going into an automotive interior application, there are a lot of things in that compound that could generate odors,” Mike Fulmer, Struktol vice president for plastics and wood-plastic composites, says. “Fillers can generate an odor, an antioxidant system can generate odor, the light stabilizer can generate odor and the polymer itself can generate odor. If you are using a polypropylene that has been modified with a peroxide to change the molecular weight, that peroxide can leave a residual odor. There are a lot of things that can cause odors.”

RP 53 and RP 59 are the two newest odor-control products from Struktol. They can be used in recycled plastics as well as in automotive interior compounds where having a neutral odor may be a requirement.

Odors in recycled and virgin plastics can come from many sources, including additives, such as fillers and light stablizers, and the polymer itself.

Struktol RP 53, which contains a blend of odor-neutralizing substances, is designed for difficult, high-odor compounds containing mercaptans, amines and phosphites. The product can be used in a variety of resins but is targeted at polyolefins. The additive is approved for Food and Drug Administration (FDA) applications, meaning it can be used in polymers and compounds that contact food.

“RP 53 is not really a shotgun approach, but it handles a lot of those different types of chemistries and can help neutralize them and reduce that odor. If you are borderline on the odor level in your compound, a small amount of this can allow you to pass a specification.”

Struktol RP 59 pairs a blend of odor-neutralizing components with volatile organic compound (VOC) absorbers and is intended for difficult, high-odor and high-VOC-content compounds. The product, while designed to work with a variety of polymer resins, primarily is targeted at polyolefins.

RP 59 in plastic packaging can eliminate odors in the packaging and odors coming from the product, the company says.

RP 59 works in a similar fashion to RP 53 but contains the VOC absorber. VOCs are organic chemicals that have a high vapor pressure at ordinary room temperature. The presence of VOCs can cause problems with the physical properties of plastic, and VOCs can produce odors and present health concerns.

Struktol RP 17, which has been on the market longer, also was highlighted at NPE2018 and is a combination lubricant and odor-neutralizing mask designed to reduce or eliminate odors in wood-filled plastic compounds. The company recently modified it for use in a variety of resins and compounds that require the multifunctionality of providing lubrication, acting as a mold-release agent and reducing odors.

“When you compound [recycled milk jugs], that odor is often magnified. ... A little bit of that odor-control additive can take care of it.” – Mike Fulmer, Struktol

All three products work at low loading levels and easily can be added into most processes, including compounding, direct extrusion and injection molding, Struktol says.

In addition to these products, Struktol designs custom products for odor and VOC reduction in several resin types.

Odor-control technology can be important when recycling certain types of plastic for use in automobile interiors.

“On the recycled side, where this becomes a problem is where you have a lot of different recycled streams that are coming in, and some can have significant odors,” Fulmer says. “For example, recycled milk jugs, if they are not cleaned properly, or if you are buying raw ground milk jugs, they might have a sour odor from milk on it. When you compound it, that odor is often magnified and can be incorporated into the piece or part you are making. A little bit of that odor-control additive can take care of it.”

Even if plastic milk jugs are thoroughly washed with detergent before recycling, they still can present a challenge.

“What can happen is you have that detergent smell,” Fulmer says. “It might not be a bad odor; it might be a good odor, but it is still an odor. A lot of times, people don’t want any odor at all. They want it to be as neutral as possible.”

The author is a senior staff reporter for Plastics Machinery Magazine. He can be contacted at bgeiselman@plasticsmachinerymagazine.com.

For more information:
Aesse Sales & Distribution, 920-889-0610, www.aessesd.com
Struktol Co. of America LLC, 330-928-5188, www.struktol.com
Vertellus Holdings LLC, 616-748-7802, www.vertellus.com