Agricultural fiber composite brings sustainability, cost advantage to plastics

Natural fiber processing technology expert AdvancedBMT has partnered with industry leaders to develop an innovative new natural fiber supply chain using the company’s patented technology.

AdvancedBMT’s natural fiber material offers a high-performance-to-weight ratio along with acceptable odor characteristics. The fiber material’s aspect ratio and density result in high rigidity with minimal weight. The equipment supply partner Cretes is to provide highly automated manufacturing equipment capable of producing consistent materials in large quantities.

By optimizing natural fiber processing technology, the company seeks to deliver more consistent natural fiber materials compared to existing competitors that already provide natural fibers for use in injection and extrusion molding.

Because of the cost advantage, natural fiber composites are expected to be the material of choice in a number of applications, especially those where weight reduction is valuable. The composites also produce fewer CO2 emissions than competing materials, such as calcium and talc, making them an alternative to non-sustainable materials currently in use. Most importantly, a domestic supply chain that utilizes an abundant waste stream as raw material is expected to provide a stable, low-cost and consistently available material that is not impacted by the volatility of oil prices or competition from international demand.

“AdvancedBMT’s natural fiber polypropylene composites are an ideal combination to achieve a sustainable material that retains high levels of performance,” said CEO Robert Ziner. “The production of natural fiber composite feedstock materials has traditionally been efficient, hampered by excessive material handling and transportation needs. Our proprietary natural fiber processing technologies and model increase the desirability and maximize the economic efficiency.”

The natural fiber composite material is expected to have commercial applications across many industries, especially automotive interiors and computer housings.

finished parts have biomass loadings ranging from 10-30% of the finished components and can be combined with recycled materials to produce a 100% sustainable plastic product.

The company expects to pursue the development of new biocomposites and research additional biomass fillers.

AFTER DRYING, MOLDED WITH EASE

Ziner told CanPlastics that to support the new product, and with the help of a Canadian Agricultural Partnership Grant Approval, the company developed a new patented Technology. So, how hard is it to mix natural fibers and plastics? Apparently, not very, according to Ziner.

“The material processes very well below 190C,” Ziner said, “and shrink is very minimal due to the fibers.”

Natural fibres in plastics are becoming increasingly popular among plastics processors, compounders and their customers, especially in the European Union. This trend has been driven by environmental concerns, and improvements in the quality and availability of natural fibers.

The use of fibers is limited to polymers that can be processed at low temperatures, such as PP, PE and PVC and PLA.

WIth polyolefins, compatibilizers are used to enable adhesion between the fibers and polymer matrix.

There is a strong interest in using natural fibers to reinforce PLA, to maintain the 100% biobased claim while providing unique performance characteristics that would typically be achieved with a mineral or synthetic performance additive like glass fibers or talc. TPS is also well suited as a polymer matrix.

AdvancedBMT’s experience suggests that while using a co-rotating twin screw extruder, polymer should be added through the main feeder while fibers are best added later via a side feeder. Difficulties can arise due to the fibers’ low apparent density, which makes it hard to feed into the extruder consistently, and it is important to consider the fibers’ tendency to clump, which if not managed effectively can reduce the performance of the composite. One way to manage both issues is pelletizing fibers before compounding yet this increases the shear required for dispersion, which can cause tearing and or degradation of the fibers.

Adding fibers also impacts melt flow, typically increasing viscosity. The optimal melt flow of the polymer matrix will depend on the application, ie: injection molding will require a higher mfi polymer than extrusion.

The max loading of fibers that can be achieved depends both on the manufacturing process, for example, 30% can be achieved easily in extrusion, yet would be much more difficult to achieve with injected part. Max loading is also impacted by the fibers ability to bond with the matrix, which can be influenced by the presence and loading of compatibilizers. Even more critical to consider are the desired outcomes: the best balance of properties is achieved at relatively low loadings, so high loadings will only make sense in certain applications – the optimal loading is impacted greatly by the availability and cost of the matrix polymer.

It’s also important to consider that the same mass of natural fibers will fill ~ 2x the volume of mineral fillers meaning there is potential not only to reduce the cost of the additive / filler, but also to reduce the volume of polymer needed, a major potential source of cost reduction.

By far the biggest benefit of natural fibers is the potential for weight savings, especially in automotive and other transportation related industries.  Coupled with good strength and stiffness properties, it’s easy to see the potential for this technology playing a great role in the future of efficient transportation. Another benefit for automotive applications is that natural fiber filled plastics provide improved acoustical and vibration dampening.

For the plastic industry, the fine, non-abrasive qualities of natural fibers, especially those from flax, hemp, kenaf, and wood are a boon and it will also be appreciated that they are non-toxic, and not irritating to the skin or respiratory system. Also, energy costs associated with compounding and molding are reduced compared to traditional, denser alternatives.

An up and coming opportunity is the marketing benefits associated with an environmentally friendly, carbon sequestering, and fully renewable raw material.

Ziner also acknowledges that he has been hard at work overcoming the challenges associated with natural fiber materials saying, “moisture absorption, impact strength compared to glass fibers, processing temperatures, the cost of pelletizing before compounding, these are all things my team is talking to me about day in and day out.”

Ziner is not the first to champion natural fiber’s use in thermoplastics. Faurecia, a large global producer headquartered in Europe has commercialized a range of grades using the moniker “NAFILEAN,” natural fiber filled polypropylene used for the injection molding of structural automotive parts, which has been installed in over 13 million vehicles to date. Many European compounders like Beologic, Tecnaro, Advanced Compounding, Et Al, along with Michigan based compounder RheTech are known to offer natural fiber filled grades of PP and PE.

It seems the team at AdvancedBMT has a vision to expand the possibilities for natural fiber plastics: to supply the industry as cost-effectively as possible and with the highest degree of quality and consistency, increasing competitiveness of the material – and increasing the utilization of natural fibers in plastics. When asked why he is pursuing this opportunity, Ziner responded, “The sample parts we’ve helped our strategic partners create demonstrate to me that the performance of natural fiber filled polypropylene is extremely useful in certain applications and I’m particularly excited about the opportunity in lightweight automotive parts.”

According to Ziner over 1 million tonnes of flax straw from the flax seed harvest is burned annually in North America – enough to support 20 AdvancedBMT facilities converting the leftover biomaterials into plastics.

Roebert Ziner is the founder & CEO at Toronto-based Advanced Bio-Material Technologies Corp.