Making Plastic Parts More Sustainable

Incorporating sustainable raw materials into your polymers is a great way to enhance the environmental impact of your products. Sustainable polymers are typically processed with bio-based or recycled materials. These materials can help companies hit their sustainability targets – whether those goals are short-term or long-term.  

This article will explain bio-based and recycled raw materials often used in plastics while exploring key factors such as color, performance, regulations, price, and supply.

What are Sustainable Raw Materials?

Sustainable raw materials typically derive from sources that are bio-based or recycled. Many polymers can be formulated with varying levels of these raw materials to achieve sustainability goals.

Bio-based raw materials are commonly derived from renewable plant sources such as corn, wheat, straw, sugarcane, and food and agricultural waste. Despite their different sources, biopolymers are typically used in the same manufacturing process as petroleum-based polymers. To be clear, biopolymers can be either bio-derived or biodegradable, leading to the common misperception that biopolymers make your final products biodegradable – but that is not the case.

Recycled raw materials come in two forms: post-industrial recycled (PIR) and post-consumer recycled (PCR). PIR content is derived from scrap reclaimed within the manufacturing process via skimmers and sieves. PIR content is typically polymer scraps in pellet, flake, or powder form routed through waste treatment before being placed back into the manufacturing process. PCR content is recovered at the end of the product life cycle, collected and processed by local recycling facilities, rather than at the original polymer manufacturing site like PIR content. 

Both bio-based and recycled materials are beneficial in developing more sustainable products for eco-conscious consumers – a growing segment of buyers, as 78% of consumers value a sustainable lifestyle (NielsenIQ, 2023). 

Which Path is Right for You?

Determining the best sustainable raw material for specific applications will depend on various factors including requirements related to color, performance, regulations, supply, and price. 

Color 

Does your product need unique aesthetic appeal? Recycled and bio-based materials do not necessarily hinder the ability to achieve a desirable color for your products but may impact the color choices and consistency. It is important to factor in the impact of the base color of the raw material when choosing the aesthetic for your final product. Biopolymers and recycled materials can be colored using sustainable colorants and additives. Utilizing sustainable-based colorants and additives can lead to a stronger environmental story and the potential for sales to increase up to 2.5% (McKinsey & Company, 2023). 

Compared to recycled materials, bio-based materials generally offer more color flexibility because of their consistency in feedstocks.

• Biopolymers generally offer better control over translucent or opaque shading properties. 
• When coloring biopolymers, there is generally limited differentiation between a pre-colored solution and being colored at the press. 

Black or dark gray colors are typically easier to achieve with recycled materials due to the comingled items that may contaminate the recycling stream. This is especially true with PCR content.

• The most challenging colors to maintain are those with a tight color tolerance. 
• Another consideration is that recycled materials are susceptible to aesthetic defects such as tiger striping, splay, and scratch and mar resistance. 
• The coloration of recycled materials is typically more consistent in pre-colored form rather than being colored at the press.

However, black or dark gray colors can be difficult to be detected by near-infrared (NIR) automatic sorting equipment at recycling facilities. Avient offers colorants that it is detectable by NIR equipment that can help improve recycling streams.

While bio-derived and recycled materials have limitations, there are a number of aesthetic possibilities with sustainable content. Avient can help you digitally predict what colors are possible for the various raw material options. 

Performance 

Incorporating sustainable raw materials into final products may raise concerns about the impact on final product performance. This can depend on the application and the percentage of sustainable content in the final formulation.

• Bio-based raw materials generally have a broader performance range because of the purity of the source. 
• With the current state of recycling streams, polymers formulated with recycled raw materials often don’t perform as well as traditional polymers. Fortunately, custom formulations can help provide comparable performance.

Exploring custom formulations may be extremely valuable because each application is different. Customizing the material may include incorporating functional additives and modifiers such as fibers, foaming agents, oxygen scavengers, flame retardants, and UV blockers. This specialization can help enhance product performance without sacrificing sustainability benefits.

Regulations 

Complying with critical regulation requirements can be challenging based on the maturity of each sustainable raw material. Standards and regulations vary by geographic location as well as the application of the final product. Similar to traditional materials, confirming which standards must be met and ensuring the sustainable plastic formulation is compliant is important. Here are some key questions to consider when sourcing sustainable content:

• In what region will the sale of the final product occur? If raw materials are sourced in one region but sold in another, they must follow the regulations of where they are sold. For example, regulations in food-contact applications include EU 10/2011 (Plastics Implementation Measures, Europe), National Standards (GB, China), and regulations established by the Food and Drug Administration (FDA, USA).
• In what application will the final product be used? Standards are application and industry-specific, but some of the primary industries to consider for regulations include healthcare, automotive, consumer products, and anything in contact with food. 
• Are there any substances to be aware of when looking for sustainable raw materials? This depends on the application, but generally speaking, the substances to be mindful of include phthalates, BPA, allergens, latex, and PAH.

As the supply chain matures, there will likely be more flexibility to meet stringent regulatory demands. Avient’s support teams can help you navigate the regulatory process, provide applicable documentation support, and can help formulate specialty products to meet your project needs.

Supply & Price

The initial costs of using sustainable raw materials may be more expensive than traditional materials. When considering the price of sustainable materials, there are three main drivers:

Supply chain maturity 

• Using bio-based or recycled raw materials in final products is a relatively new concept. Therefore, it takes more time and resources to develop economies of scale. 

High demand, limited supply 

• Suppliers are continually looking to source sustainable raw materials to meet consumer demand, which can help bring down the price. 

Location of source and supplier

• It is important to consider the proximity between the source of the raw materials, supplier, and polymer manufacturing location, as it can contribute to lead times and the total production cost. 

While there are economic challenges during growing demand, the long-term environmental benefits of sustainable materials can far outweigh the cost. 

Key Takeaways

Even with the aforementioned varying factors, consumer demand for eco-conscious products continues to rise. Choosing to incorporate sustainable raw materials into your polymers in an effort to reach your environmental goals can benefit your company for years to come.

• Two of the more widely used types of sustainable raw materials available to use in your products are bio-based or recycled. These include bio-derived content, post-industrial recycled (PIR) content, and post-consumer recycled (PCR) content. 
• Sustainable materials can still achieve an aesthetic appeal for your product. Biopolymers generally can attain consistent colorability because they do not derive from complex recycling streams like PIR and PCR content. 
• The performance of sustainable raw materials can be comparable to petroleum-based materials, depending on the application and the amount of sustainable content used. 
• Sustainable end products must comply with their respective applications, geographic locations, and regulatory requirements – just like traditional materials. 
• Using sustainable raw materials may cost more, but the overall benefits to your company and customers can help offset the cost difference. 

Sustainability goals are here – and they are real. Avient will help support your goals with our material science expertise. If you would like to explore the possibilities of using sustainable raw materials, contact us.