Authored By: SDI Plastics

Plastic waste is one of the biggest environmental challenges we face today. With over 380 million tonnes of plastic produced globally each year, only about 10% is recycled. The rest ends up in landfills, oceans, and elsewhere in the environment, causing significant harm to wildlife, spreading toxins, clogging waterways, and contributing to climate change.

To create a more sustainable future, we need solutions that reduce reliance on conventional plastics derived from fossil fuels. Biodegradable plastics present a promising option, offering alternatives that can decompose naturally after disposal. For manufacturers who rely heavily on plastics, adopting biodegradable alternatives can be an impactful way to reduce environmental footprint.

What are biodegradable plastics?

Biodegradable plastics are designed to break down more quickly and naturally in the environment compared to traditional plastics. They can be derived from renewable biological sources or from petrochemicals with additives that enhance their biodegradation. The two main types are:

1. Bio-based biodegradable plastics: Made from renewable biological sources such as corn, potatoes, or sugarcane. Common examples include polylactic acid (PLA) and polyhydroxyalkanoates (PHA).
   
2. Petroleum-based biodegradable plastics: Made from petrochemicals but designed to degrade more quickly than conventional plastics. Examples include polybutylene succinate (PBS) and polycaprolactone (PCL).

How do they degrade?

Biodegradable plastics break down through the action of microorganisms such as bacteria and fungi. The degradation process involves:

• Hydrolysis: Water molecules break the polymer chains into smaller fragments.
• Microbial Digestion: Microorganisms consume the smaller fragments, converting them into natural substances like carbon dioxide, methane, water, and biomass.

Environmental impact

The main advantages of biodegradable plastics include:

• Reduced pollution: They can help decrease plastic pollution in oceans and landfills.
• Lower carbon footprint: Bio-based biodegradable plastics often have a smaller carbon footprint compared to conventional plastics, as they are derived from renewable resources.
• Compostability: Some biodegradable plastics are compostable, meaning they can decompose into nutrient-rich compost under controlled conditions.

However, there are also some challenges:

• Degradation conditions: Many biodegradable plastics require specific conditions (such as industrial composting facilities with high temperatures and humidity) to break down efficiently. In natural environments, degradation can be much slower.

Benefits of biodegradable plastics for injection moulding

For manufacturers using plastic injection moulding techniques, switching to biodegradable plastics offers many advantages:

1. Reduced environmental impact

Bioplastics divert reliance away from fossil fuels, reducing carbon footprint. And their decomposability eliminates plastic waste buildup. For instance, PLA releases up to 68% less greenhouse gases compared to traditional plastics. Using bioplastics for plastic injection moulding parts can tremendously lessen environmental impact.

2. Compliance with new regulations

Governments worldwide are banning certain conventional plastics and requiring more recyclable or sustainable alternatives. For example, France banned all single-use plastics by 2040. And the EU aims for all plastic packaging to be recyclable by 2030. Transitioning to biodegradable resins like PLA enables manufacturers to comply with growing sustainability regulations.

3. Meeting consumer demand

Consumers increasingly want eco-friendly products. A Nielsen study found 81% of global respondents feel strongly that companies should help improve the environment. Using bioplastics satisfies consumer demand for environmentally responsible products. Companies can build brand reputation by switching to bioplastics.

4. New business opportunities

Focusing on sustainability and biodegradability can open up partnership opportunities, like working with waste management firms on composting solutions. Companies can also qualify for certain green business grants and tax incentives offered for environmentally progressive practices.

5. High performance materials

Bioplastics like PLA can match conventional plastics for durability, flexibility, transparency, and other material properties important for plastic injection moulding. PLA makers are also innovating new composites, like PLA blended with silicone or other polymers, for even greater performance capabilities.

6. Renewable inputs

Unlike finite fossil fuel sources, the plant-based inputs for most bioplastics like corn and sugarcane can be grown year after year. This allows for a continuously renewable supply, rather than relying on unsustainable raw materials that will eventually run out.

Applications of biodegradable plastics for injection moulding

Here are some promising applications where manufacturers can use biodegradable plastics for injection moulded parts and products:

Food packaging

PLA is commonly used for food containers, cups, bottles, utensils, and more. Some brands use plant-based packaging grown from sustainable sources.

Agriculture

Rigid bioplastic pots and trays for seedlings, cuttings, and garden planting offer an eco-friendly alternative to plastic planters that often end up in landfills.

Consumer goods

Personal care, electronics, toys, and household products use many injection moulded plastic parts that can be replaced with PLA or PHA versions. For example, PLA is used to make cosmetics packaging, pens, razors, and phone cases.

Textiles

Plastic Injection moulding with bio resins allows creating plastic fasteners, buttons, snaps, clips, hangers and other accessories used in clothing and shoes. For instance, PLA sewing thread is an alternative to nylon.

Medical supplies

PLA is already widely used for medical implants, scaffolds, and drug delivery devices. More disposable medical tools and parts like syringes, IV tubes, and casts can be injection moulded using bioplastics.

Factors to consider in adopting biodegradable plastics

While biodegradable plastics have tremendous promise, manufacturers looking to switch need to assess a few crucial factors:

Costs

Bioplastic resins currently cost 20-50% more than conventional plastic. Prices are expected to decrease as technology improves and demand rises, but initial investment is higher. Government incentives like subsidies or tax breaks can improve feasibility.

Performance requirements

PLA and PHA can mimic plastic properties quite well, but businesses should evaluate if bio resins match all the mechanical, thermal, chemical and other performance needs for their specific plastic injection moulding parts before transitioning completely.

Supply chain coordination

To ensure proper decomposition, steps like establishing composting systems and recycling partnerships may be needed. Manufacturers should assess if their downstream supply chain is ready for wide adoption of bioplastics.

Stakeholder engagement

Bringing employees, suppliers, distributors and consumers on board with sustainability initiatives is key to overcoming obstacles and easing transition costs. Manufacturers can build support through education, incentives and demonstrating commitment.

Facility retrofitting

Some equipment modifications may be necessary to switch moulding processes and protocols to new bioplastic resins. Assessing required facility upgrades for successful adoption is essential.

With proper consideration given to these factors, manufacturers can implement biodegradable plastics for injection moulding in a smooth, practical way and play a big role in improving the sustainability of our planet.

The future of biodegradable plastics

In the near future, we can expect great strides in expanding bioplastic usage across industries as technologies continue advancing and costs decrease. Here are some exciting innovations in development:

• Hybrid biocomposites: Blending bioplastics with other sustainable materials like recycled textile fibres can produce injection moulding resins with enhanced properties. Toyota is developing PLA composites for car parts.
  
• Multilayer bioplastic packaging: Combining layers of different bioplastics together can optimise characteristics like gas barrier, strength, and transparency. This allows creating food packaging with a shelf life similar to conventional plastics.
  
• PLA manufacturing from methane: Using methane as the feedstock to create PLA significantly lowers environmental impact. Newlight Technologies has produced AirCarbon PLA this way on an industrial scale.
  
• Self-destructing bioplastics: Incorporating special additives can make plastics rapidly degrade when triggered by heat, moisture, or other factors. This can expand single-use applications.
  
• Bioplastic recycling: Chemical recycling techniques are being developed to break down used PLA and PHA polymers and turn them back into fresh resin for re-moulding. Moving towards a circular production model.

In conclusion – sustainability for future generations

Biodegradable plastics represent a groundbreaking solution in our quest to reduce the environmental damage. By embracing these innovative materials, we not only reduce our reliance on fossil fuels but also pave the way for a cleaner, greener planet. The ability of biodegradable plastics to decompose into harmless natural substances offers a hopeful vision of a future where plastic waste no longer pollutes our oceans and landscapes.

As technology advances and infrastructure improves, the widespread adoption of biodegradable plastics can lead to a significant reduction in plastic pollution, fostering a healthier ecosystem for generations to come. 

In this journey towards sustainability, biodegradable plastics stand as a testament to human ingenuity and our commitment to preserving the Earth for future generations. Let us champion this change and support the transition to biodegradable alternatives, ensuring a legacy of environmental stewardship towards a brighter and more sustainable future.