What Can PHA Be Used For?

PHA can be used in many different types of products, from packaging and consumer goods to agricultural products and specialised biological applications. But the more important question is not only where PHA can be used, but also when it actually makes sense to choose PHA.

PHA is especially interesting when the material’s end-of-life matters. This can be the case for products that are difficult to collect after use, products that may unintentionally end up in soil or water, or applications where biodegradation is part of the intended end-of-life strategy.

At the same time, PHA is not one single polymer. Different PHA types can vary significantly in stiffness, flexibility, crystallinity, thermal behaviour and processing characteristics. This means that the right material depends strongly on the application.

When does it make sense to use PHA?

PHA is not automatically the best choice for every plastic product. In many conventional applications, an existing material may already perform well and have an established recycling route.

PHA becomes more interesting when there is a clear reason to look beyond conventional plastics. One example is an application where complete collection after use is difficult. Agricultural products, small components and products used outdoors may have a greater chance of remaining in the environment after their useful life.

PHA can also be relevant when biodegradation is intentionally part of the product design. In these cases, the exact material, formulation, product thickness and environmental conditions all influence how the final product behaves after use. Biodegradability therefore needs to be considered as part of the complete product design rather than as a general claim.

Another reason to choose PHA is that its properties can be adjusted through the polymer type, formulation and compounding. This allows PHA to be developed for applications ranging from relatively rigid products to much more flexible materials.

Not familiar with PHA yet? Start with our introduction to What is PHA?, where we explain how the material is produced, how it differs from conventional plastics and why PHA is a family rather than one single polymer.

Packaging and food-contact applications

Packaging is one of the most visible application areas for PHA. Depending on the grade and formulation, PHA can be processed into rigid trays, containers and cups, but also into flexible films and other packaging structures.

These products can require very different material properties. A rigid container needs sufficient stiffness and dimensional stability, while a flexible film needs more elongation, toughness and melt strength. The choice of PHA therefore depends on much more than simply selecting a biodegradable polymer.

PHA can also be used in food-contact applications when the specific material and complete formulation meet the applicable requirements. In these cases, processing behaviour, heat resistance, surface quality and the intended lifetime of the product all need to be considered alongside regulatory compliance.

Durable and reusable products

PHA does not have to be used only for short-life or disposable products. It can also be developed for durable applications where the product needs to remain functional for a much longer period.

A good example is BitByBit, a reusable cutting board developed from PHA. The cutting board is produced by Wicro Plastics in Kessel, the Netherlands, where the PHA material is injection moulded into the final product. In an application like this, the surface is deliberately exposed to repeated cutting and abrasion during use, which makes material selection especially important.

With conventional plastic cutting boards, this wear can result in small persistent plastic particles being released from the surface. Using PHA offers a different material approach because the polymer is biodegradable rather than designed to persist indefinitely in the environment.

At the same time, the cutting board still needs to function as a durable product. It needs sufficient stiffness and toughness, a suitable cutting surface, dimensional stability and resistance to repeated cleaning. The material should therefore remain stable during its intended service life, while its end-of-life behaviour is considered separately.

This illustrates an important point about PHA: biodegradable does not mean that the product should degrade during use. The challenge is to develop a formulation and processing route that provides the required performance during the product’s lifetime while still offering a different end-of-life profile from conventional persistent plastics.

Agriculture and products used close to nature

Agriculture is an area where the end-of-life of a product can become particularly important. Products such as plant pots, clips and other agricultural components can be difficult to collect completely after use.

Helian Polymers has, for example, worked on PHA formulations for a Plantaz plant pot. The plant pot is also produced by Wicro Plastics, using injection moulding. A product like this illustrates why application requirements need to come first: the pot needs sufficient stiffness and stability during production, transport and plant growth, while its intended end-of-life can create a reason to investigate biodegradable materials.

The same principle can apply to other agricultural products. If a component has a realistic chance of remaining in soil or is intentionally designed for a biological end-of-life route, PHA may offer an interesting material option. The exact environmental conditions still matter, however, and not every PHA product will degrade at the same rate or under the same conditions.

PHA as a functional material: NPX Bioballs

Some PHA applications go beyond simply replacing the structural function of a conventional plastic.

The NPX Bioballs are an interesting example. These biological filter materials are used in aquariums and fish tanks for nitrate removal. In this application, the PHA itself plays a functional role because it can act as a carbon source for bacteria under the right conditions.

This is fundamentally different from using PHA only as a tray, cup or housing. Here, the biological behaviour of the material is part of how the product works.

Applications such as this show why the PHA family is interesting from a material-development perspective. Molecular structure, formulation and degradation behaviour can all influence the performance of the final application.

Films, coatings and other material formats

PHA can also be processed into films and coatings. These applications require very different material behaviour from injection moulding.

For flexible films, properties such as elongation, toughness, melt strength and crystallisation behaviour are important. For coatings on paper or fibre-based substrates, adhesion, viscosity, processing temperature and barrier performance become more relevant.

This means that the same PHA grade will not automatically work for every processing technology. Formulation and compounding are often required to adjust the material to the desired process and final performance.

Researching new PHA applications

Many PHA applications are still actively being developed. Helian Polymers is involved in several research projects in which new formulations, processing routes and applications are being investigated.

Projects such as VISS, PHAntastic, ELLIPSE, ECOFUNC and PPG are examples of this broader development work. These projects help explore how PHA can be processed, modified and applied in new product concepts.

This research is important because replacing an existing material is rarely as simple as choosing a new polymer. Mechanical performance, processing, crystallisation, additives, product design and end-of-life all need to work together.

Why the application should come first

The examples above show that PHA can serve very different functions. A cutting board, a plant pot, a packaging film and a biological filter material can all contain PHA, but they have almost nothing in common when it comes to their performance requirements.

That is why material selection should begin with the application rather than with the name of the polymer.

For one product, stiffness and dimensional stability may be critical. For another, flexibility or biodegradation behaviour may be more important. Processing technology, lifetime, food-contact requirements and intended end-of-life can all influence which PHA type and formulation is suitable.

At Helian Polymers, this development process can include:

Application requirements → material selection → formulation → compounding → processing trials → final application

The polymer is therefore only the starting point. The final material needs to be developed around what the product actually has to do.

Final takeaway

PHA can be used in applications ranging from packaging and reusable consumer products to agriculture and specialised biological systems.

But PHA is most interesting when there is a clear reason for choosing it. That could be a product where biodegradation is part of the intended end-of-life, an application where collection after use is difficult, or a product where a PHA formulation can provide a useful combination of mechanical performance and biological behaviour.

The question is therefore not simply:

“Can this product be made from PHA?”

A better question is:

“Why would PHA make sense for this application, and which PHA material would provide the required performance?”