More and more companies are reviewing the materials they use. Very often, that conversation begins with the search for an alternative to the current raw material.

The problem is that, in many cases, this search begins before properly defining what needs to be improved, what must be maintained and what the new solution has to comply with.

Not all bioplastics are the same, nor do they perform in the same way across all applications. To make the right decision, you need to look at the full picture: the product, the process, the use, the end of life and market requirements. That is where the analysis should begin.

In this article, we explain which variables should be reviewed to determine whether a bioplastic can fit your product, and which mistakes should be avoided when considering a material change.

How to choose a bioplastic according to your application

To know whether a bioplastic can fit a product, it is not enough to look at the material in isolation. Several variables must be reviewed, as they directly affect its technical, industrial and commercial feasibility. These are the main ones.

1. The application

The first step is to understand what function the product fulfils and what its real requirements are. A rigid part does not require the same as a flexible film. Nor does a food, cosmetic or agricultural application. Before assessing a material, it is important to be clear about what the product needs to do, under what conditions it will be used and which performance features it cannot lose.

A rigid cosmetic cap that needs a good surface finish, dimensional stability and colour consistency does not pose the same challenge as an agricultural film, where what matters is how it performs in the field, how long it needs to last and what end of life makes sense.

Nor is a food tray that must maintain its shape and functionality during use the same as a small single-use item where the main issue is not mechanical resistance, but how it is managed afterwards and whether there is a clear recovery route.

Even within the same category, there are important differences. A thick injected part does not have the same requirements as a thin wall. Secondary packaging is not assessed in the same way as packaging in direct contact with the product. And an application where visual finish is decisive does not require the same as one where functionality comes first.

That is why, before talking about material, it is worth clearly defining questions such as these:

• Is it primary or secondary packaging?
• Will it be in direct contact with the product?
• Does it have a structural function, or is it mainly for presentation?
• Does it need to maintain shape, resistance or barrier properties for a specific period of time?
• Will it be exposed to humidity, heat, friction or outdoor conditions?

A cap for premium cosmetics, where finish, colour and rigidity are key, is not the same as an agricultural film, where field performance and end of life condition the entire decision. Nor is a food tray with mechanical requirements and stability during use the same as a single-use item with a very short life and a very limited recovery circuit.

When this part is not properly defined, the project usually starts off badly because the material is compared before the problem has even been clearly delimited.

If you are considering a material change, at Benviro we can help you define those requirements before you start comparing options. Contact us

2. The transformation process

It is not enough for the material to make sense for the application; it must also be processed properly. Injection moulding, extrusion, blow moulding and thermoforming do not require the same things, and a material that works in one context may not perform in the same way in another. That is why, before moving forward, it is necessary to assess whether the solution fits the existing production process and whether it can be transformed with stability.

This point is often underestimated at the beginning, and later becomes decisive. In many projects, the main barrier is not the concept of the material itself, but how it behaves during transformation.

This involves variables such as:

• The flowability of the material
• Its thermal stability
• The processing window
• Repeatability between cycles or batches
• The final finish of the part
• Its sensitivity to specific machine conditions

For example, a solution that performs well in an injected part does not necessarily transfer well to a film extrusion application. Likewise, a material that works in a one-off test may not maintain the same behaviour when repeated under industrial conditions, with longer runs, parameter variation or specific productivity requirements.

The question worth asking is quite simple: does this material fit the current process, or will it force the transformation process too much?

If one of your doubts is how the material may behave in your current process, we can help you review that fit from a real industrial transformation perspective.

3. The properties the product needs

Each application has different priorities: in some cases, rigidity is more important; in others, flexibility, finish, thermal resistance or dimensional stability. The mistake is often trying to keep everything at once without distinguishing what is truly essential and what is not. To choose well, you need to define which properties the product must meet and which ones can be adjusted.

This point requires a fair amount of honesty, as many companies start from an implicit idea: changing material without changing anything else. Sometimes that is reasonable; other times it is not.

If the current material has been optimised for years for a very specific application, it is normal for the starting point to be highly refined. Trying to replace it while maintaining exactly all its performance features, the same finish, the same processing response, the same visual perception and, in addition, incorporating new sustainability requirements is not always feasible in the first instance.

That is why it is worth organising priorities and clearly separating three levels:

• What is essential, because it directly affects the function of the product
• What is important, but allows some margin for adjustment
• What can be reviewed, if the change improves the overall fit of the solution

When analysing an application, some of the properties that usually come into play are:

• Rigidity or flexibility
• Mechanical or impact resistance
• Dimensional stability
• Thermal behaviour
• Surface finish
• Colour, gloss or texture
• Feel and visual perception
• Behaviour during use

In fact, this often happens when the starting point is a conventional plastic such as polyethylene or polypropylene. They are widely used materials precisely because they offer a broad balance of properties and work well in many applications. But that does not mean that, in every case, all those performance features are truly necessary.

For example, in certain flexible packaging applications, polyethylene may provide a level of resistance, flexibility or barrier behaviour that exceeds what the actual use requires. And in some injected polypropylene parts, the material may be offering a combination of rigidity, thermal resistance and durability designed for more demanding uses than the specific application.

This does not mean that those properties are always “unnecessary”, but it does mean they should be reviewed one by one. Because sometimes the project does not need to replicate the entire performance package of the current material, but only maintain the features that truly condition the function, use or acceptance of the product.

For example:

• A cap or secondary part may not need the same thermal resistance as a component exposed to heat
• A short-life package may not require the same durability as a format designed for prolonged use
• A part with low mechanical requirements may not need the same level of rigidity or impact resistance as the conventional starting material

That is an important part of the analysis: distinguishing which properties come from the current material and which are truly necessary for the application to work properly.

If you need to review which properties are truly critical in your product and which allow some margin, we can help you here to organise those priorities before considering a material change.

4. The context of use and end of life

The material must also make sense during use and when the product is no longer used.

An application with a clear collection and recycling route is not the same as another that, because of its size, format or contamination after use, has very few real recovery options. Nor should a short-life product be assessed in the same way as one that must remain stable for longer.

That is why, when assessing a material, it is worth reviewing four questions:

• How the product will be used
• What happens during its use
• What happens to it after use
• Which end of life makes sense for that specific application

Many decisions are oversimplified here. It is assumed that if a material is recyclable, then it is sustainable. Or that if it is biodegradable, it is automatically a better option. But that is not how it works.

There are formats where recyclability is a reasonable route, because there is a more or less clear collection, sorting and recovery system. But there are also others where that recovery is much less likely. For example:

• Small components that are often not properly separated in the plant
• Multimaterial formats where different layers or components make recovery more difficult
• Packaging that is highly contaminated after use, where real management does not always match the theoretical logic of the design

But not everything is decided at the end of the product’s useful life; it is also worth looking at what happens while the product is being used. In certain applications, the material may be exposed to friction, heat, humidity, repeated handling or contact with other substances.

This is where an increasingly important issue comes in: the generation of microplastics. If the debate is limited only to whether or not the material is recycled, an important part of the problem is left out. There are products and packaging that, during use, wear or fragmentation, may release persistent particles. And that requires looking at the material with greater judgement, not only from the perspective of waste management, but also from its behaviour throughout its useful life.

This is especially relevant in applications where:

• There is friction or wear during use
• The material is exposed to humidity, heat or radiation
• The product has a high probability of ending up dispersed in the environment
• The format is difficult to recover and, in addition, may fragment easily

The conversation about materials is no longer limited to final waste: it also includes the growing concern around microplastics and their persistence in the environment.

If you want to review which logic of use and end of life makes the most sense for your application, we can help you analyse it case by case, including the behaviour of the material throughout its useful life. Speak to our technical team!

It is not about reviewing each point separately

Choosing the right bioplastic is not about finding a “more sustainable” alternative and checking whether it can replace the current material. It is about understanding what the application needs and assessing whether that solution can respond coherently to everything the project requires: function, process, properties, use, end of life and market fit.

This is where many decisions are oversimplified. The material is compared before the problem has been properly defined. The aim is to replicate the starting point without reviewing which performance features are truly necessary. Or a solution is considered valid because it meets part of the requirement, even though it later creates friction in transformation, finish, behaviour during use or end-of-life logic.

That is why, when assessing a material change, it is not enough to ask whether a bioplastic can work. The useful question is different: whether it makes sense in that specific application, under those process conditions, with those product requirements and within that context of use and subsequent management.

When that analysis is carried out properly, the conversation changes. It no longer revolves around a generic substitution of raw material, but around how to develop a solution that can be integrated with judgement into a real product. And that is where a project stops being an intention and begins to have a chance of reaching industrial validation.

If you are considering a material change and want to analyse whether a biodegradable solution fits your application, at Benviro we can help you review the project from a technical, industrial and real-use perspective. You can contact our team here.