Bio-based materials for your Injection Molding Projects
In recent years, bio-based materials have gone from being an emerging trend to becoming a strategic alternative within the plastic injection moulding industry.
More and more companies, especially in regulated sectors such as medical and automotive, are seeking to reduce their carbon footprint without compromising the technical performance of their parts.
What are Bio-based materials?
Bio-based materials are polymers that originate, either wholly or partially, from renewable resources such as plants, vegetable oils or biomass, rather than fossil sources.
From a technical point of view, their polymer structure may be identical or very similar to that of conventional plastics.
In the industrial environment, it is driven by corporate sustainability goals, stricter environmental regulations and the need to improve the Life Cycle Assessment (LCA) of end products.
Difference between bio-based and biodegradable
One of the main misconceptions in the market is to equate ‘bio-based’ with ‘biodegradable’, when in fact they are separate concepts.
A bio-based material refers exclusively to its origin. It can come from plant sources and still not be biodegradable. Clear examples are Bio-PE or Bio-PET, which offer the same durability, chemical resistance and long-term stability as their fossil-based equivalents. This makes them ideal choices for long-life technical parts, such as automotive components or medical devices.
In contrast, biodegradability describes the end of life of the material and is not always desirable in industrial applications where reliability and durability are critical.
Bio-PP, Bio-PA, Bio-LSR polymers and PLA or PHA polymers
It is essential to differentiate between these two terms:
- Bio-based materials that replicate the structure and behaviour of traditional plastics, such as Bio-PP, Bio-PA or Bio-LSR: These allow the material to be replaced without modifying the design, mould or production process.
- Biopolymers such as PLA or PHA, with specific properties but also greater technical and processing uncertainties.
For critical projects, especially in highly regulated sectors such as medical and automotive, drop-in polymers are usually the recommended option, as they minimise technical and approval risks.
Technical performance of bio-based material: Do they meet the requirements for injection moulding?
In fact, many bio-based materials offer technical performance equivalent to or even superior to that of conventional polymers, provided they are selected and processed correctly.
In plastic injection processes, performance depends both on the material and on the control of process parameters.
Comparing mechanical and thermal properties of biobased plastic
In terms of tensile strength, impact resistance and thermal behaviour, bio-based polyamides (PA) stand out.
These Bio-PAs are used in fuel lines, technical connectors and components subjected to high temperatures, thanks to their excellent dimensional stability and chemical resistance.
For applications where mechanical performance is critical, bio-based technical materials enable industrial specifications to be met without sacrificing reliability.
Processing Challenges: Temperature Window and Cycle Times
Some bio-based materials have a narrower processing window or greater sensitivity to moisture. This can affect:
- Thermal stability during plasticisation
- Appearance of aesthetic defects
- Variations in viscosity and mould filling
At OSF, these challenges are managed through strict control of parameters such as material drying, temperature, injection pressure and cycle times.
In addition, other relevant factors such as thermal degradation and process repeatability in long runs are taken into account.
Real-world applications in regulated Industries: Medical and Automotive sectors
The adoption of bio-based materials is particularly important in sectors where regulations and safety are a priority. In these environments, sustainability must always be accompanied by technical validation.
Medical Sector: Bio-based Polymers and Clinical Validation
In medical applications, materials such as bio-based COC/COP or Bio-PC are used in device casings, diagnostic components and single-use systems.
The priority is not only renewable origin, but also dimensional stability, biocompatibility and resistance to sterilization processes (steam, ethylene oxide or radiation).
Material selection is always carried out under strict technical criteria, ensuring compliance with regulatory and functional requirements.
Automotive: Lightweighting and Carbon Footprint Reduction
In the automotive industry, bio-based engineering thermoplastics contribute to the lightweighting of components, a key factor in electric vehicles, for example, to improve range.
In addition, they reduce the vehicle's carbon footprint without compromising mechanical strength or safety.
The use of bio-based materials improves the life cycle assessment (LCA) of the assembly and helps manufacturers meet increasingly demanding environmental targets.
How to select the right Bio-based Material for your Bio-based products
The choice of the right material should not be based solely on sustainability criteria.
At OSF, selection is approached as an engineering process, not as an isolated commercial decision.
Decision matrix: Balancing sustainability and performance of biobased materials
There is no such thing as a universally perfect material, only the most suitable material for each application.
The process begins by analysing the CTQs (Critical to Quality) of the part: Is thermal resistance a priority, as in an engine component? Or optical transparency and stability, as in medical devices?
Based on these requirements, OSF advises on the suitability of a Bio-PE, a Bio-PA or a bio-based LSR, always balancing sustainability and technical performance.
Preliminary Technical Validation
Bio-based materials may exhibit different flow behaviours than conventional materials. Therefore, prior technical validation is key.
This includes performing injection tests and the necessary trials to verify the correct processing of the material. It also includes validating the functionality, quality and final performance of the part.
OSF: Your Industrial partner for high-performance Bio-based Injection Molding
The transition to bio-based materials does not have to be risky when carried out with the right industrial partner.
At OSF, we provide specific knowledge of materials, plastic injection moulding and liquid silicone rubber (LSR) processes, and proven experience in sectors such as medical and automotive, among others.
We provide the engineering, technical validation and materials expertise. Request a viability study or specialized technical consultancy to assess how to integrate bio-based materials into your upcoming industrial projects.