Spindles suited to new sustainable materials (bio-composites, recycled materials)
The shift towards more sustainable materials — bio-composites based on natural fibres, recycled plastics and composites — is bringing into machining workshops materials whose behaviour is still poorly understood, with direct consequences for the choice and design of the spindles and motor spindles used.
A new generation of materials that upsets machining habits
TLDR: Bio-composites (flax, hemp or bamboo fibres combined with bio-based resins) and recycled materials (second-life plastics and composites) are spreading across many industrial sectors under regulatory and environmental pressure, with cutting behaviour often different from conventional virgin materials.
Regulatory and environmental pressure is pushing many industrial sectors — automotive, furniture, packaging, construction — to bring more sustainable materials into their production: bio-composites based on natural fibres (flax, hemp, bamboo) combined with bio-based resins, or recycled materials from second-life plastics and composites. These materials, still relatively new in industrial machining workshops, show cutting behaviour that often differs from conventional virgin materials: natural fibres have a cellular structure different from synthetic fibres, with sensitivity to moisture and more pronounced heterogeneity; recycled materials, for their part, can show a less homogeneous composition from batch to batch, sometimes with inclusions or hardness variations linked to their recycling origin.
What these new materials imply for choosing a spindle
TLDR: Machining bio-composites and recycled materials calls for adapting conventional cutting parameters (speed, feed, cooling) to materials whose behaviour is still poorly documented compared with reference virgin materials, with consequences for spindle sizing and component selection.
Machining bio-composites and recycled materials calls for adapting conventional cutting parameters, still poorly documented compared with the well-known references of virgin materials. The moisture sensitivity of natural fibres, for example, can influence chip behaviour and require finer control of cutting parameters to avoid local heating and degradation of the bio-based matrix, often less heat-resistant than conventional synthetic resins. The heterogeneity of recycled materials, for its part, can translate into cutting forces that vary more from part to part, which loads the spindle's bearings and dynamic balancing differently than a homogeneous material would. These specifics are gradually pushing spindle designers to build a greater margin of adaptation into their component choices (bearings, cooling systems, thermal management) to anticipate the behavioural variability characteristic of these emerging materials.
What sustainable materials demand of spindles and motor spindles
- Tolerance to variable material behaviour, more pronounced than on conventional virgin materials
- Suitable thermal management, particularly for bio-composites whose matrix is sensitive to heating
- Rethought cooling and chip evacuation systems, facing chips sometimes unlike those of conventional synthetic composites
- Robust dynamic balancing, to absorb more irregular cutting forces on heterogeneous recycled materials
- Flexible parameter setting, to keep up with the fast-changing composition of these still-developing materials
A development driven by the environmental transition
The rise of bio-composites and recycled materials is directly linked to the environmental targets set for many industrial sectors, and that momentum is set to accelerate in the coming years. This evolution informs our thinking on designing spindles and motor spindles able to adapt to materials whose cutting behaviour still remains, in part, to be documented — thinking we also pursue through other projects presented in our innovation pages.
Frequently asked questions
Are there standardised recommendations for machining bio-composites?
References are still fewer than for conventional synthetic composite materials; each application often requires a specific trial and adjustment phase.
Can a standard spindle machine recycled materials without particular adaptation?
It depends on how heterogeneous the recycled material is — a case-by-case assessment remains advisable before series production.
Can Brochexpress support a project machining emerging sustainable materials?
We study this type of project case by case according to your material and your application — contact us to discuss it.
Brochexpress, watching how the motor spindle evolves
Our engineering office follows technological developments in the sector, including emerging issues linked to sustainable materials.
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