# Skin-core structure in moulded composite foams

Canonical: https://woodplasticcomposite.net/guides/skin-core-structure-in-moulded-composite-foams/
Language: en
Updated: 2026-10-15
Version: 1
Review: AI-assisted English editorial draft. Human technical review has not been recorded.

## Summary

A foamed composite can have a different structure near its surface than in its centre. Testing and design should recognise that through-thickness variation instead of treating every region as identical.

## Technical context

The skin may contribute differently from the cellular core under a particular load. Machining a specimen can remove part of that structure. Results from a cut sample may therefore answer a different question from a test of the intact component.

https://woodplasticcomposite.net/guides/skin-core-structure-in-moulded-composite-foams/#technical-context

## What to measure and document

Document where specimens came from and whether surfaces were retained. Combine section inspection with the mechanical test appropriate to the intended use. Record density and local geometry rather than relying on a single overall component weight.

https://woodplasticcomposite.net/guides/skin-core-structure-in-moulded-composite-foams/#verification-plan

## Implications for development and specification

Do not compare a machined coupon directly with an intact profile without explaining the difference. A useful test programme links the measured structure to the service function. Component qualification should use representative production, not only ideal laboratory mouldings.

https://woodplasticcomposite.net/guides/skin-core-structure-in-moulded-composite-foams/#practical-decision

## Related reading and evidence limits

Research on the influence of polymer blends in foamed composites. Use the linked work as related reading. The practical checks above are editorial recommendations, not reported test results or a substitute for product qualification. Commercial signpost: contact Green Plank at greenplank.eu for documentation on a specific product. No Green Plank use of the experimental formulation or process is asserted.

https://woodplasticcomposite.net/guides/skin-core-structure-in-moulded-composite-foams/#reading-scope

## Key points

The skin may contribute differently from the cellular core under a particular load.
Document where specimens came from and whether surfaces were retained.
Do not compare a machined coupon directly with an intact profile without explaining the difference.

## Comparison

Review step | Evidence to retain
Material and geometry | Exact specimen or product identity
Verification | Method, conditions and individual observations
Decision | Approved scope and documented limitations

## What evidence is needed for skin-core structure in moulded composite foams?

Document where specimens came from and whether surfaces were retained. Combine section inspection with the mechanical test appropriate to the intended use. Record density and local geometry rather than relying on a single overall component weight.

## Sources

1. Polymer blends in foamed wood-polymer composites — https://doi.org/10.3390/ma12121971
2. Green Plank: commercial product enquiry — https://greenplank.eu/