Table 1.

Some PLA based composites.

1. Filler	2. Composite Fabrication Process	3. Observation	4. Reference
Hemp fibres	Twin extruder, compression and injection moulding	− Increased tensile strength, young’s modulus and impact strength − Fibre treatments with alkali and saline increased tensile and impact strength	[107]
Fine grain filler of native cellulose	Melt-mixing	− Good dispersion of the filler giving an aesthetic appearance, creamy colour and glossy surface − Good thermal stability	[98]
Ceramic food waste from grinding egg shells and mussel shells	Melt-mixing	− High filler amounts of 140 over 100 parts of PLA − Thermoplastic, biodegradable and low carbon footprint composites − Composites do not release volatiles typical of fossil-based plastics that are hormone disruptors or priority air pollutants that pose public health	[66]
Silver skin (waste from roasting coffee beans)	Melt-mixing	− Up to 30%wt% of filler content can be added − Increase in young’s modulus	[103]
Waste from wine production (grape skins, seeds and stalk fragments)	Molding	− Up to 20% of filler can be added − High elastic modulus and impact strength but lower tensile strength − Increase in moisture absorption with increase in filler content	[102]
Cocoa bean shells	Solution casting	− Improved physical properties of the composites − Low levels of food migration and improved barrier properties	[108]