TPS FOAM
Grade
FOAM = extruded starch foam
Water-steam expanded starch foam replacing EPS loose-fill and protective packaging; dissolves in water.
Values for the FOAM condition
Other TPS grades and fills
TPS is listed in 8 conditions; see the grade overview at TPS.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
FOAMThis page Extruded starch foam | Water-steam expanded starch foam replacing EPS loose-fill and protective packaging; dissolves in water. | 0.08 | 0.1 | 8 | — |
Soft / high-plasticizer TPS | Pick for flexible film, bags and cushioning where elongation matters more than stiffness. | 2 | 3 | 110 | 25 Shore D |
TPS/PHA blend (20–50% starch) | Choose where marine/soil biodegradation of the whole compound is required, accepting higher resin cost. | 16 | 18 | 12 | 65 Shore D |
TPS/PBAT compostable blend (30–60% starch) | The dominant commercial form — blown-film grade for shopping/compost bags and mulch film; starch cuts cost, PBAT gives toughness and water tolerance. | — | 20 | 350 | — |
TPS/PBS blend (20–50% starch) | Balanced stiffness/toughness compostable compound for injection-moulded tableware and thermoformed trays. | 20 | 25 | 90 | 58 Shore D |
Natural-fibre / cellulose reinforced TPS | Pick for stiffer, more dimensionally stable and less moisture-sensitive moulded parts (pots, trays, packaging inserts). | — | 20 | 4 | — |
Rigid / low-plasticizer TPS | Pick for injection-moulded rigid disposables (cutlery, trays) where stiffness matters and brittleness is acceptable. | 22 | 25 | 6 | 68 Shore D |
TPS/PLA blend (20–40% starch) | Pick when rigidity and clarity-free structural disposables are needed at lower resin cost than neat PLA. | — | 32 | 5 | — |
What is TPS FOAM?
TPS FOAM is TPS in the FOAM grade — water-steam expanded starch foam replacing EPS loose-fill and protective packaging; dissolves in water. TPS FOAM has a yield strength of 0.08 MPa (0.0116 ksi) and a tensile strength of 0.1 MPa (0.0145 ksi) — weaker than 99% of polymer grades. Elongation at break is 8% and the elastic modulus is 0 GPa (5.8×10⁻⁴ Msi). TPS FOAM has a density of 0.04 g/cm³ (0.0013 lb/in³), lighter than 92% of polymer grades. Its glass-transition temperature is 10°C (50 °F).
Advantages
- Low embodied carbon — 1.4 kg CO₂/kg, better than 99% of polymer grades
- Lightweight — 0.04 g/cm³ (0.0013 lb/in³), better than 92% of polymer grades
Limitations
- Needs corrosion protection — 8/100, worse than 100% of polymer grades
- Absorbs moisture — dry before molding — 35%, worse than 100% of polymer grades
- Low strength — 0.08 MPa (0.0116 ksi), worse than 99% of polymer grades
- Difficult to machine — 15/100, worse than 99% of polymer grades
- Limited service temperature — 50°C (122 °F), worse than 94% of polymer grades
TPS FOAM properties
Typical room-temperature values for TPS FOAM; 19 are specific to this condition. Other listed values are TPS reference data and may not represent this condition. Bars are the position among polymer grades.
Physical7
TPS FOAM has a density of 0.04 g/cm³ (0.0013 lb/in³), lighter than 92% of polymer grades. Its glass-transition temperature is 10°C (50 °F).
Mechanical12
TPS FOAM has a yield strength of 0.08 MPa (0.0116 ksi) and a tensile strength of 0.1 MPa (0.0145 ksi) — weaker than 99% of polymer grades. Elongation at break is 8% and the elastic modulus is 0 GPa (5.8×10⁻⁴ Msi).
Thermal11
TPS FOAM is rated for continuous service to 50°C (122 °F). It conducts heat at 0.05 W/m·K (0.026 BTU/hr·ft·°F), worse than 85% of polymer grades. Thermal expansion is 150 µm/m·K (83.3 µin/in·°F).
Electrical5
TPS FOAM is an electrical insulator with a dielectric strength of 15 kV/mm (381 V/mil) and a resistivity of 1×10⁹ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (8/100), worse than 100% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of TPS FOAM takes about 25 MJ of energy and emits 1.4 kg of CO₂ — less than 100% of polymer grades. Typical recycled content is 0%.
Manufacturability8
TPS FOAM's machinability is poor (15/100, worse than 99% of polymer grades); weldability poor (20/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TPS FOAM
Is TPS easy to machine?
Machines poorly — soft and gummy, absorbs coolant water; use sharp tools, high rake, dry cutting and light passes, and expect swelling/dimensional drift with humidity.
Can TPS be welded?
Heat-seals and hot-plate/ultrasonic welds at low temperature (110–150 °C); solvent bonding with water or aqueous adhesives is possible because of its hydrophilicity.
Can TPS be formed, bent or molded?
Extrude/inject at 110–170 °C melt with degassing (water vapour) and low back pressure; degradation and browning start above ~180 °C, so keep short residence time; blown film runs best in PBAT/PLA blends.
What surface finishes work on TPS?
Water-based inks and coatings adhere well; a barrier lacquer or PBAT skin is usually needed to control moisture pickup; not paintable with solvent systems that dissolve the plasticizer.
TPS chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| starch (amylose+amylopectin, maize/potatdry basis; amylose 20–30% of starch typical | 55 – 80 | 68 |
| glycerol (plasticizer)may be partly replaced by sorbitol, urea, glycols | 15 – 35 | 25 |
| waterco-plasticizer; equilibrium content varies with RH | 3 – 15 | 6 |
| processing aids / emulsifier / lubricantlecithin, stearates, mono-glycerides | 0.5 – 3 | 1 |
TPS FOAM — frequently asked
What is TPS FOAM used for?
TPS FOAM is typically used for biodegradable shopping bags, loose-fill packaging foam, PLA/PBS cost-reduction blends and agricultural mulch film. In short: lowest-cost bio-based resin; fully compostable blend base; moisture-sensitive, low strength.
What is the yield strength of TPS FOAM?
TPS FOAM has a typical yield strength of 0.08 MPa (0.0116 ksi) and a tensile strength of 0.1 MPa (0.0145 ksi) — weaker than 99% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is TPS FOAM easy to machine?
Not especially — machinability is rated poor (15/100, worse than 99% of polymer grades). Machines poorly — soft and gummy, absorbs coolant water; use sharp tools, high rake, dry cutting and light passes, and expect swelling/dimensional drift with humidity.
Can TPS FOAM be welded?
Not readily — weldability is rated poor (20/100). Heat-seals and hot-plate/ultrasonic welds at low temperature (110–150 °C); solvent bonding with water or aqueous adhesives is possible because of its hydrophilicity.
What surface finishes work on TPS FOAM?
Water-based inks and coatings adhere well; a barrier lacquer or PBAT skin is usually needed to control moisture pickup; not paintable with solvent systems that dissolve the plasticizer.
Can TPS FOAM be formed, bent or molded?
Extrude/inject at 110–170 °C melt with degassing (water vapour) and low back pressure; degradation and browning start above ~180 °C, so keep short residence time; blown film runs best in PBAT/PLA blends.
What is the maximum service temperature of TPS FOAM?
TPS FOAM is rated for continuous use to about 50°C (122 °F), and briefly to 90°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Biodegradable Multiphase Systems Based on Plasticized Starch (Avérous, J. Macromol. Sci. Part C) — Taylor & Francis (2004)
- Materials and the Environment: Eco-Informed Material Choice — Butterworth-Heinemann (Ashby) (2021)
- Solanyl potato-starch biopolymer compounds — Rodenburg Biopolymers (2023)
- BIOPLAST starch-based compounds (film & injection grades) — BIOTEC GmbH (2023)
- Mater-Bi starch-based bioplastic family data — Novamont (2023)
- EN 13432 / GB/T 19277 compostability requirements — CEN / SAC (2011)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.