🧩 PHBV – Polyhydroxybutyrate-valerate
(Natural biodegradable material produced via bacterial fermentation, with properties similar to PP and ABS but fully compostable. PHBV is a bio-copolymer offering an ideal balance between strength, elasticity, and thermal stability.)
🔹 What is PHBV
PHBV belongs to the PHA family and is obtained by fermenting sugars or vegetable oils with specialized bacteria. At ReplastMD, we treat this as one of the most promising bio-variants for technical parts. The addition of valerate units (PHV) reduces the brittleness of standard PHB, making the material more flexible and impact-resistant. It is 100% bio-based and offers a smooth, glossy finish.
🔧 Composition & Properties
- Polymer Base: Bio-copolymer (PHB + PHV).
- Source: Bacterial fermentation (sugar, starch, vegetable oil).
- Density: 1.23 – 1.26 g/cm³.
- Melting Point: 160 – 175 °C.
- Operating Range: –20 °C to +90 °C.
- Chemical Resistance: Very good (oils, detergents, greases).
🚗 Where PHBV is used in the automotive industry
| Component | Example parts | Observations |
| Bio Caps & Covers | Protectors, handles, plugs | Durable, rigid, compostable |
| Interior Decor | Inserts, interior panels | Glossy, rigid, eco-friendly |
| Bio Films | Interior foils, coatings | Clarity, good chemical resistance |
| Functional Prototypes | Eco-compatibility testing | Green alternative to PP/ABS |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | ✅ 110 – 130 °C | Welds slowly, controlled flow |
| Heat Plate (Mirror) | ✅ 120 – 130 °C | Smooth joint, no bubbles |
| Manual Extrusion | ⚠️ 130 – 140 °C | Possible, requires pressure control |
| Chemical Bonding | ✅ Recommended | Bio-compatible polyester adhesives |
💡 ReplastMD Recommendation: PHBV welds well at 120 °C. Maintain constant pressure and slow cooling for a glossy, clean joint. It behaves similarly to PBS and PHA but is slightly more rigid.
🧠 How to Identify PHBV
- Smooth, glossy, rigid-elastic texture.
- Color: Milky white or yellowish, translucent.
- ReplastMD practical test: Moderate elasticity, high density; softens at 110–130 °C without fumes.
- Common markings: >PHBV<, >PHA<, >NODAX<, >MIREL<, >ENMAT<.