PLA
PLA is a biobased polymer derived from natural resources and offers a significant reduction in carbon footprint compared to oil-based plastics. PLA is a high viscos- ity, low flow, amorphous, transparent PLA resin suitable for film extrusion, thermo- forming or fiber spinning.
Overview
PLA is a biobased polymer derived from natural resources and offers a significant reduction in carbon footprint compared to oil-based plastics. PLA is a high viscos- ity, low flow, amorphous, transparent PLA resin suitable for film extrusion, thermo- forming or fiber spinning.
Advantages
Exceptional Printing Precision & Stability
Large-Scale Industrial Capability
Advanced Monitoring & Automation
Quiet, High-Speed Performance
Typical Properties
| Physical properties | Method | Typical value | ||||||
| Density | Literature value | 1.24 g/cm³ | ||||||
| Melt flow index | ISO 1133-A(210℃/2.16kg) | 6g/10 min | ||||||
| Melt flow index | ISO 1133-A(190℃/2.16kg) | 3 g/10 min | ||||||
| Stereochemical purity | Total Corbion PLA method | 96%(L-isomer) | ||||||
| Appearance | Visual | Crystalline white pellets | ||||||
| Residual monomer | Total Corbion PLA method | ≤0.3% | ||||||
| Water/moisture | Coulometric Karl-Fischer | ≤400 ppm | ||||||
| Melting temperature | DSC | 155℃ | ||||||
| Glass transition temperature | DSC | 60℃ | ||||||
| Mechanical properties | Method | Typical value | ||||||
| Tensile modulus | ISO 527-1 | 3500 MPa | ||||||
| Tensile strength | ISO 527-1 | 45 MPa | ||||||
| Elongation at break | ISO 527-1 | ≤5% | ||||||
| Charpy notched impact,23℃ | ISO 179-1eA | ≤5kJ/m² | ||||||
| Heat deflection temp., amorphous² | ISO 75-1 | 60°C | ||||||
* Typical properties, not to be interpreted as specifications * HDT B, 0.45MPa flatwise. HDT depends on processing conditions.
Processing Information & Recommendations
Standard PLA can be processed on conventional extrusion equipment and can be used as neat resin or as part of a compound to further optimize overall material properties. It is recommended to use a general purpose screw with L/D ratios between 24 and 32. Pre-drying of the resin is recommended.
| Predrying | 4-6 hours at 85°C |
| Feed zone | 20-40°C |
| Melt zone | 170-190°C |
| Mixing & conveying | 190-210°C |
| Die head temperature | 190-210°C |
| Typical settings, may require optimization | |
Start-up and Shutdown
1. Purge the system with a polyolefin or a purging compound (e.g. Dyna-Purge, Clean LDPE) at its recommended temperature settings.
2. Reset the temperature settings to the recommended PLA temperature profile.
3. Purge with PLA resin or PLA compound until stable processing is obtained free of contaminants.
4. Reset the temperature settings to the recommended purging compound temperature profile.
5. Purge with a polyolefin or a purging compound for 5 times the average residence time.
After completion of the run, PLA must be removed from the whole system. PLA can degrade into lactic acid causing corrosion of the equipment (e.g. die plates).
Moisture & Pre-drying
It is recommended to dry the packaging for 4-6 hours at 85°C. Drying of standard PLA can be performed in a desiccant hot air dryer, with a dew point of -40°C or less. It is recommended to reduce the moisture content before melt processing to a level less than 250ppm and preferably less than 100 ppm, measured by e.g. Karl-Fischer or Brabender aquatrac method. Predrying is in particular important prior to injection molding, film and sheet production. Moisture causes hydrolysis of the PLA polymer during melt processing, resulting in reduced mechanical performance in the final part.