Processing PLA bioplastics
Poly Lactic Acid (PLA) bioplastics can be processed using existing equipment across a variety of methods, including extrusion, thermoforming, injection molding and fiber spinning.
Storage and pre-drying
We recommended storing PLA neat resin and PLA compounds in their closed, original packaging at ambient conditions (around 15-35°C).
Before processing, it is recommended to pre-dry the material. In most cases, pre-drying the material for 4 – 6 hours at 80°C in a dessicant dryer is sufficient. When exposed to air, moisture uptake can reach critical levels within 10 minutes. Our team of processing experts can offer more detailed advice and recommendations.
Choosing the right grade of PLA
A portfolio of neat PLA resins are available, ranging in viscosity and stereochemical purity. Depending on your product and processing requirements, we can help you select the most optimal grade of PLA.
The product portfolio includes standard PLA, PLLA homopolymers and PDLA homopolymers. PLLA and PDLA homopolymers are also often referred to as high heat PLA or PLA homopolymers.
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Standard PLA and PLLA/PDLA homopolymers can be processed on conventional compounding equipment. A co-rotating twin screw extruder with a minimum L/D ratio of 28 is ideal; while conventional pelletizing technologies can be used (including strand and underwater pelletizers).
Extrusion & thermoforming
Neat PLA resin, PLA compounds and our high heat PLA homopolymers can be processed using the traditional extrusion, film blowing and / or thermoforming process.
Working with industry partners, weve developed a high heat resistant extrusion and thermoforming recipe based on our PLA homopolymers: It crystalizes fast enough to allow thermoforming production speeds in the same range as conventional PS thermoforming speeds. The recipe is available as pre-compound but could also be made by adding the various ingredients on the extrusion line. The resulting material has a high crystallinity that results in increased heat resistance. Our in-house processing experts can offer advice and help you during PLA extrusion and thermoforming trials.
PLA and PLA compounds can be processed using conventional injection molding equipment. As mentioned, sufficient predrying is strongly recommended.
If high heat is not required and / or in case transparent products are produced, standard PLA can be processed in a cold mold.
In order to achieve products with a higher heat resistance, it is recommended to use a high heat PLA compound. Optimum heat performance and cycle time are achieved when PLA is processed on a hot mold, ranging in temperature from 90 to 100°C.The resulting parts will have a semi-crystalline PLA structure which results in a higher HDT/B temperature resistance.
Our in-house team of downstream processing experts can help you with production trials and blend selection; so dont hesitate to contact us with your bioplastic challenges.