Eco Solution GP1025 High Toughness Aliphatic Polylactic Acid Film Grade is an aliphatic PLA resin supplied in pellet form for converted flexible film applications that require tensile elongation, tear propagation resistance, and dimensional stiffness without aromatic comonomer content. The product carries the model designation GP1025 and is specified for cast film and blown film lines where unmodified poly(L-lactic acid) grades fail through low elongation at break and brittle fracture. A single aliphatic polyester backbone is maintained; the high-toughness behavior derives from controlled molecular architecture rather than from blending with fossil-based aromatic polyesters. This compositional boundary is relevant for converters that require compostability documentation under industrial composting schemes and for those seeking to avoid aromatic constituents in food-contact film structures.

Representative physical and thermal data for GP1025 are determined according to the following standard methods. Density at 23 °C is 1.24–1.26 g/cm³ per ISO 1183-1. Melt volume-flow rate at 190 °C under 2.16 kg load is 4–8 g/10 min per ISO 1133-1. Differential scanning calorimetry per ISO 11357-2 gives a glass transition temperature of 55–60 °C and a melting endotherm peak at 165–175 °C. Film specimens prepared at 40 µm thickness and conditioned for 48 h at 23 °C and 50% relative humidity exhibit tensile strength at break of 45–55 MPa, elongation at break of 180–250%, and secant modulus of 2.0–2.5 GPa when tested according to ASTM D882. Elmendorf tear strength per ASTM D1922 is 6–10 N/mm, depending on film orientation and processing history.

• Melt volume-flow rate: 4–8 g/10 min per ISO 1133-1
• Density: 1.24–1.26 g/cm³ per ISO 1183-1
• Glass transition temperature: 55–60 °C per ISO 11357-2
• Melting endotherm peak: 165–175 °C per ISO 11357-2
• Film tensile strength at break: 45–55 MPa per ASTM D882
• Film elongation at break: 180–250% per ASTM D882
• Elmendorf tear strength: 6–10 N/mm per ASTM D1922

Water vapour transmission rate for 40 µm GP1025 film at 38 °C and 90% relative humidity is 300–400 g/m²·day per ISO 15106-2; oxygen transmission rate at 23 °C and 0% relative humidity is 800–1200 cm³/m²·day·bar per ASTM D3985. These values position GP1025 between low-barrier PBAT films and high-barrier PET or nylon structures, making it suitable for short-shelf-life fresh produce and bakery films rather than retortable or oxygen-sensitive food packaging.

What distinguishes GP1025 from unmodified PLA film resins?

The primary performance gap between GP1025 and standard PLA film grades appears in elongation at break and tear propagation. Standard PLA film resins often exhibit tensile elongation below 10% and Elmendorf tear values below 3 N/mm. GP1025 shifts these values into ranges that allow flexible packaging to be converted without orientation-induced longitudinal splitting. Table 1 compares film data generated under identical laboratory conditions on 40 µm monolayer cast film. The data illustrate that GP1025 retains a modulus above 2.0 GPa, which is substantially higher than PBAT film, while providing the elongation and tear resistance that unmodified PLA does not. This combination means the material can be down-gauged in some applications where PBAT would require excessive thickness to maintain stiffness.

On production-scale cast film lines equipped with 30:1 L/D single-screw extruders and barrier screws, GP1025 is typically melt processed at 190–210 °C. Die gaps of 0.8–1.2 mm and chill roll temperatures of 15–25 °C are used to limit spherulitic crystallization and maintain film clarity. For blown film conversion, screws with Maddock mixing sections and die gaps of 1.0–1.5 mm are preferred. Blow-up ratios of 2.0–3.0 and frost-line heights of 3–5 die diameters provide stable bubble geometry; blow-up ratios above 3.5 have been associated with gauge variation and asymmetric tear behavior in converter reports. Back-pressure is maintained between 80–150 bar, and screen packs are commonly 60/80/100 mesh to remove gel particles without excessive melt shear.

Thermal transitions, melt rheology, and moisture-handling limits

Moisture control is the primary processing boundary for GP1025. As with most PLA resins, hydrolytic chain scission occurs when residual pellet moisture exceeds 250 ppm at melt temperatures above 200 °C. Pre-drying in a desiccant dryer at 80 °C for 4–6 h, using an air dew point no higher than -40 °C, reduces moisture to processable levels. On equipment without desiccant drying, melt-flow rate values measured by ISO 1133-1 can increase by 20–40% within 15 min of residence time at 210 °C, creating surging, die-lip build-up, and gauge instability. The recommended maximum melt temperature is 220 °C. Extended exposure above 230 °C accelerates lactide reformation and produces volatile deposits on chill rolls and downstream idlers.

Thermogravimetric analysis per ISO 11358-1 under nitrogen shows 1% mass loss at approximately 280–300 °C. This degradation onset is lower than typical polyolefin film resins and therefore excludes GP1025 from processes that require high-temperature retort sterilization or prolonged melt residence times above 240 °C. The crystallization half-time is longest near 110 °C, but rapid quenching on chilled rolls suppresses spherulitic haze. Injection molded discs used for melt rheology screening show shear viscosity at 190 °C of approximately 800–1200 Pa·s at 100 s⁻¹, which supports both cast film melt curtain stability and blown film bubble retention. Capillary rheometry at 190 °C indicates shear thinning with a power-law index of approximately 0.5–0.7 over shear rates of 50–1000 s⁻¹. Extensional viscosity, measured by melt elongation in a Rheotens test from a capillary die, is 0.5–1.5 Pa·s at draw ratios of 5:1–20:1, which supports bubble stability in blown film. Standard PLA film grades often show lower extensional viscosity at equivalent draw, causing bubble collapse at high blow-up ratios.

GP1025 pellets absorb moisture from ambient air; open containers should be resealed and returned to dry storage. Regrind from edge trim is reused at up to 20 wt% provided the trim remains dry and free of polyolefin contamination. Polyolefin contamination above 5 wt% creates visible islands and reduces tear strength; density-based separation or dedicated PLA reclaim lines are required if post-consumer structures are introduced.

If GP1025 is processed on high-draw-down cast film equipment

When GP1025 is processed on high-draw-down cast film equipment with line speeds above 150 m/min, the melt curtain must be drawn to final thickness while the polymer remains above its crystallization onset. Standard operating practice for this grade sets the die exit melt temperature at 195–215 °C, with air knife or vacuum box assist to stabilize the melt curtain before contact with the chill roll. Chill roll surface finish controls gloss: a polished roll at 20 °C yields haze values of 2–5% per ASTM D1003, while a matte roll raises haze above 15% and reduces blocking. Draw ratios between 10:1 and 25:1 are typical for GP1025. Above 30:1, molecular orientation in the machine direction increases machine-direction tensile strength to 70–90 MPa but reduces transverse-direction elongation to 40–80%, creating anisotropic tear behavior and a tendency toward splitting at folded edges.

Heat-seal initiation temperature on a laboratory heat sealer at 0.3 MPa jaw pressure and 1 s dwell is 80–90 °C; seal strength reaches 8–12 N/15 mm at 110 °C jaw temperature. The seal strength plateau narrows above 130 °C because the amorphous PLA film softens and can adhere to the sealing jaw. Converters using horizontal form-fill-seal equipment have observed that jaw release coatings and reduced dwell times below 0.5 s minimize film tearing at the seal edge.

In monolayer blown film, the frost-line height acts as the primary balance point between quench depth and crystallinity. GP1025 films quenched at excessively low frost lines contain higher amorphous orientation and show post-shrinkage below the Tg. Film rolls stored at warehouse temperatures above 40 °C can exhibit blocking because the aliphatic polyester surface softens near the glass transition. For applications requiring low coefficient of friction, external slip additives are added by the converter at 0.5–2.0 wt%; these should be non-amine slip masterbatches because amine-based additives under alkaline hydrolysis conditions can accelerate polyester chain cleavage.

Comparing high-toughness PLA grades under multiaxial strain

GP1025 differs from some high-toughness biodegradable film materials in that it does not depend on PBAT or polycaprolactone blending to achieve elongation. PBAT-rich films typically show elongation above 500% but secant modulus below 0.2 GPa, which can produce excessive stretch and poor machinability on vertical form-fill-seal packaging lines. GP1025 retains secant modulus above 2.0 GPa, allowing the film to be sealed and cut without excessive deformation. Under multiaxial strain imposed by laboratory burst testing at 23 °C, the material resists pinhole formation better than standard PLA and shows stable expansion without the necking failure that characterizes unmodified PLA film. Published data for this specific configuration in high-speed pouch converting is limited; converter trials remain necessary to establish seal jaw temperature and dwell windows because the toughness modification shifts heat-seal initiation temperature to 80–90 °C on impulse sealers.

Compared to PLA/PBAT blends, the single-polymer approach reduces interfacial phase separation, which can appear as haze and delamination after repeated folding. However, the aliphatic polyester backbone of GP1025 still hydrolyzes under high-humidity aging conditions above 60% relative humidity at 38 °C, and film tensile strength can decline by 15–25% over 6 months under these conditions. Converters should not specify this grade for long-term outdoor exposure unless the film is protected from moisture and UV irradiation.

Food-contact and compostability documentation requirements are not interchangeable

GP1025 is intended for use in food-contact films when converted under conditions that maintain melt temperature below 220 °C and moisture below 250 ppm. Compliance documentation is based on the aliphatic PLA backbone and the absence of intentionally added aromatic ester monomers. For the European Union, overall migration testing per EN 1186-1 and specific migration testing under EU Regulation 10/2011 are performed by the converter on finished film. For the United States, the food-contact status of polylactic acid resins is generally addressed under FDA 21 CFR 175.300 for coatings and components, but finished food-contact approval remains application-specific. Industrial compostability certification for film thickness up to 80 µm may be evaluated under EN 13432; home composting conditions at 25 °C should not be assumed because hydrolysis and mineralization rates drop significantly below 40 °C.

In fresh-cut produce packaging, GP1025 films are used at thicknesses from 20–60 µm. The high elongation at break allows film to be tray-wrapped without splitting at corners, and the aliphatic polyester chemistry supports industrial composting documentation if the finished film passes disintegration testing. In shrink-label applications, the material can be oriented at temperatures above the Tg but below the cold-crystallization onset; transverse-direction shrinkage of 35–50% is achievable in pilot trials, but published data for full commercial shrink lines is limited. The grade is not recommended for retort pouches, hot-fill containers above 85 °C, or applications requiring long-term UV exposure and constant high-humidity aging because the PLA backbone hydrolyzes and loses tensile strength under those conditions.