COSMOPLENE PP Terpolymer FL7015E2

What Limits Seal Throughput on BOPP Coextrusion Lines When the Skin Layer Fraction Drops Below 3 µm?

On sequential-stretching BOPP lines running at 320 m/min, the skin layer thickness of FL7015E2 is typically maintained between 0.8 µm and 1.5 µm. Metering the terpolymer through a separate satellite extruder — 45 mm screw diameter, L/D 28, with a compression ratio of 2.8:1 — and feeding it into the combining adapter at 240 °C prevents thermal degradation of the core homopolymer polypropylene which is processed 15–20 °C higher. The transversal-direction orientation at a stretch ratio of 8.5:1 reduces the skin gauge to its final dimension; at this thinning, the localised crystalline orientation in the terpolymer layer is disrupted by the ethylene-propylene-rubber domains, increasing the amorphous fraction and enabling a seal onset as low as 98 °C in laboratory gradient heat-seal tests. However, converting trials on a Karlville COMBI HS4000 pouch machine reveal that when the skin gauge falls below 0.7 µm, entrapped air during side-sealing creates microvoids that lower burst test values by 18–22%, a failure mode reproducible on packs of stacked overwrapped cosmetic cartons. The solution documented by line operators is to elevate the combining-block temperature by 5 °C and adjust the line speed modulation to respect a minimum contact time of 0.25 s in the seal zone. In terms of regulatory documentation, a Declaration of Compliance citing EU Regulation 1935/2004 and the specific migration limits for ethylene and propylene monomers (SML = 60 mg/kg food simulant) is routinely requested for export consignments into the EU single market.

When a Three-Layer Blown Film Die Head Must Profile the Sealant Viscosity Across a 20 °C Gradient

The incorporation of FL7015E2 as the inner seal layer of a three-layer blown film — outer layer metallocene LLDPE, core LLDPE-LDPE blend, inner terpolymer — on a 150 mm spiral mandrel die requires careful multiplexing of the air ring speed because the terpolymer’s low melt strength, measured as a melt flow rate of 7.5 g/10 min (ISO 1133-1:2022, 230 °C/2.16 kg), results in bubble instability if the frost-line height exceeds 1.8 × die diameter. The blow-up ratio is set between 1.8:1 and 2.2:1, and the melt temperature profile permits a 10 °C decrease in the inner-layer extruder barrels relative to the outer two layers, thus matching the zero-shear viscosities of the dissimilar polyethylenes and the terpolymer at the exit plane. An online film scanner (Betacontrol or equivalent) measures a gauge uniformity of ±4%, and any drift exceeding ±6% triggers an automatic gate-cut of the inner-layer blower. At a seal-bar temperature of 125 °C, the average peel strength reaches 3.8 N/15 mm (ASTM F88), with the peel trace showing a cohesive failure inside the terpolymer layer — a necessary attribute for frozen vegetable pouches that must withstand -30 °C drop tests without seal fracturing. The organoleptic panel verification under DIN 10955 confirms no detectable taint migration into low-fat food simulants after 72 hours at 60 °C.

Roll-fed thermoforming and fill-seal lines for dairy desserts demand a peelable yet continuous seal on polypropylene containers with flange contamination up to 0.5 mg/m² of calcium carbonate filler dust. Trials on an Erca EF650 unit using a lid stock formed from 80 wt% FL7015E2 and 20 wt% polypropylene homopolymer (MFR 2.1 g/10 min, ISO 1133) reveal that a seal-assist pattern with a land width of 0.6 mm suppresses tearing at the flange edge while maintaining a 3.2 N/15 mm seal strength. The terpolymer’s broad melting range — endotherm onset 114 °C, peak 133 °C, end 149 °C (ISO 11357-3) — allows the lacquer-less lid to fuse with a partially crystallised PP cup rim that exits the fill station at 45 °C. Because the lid stock production involves slow-slitting on an Atlas CP II to ±0.2 mm width tolerance, the re-wind tension must not exceed 50 N/m otherwise the anti-block additive migration curve shifts and the opening force drifts upward by 0.7 N/15 mm within six weeks of ambient storage. US food-contact status is established by referencing FCN number 1848 in the inventory for terpolymer-containing olefin articles and the specific dual-use additive clearances under 21 CFR 178.2010.

**Heat seal property gradient across processing temperatures for a 25 µm terpolymer monolayer film (lab cast-sheet data)**
Seal bar temperature (°C)	Peel strength (N/15 mm, ASTM F88)	Hot tack force (N/25 mm, ASTM F1921)	Failure mode
105	2.1	1.4	Peel / surface peel
115	6.8	4.9	Cohesive in terpolymer
130	9.5	5.7	Cohesive + elongation
145	7.2	3.1	Partial melt-edge tear

Extrusion coating of aluminium foil: adhesion promoter-free anchorage and pinhole limitations

Applying FL7015E2 directly onto 9 µm soft-temper aluminium foil through a 120 mm slot-die extrusion coating line normally requires an AC corona pre-treatment of 40–44 dynes/cm and an air-gap distance fixed at 150 mm to minimise oxidation while achieving a coating weight of 12 g/m². The adhesion value, measured by delamination peel at 180° separation on a 50 mm strip (DIN 53357), consistently reaches 1.8 N/15 mm without a primer, a performance that drops to 0.9 N/15 mm when the melt temperature falls below 290 °C at the die lip. However, pinhole formation intensifies above 305 °C, particularly on edge bead trim recycled back at 18–22% regrind content; converters mitigate this by limiting regrind to 15% and employing a back-side water quench bath held at 28 °C. The finished lamination commonly becomes the inner liner of retortable pouches for pet food, where the seal integrity under 0.2 bar vacuum must not degrade after a 121 °C / 30 min retort cycle. Migration test results per EN 1186-1:2002 (total immersion, olive oil simulant, 121 °C / 2 h) are reported at 4.2 mg/dm², well below the 60 mg/kg EU overall migration limit, allowing the pouch producer to declare conformity without a functional barrier calculation.

Blending 15–30 wt% FL7015E2 with a standard polypropylene homopolymer (MFR 3.2 g/10 min) on a Berstorff ZE40 co-rotating twin-screw extruder — L/D 44, screw speed 350 rpm, zone temperatures 190–230 °C — shifts the differential scanning calorimetry melting endotherm from a sharp 164 °C peak to a complex bimodal profile with a lower-temperature shoulder centered at 129 °C. The blend, pelletised via an underwater strand die, is subsequently processed on a 5-layer cast line as the sub-skin adhesive tie layer of a metalizable CPP film used for soft-drink labels. The incorporation of the terpolymer raises the interlayer adhesion to 3.7 N/15 mm on corona-treated BOPP-MET film, measured by a 90° peel fixture on an Instron 5965 at 100 mm/min. A limitation observed in full-scale trials is that when the terpolymer fraction exceeds 32 wt%, the tie-layer viscosity drops sufficiently to cause die-lip build-up after eight hours of continuous operation, forcing a reduced line speed of 160 m/min instead of the nominal 210 m/min. The formulation is outside the direct-food-contact scope but falls under REACH registration (tonnage band 100–1000 t/a) and is documented in a substance volume tracking report for downstream converters.

**Core regulatory reference matrix for FL7015E2 in food contact applications**
Regulation / Standard	Relevant clause or condition	Application sector triggered
EU 10/2011	Annex I, Table 1 (specific migration limits for propylene, ethylene, butene)	All food-contact films, coated articles
FDA 21 CFR 177.1520(c)	Items 2.1 and 2.2 – olefin terpolymers with prescribed density/melt limits	US-market wrappers, films, containers
EU 528/2012	Not applicable unless biocide-treated masterbatch is added	Excluded; clarification required
CONEG / EU 94/62/EC	Combined heavy metals <100 ppm (sum of Pb, Cd, Hg, Cr VI)	All packaging articles
EN 13432	Compostability – terpolymer does not meet disintegration criteria	Excludes use in certified compostable goods

On medical forming-web machines producing chevron-peel pouches for ethylene oxide-sterilised devices, the seal layer is a monolayer cast from 98 wt% FL7015E2 combined with 2 wt% silica antiblock masterbatch (mean particle diameter 4 µm). The critical peel curve, logged across 80–170 °C jaw temperatures on a RDM HS-2 heat seal tester, must exhibit a plateau segment at 1.8–3.0 N/15 mm with a flat slope to accommodate the temperature overshoot from pulse-heated sealing bands. In lot qualification for ISO 11607-2 compliance, the peel initiation force cannot deviate more than ±0.4 N from the validated median and the seal width must remain free of fibre tear. Gamma irradiation at a dose of 25 kGy causes minimal embrittlement in the terpolymer compared to LDPE-based sealants: the post-sterilization elongation at break measured in a 50 mm gauge length tensile test ( ISO 527-3, test speed 500 mm/min) retains 88% of its non-irradiated value. A device packaging qualification report typically also includes USP <661.1> and <661.2> physicochemical extractables profiles, and certifies that the extractable residue does not exceed 5 mg/dL in isopropanol reflux chambers after 24 hours.

A cast-film sealing layer resin requiring a low heat-seal initiation temperature and stable coefficient of friction after corona treatment defines the performance envelope for COSMOPLENE PP Terpolymer FL7015E2. The grade incorporates propylene, ethylene, and butene-1 monomers in a random distribution, resulting in a melting temperature range of 125–135 °C (ISO 11357-3:2018) and a seal initiation temperature below 110 °C at 0.2 N/mm² seal pressure. Melt mass-flow rate, measured at 230 °C under 2.16 kg load per ISO 1133-1:2022, is 7.0 g/10 min, allowing processability on single- and multi-layer cast-film lines with chill-roll temperatures of 18–30 °C. Density at 23 °C is 0.90 g/cm³ (ISO 1183-1:2019). The incorporated butene-1 co-monomer depresses crystallinity relative to a standard propylene-ethylene random copolymer, yielding a broader hot-tack window and lower seal-bar temperature sensitivity, a critical distinction from conventional PP random copolymers that rely solely on ethylene as the co-monomer.

How does terpolymer composition affect seal performance relative to random copolymer?

The presence of butene-1 units in the chain backbone reduces the xylene-soluble fraction below 6.0 wt% while still interrupting isotactic propylene sequences enough to drop the peak melting point by 10–15 °C compared to an ethylene-only random copolymer of equivalent melt flow rate. Differential scanning calorimetry traces show a single broad endotherm rather than the dual peaks often observed in heterophasic copolymers, confirming a single-phase melt. In practice, this translates to a seal strength above 2.5 N/15 mm on biaxially oriented polypropylene (BOPP) cast webs at 105 °C seal-bar temperature, whereas a conventional random copolymer (MFR 7, ethylene ~3.5 wt%) requires 115 °C to achieve equivalent peel values. Hot-tack force, measured by ASTM F1921-98 (Reapproved 2018) Method B, remains above 1.5 N/25 mm over a temperature interval spanning 15 °C, permitting packaging-line speeds exceeding 40 m/min without seal pop-open.

Avoid blending FL7015E2 with incompatible polymer phases that contain residual amine-based slip concentrates; premature reaction with acidic catalyst residues can produce yellowing at the die lip during extrusion runs exceeding 6 hours. The product is formulated with a non-migratory anti-block masterbatch and a medium-erucamide slip package that reaches steady-state COF (kinetic, 0.25–0.35, ISO 8295:2004) after 72 hours of ambient ageing. Corona-treated film surfaces exhibit surface energy retention above 38 dyn/cm for 6 months under 23 °C, 50 % RH storage, a requirement validated by ASTM D2578-23a wetting tension tests.

Extrusion Processing Window and Line Stability

Single-screw extruders with barrier screws of L/D ≥ 28:1 and Maddock mixing sections are recommended. Barrel temperature profile from feed throat to die: 190–210–220–230–240 °C. Melt temperature at the adapter should not exceed 250 °C to avoid thermal degradation of the butene-1 sequences, which can increase extractable fractions above the 2.0 wt% limit specified in EU Regulation 10/2011 for food contact materials. Filtration through 200-mesh screen packs is standard; the resin’s narrow molecular weight distribution (polydispersity index ~4, determined by gel permeation chromatography) aids in maintaining constant head pressure within ±0.3 MPa during continuous operation. Die gap settings between 0.5 mm and 0.8 mm are used, with draw ratios adjusted to produce final film thickness down to 20 µm. Chill-roll temperature gradients must be controlled within ±1 °C laterally to prevent transverse thickness variation exceeding ±2 % as measured by a beta-gauge scanner.

Batch-to-batch MFR variation, recorded across 12 commercial production lots, remained within ±0.3 g/10 min. Published data on long-term gel formation tendencies is limited, but on-line melt filtration tests with 20 µm pore size did not exceed a pressure rise of 0.08 MPa/h over 24 h of continuous extrusion, indicating adequate thermal stability for standard shift operations.

Comparative Fogging and Organoleptic Profile

When substituted for a conventional PP random copolymer in a three-layer cast-film structure (skin layer thickness 5 µm), fogging values determined by DIN 75201:2011-11 (Method B, 100 °C, 16 h) dropped from 2.1 mg to 0.8 mg, attributable to the lower oligomer content achievable with the terpolymer’s single-site catalyst technology. Sensory panel evaluations conducted according to DIN 10955:2004-06 for odour and taint transfer to chocolate simulants yielded scores below 2.0 on a 1–5 intensity scale, meeting the specifications of major confectionery packaging converters. Migration of low-molecular-weight fractions into aqueous food simulants (3 % acetic acid, 10 % ethanol, 95 % ethanol) was tested per EU Regulation 10/2011 Annex V and found below the 10 mg/dm² overall migration limit for all simulants at 40 °C for 10 days.

Typical property comparison: COSMOPLENE FL7015E2 versus standard PP random copolymer
Property	Test method	FL7015E2	PP random copolymer (ethylene ~3.5 wt%)
Melt flow rate (230 °C/2.16 kg)	ISO 1133-1	7.0 g/10 min	7.5 g/10 min
Tensile modulus (1 mm/min)	ISO 527-2:2012	800 MPa	950 MPa
Dynstat impact (-20 °C)	ISO 8256:2023	140 kJ/m²	85 kJ/m²
Seal initiation temperature (0.2 N/mm²)	Internal, 0.5 s dwell	108 °C	115 °C
Haze (50 µm film)	ASTM D1003-21	2.0 %	3.5 %
Gloss (60°, 50 µm film)	ASTM D2457-21	90 GU	85 GU
Xylene solubles	ISO 16152:2005	5.5 wt%	7.0 wt%

When lamination grades demand a balance between bond strength and thermal resistance

In extrusion-lamination applications at coating weights of 15–25 g/m² onto PET and aluminium foil substrates, FL7015E2 provides peel strengths above 3.0 N/15 mm (ISO 11339:2022, 100 mm/min crosshead speed) after a 24-hour post-treatment cure. Elevated-temperature resistance tested in a 90 °C air-circulating oven for 72 hours did not reduce peel values by more than 15 %, thanks to the terpolymer’s higher softening point relative to ethylene-vinyl acetate or polyethylene-based lamination tie layers. In direct coextrusion with barrier polymers, an adhesive tie layer of maleic-anhydride-grafted polypropylene (MAH-PP) is still recommended when bonding to PA or EVOH layers; the terpolymer alone cannot generate covalent bonds with polar barrier surfaces. Misuse in such configurations without a tie layer has led to delamination within 48 hours of thermoforming on documented production trials.

Regulatory Compliance and Food Contact Status

Compliance checklist for food contact and environmental regulations
Regulation/Standard	Relevant Clause/Requirement	Status
EU Regulation 10/2011	Overall migration < 10 mg/dm²; specific migration limits for ethylene, propylene, butene monomers	Compliant, with supporting migration test reports at 40 °C/10 days
FDA 21 CFR 177.1520	Olefin polymers, conditions of use A–H	Compliant for all food types up to 100 °C
REACH (EC 1907/2006)	Registration for substance: propylene-ethylene-butene terpolymer	Registered, tonnage band 100–1000 t/a
RoHS Directive 2011/65/EU	Restriction on lead, mercury, cadmium, hexavalent chromium, PBBs, PBDEs	Below permissible concentrations; test reports per IEC 62321
CONEG Model Legislation	Heavy metals in packaging < 100 ppm total	Confirmed by XRF screening of finished film samples

The slip additive system utilizes erucamide derived from non-GMO vegetable oil sources, and the anti-block is synthetic silica with a particle size distribution centered at 4 µm (D50 by laser diffraction). No animal-derived ingredients or phthalate plasticizers are present, aligning with Halal certification requirements.

Long-Term Ageing of Sealed Seams in Frozen Conditions

Seal integrity after 12 weeks at -25 °C was evaluated using burst-test apparatus conforming to ASTM F1140/F1140M-22. Seals produced with FL7015E2 at 120 °C and 0.4 MPa for 0.8 s dwell time retained 90 % of the initial burst pressure of 28 kPa, whereas ethylene-copolymer-based seal layers showed a 25 % decline due to stress-induced micro-cracking at low temperature. The butene-1 component enhances segmental mobility in the amorphous phase without introducing a secondary beta-relaxation peak above -30 °C, as confirmed by dynamic mechanical analysis (DMA) at 1 Hz.

The COSMOPLENE PP Terpolymer FL7015E2 thus offers a distinct sealing-temperature advantage over standard propylene-ethylene random copolymers while preserving optical clarity, organoleptic neutrality, and sufficient thermal stability for coextrusion with higher-melting polypropylene backbone layers. The operational boundary is delineated by a maximum continuous service temperature of 100 °C in air and a minimum processing temperature of 190 °C; outside this window, the balance of sealability and thermal robustness shifts unfavorably.

HS Code	245939
Density	0.9 g/cm³
Melt Flow Rate	7.0 g/10 min (230°C, 2.16 kg)
Melting Temperature	145°C
Vicat Softening Point	130°C
Heat Deflection Temperature	85°C
Tensile Strength At Yield	28 MPa
Elongation At Break	300%
Flexural Modulus	750 MPa
Notched Izod Impact	5.5 kJ/m²
Rockwell Hardness	R85

Packing	COSMOPLENE PP Terpolymer FL7015E2 is packaged in 25 kg multi-layer paper bags, palletized and wrapped for safe transport and storage.
Container Loading (20′ FCL)	20' FCL: 20 metric tons packed in 25kg woven bags, palletized and shrink-wrapped, totaling 800 bags per container.
Shipping	COSMOPLENE PP Terpolymer FL7015E2 is supplied as free-flowing pellets in moisture-protective bags or bulk containers. It is non-hazardous for transport, but should be shipped dry, away from heat, ignition sources, and UV exposure. Avoid rough handling to prevent bag damage and contamination. Store in a cool, ventilated area.
Storage	Store COSMOPLENE PP Terpolymer FL7015E2 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers tightly sealed to prevent moisture contamination and dust accumulation. Avoid contact with strong oxidizing agents. Maintain indoor temperatures below 40°C and protect from mechanical damage.
Shelf Life	Shelf life is typically 2 years from manufacture when stored unopened in a cool, dry place away from heat and sunlight.

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