7 9-layer Greentec Blown Film Extrusion Line

equipment supports a flexible 7-layer or 9-layer structure (A/B/C/D/E/F/G up to I), with a maximum film width covering 1500–2200 mm and film thickness range of 0.03–0.12 mm. It is suitable for producing high-barrier food packaging, industrial heavy-duty shrink film, medical packaging, and agricultural film. Installed power: 250–350 kW, maximum output up to 600 kg/h (GT-2200-7/BX). Adopting energy-saving extrusion systems and precision dies, it achieves low energy consumption and high output while maintaining the stability of multi-layer structures.

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Application

Thanks to its 7-layer or 9-layer A/B/C/D/E/F/G (up to I) structure, the GT-BX series is widely used for high-barrier and functional films:
High-barrier food packaging – 9-layer structures using EVOH or PA provide oxygen/water vapor barriers for meat, cheese, and coffee. *Example: A German meat packaging producer switched from 5-layer to GT-1800-7/BX (9-layer), extending product shelf life by 40%.*
Industrial heavy-duty shrink film – Width 1500–2200mm, thickness 0.03–0.12mm, suitable for pallet wrapping and chemical packaging.
Medical and pharmaceutical films – Precise layer control ensures contamination-free, sterilizable materials.
Agricultural films – Multi-layer UV-resistant mulch films or silage stretch films.
Case study: A Turkish agricultural film manufacturer uses the GT-2200-7/BX (max width 2200mm) to produce 9-layer UV-resistant silage film at 550 kg/h output. By achieving the same strength with thinner gauge, raw material costs were reduced by 12%.

Advantages

Layer structure flexibility – Switch between 7 and 9 layers without modifying the production line. Allows thickness reduction while maintaining stiffness/barrier properties.
Wide thickness window – Produce from 0.03mm (ultra-thin breathable film) to 0.12mm (heavy-duty FIBC) on the same line.
Lower energy consumption per kg – At 500–600 kg/h output, total power of GT-2200-7/BX is only 250–300 kW, consuming approx. 0.5 kW per kg – better than many traditional lines.
Modular die design – Enables fast changes of layer ratios, minimizing material waste when switching grades.

Process

Greentec integrates online and offline quality control to ensure every roll meets specifications.
Online monitoring (during extrusion):
Thickness control system – Ultrasonic or NIR sensors scan the film transversely every 50 ms. Thickness tolerance ≤ ±3% across 2200mm width.
Layer ratio feedback – Screw speed of each extruder is automatically adjusted based on melt pressure sensors. For 9-layer A/B/C/D/E/F/G/H/I, layer thickness deviation <2%.
Melt temperature and pressure – Alarms triggered if overheating degradation occurs (e.g., EVOH overheating).
Vision inspection – High-speed cameras detect gels, black spots, or fish eyes down to 0.1mm.
Offline lab testing (per ASTM/ISO standards):

Test	Equipment	Acceptance criteria
Tensile strength	Universal tester	MD/TD ≥ 30 MPa
Dart drop impact	Dart drop impact tester	≥ 150 g for 0.05mm film
Heat seal strength	Heat sealer + tensile tester	≥ 25 N/15mm
Oxygen transmission rate (OTR)	Mocon OTR tester	Barrier grade < 5 cc/(m²·day)
Haze & gloss	Haze meter	Haze <8%, gloss >70° for transparent films

Example from a Vietnamese packaging plant: They cut one sample from every 2000 kg batch of GT-1800-7/BX 9-layer PA/EVOH film per day. OTR remained below 3 cc/(m²·day) – meeting pharmaceutical packaging standards.

Parameters

Model	Max. layflat film width (mm)	Products thickness (mm)	Lay structure	Total power (KW)	Max. capacity (KW/H)
GT-1500-7/BX	1500	0.03-0.12	A/B/C/D/E/F/G & A/B/C/D/E/F/G/H/I	250-300	300-400
GT-1800-7/BX	1800	0.03-0.12	A/B/C/D/E/F/G & A/B/C/D/E/F/G/H/I	300-350	400-500
GT-2200-7/BX	2200	0.03-0.12	A/B/C/D/E/F/G & A/B/C/D/E/F/G/H/I	250-300	500-600

Q1: Can I produce both 7-layer and 9-layer structures on the same line?
A: Yes. The GT-BX series die accepts either a 7-layer or 9-layer distributor. Switching takes about 2 hours (cleaning and replacing distribution plates). Many customers run 7-layer for commodity films and 9-layer for high-barrier orders on the same machine.

Q2: What materials are compatible?
A: All common polyolefins (LDPE, LLDPE, HDPE, mLLDPE), barrier resins (EVOH, PA6, PA66), tie resins, and biodegradable PLA/PBAT. Melt temperature range 160–260°C. Tip: For EVOH (highly hygroscopic), we recommend installing hot-air dryers on extruders E/D/C (barrier layer positions).

Q3: How do you maintain thickness uniformity on ultra-thin 0.03mm film?
A: Three factors: (1) automatic air ring with 24 heating zones, (2) IBC (internal bubble cooling) with realtime diameter control, (3) oscillating haul-off. On GT-1500-7/BX, we achieved ≤0.03mm ±0.0015mm accuracy for a Japanese stretch wrap customer.

Q4: What is the typical material changeover time when switching 9layer recipes?
A: Using the “purge valve” system, for materials with similar melting points (e.g., LDPE to LLDPE) it takes 20–30 minutes. When switching to EVOH, allow 45–60 minutes and use PP purging compound.

Q5: What output can I expect for highbarrier 9layer films?
A: For a 9-layer structure: (outer) LLDPE / tie / PA / tie / EVOH / tie / PA / tie / LLDPE (inner). At total thickness 0.08mm, GT-2200-7/BX outputs approx. 520–550 kg/h. Actual barrier performance: OTR < 1.5 cc/(m²·day), WVTR < 3 g/(m²·day).

Q6: How often do screws and barrels need replacement?
A: With routine maintenance (regular cleaning, corrosion-resistant screws for EVOH), bimetallic barrels can last 40,000–50,000 hours. For 24/7 continuous operation, that is about 5–6 years.