9-micron 1235 composiet aluminiumfolie

1. Invoering

9-micron 1235 composiet aluminiumfolie is een zeer gespecialiseerd bedrijf, multi-layer material that serves as a cornerstone of the modern flexible packaging industry.

This material system is engineered to provide a high-performance barrier at an optimal cost and weight. Its core is an ultra-thin, 9µm (0.009mm) foil made from 1235 aluminium profiel, een hoge zuiverheid (≥99,35% Al) grade prized for its exceptional softness and workability.

While the 9-micron foil itself provides a near-perfect barrier to light, gassen, en vocht, its thinness makes it mechanically fragile and susceptible to pinholes.

These weaknesses are overcome by laminating it with other polymer films (such as PET, BOPP, and PE). The resulting composite structure leverages the absolute barrier of the aluminum core while gaining the strength, afdrukbaarheid, and sealability of the polymer layers.

This makes 9-micron 1235 composite foil the go-to solution for a vast range of applications, inclusief voedselverpakkingen (snacks, koffie, melkpoeder) and pharmaceutical sachets, where a high barrier, lichtgewicht, and cost-effectiveness are all critical requirements.

9-micron 1235 composiet aluminiumfolie

2. Begrip 1235 Aluminium profiel

2.1 Chemische samenstelling

De 1235 aluminiumfolie belongs to the 1xxx series of commercial purity aluminum, specifically engineered for converter foil applications where formability and barrier performance take precedence over structural strength.

The chemical composition adheres to strict limits that maximize rolling efficiency and surface quality.

2.2 Microstructure and Temper

De 1235 alloy achieves its optimal properties through careful thermal processing.

Manufacturers produce 9-micron foil in two primary tempers, each serving distinct converting requirements:

O Temper (Zacht, Gegloeid):

• Treksterkte: 60–90 MPa (8.7–13.0 ksi)
• Opbrengst sterkte: 20–35 MPa (2.9–5.1 ksi)
• Verlenging: 25–35% (A50mm gauge)
• Hardheid: 20–25 HB
• Microstructuur: Fully recrystallized equiaxed grains (ASTM 6–9) with minimal dislocation density

The O temper maximizes ductility for deep drawing, vouwen, and complex forming operations.

The 25–35% elongation enables 9-micron foil to conform to sharp creases in cigarette inner liners and sachet corners without cracking.

This temper also optimizes adhesive wet-out during lamination, as the soft surface conforms to microscopic surface irregularities in plastic films.

9-micron 1235 H18 aluminiumfolie

H18 Temper (Volledig moeilijk, Cold-Worked):

• Treksterkte: 110–150 MPa (16.0–21.8 ksi)
• Opbrengst sterkte: 100–130 MPa (14.5–18.9 ksi)
• Verlenging: 1–3%
• Hardheid: 45–55 HB
• Microstructuur: Elongated grains with high dislocation density from cold rolling

H18 temper provides handling stiffness for unwind operations and slit-edge stability.

Converters often specify H18 for foil that must traverse long web paths at high speed before lamination, as the increased rigidity reduces wrinkling and edge weaving.

The laminate structure subsequently provides flexibility in the finished product.

3. 9 Micrometer (urn) Dikte: Opportunities and Challenges

3.1 Opportunities (Why pursue 9 micrometers?)

• Lichtgewicht & material cost reduction. Moving from e.g., 12–15 µm down to 9 µm reduces aluminum mass by ~25–40%, lowering raw-material cost and package weight. (9 µm = 0.009 mm).
• Excellent barrier per unit mass. Even at 9 µm a continuous aluminum layer provides near-opaque light barrier and very low oxygen and moisture transmission when incorporated into a laminate; suppliers report OTR and WVTR figures that place such laminates in “high barrier” class for many food and pharmaceutical applications.
• Improved form-factor and aesthetics. Thin foil conforms to complex shapes (labels, lidding) with smaller step heights and less bulk.

3.2 Uitdagingen (Inherent weaknesses of 9 micrometers)

• Mechanical fragility: reduced puncture resistance, higher sensitivity to handling, and increased risk of pinholes during rolling and lamination. Typical practical tensile/puncture performance must be validated for the stack and forming process.
• Gaatjes & defects control: process cleanliness and rolling/anneal schedules must be tightly controlled; pinhole density scales unfavorably with decreasing gauge.
• Adhesion and delamination risk: ultra-thin foil has less cohesive thickness for adhesives to “bite”; surface treatments or lacquers are often required to secure bond strength to polymers.
• Converting difficulty: scheuren, embossing, die-cutting and rewinding require specialized tension control, anti-static measures and skilled equipment operators.

4. Structure of 9-Micron 1235 Composite Aluminum Foil

4.1 Typical Composite Structures

The 9-micron 1235 foil rarely serves as standalone packaging. In plaats van, it functions as the critical barrier layer within multi-material laminates that combine complementary properties.

Engineers design these structures to position each material where its properties deliver maximum value:

Structuur 1: PET/AL/PE (General-Purpose Food Packaging)

• HUISDIER (12–25μm): Exterior print carrier providing mechanical strength, dimensionale stabiliteit, and gloss
• Zelfklevend (1.5–3.0 g/m²): Polyurethane two-component system creating chemical bond
• AL (9urn): Core barrier layer blocking oxygen, vocht, en licht
• Zelfklevend (1.5–3.0 g/m²): Tie layer for polyethylene adhesion
• PE (40–80μm): Interior sealant providing heat-sealability, chemical resistance, and food contact compliance

Total thickness: ~65–120μm | Barrière: OTR <0.1 cc/m²·day, WVTR <0.01 g/m²·dag

Structuur 2: Paper/AL/PE (Cigarette Inner Liner)

• Papier (40–60 g/m²): Exterior providing dead-fold characteristics, dekking, and tactile quality
• AL (9urn): Barrier against moisture and aroma loss
• PE (20–60μm): Heat-seal layer for pack closure

This structure leverages the “dead-fold” property of 1235-O foil—the ability to retain a crease without spring-back—essential for cigarette pack forming at 400+ packs/minute.

Structuur 3: BOPP/AL/CPP (Confectionery and Snacks)

• BOPP (20urn): High-clarity exterior with excellent machinability
• AL (9urn): Barrier and light protection
• CPP (40–70μm): Hot-tack sealant for high-speed form-fill-seal operations

The biaxially oriented polypropylene (BOPP) provides superior crack resistance compared to PET, while cast polypropylene (CPP) offers broader heat-seal windows for confectionery packaging.

Structuur 4: PA/AL/PE (Puncture-Resistant Pouches)

• VADER (15urn, Nylon): Exterior providing exceptional puncture and abrasion resistance
• AL (9urn): Barrier layer
• PE (60–80μm): Sealant and structural bulk

This configuration suits vacuum-packed meats and cheeses where bone edges or sharp corners threaten package integrity.

Tea packaging used 9-micron 1235 composiet aluminiumfolie

4.2 Why Composite for 9-Micron Aluminum Foil

Mechanical Protection:

The 9-micron foil cannot survive handling, Verzenden, or retail display as a single layer.

HUISDIER (tensile strength 200–300 MPa) or paper (stiffness 2–5 Nm/g) provide structural armor that prevents flex cracks and abrasion.

Afdicht integriteit:

Aluminum lacks thermoplasticity—it cannot heat-seal. PE or CPP layers (melting point 110–135°C) create hermetic closures through impulse or hot-bar sealing.

Chemical Isolation:

Acidic or alkaline products (tomatensaus, wasmiddelen) corrode aluminum. PE and PP provide inert barriers preventing chemical attack.

Afdrukbaarheid:

Aluminum accepts only limited printing technologies. PET and paper substrates enable high-resolution gravure or flexographic decoration.

Cost Optimization:

At $8–12/kg for aluminum foil versus $2–4/kg for PE, composite structures minimize aluminum usage to the absolute barrier requirement while leveraging cheaper polymers for bulk.

5. Manufacturing Process of 9-Micron 1235 Composite Aluminum Foil

Key steps and control points:

1. Casting and hot rolling to produce coil stock.
2. Cold rolling schedules with multiple passes to progressively reduce gauge toward foil thickness. Intermediate and final anneals are applied to restore ductility and control grain structure. Precise pass schedules and roll gap control are critical to reach a uniform 9 µm target without excessive edge-wave or thickness variation.
3. Surface preparation and cleaning to remove rolling oils and particulates (important to minimize pinholes).
4. Coating/lacquering (optioneel) to provide printability and corrosion resistance prior to lamination.
5. Lamineren (composite formation) — can be by solventless adhesive, extrusie lamineren (melt adhesive), or solvent/wet adhesives depending on stack and end-use. Proper adhesive selection, nip temperature and pressure are tuned to avoid foil wrinkles and to achieve peel strength targets.
6. Slitting and rewinding with strict tension control and anti-static handling for 9 µm gauges.
7. Quality inspection (pinhole detection, dikte in kaart brengen, surface inspection) and final packing.

Process control charts for foil production typically track gauge tolerance (bijv., ±0.5 µm target for 9 µm), pinhole counts per m², and laminate peel strength.

6. Applications of 9-Micron 1235 Composite Aluminum Foil

6.1 Flexibele voedselverpakkingen

The 9-micron 1235 foil serves as the barrier backbone for dry goods packaging:

• Coffee and Tea: Aroma retention critical; 9μm foil with <40 pinholes/m² maintains freshness 12–18 months
• Snack Foods: PET/AL/PE structures provide light protection for photosensitive vitamins and flavors
• Powdered Beverages: WVTR <0.01 g/m²·day prevents caking and preserves solubility

High-speed form-fill-seal (FFS) lines operate at 200+ cycles/minute with 9-micron foil, validating its mechanical stability under rapid flexing.

Sachet Strips For Medical Packaging

6.2 Pharmaceutical and Medical Packaging

Secondary overwraps for pharmaceuticals utilize 9-micron foil in:

• Sachet Strips: PET/AL/PE for unit-dose powders and granules
• Dekselfolie: 9μm 1235-O replaces thicker gauges for cost-sensitive OTC products
• Tropical Blister Alternatives: Non-PVC laminates for high-humidity markets

Migration testing per EU 10/2011 and FDA 21 CFR 177.1390 ensures compliance for indirect food contact.

6.3 Tobacco Packaging

Cigarette inner liners represent a major 9-micron application:

• Structuur: Papier (40–60 g/m²)/AL (9urn)/PE (20–30μm)
• Dode vouw: 1235-O temper retains sharp creases without spring-back
• Aromabarrière: Prevents moisture loss and flavor cross-contamination
• Speed Compatibility: Runs at 400+ packs/minute on G.D. and Focke machines

6.4 Industrial and Technical Applications

Cable Wrap: Non-woven/AL/PE laminates provide electromagnetic interference (EMI) shielding with 9-micron foil delivering >60 dB attenuation at 1 GHz.

Bouwisolatie: Foil-faced radiant barriers utilize 9μm 1235 for cost-effective reflectivity (>88% solar reflectance).

Battery Pouch Films: Lamination with nylon and polypropylene creates containment for lithium-ion cells, with 9-micron foil providing moisture barrier and electrical isolation.

1235 aluminum foil for Cable Wrap

7. Comparative Alloy Analysis

Engineers selecting aluminum foil must evaluate alternatives to 1235. The following matrix compares key options for 9-micron applications:

8. Huawei 9-Micron 1235 Composite Aluminum Foil Specification

(Representative supplier specification drawn from typical product pages — engineers should request a manufacturer-run Material Test Certificate and sample tests before approving for production.)

Supplier example: Henan Huawei Aluminium Co., Ltd (commercial supplier listing for “9-Micron 1235 Composite Aluminum Foil”). Reported or typical specification items include:

• Legering: 1235 (O temper typical for lamination).
• Nominal aluminum thickness: 9 µm (0.009 mm).
• Composite stacks offered: PET/AL(9)/PE; Paper/AL(9)/PE; BOPP/AL(9)/PE.
• Typical WVTR / OTR for laminated structures (supplier reported example): OTR < 0.1 (units depend on test method; usually cc/m²·day), WVTR < 0.01 (g/m²·dag) for finished laminate — confirm test method and units with supplier before quoting shelf life.
• Dichtheid van gaatjes: marketed as “low pinhole density” — suppliers commonly specify pinhole counts per m² or qualitative grades; ask for measured pinhole counts at acceptance.
• Woedeaanval: O (gegloeid) or light cold-work (as required).
• Coating: optional lacquer for printability; adhesive systems per laminate.
• Pakket: jumbo rolls, typical widths 200–1,600 mm; coil ID/OD to buyer spec.
• Kwaliteitscontrole: thickness tolerance band (voor 9 µm often specified ±0.5–1.0 µm depending on supplier), visual surface class, pinhole acceptance, MTC available on request.

Huawei Aluminum Foil Export Packaging

9. Conclusie

De 9-micron 1235 composiet aluminiumfolie is a testament to the power of systems thinking in material science.

It is a highly optimized solution that acknowledges the limitations of a single material and overcomes them through intelligent combination.

By pairing the absolute barrier potential of an ultra-thin 1235 aluminum foil with the mechanical strength of polymer films, the packaging industry has created a material that is both high-performing and highly economical.

It is not the most robust barrier available, but for the vast majority of flexible packaging needs, it represents the perfect equilibrium of protection, kosten, en efficiëntie.

Veelgestelde vragen

1. If 9-micron foil has pinholes, is it still a “high barrier”?
Ja. In a composite structure, the barrier performance is not determined by the foil alone. The adhesive and polymer layers create a “tortuous path” that effectively seals the microscopic pinholes. The final laminate still provides an exceptionally low OTR and WVTR (bijv., <0.5), which is firmly in the high-barrier category and far superior to any non-foil-based film.

2. Why not just use a thicker foil to avoid pinholes?
You can, but it comes with trade-offs. A thicker foil (bijv., 12µm or 15µm) will have fewer pinholes and more strength, but it will be more expensive, heavier, and result in a stiffer final package, which may not be desirable. 9 microns is often the most cost-effective solution that meets the required barrier specifications for a huge range of products.

3. What is the difference between this and “Alu-Alu” foil?
“Alu-Alu” (koude vorm) foil is a much thicker, soft-temper aluminum foil (typisch 45-60 micron) laminated with OPA and PVC. It is designed to be plastically deformed (cold-formed) into a blister cavity, providing an absolute, 100% barrière. 9-micron composite foil is a thin, flexible material used for flat pouches and bags; it cannot be formed into a deep cavity.