What are the key characteristics of Aluminum Foil Grade 1235 O for lamination applications?
Grade 1235 O aluminum foil is specifically designed for lamination due to its high purity (99.35% aluminum content) and superior surface quality. The "O" temper indicates it's fully annealed, providing excellent formability and flexibility. It has a clean, uniform surface that ensures strong adhesive bonding during lamination processes. The foil demonstrates consistent thickness tolerance (±5%) across production batches. These properties make it ideal for packaging laminates requiring precise layer integration.
Why is Grade 1235 particularly suitable for pharmaceutical blister packaging lamination?
This grade offers exceptional barrier properties against moisture and gases, crucial for drug preservation. Its chemical inertness prevents reactions with active pharmaceutical ingredients. The soft temper allows deep drawing without cracking during blister formation. It complies with stringent pharmacopeia standards for extractables and leachables. Additionally, its smooth surface facilitates easy heat sealing with PVC or other polymer layers.
How does the manufacturing process of 1235 O foil differ from other grades?
The production involves multiple cold rolling passes with intermediate annealing to achieve the soft temper. Special rolling oils are used to maintain surface cleanliness for lamination purposes. Final annealing is conducted in controlled atmosphere furnaces to prevent oxidation. The process emphasizes minimizing pinholes (typically <50/m²) through precise rolling tension control. These specialized steps ensure the foil meets lamination-specific mechanical properties.
What types of laminates commonly incorporate 1235 O aluminum foil?
It's widely used in pharmaceutical foil/PVC/PVDC laminates for blister packs. Flexible food packaging often combines it with PET/PE or paper layers for snack wraps. High-barrier retort pouches laminate it between nylon and polypropylene layers. Some technical applications use it in insulation materials with fiberglass or polyester films. The foil also appears in aseptic packaging laminates for liquid food products.
What quality control tests are critical for 1235 O lamination foil?
Tensile testing verifies elongation properties (typically 15-25% for O temper). Pinhole detection uses backlight inspection systems. Surface energy tests (dyne level) ensure proper adhesive wettability. Thickness mapping with laser micrometers guarantees uniformity. Lamination bond strength is measured through peel tests (usually requiring >1.5N/15mm). Additional tests include residual solvent analysis and microbial contamination checks for medical applications.
