Home ApplicationWhite Wine Cap
2025-03-05 07:02:01
Aluminum is indeed a common and effective material for white wine bottle caps, specifically the screw cap type (also known as a Stelvin closure).
Oxygen Barrier: Aluminum provides an excellent barrier against oxygen. This is crucial for white wines, which are generally more susceptible to oxidation than red wines. Oxidation can lead to browning, loss of fruity aromas, and a generally stale taste.
Preservation: By minimizing oxygen ingress, aluminum screw caps help preserve the wine's freshness, aroma, and flavor profile for a longer period. This is especially important for delicate white wines.
No Cork Taint: Unlike natural cork closures, aluminum screw caps eliminate the risk of cork taint, a musty or moldy off-flavor caused by the presence of trichloroanisole (TCA).
Convenience: Screw caps are easy to open and reseal, making them consumer-friendly.
Cost-Effective: Aluminum is a relatively inexpensive material, contributing to the overall cost-effectiveness of the closure.
Recyclable: Aluminum is highly recyclable, making it an environmentally responsible choice.
Neutrality: Aluminum doesn't impart any flavors or odors to the wine.
The aluminum sheets used for wine caps need to be of a specific thickness and composition to ensure they perform their function effectively. Some key considerations include:
Thickness: The thickness is typically in the range of 0.20 - 0.24 mm (0.008 - 0.009 inches). This provides the necessary strength and flexibility for forming the cap and creating a tight seal.
Alloy: The aluminum alloy used is typically of the 8000 series, such as 8011 or 8079. These alloys offer good formability, corrosion resistance, and sealing properties.
Temper: The aluminum sheet will have a specific temper (degree of hardness) to ensure proper performance during forming and sealing.
Lacquering: The aluminum sheet is coated on both sides with a protective lacquer. This lacquer prevents the aluminum from reacting with the wine and ensures that the cap remains inert. The lacquer can also be colored or printed with designs and branding.
Liner: Inside the screw cap is a liner, often made of polyethylene (PE) or tin/Saranex. This liner provides the actual seal against the bottle lip.
The process of making aluminum screw caps for wine bottles generally involves:
Receiving Aluminum Sheets: The aluminum sheets arrive at the cap manufacturer in large rolls.
Lacquering and Printing: The sheets are lacquered and printed with the desired design and branding.
Slitting: The sheets are slit into narrower strips.
Forming: The strips are fed into forming machines that progressively shape the aluminum into the screw cap shape.
Lining: The liner is inserted into the cap.
Inspection: The caps are inspected for quality and defects.
Packaging: The caps are packaged and shipped to the wineries.
