Glassine Release Paper

What is Glassine Release Paper?

Glassine release paper is a high-performance specialty paper, primarily used as a backing or liner for pressure-sensitive adhesive (PSA) products like labels and tapes . The term "Glassine" originates from its characteristic glass-like smoothness and translucency . It is manufactured by applying a supercalendering process to the base paper, which involves high-pressure pressing to create an extremely dense, smooth, and uniform substrate . This base paper is then typically coated with silicone oil on one or both sides to provide non-stick properties.

Key Characteristics and Advantages

Glassine release paper is valued for several key physical and functional properties:

• High Density and Strength: The supercalendering process results in a tightly packed fiber structure, giving the paper excellent internal strength and resistance to tearing. This makes it particularly suitable for p recision die-cutting and high-speed converting processes without breaking.
• Smoothness and Uniformity: Its surface is very smooth, which ensures consistent silicone coating and reliable, controlled release force (the force required to peel the adhesive material off the liner).
• Good Transparency: Glassine paper offers good light transmission, which is crucial for applications like barcode labels, as it allows scanners to read codes through the liner.
• Functional Properties: It possesses functional resistances including temperature resistance (typically from -20°C to 150°C, with some grades tolerating even higher temperatures), moisture resistance, and grease resistance.
• Eco-Friendliness: Being a plastic-free, cellulose-based material, it is biodegradable and environmentally friendly compared to some plastic-based liners .

Primary Applications

Due to its excellent properties, glassine release paper is widely used across various industries:

• Label Industry: It is the backbone material for the facing paper of self-adhesive labels, especially in high-speed automatic labeling applications for retail, logistics, and food packaging.
• Tape and Adhesive Products: It serves as a protective liner for single-sided and double-sided adhesive tapes, ensuring they do not stick to themselves during storage and shipment.
• Medical and Hygiene Products: It is used as a release liner for medical tapes, wound dressings, and electrode pads due to its purity and compatibility with skin-contact applications.
• Electronic Die-Cutting: Its dimensional stability and strength make it ideal for precise die-cutting of adhesive components used in electronics manufacturing.

Comparison with Other Release Liners

Within the category of release papers, glassine is a type of plastic-free release paper . It is often compared to other liners like PE-coated Kraft (PEK) and Clay-Coated Kraft (CCK). The key difference lies in the base paper: glassine's supercalendered base provides superior smoothness and die-cut performance, while CCK, for example, offers exceptionally high heat resistance, making it suitable for carbon fiber production.