Release papers play a crucial role in various industries, serving as the backing paper for self-adhesive labels and finding applications in packaging sticky materials and industrial processes such as casting papers. The key component of release papers is the release material, with silicon being the most common choice. Silicon is applied in a thin layer on the base paper, and due to its expensive nature, the coating layer is kept as thin as possible, usually less than a micron thick. However, to ensure optimal release performance, it is essential for the silicon to form a uniform film without any holes.

The critical property of a high-quality siliconizing base paper lies in its ability to support the formation of a thin film with minimal silicon usage. This requires the paper to have a smooth and closed surface that facilitates the formation of the thin film, while also possessing a structure that is compatible with the silicone, allowing it to anchor firmly to the paper.

To create the release surface, a paper is coated with an open fiber structure or supercalendered, which involves compressing a glassine-type paper to close the fiber structure and form a dense surface. Glassine paper is a type of paper in which the pores are closed to create a compact and transparent film of cellulose. To further enhance the formation of the silicon film, glassine papers are often sized using a size press or a film press.

The process of siliconizing the base paper involves applying a solution or an emulsion of silicon, which is then cured on the paper. However, the curing of the film can be sensitive to inhibitors that may be present in the paper. Therefore, specific silicones require specific formulations of the paper surface to ensure optimal curing.

In the past, siliconizing base paper was considered a specialty product and was manufactured on small machines with widths ranging from 2 to 3.5 meters. However, with the increasing demand for release papers in various industries, the production of siliconizing base paper has evolved and expanded to meet the growing needs of the market.

In conclusion, release papers are essential in the production of self-adhesive labels, packaging sticky materials, and various industrial processes. The choice of silicon as the release material, along with the specific properties of the base paper, plays a crucial role in achieving optimal release performance. As the demand for release papers continues to grow, the production of siliconizing base paper has become more advanced and widespread, ensuring a steady supply to meet the diverse requirements of different industries.