Paper substrates occupy an unshakable dominant position in the application of silicone release agents. This phenomenon contains profound market demand and technical logic. Paper has a long history as a carrier of release agents. Its porous fiber structure provides an ideal anchoring foundation for release agents, and its relatively low cost gives it a clear advantage in large-scale commercial applications. Solvent-free silicone release agents are currently widely used in many fields including food paper coating, covering kraft paper, release paper, labels, barcode paper, imitation paper, isolation paper, non-dry label paper, food paper, PET release paper, white coated paper and other paper types that require anti-sticking1. This wide range of applications fully demonstrates the adaptability and flexibility of paper as a substrate, which can meet the diverse needs from daily packaging to professional industrial use.


From the perspective of technical adaptability, paper and solvent-free silicone release agents form a highly synergistic combination. After proper treatment (such as coating) on the paper surface, it can effectively prevent the penetration of release agents and ensure the stability of curing effect and release performance6. For example, coated release paper provides a uniform and smooth coating surface for silicone oil by coating a polyethylene (PE) layer (usually about 16 grams per square meter) on the base paper, avoiding the problem of uneven coating caused by rough paper fibers. In contrast, plastic films such as PET have low surface energy and dense structure, and it is difficult for release agents to form a strong bond, which is prone to "desiliconization". In view of the characteristics of paper, release agent developers have developed a special formula system. For example, by adjusting the branched structure and system rigidity of silicone resin, the release force and stability can be accurately adjusted to meet the needs of different paper application scenarios2. This high degree of adjustability enables paper substrates to adapt to a full range of products from light release (3-4 grams/25mm) to super heavy release (100 grams/25mm or more).


Market demand factors are the core driving force for the widespread application of paper substrates. With the rapid development of e-commerce logistics, food packaging, medical supplies and other industries, the demand for release paper is showing a continuous growth trend. Especially after the COVID-19 pandemic, the explosive growth of products such as sanitary care products (such as diapers), medical tapes, and express labels has directly driven the expansion of the release paper market6. Paper substrates have shown irreplaceable advantages in these applications: low cost, biodegradability, good processing performance, and high end-user acceptance. According to industry data, domestically produced solvent-free silicone release agents have achieved large-scale production and sales of more than tons, serving leading high-end packaging manufacturing companies, and some products have successfully replaced imports2. This large-scale commercial application further consolidates the dominant position of paper in the field of release agents and forms a complete industrial chain from raw materials to terminal applications.


In terms of process maturity, paper coating technology has formed a highly specialized production system after decades of development. Laminated release paper, glassine release paper, and CCK release paper constitute the three major mainstream product types, each with its own specific production process and performance characteristics6. Take glassine release paper as an example. Its base paper has been super-calendered and has high compactness, which is particularly suitable for die-cutting. Although domestic glassine paper can only produce 60-80g products at present, it can meet the needs of high-end die-cutting by importing high-quantity base paper such as 120g and 140g. In contrast, the production process of PET release film is more complicated, with higher requirements for coating equipment and curing conditions, and it is necessary to solve the technical problem of poor adhesion between silicone oil and film4. This process threshold restricts many small and medium-sized enterprises from entering the field of PET release film, indirectly strengthening the market position of paper substrates.


Table: Comparison of main release paper types and their characteristics


Release paper type Production process characteristics Main performance advantages Typical application areas
Coated release paper Base paper coated with silicon after PE coating High flatness and good anti-permeability Tape, label, food packaging
Glasine release paper Base paper super calendered and coated with silicon High compactness and good die-cutting performance Self-adhesive label, medical tape
CCK release paper Base paper coated with clay and then coated with silicon Excellent high temperature resistance Carbon fiber prepreg, special industrial use
Plastic-free release paper Specially treated base paper directly coated with silicon Environmentally friendly and degradable, low cost General packaging, temporary protection
Environmental protection and sustainability considerations further strengthen the dominant position of paper substrates. In the context of global advocacy of circular economy and sustainable development, paper, as a renewable resource, is favored by end consumers for its environmentally friendly image. Many brand owners give priority to recyclable and degradable paper-based solutions when choosing packaging materials. The combination of solvent-free silicone release agent and paper just meets this market demand and forms a complete green product chain. It is worth noting that the PE layer in the coated release paper is still a difficult point for recycling and the industry is actively exploring innovative solutions such as bio-based coated materials. In contrast, although PET film is theoretically recyclable, the actual recycling rate is not ideal, and the recycling of PET film after silicon coating is more complicated. This full life cycle assessment further highlights the potential advantages of paper substrates in sustainable development.


Overall, paper substrates have dominated the application of silicone release agents due to their technical adaptability, market demand, process maturity and environmental protection characteristics. With the advancement of solvent-free technology and the optimization of coating processes, paper-based release products will continue to expand their application range to meet increasingly diverse market needs. In the future, this traditional combination will continue to maintain strong market competitiveness by developing higher-performance paper-based materials and more environmentally friendly release agent formulations.