A request to "seal silicone" concerns a “difficult-to-adhere substrate.” Conventional acrylic and rubber-based pressure-sensitive adhesives tend to peel off easily after application; even with commercially available silicone-based pressure-sensitive adhesives, most require prior plasma treatment or the application of a surface treatment agent to achieve reliable adhesion—a process that is cumbersome and yields inconsistent results.
The introduction of a new type of BPO silicone pressure-sensitive adhesive has overcome this limitation, enabling true “bonding to” silicone surfaces without the need for silicone surface treatment; this represents a novel adhesive formulation for manufacturing high-reliability silicone adhesive tapes.
1. Why is silicone difficult to bond?
Silicone is a typical low-surface-energy material, with a surface tension of only approximately 20–24 mN/m, whereas conventional pressure-sensitive adhesives typically require the surface energy of the bonded surface to be ≥38 mN/m to achieve effective adhesion.
At the molecular level: the main chain of the silica gel consists of siloxane bonds, and its surface is densely covered with nonpolar methyl groups, conferring extremely high chemical inertness; consequently, conventional adhesives cannot fully wet the surface and can only establish very weak physical adsorption.
Failure characteristics: In conventional bonding failures, the primary failure mode is interfacial delamination—where the adhesive layer remains intact but detaches directly from the silicone surface; simply increasing the amount of adhesive applied or the bonding pressure cannot enhance the bonding strength.
The conventional industry solution involves activating the surface of the silicone; however, this additional step increases production costs, and ensures consistent performance in mass production is difficult to guarantee.
II. Key Characteristics of This New Pressure-Sensitive Adhesive
This silicone-based pressure-sensitive adhesive, specifically developed for silicone materials, achieves its key breakthrough by bypassing the surface treatment step, enabling high-strength bonding directly to silicone substrates. Its key characteristics are as follows:
1. No surface treatment required—guaranteed strong adhesion to silicone.
This is its most fundamental distinction from competing products on the market:
No silicone surface treatment agent is required; direct bonding alone ensures effective, high-strength adhesion, significantly reducing product manufacturing costs.
The bonding strength exceeds the intrinsic cohesive strength of the silicone substrate; during peeling tests, failure occurs within the silicone substrate itself rather than at the interface—this phenomenon is referred to in the industry as the “bond-failure” effect.
Compatible with a variety of low-surface-energy silicone materials—including silicone gaskets, silicone foam, and silicone release films (silicone oil release films)—ensuring broad bonding compatibility.
2. Excellent environmental resistance, making it suitable for harsh operating conditions.
Stable weather resistance: The material passes an 85 °C/85 % relative humidity (double 85) 1,000-hour aging test, exhibits minimal reduction in adhesion performance under high-temperature and high-humidity conditions, and maintains adhesion integrity during prolonged service.
Exceptional high-temperature performance: Upon crosslinking, a stable three-dimensional network structure is formed, ensuring that the adhesive layer does not soften, leak, or leave residue under prolonged high-temperature conditions, thereby guaranteeing high bonding reliability.
3. Excellent coating adaptability, facilitating the production of finished adhesive tapes.
It can be applied to various film substrates, including PET and PI; once formed into adhesive tape, it exhibits both flexibility and dimensional stability, making it suitable for subsequent processing steps such as die-cutting and punching.
III. Instructions for Use
Typical tape preparation process
Evenly apply the adhesive solution onto the substrate → cure by baking at 140–150 °C → laminate with a release film and roll up → after die-cutting, the product is ready for use.
IV. Application Areas
This type of adhesive tape is primarily used in high-end applications where high reliability of silicone bonding is required:
New energy sector: adhesion and fixation of aerogels in cell thermal insulation layers, aerogel encapsulation for blade batteries, and ternary adhesive coating, among others;
Battery PACK: The protective adhesive layer applied over the silicone foam provides cushioning, vibration damping, and sealing protection.Overall, this new BPO silicone pressure-sensitive adhesive addresses the bonding challenges of silicone-based materials at the molecular compatibility level, eliminating the need for traditional surface treatment steps. Simultaneously, it offers excellent temperature and weather resistance alongside optimal process compatibility, providing a more efficient and reliable solution for silicone bonding applications in sectors such as new energy and electronics.
Assess a "Seal Silicone" Request Using the Actual Tape and Surface
When a "seal silicone" request involves silicone bonding tape, the adhesive layer is only part of the construction that needs evaluation. The backing, release liner and bonded rubber surface each influence what happens during converting and use. Start with the actual molded component or foam rather than assuming that a laboratory sheet represents every production surface. Surface texture, molding residues and material history can alter contact, while a flexible foam can deform under application pressure. An adhesive that appears firmly attached may still have limited contact around a textured region or a curved edge. Why judge the tape only by an immediate hand peel when the intended part will also bend, remain compressed or experience a sustained load? Separate initial tack, peel behavior and resistance to slow movement under load in the evaluation plan. They describe different aspects of the joint. A stiff backing can direct force into the edge of a soft substrate; a more conformable backing may follow the shape but requires evaluation during handling and die-cutting. If the tape will form a gasket, also check whether its edges remain in contact as the assembly is opened and closed. Adhesion and sealing are related assembly functions, but a successful peel test does not establish leak resistance. It’s useful to inspect a removed sample for adhesive transfer, torn foam and clean interfacial separation rather than relying on the force observation alone. The silicone sealant material category concerns a different product form from pressure-sensitive tape; comparing the required joint function helps clarify whether a preformed tape or a dispensed seal is appropriate.
Follow the coated web through converting and service exposure
To evaluate silicone tape for a "seal silicone" request, check how the coating process affects the finished adhesive surface before discussing application performance. Uneven coating, incomplete cure or contamination during winding can create regions that behave differently within the same roll. Use the formulation-specific coating and curing instructions, then inspect samples from the coating start, steady operation and a restart. The release liner should separate without pulling the adhesive away from the backing or disturbing the cut edge. A liner that feels convenient during manual use may behave differently during automated removal, so include the intended converting path in the trial. Examine whether adhesive accumulates on cutting tools, bridges between nearby pieces or lifts as the waste matrix is stripped. These observations can reveal a mismatch between coating condition and converting demands without introducing a new adhesive chemistry. Apply finished samples to the intended rubber using controlled alignment and pressure, and keep the handling history consistent when comparing candidates. Conditioning should reflect the relevant environment: heat, moisture, contact fluids and sustained deformation need separate consideration where they are part of service. After conditioning, inspect both the adhesive interface and the backing, because a dimensional change in the carrier can affect the joint even if the adhesive remains attached. For foam laminates, distinguish tearing of the foam from loss of adhesion; substrate failure is not automatically acceptable if the component can no longer perform its cushioning or sealing function. Preserve the unconditioned comparison samples and document the observed failure location. The broader industrial sealant and gasket material category can support discussion of the assembly’s sealing duty, while tape adhesion and converting behavior still require their own process trials.
Selection of the right grade from the sealant and gasket range usually starts with drawings and service conditions. The companion piece on Which adhesives are suitable for forming a sits alongside this guide, the Shanghai JOME Industrial adhesive portfolio lists every family, and the contact the JOME technical team handles enquiries.