We all know that silicone PSA can be used in many aspects, such as bonding and insulation, but what conditions should an effective glue meet?
As long as this condition is satisfied: cohesion > adhesion > peeling force > initial adhesion
Cohesion: the strength and tensile strength of the glue itself. The stronger the cohesion, the better the strength of the glue. Cohesion > adhesion. Good cohesion can make the glue without residue and damage
Adhesion: the force between the base material and glue. Primer can improve the integration of glue and base material. Adhesion > stripping force: after the tape is torn off, the glue will not separate from the base material so that the tape can be torn off
Stripping force: the force when tearing the adhesive layer and the pasted object. The stripping force is greater than the initial adhesion force. The adhesion force is greater after being pressed by the external force
Initial adhesion force: the adhesion force without pressure. The higher the initial adhesion force, the softer it is, the easier it is to paste, and the better the adhesion force. Different substrates have different initial adhesion requirements
This article will introduce below:
Silicone pressure-sensitive adhesives(PSA) have excellent adhesive properties in heat and cold environments, electrical insulating properties and excellent reliability. Tapes using silicone PSA have good removability and have good peel adhesion properties to many substrates. So silicone PSA can be applied to various kinds of tapes and protective films.
According to the desired application, adhesive materials are combined into adhesives with various functions, which are used in tapes. The tape is extremely convenient, can be applied immediately, and can be prefabricated into specified shapes, so it is widely used in LCD TVs, mobile phones and automobiles. In applications that require the permanent attachment of items, such as automotive parts, adhesives must be strong, while protective films on mobile phone screens must be easy to peel and leave no adhesive residue. Silicone adhesives used in polarizing films must be clear and weather-resistant, and adhesives used in vehicle interiors must have minimal VOCs. For each of these different applications, different types of adhesives are required.
Difference from other materials
Compared with domestic traditional acrylic pressure-sensitive adhesive, the excellent properties of silicone PSAs are profoundly manifested in chemical resistance, performance stability at extreme temperatures and dielectric properties. Among all pressure-sensitive adhesives, the critical temperature value of silicone PSA performance makes it perfect for use in almost any environment on earth (high-temperature critical value: 300 ℃, low-temperature critical value: -75 ℃), in somewhere the index of environmental requirements is relatively high, silicone pressure-sensitive adhesives have almost no pressure. In addition, it can also bond a variety of difficult-to-stick materials, such as untreated polyolefins, fluoroplastics, polyimides and polycarbonates that cannot be attached by ordinary pressure-sensitive adhesives, and silicone pressure-sensitive adhesives. The experimental results are satisfactory. And resistant to migration and has no glue residue.
Relatively speaking, the temperature resistance of traditional pressure-sensitive adhesives is far inferior to that of silicone, and it is easy to migrate to the surface of the object, resulting in residual adhesive. Moreover, due to the residual adhesive, many applications that require residual adhesive cannot use traditional pressure-sensitive adhesives.
- The process is complicated and the cost is relatively high. Its cost is about 2-3 times that of acrylate PSA and 4-5 times that of natural rubber pressure-sensitive adhesive;
- Most silicone pressure-sensitive adhesives are solvent-based and cause air pollution;
- The drying and heat treatment temperature is relatively high (generally between 100 and 180 ℃);
- The adhesive force is small, so the processing technology of the substrate is very important;
Application of different substrates
Gold finger tape, also known as Kapton tape or polyimide tape, the tape is based on a polyimide film, coated with high-performance silicone PSA on one side, and has a single-sided fluorine plastic release material compound or not. Composite two types of materials. Coating high precision reaches ±2.5um, no scratches, wire drawing, etc., good shearing, easy punching die-cutting, excellent high-temperature resistance and solvent resistance!
The different applications of gold finger tape, can be divided into gold finger double-sided tape, anti-static gold finger tape, composite gold finger tape and SMT gold finger tape, etc.
Features and Applications
1. The electronic and electrical industry can be used for insulation wrapping of H-class motor and transformer coils with high requirements, wrapping and fixing the ends of high-temperature coils, temperature measuring thermal resistance protection, capacitance and wire entanglement and other paste insulation under high-temperature working conditions.
2. It can be used for electronic protection paste in the circuit board manufacturing industry, especially suitable for SMT temperature resistance protection, electronic switches, PCB board gold finger protection, electronic transformers, relays and other electronic components that need high-temperature resistance and moisture-proof protection.
3. Polyimide tape with low static electricity and flame retardant is provided according to the needs of a special process.
4. Reinforcement and protection of the high-temperature surface, high-temperature spray painting and sandblasting coating of metal materials to cover surface protection, after high temperature spray painting and baking, it is easy to peel off without leaving glue residue.
5. It has the advantages of high-temperature resistance, high tensile strength, good chemical resistance, no residual glue, and ROHS environmental protection and halogen-free. It is suitable for wave solder shielding of electronic circuit boards, protecting gold fingers and high-grade electrical insulation, motor insulation, and fixing the positive and negative lugs of lithium batteries.
The characteristics of PET and silicone are high-temperature resistance, so PET silicone adhesive is mainly used as high-temperature resistance tape, which we usually call shuttle tape. It is mainly made of soft PET polyester film as the base material and coated with high-performance SPSA on one side. PET silicone tape is mainly used for high-temperature environment work surface treatment and shielding protection, like electroplating, electrophoresis, ultra-high temperature baking paint, powder coating and the use of terminal electrodes for chip components, etc. In addition to excellent high-temperature resistance, PET silicone pressure-sensitive adhesives tape also have high adhesion, no adhesive residue after peeling, and solvent resistance.
Five applications of PET silicone adhesives
1. It is mainly suitable for metal surface treatment such as computer chassis and cabinets, the high-temperature powder is not sprayed, and baking paint is used for shielding protection.
2. It is also suitable for shielding protection and insulation during high-temperature spraying of electronic products, automotive industry, coating and other products.
3. Printed circuit boards, electronic parts, resistors and capacitors are fixed during production and shielded during the impregnation process of PCB boards to prevent immersion and pollution of electroplating solution.
4. The industries such as household appliances, machinery, and electronics require high-temperature coating and spraying protection. PET silicone PSA high-temperature tape plays a role in high-temperature binding and fixing.
5. Coating. The tape made of specially treated adhesive can be used as a release paper joint.
PTFE is one of the low surface energy materials, the critical surface tension is only 1.85 × 10-4N / cm, the untreated surface bonding strength is very low so that when it is used as a tape substrate, the surface without chemical treatment, pressure-sensitive adhesives are simply not adhered to, let alone made of silicone tape. If the fluorine rubber PSAs are coated on the PTFE film made of pressure-sensitive adhesive tape, the performance is very good. However, fluoro rubber PSA has not been developed, and other pressure-sensitive adhesives can only be used instead. At present, the silicone adhesive is still more ideal for silicone pressure-sensitive adhesive.
Silicone PSAs can be used in a wide range of temperatures from -73 ℃ to +250 ℃ and can bond a variety of difficult-to-stick materials, with excellent electrical properties as well as acid and alkali corrosion resistance and anti-aging properties, a variety of sticky materials have good adhesion. Therefore, the silicone pressure-sensitive adhesive coated on PTFE film to make high-quality, high-grade pressure-sensitive adhesive tape is ideal.
XJY--First choice supplier of silicone PSAs
XJY-301 and XJY-302 series silicone PSAs are colorless and transparent viscous liquid, which can be used for various adhesive tapes, has good shear and tack properties, and has unique features of silicone such as aging-resistance, high and low-temperature resistance, no residue after stripping for crepe paper, PET film and other adhesion tapes, has the good adhesive ability. Further information? CONTACT US NOW!