Silicone material is undoubtedly one of the most commonly used materials in manufacturing industries worldwide. The primary reason for such a strong preference for silicone is its extreme flexibility, chemical resistance, heat resistance, and biocompatibility. But you know what? Silicone has a low surface energy due to its methyl-siloxane (Si-O-Si) structure. This structure makes it difficult to achieve the required bonding/adhesive strength.
To address this flaw, manufacturers have adopted a UVC irradiation method to form an efficient coating layer over the silicone. This coating layer enables it to feature strong bonding and adhesion. So when it comes to dealing with high-end properties, silicone products. The UVC Irradiation treatment is well able to meet the requirements of businesses in the medical, consumer, and industrial Sectors. Let's explore in detail the importance of UVC.
UVC Irradiation Treatment
UVC Irradiation is a process that uses ultraviolet light to form a coating layer on the silicone surface. During this treatment, the silicone surface is exposed to UV-C light, triggering a photochemical reaction that improves bonding and adhesion strength.
Unlike the traditional methods, such as primers, chemical etching, and plasma treatment. The UVC Irradiation is the most advanced, energy-efficient, cost-effective, and environmentally friendly. It helps achieve the required silicone surface properties for durable adhesion.
How does It Actually work?
Photon Absorption: When silicone is exposed to UV light (200–280 nm), the photons enter the silicone surface.
Bond Cleavage: Photons break the initial bond between Silicon & Methyl (Si–CH₃), to create the reactive free radicals.
Oxidation Groups: Reactive free radicals then react with oxygen to form Hydroxyl, Peroxide, and Carbonyl groups.
Surface Activation: The formation of these groups increases surface energy, making silicone chemically active.
End Result: The UVC-irradiated silicone is now compatible with strong bonding and durable adhesion.
Why Silicone Needs UVC Treatment?
Silicone material naturally features low surface energy (20-25 mN/m).
If not UVC-treated, the silicone surface exhibits weak adhesion or bonding.
An untreated silicone surface is hydrophobic, resulting in minimal wetting by liquids.
An untreated silicone surface does not meet medical-grade standards.
Dust, dirt, and other contamination can impact the untreated silicone surface.
Types of UVC Treatments
1: Direct UV-C Surface Activation
In this type of UVC treatment, a direct UVC light hits the outer layer of the silicone surface. It results in breaking the Silicon & Methyl bonds, then creates reactive groups. This method enhances the silicone surface for bonding. Direct UV-C surface activation requires no curing time or chemical additives.
2: UV-Curable Silicone Primers
In the UV-curable silicone primer type, experts apply a thin layer of primer over the silicone. The UVC light then cures and activates its functionality. So the silicone becomes compatible with adhesives and bonding. This treatment method is considered durable and effective for dealing with difficult bonding.
3: UV-Activated Coatings
When it comes to UV-activated coatings, manufacturers apply specific coatings (hydrophilic, anti-fouling, conductive, protective) over the silicone material. Once the coating is applied accordingly, they expose the material to UVC light, activating its compatibility with bonding and crosslinking.
Industrial Applications
1: Medical Industry
As we know, the medical industry prefers silicone for its biocompatibility, flexibility, and chemical resistance. It is used in catheters, medical tubing, silicone valves, and wearable health devices. Core functionalities include,
Bonding of tubing connectors, seals, and implants
Provides hydrophilic, antimicrobial, and protective coatings
Ensures long-term performance and repeated use
2: Electronics Manufacturing
The electronics industry is a major user of silicone materials, specifically for PCB encapsulation, LED modules, sensors, and display assemblies. In relevance to the UVC-treated silicone surface, it helps in potting, sealing, and encapsulation.
Bonding of potting compounds
Stops delamination in PCBs, sensors, and connectors.
Maintains thermal and electrical stability in electronic devices.
3: Automotive Industry
Silicone material is the preferred material for both the traditional and NEV automotive industries. It is used in engine gaskets, EV Battery seals, dashboard buttons, sensors, and other relevant components.
Enhances the sealing system
Bond silicone hoses and other metal or plastic parts
Manages thermal cycling and mechanical stress
4: Consumer Electronics
In consumer electronics, silicon is used in applications such as smartwatches, earphones, silicone cases, and other smart devices. The UVC-treated silicone makes printing and coating easier for information, as well as improving durability.
Highlights functional marks and indications
Protects against sweat, oil, dirt, and dust
Coating enhances scratch resistance and other markings
5: Consumer Products
In consumer products, UVC-irradiated silicone has been used across a wide range of applications. From baby and pet care to travel products, silicone has made notable contributions while also helping maintain health and safety standards.
Silicone baby products, food bags, travel bottles, and pet care products.
Baking mats, utensils, and other kitchen-related silicone products.
Ensures heat resistance, contamination resistance, and health and safety through strong adhesion and coating
6: Industrial Manufacturing
Silicone is widely used in industry to manufacture components such as gaskets, seals, protective coatings, O-rings, pumps, and valves. Once a treated silicone surface is utilized, it ensures long-lasting results and adhesion.
Resists wear and tear caused by environmental factors
Improves adhesion in sealing compounds
Tackles sensitive components like sensors and high-performance parts
Key Benefits
1: Improved Adhesion
The main notable benefit of UVC irradiation of the silicone surface is the resulting enhanced bonding and stable adhesion. It helps to achieve the required adhesion performance without using harsh chemicals or mechanical abrasion. The treatment features adhesion with inks, coatings, and overmolding materials.
2: Enhanced Production
UVC irradiation is known for its speed, reliability, and automation. It does not require any warm-up time and activates the surface in just 0.5 to 5 seconds. Such an instant response helps manufacturers to achieve high production volumes, reduced cycle time, and balanced cost of the production system.
3: Eco-Friendliness
If we compare the UVC irradiation with the other traditional methods. It tends to be a more eco-friendly technology as there is no mention of VOCs, hazardous materials, or chemical use. Moreover, these irradiation standards comply with RoHS and REACH, making it a strong choice for industries.
4: Less Heat Exposure
The low heat exposure can be considered another notable benefit of UVC irradiation treatment for the silicone surface. This method operates at low temperatures and enhances only the surface of silicone, without affecting its inherent mechanical properties. It results in more energy-efficient operation and less surface thermal stress.
5: Excellent Durability
In simple terms, surface enhancement via UVC irradiation improves silicone's reliability, durability, and longevity. It becomes better able to tackle moisture, aging, heat, and other environmental impacts more stably. In return, the overall performance and lifespan of its applications remain at their finest.
Implementation Considerations for Manufacturers
Silicone Type: Each type has a different outcome to UVC treatment. LSR, HCR, RTV, Silicone foam, and Optical-grade silicone.
Equipment Type: UV-C conveyor systems, handheld UV units, robotic UV spot-treating heads, and UV-A curing tunnels.
Production Speed: Have a strong grasp of production speed requirements in line with conveyor speed, curing intensity, and the production schedule.
Treatment Parameters: Information about the light intensity (mW/cm²), exposure time, and distance from lamp.
Safety Considerations: Fulfillment of required safety protocols like shielded enclosures, protective eyewear, UV leak sensors, and warning signs.
Cost and ROI: Research to evaluate the cost of overall operations and equipment in parallel to return on investment.
Quality Assurance
These quality assurance tests are performed after the UVC irradiation treatment of the silicone surface.
ASTM D3359: for coating paint adhesion after UVC irradiation method
Peel Strength: for measuring the force to peel bonded material from silicone.
Contact Angle: for easily evaluating surface response to adhesives.
Environmental Stress: for real-time stress testing of thermal stability, UV aging, chemical resistance, and others.
Final Remarks
At KEAN, we have always been committed to producing the highest quality products for our clients, and our precision surface treatment process is one of the key reasons customers choose us. Leveraging advanced UVC irradiation technology, we enhance the surface energy of silicone-based materials, enabling outstanding performance in bonding, coating, printing, and other processes. This not only improves product reliability and durability but also helps customers achieve performance breakthroughs in high-end and sensitive applications.
We understand that every step of the process affects the final product outcome. That’s why, from material selection and equipment configuration to quality inspection, KEAN consistently adheres to high standards and rigorous requirements. We ensure that every UVC-treated silicone product delivers stable and long-lasting adhesion, meeting your most demanding quality expectations.
Choosing KEAN means more than selecting a technology—it means choosing a trusted partner. We look forward to working with you, empowering your products through innovative surface treatment solutions, and creating new possibilities together. Feel free to reach out to us anytime to discuss your needs and write a new chapter of success together!