UV adhesive is a widely used adhesive type in today’s market, applied across various manufacturing industries due to its superior properties compared to other types of adhesives. This article will provide an overview of UV adhesive, its characteristics, and relevant information.
1. What is UV Adhesive?
UV curing adhesive or often called light curing, photo-curing adhesives, are adhesives that cure when illuminated with light within a specific wavelength, usually of UV-A or “blue-light” approximately 365 nm to 405 nm. This is the main reason why the term UV curing adhesive has been developed.
A light-curing adhesive is not really a type of adhesive but a curing mechanism.
Prostech offers a wide range of UV adhesive products which can deliver clearer results, and are suitable for each industrial manufacture. Contact us to receive valuable information and consultation from our qualified experts.
2. UV Adhesive Characteristics
- High Strength Bonds
- Cure Only When Exposed to Light – permits alignment of parts prior to bonding.
- Select a Cure Speed – double production speed by simply adding another lamp to the line.
- Solvent-free – Non-flammable – increase safety
- Single Part Product – No mixing required
- 100% solids – No waste.
- Save energy – UV lamps require less electricity than heat cure ovens for epoxies
- Space savings – UV lamps require less space than heat cure oven tunnels
- Appearance – UV glue is available in clear colorless formulations
- Technical Support – application specialists available for assistance with joint design, adhesive selection, and production process.
Bonding tubes by using UV adhesive
3. Basic composition and types
A typical UV adhesive formula consists of key components: photoinitiators, monomers, and oligomers. Since solvents are not used in creating UV-curable systems, photoinitiators are responsible for absorbing light, while monomers and/or oligomers ensure the crosslinking polymerization process.
Photoinitiators possess the following characteristics:
- High sensitivity within the wavelength range of the light source.
- Good solubility and reactivity in monomer/oligomer systems.
- Excellent stability during storage and adhesive lifespan.
Additionally, the chemical structure of monomers/oligomers is another crucial factor in adjusting the properties of the crosslinking material. Notably, variations in structures such as aliphatic, aromatic, and hydrocarbon, polyether, polyester, polyurethane, fluorochemical, or siloxane chains result in significant differences in mechanical properties, chemical resistance, weatherability, and optical properties.
The most common monomers and oligomers in photopolymerization are acrylic and methacrylate, widely used in various industries. Low molecular weight monomers are readily available and prevalent in the market. Many types of prepolymers, especially epoxies, polyethers, polyesters, and polyurethanes, are functionalized with compounds containing -OH, NH2, NCO groups. Specifically, these prepolymers are often processed with acrylic XR-OCO-CH=CH2 or methacrylic XR-OCO-C(CH3) = CH2 compounds to meet market demands for UV light curing materials.
Functionalizing other prepolymers like epoxies, polyethers, polyesters, polyurethanes with acrylic or methacrylic groups can offer certain benefits:
- Product versatility: Functionalizing other prepolymers allows for the creation of a range of monomer or oligomer products with different properties, catering to diverse requirements and applications.
- Property enhancement: Functionalization can improve the properties of monomers and oligomers, including adhesion, heat resistance, flexibility, or chemical resistance, thereby enhancing the performance and durability of the final product.
- Specific demand fulfillment: Some specific requirements from the market or particular applications may not be adequately met by the acrylic monomers and oligomers readily available in the market. Therefore, functionalizing other prepolymers can generate products better suited to those demands.
Prostech, with many years of providing specialty material for manufacturing, we can advise you comprehensive solutions of applying UV adhesive process, help you to improve your production efficiency, quality, and long-term benefits.
4. When/ Which applications are light curing used?
The “cure-on-demand” property of UV adhesives, coupled with rapid polymerization processes, has led to their use in high-volume assembly processes where fast processing speeds and reduced workload result in significant cost savings. The attractiveness of this method lies in its outstanding advantages over conventional heat processing methods: rapid processing, low energy requirements, processing at room temperature, formulas that are non-polluting and solvent-free.
UV adhesives are typically single-component adhesives that allow for easy application, although some applications may require activators or primers to enhance adhesion and/or curing processes, especially if the adhesive is shielded from the UV light source. Clearly, UV light must penetrate to the bond line for the adhesive to cure, so at least one substrate must be transparent or translucent to allow sufficient UV light transmission. However, recent developments have explored “delay-cure” products that allow for curing after a short period, enabling the assembly of non-transparent components.
Referring to the possibly bonding materials, these adhesives are ideal for many applications in which glass or plastic which can convey UV or visible light is bonded to itself or metals and other substrates.
5. UV Product Range
Unless light is an electron beam, photopolymerization processes occur in a gradient from the surface to depth due to light absorption competing with light penetration in the reaction. In other words, the impact of light is typically concentrated on the material’s surface and diminishes gradually as it penetrates deeper. Therefore, primary applications predominantly spread across fields utilizing polymers in thin film forms, with typical examples being coatings, inks, and adhesives.
Our product:
- UV Adhesive
- UV Conformal Coating
- UV Temporary Maskant
- UV FIP/ CIP Gasket
PROSTECH is a reputable partner, providing a wide range of UV products suitable for various applications across different manufacturing industries.