UV Glue: All You Need to Know About UV Glue

Humans have been binding things together with adhesives for the longest time. Although historians trace the invention of glue to the early Egyptians 4,000 years ago, a group of scientists actually discovered in 2017 a recipe for glue that early man used 200,000 years ago during the Stone Age.

Of course, we have since graduated from primitive glue which used largely tar and the bones, hides and skins of animals. Today’s glues are the result of highly sophisticated formulae and one of the most versatile and useful types of glue is UV glue.

Just what is UV glue, why is it better than other types of glue, and what can we use it for? We tell you all about this amazing adhesive.

What is UV Glue?

All glues are liquids that harden to hold materials together when dried. Made with polyvinyl acetate (PVA) emulsions, most glues we use are synthetic adhesives created for multiple purposes.

UV glue is a polymer, often in liquid silicone form, that dries clear when exposed to UV light in a process called curing. Curing takes place when liquid is changed into solid in a chemical reaction called cross-linking. The UV wavelength - between 240 nanometer (nm) and 270 nm, and 350nm and 380 nm - is a catalyst for a photochemical reaction which causes the polymer to harden in a crisscross network.

Because the photon energy needed to harden the glue occurs only within the UV range, exposure to ordinary light will not activate the glue. UV glues are often made of a blend of liquid polymer resins and a component called a photochemical promoter. The promoter degrades into free radicals when UV light hits it. This, in turn, causes the resin in the glue to react quickly and increase in strength.

UV glue is widely used in industrial settings ranging from munitions to decorative and art glass industries but particularly on electronic equipment, especially on the touch panels of smart devices.

Advantages of UV Glue

UV glue was introduced in the 1960s and has since grown in popularity. UV glue curing has been favoured over other methods of bonding such as drying or exposure to chemicals, its popularity growing at a rate of 10% a year.

1. Fast-drying

Using UV light to dry the glue makes the process highly efficient because the glue dries almost instantaneous and temperatures used are very low.

2. Low shrinkage

UV glue has a lower degree of shrinkage. This makes it more long-lasting and effective in bonding things together under different environmental conditions. Low shrinkage also means that when UV glue is used to bind things, the alignment remains exact and stress is minimised.

3. Durable

Since the alignment is more stable, there will also be fewer chances of cracks developing or gaps in the bond line. This makes UV glue more reliable even over long periods of time.

4. Sturdy

Water-proof and impervious to sunlight or harsh temperatures, UV glue can withstand diverse environmental conditions without degrading.

5. More consistent

Bonding with heat or by drying is inconsistent. These methods also take a longer time. UV glue solves all these problems.

6. Cheap

Unlike chemical treatments that are costly and can expose users to harmful inhalants or respiratory contaminants, UV glue is cheap and safe.

7. Safe

Since UV glue is solvent-free, it is neither flammable nor emits flammable vapours. This makes it environmentally safe. Since it also does not harden till exposed to UV light and is neither sticky nor uncontrollable, it can be safely used by children.

8. Easy to control & use

The difference between UV glue and other types of glue is the fact that until it is exposed to UV light, UV glue will not harden. This allows users to adjust the materials prior to bonding more precisely. It also minimises the odds of accidental bonding and fingers getting stuck together that are the problems that come with using instantly-drying glues like super glue. So, UV glue is ideal for use in manual assemblies. Removing the glue is just as easy. Simply dislodge it with a scraper.

9. Versatile

UV glue can be used on almost any substrate, bonding plastic, glass, metal or wood as well as glass to glass, or any other variation of materials. As such, it can bond different materials together.

It can even be used on wet surfaces and underwater. This allows it to be applied on the inside of aquariums, water containers and sinks.

The glue can also be used on three-dimensional parts and is excellent for joining small parts with limited contact surfaces together. A new layer of UV glue can be applied to a hardened coat of UV glue as well without affecting its effectiveness. So, apart from bonding materials together, UV glue can be used to seal and coat materials.

10. Strong

When cured, UV glue creates high bond strength between many materials, making it a very powerful adhesive.

UV glue is also a better alternative compared to mechanical fasteners because it is better at distributing load and stress over wider surfaces, eliminating joint fatigue and improving impact resistance.

11. Clear

Because it is also clear and leaves no trace, it is invisible. That is why UV glue is particularly sought after in the glass and decorative art industry for its aesthetic value. The fact that it does not yellow over time adds to its aesthetic appeal.

12. Less wastage

UV glues are single-component formulae so there is no mixing required and, therefore, less wastage.

Uses of UV Glue

1. Glass bonding

UV glue, being transparent and does not change colour over time or when exposed to the elements, is excellent for bonding glass. It is well-suited for bevel bonding and stained-glass windows as well.

2. Flat panel displays, touch screens, lamination

UV glue hardens only when exposed to UV light. This allows the materials it bonds to be repositioned continuously for maximum precision. UV glue is also clear and does not discolour with age. All these make it very useful for bonding touch and LCD screens on smart devices because these require precision and optical clarity as well as an easy flow for flat panel laminations.

3. Architectural bonding

Because it can be used on different materials as well as bind different materials together, and can be used as a sealant and as a coating, UV glue is useful for home repairs on glass windows, balconies and staircases.

The ability of UV glue to withstand vibration and thermal shock, and be applied to large areas also makes it ideal for architectural bonding.

4. Doors & handles

UV glue can bind different materials together such as glass to acrylic. This makes it good for fastening bathroom cabinets and doors. Being water-proof, it can also be used on shower doors.

5. Plastic bonding

UV glue can be used for plastic signs and plastic displays because it provides excellent coverage, is clear and dries bubble-free.

6. Shop fittings

Display cabinets, cases and shelves can be secured using UV glue. The fact that the bonds that are formed when the glue dries is stronger than the strength of the materials used is what makes UV glue great for holding up such displays.

7. Automotive assembly

UV glue can be used in the automobile industry as well to secure headlamps and seat belt monitoring switches. Its fast-drying property makes it efficient for large volume manufacturing or assembly.

8. Medical devices

UV glue’s ability to bond, seal, coat and repair makes it versatile and sought after for use in the medical industry. Its flexibility and lack of solvents also make it safe. In addition, it only hardens when exposed to UV light allowing the parts to be precisely positioned before being bonded, an important consideration in medical devices.

UV glue is used for bonding in a number of medical devices:

· Blood transfusion filter housing

• Bags for storing liquid contents (drips, IV, saline, waste, etc.)

· Catheter tubing and bags

• Chest drains

· IV delivery systems

• Endoscopes

· Atraumatic guidewire tips

• Cannulae

· Arterial locators

· Tubing drainage sets

· Endotracheal tubing

· Angioplasty accessories

· Blood oxygenators

• Connectors
• Hearing aids
• Syringes

· Medical filters

· Silicone rubber components

· Respiratory masks & breathing circuits

· Sensing devices

9. Printed board surfaces

Thanks to its durability – UV glue is not affected by harsh weather or ageing – it can be applied over the entire surface of a printed surface board or in select areas to protect it from the environment.

10. Repair & reinforce cable coating

Its strength, durability and water-proof property allows UV glue to be used to repair and reinforce cable coating, strengthening and protecting the cables.

11. Hobby craft

UV glue can adhere to different types of materials and it can bond materials of different types together. This makes it useful for hobbyists who want to create different art and craft work using wood, paper, plastic, ceramic, acrylic and even metal or a mix of these materials.

12. Electronic devices

UV glue is also used on electronic devices for the following purposes:

• Encapsulation and coating for environmental protection
• Glob top
• Strain relief or chip encapsulation
• Precision application to specific electronic assembly areas
• Thin coating, wicking, and underfill
• Plastic bonding, potting, and sealing
• Wire tacking and coating
• Capacitor bonding
• Chip bonding
• Tamper-proofing components
• Prevent coils from unwinding
• Sealing and potting electrical components
• HGA (head gimbal assembly) and tamper-proofing

Best-selling UV Glues

1. UV BONDY Glue

This UV glue comes in an easy-to-use tube. It promises to dry in just four seconds when exposed to UV LED light. A UV LED light and a light stand are included in the package. The light stand eliminates the inconvenience of holding the UV light in one hand, allowing users to work freely and comfortably.

The liquid plastic can repair, mend and mould. It can be used to repair wires in plugs and headphone cables, mould plastic model parts and for craft, repair accessories, and fill in defects.

Made in Japan where the entire operation is quality controlled, this UV glue offers the reliability and product excellence are hallmarks of Japanese goods. At 10ml per tube, it is a more generous quantity than other UV glues – about twice the volume – so it is better value for money.

 

2. CreativeBond Super Strong Bonding Tool

This UV glue is designed for craft and creative work as well as fixing, filling and building. Perfect for those who enjoy DIY projects, the glue is said to be 10 times stronger and bonds to several types of material including plastic, wood, glass, metal, acrylic, rubber, ceramic, vinyl, synthetics and leather. It can even be shaped, sanded and painted over.

3. Bondic Kit – Pro Kit

This kit comes with a four-gram tube of glue, an applicator, two refills, an LED UV light and a microfiber cloth for cleaning the surfaces of materials before applying the glue. Water-proof and heat-resistant when dried, it can be used on plastic, wood, metal, PVC, steel, rubber, wiring, ceramic, figurines, vinyl, kevlar, polypropylene and leather.

4. Loctite 4310

This UV glue is designed for very rapid fixturing, fillet cure or surface cure. Because UV light is used to cure the glue and the curing takes place very rapidly, blooming is minimised. Blooming or frosting is what happens when cyanoacrylates (CAs). one-part instant adhesives, are used. When blooming takes place, a rainbow or whitish haze will surround the bond line. While this does not compromise the strength or durability of the bond, it is not visually appealing and not ideal if you want a clean bond especially in products like cosmetic cases, medical equipment, electronic devices, pharmaceutical packages, appliances, automotive parts, and speakers.

5. UV Glue LOCA Liquid Glue

This UV glue is a clear adhesive with over 98% light transmittance, making it almost totally transparent. It also offers good bonding strength and is ideal for replacing defective or damaged touch screens, LCDs and glass lenses. It can be used to replace faulty parts as well.