Professional Knowledge

What is UV gel?
UV is abbreviation of Violet ray, wave length 200-450nm, and UVA is 315-400nm, UVB 280-315nm ； UVC 200-280nm； UVV 200-100nm .UV gel, also called shadowless gel or ultraviolet radiation gel, can be cured by? visible light acrylate structural gel.
UV gel chemical composition: urethane acrylate, acrylic monomer, photo initiating agent, organic filler.
UV gel performance feature: fast curing, controllable action, solvent free, non pollution, wide range of adhesion, strong adhesive, great optical performance; gel is clear and transparent, transparent rate ≥ 90% after hardness; good wearing resistance, no yellowish.
UV glue curing principle and condition: After absorbing ultraviolet ray, photo initiating agent in UV gel will give out active free radical or cation, leading to monomer chemical reaction of polymerization, cross bonding, bonding glue will be transformed to solid from liquid. UV glue must be cured with 200nm~400nm Violet ray.
二. What is hardness?
Hardness: After totally solidification, resistance ability of hard material press on glue surface, unit of hardness including Shore hardness (Shore A、Shore D) and pencil hardness(B、HB、H).
三. What is viscosity?
Viscosity: With external force movement, friction drag of liquid molecule is called viscosity. More friction drag, more viscosity, less friction drag, less viscosity. In international unit standard, viscosity unit is mPa.s, viscosity of water is 1.14 mPa.s.
四. What is curing energy?
Curing energy means violet ray energy demand for UV glue totally solidification, energy unit is mj/cm2.
五. What is thixotropy?
Before solidification, glue state change with external force, when force stop, state change stop, this character is called thixotropy.

?Technology solutions
一. Lower viscosity of UV adhesive means lower strength?
There is no direct relations between viscosity and strength of UV glue, take viscosity as strength is wrong.
二.Is there any relations between solidification speed and glue quality?
Solidification speed of UV glue especially is a data much concerned by customer. position time, solidification depth, strength, toughness of glue film .etc may determine the glue quality. We think the faster position speed, more force when glue hardness, in that case, work piece may fall off. Usual position speed is 6~10 seconds. Therefore, it’s not right to determine glue quality by solidification speed, but by consequent performance.
三.More glue, better function in application?
It's not good as much glue in application, it proves that thinner glue, much stronger. Usually glue film thickness not more than 0.2wm.
四.Difference between UV glue and other glue?
Initial solidification under violet ray in 1~5 seconds, bonding finish in 20~30 seconds. It will reach great strength which may meet the requirement of automatic production line; Second generation acrylic acid structural glue will be initial solidified in 1~10 seconds, reach highest strength after 24 hours. Room temperature epoxy structural glue will be initial solidified in 10~120 minutes, reach highest strength after 7 hours.
五、Why glue blushing after curing?
This may often happen in glass industry, blushing is small bubble in glue, because glue may shrink during solidification, if glue thickness is not good or too hard, the inner energy of shrinkage can not release, after long time there is small bubble, that is what we see blush, until the bonding material fall off. Method of solving including: choosing UV glue of toughness formulation make the glue face; choose lower power UV lamp for initial solidification, which will slow down the solidification speed, after position, use higher power UV lamp for deep solidification, because too fast speed will boost the shrinkage of glue.
六. Why glue is still not dry and stick hands after long time lamp cure？
Glue surface will touch air after curing, because Air inhibitory effect, the sticky things on the glue surface won't fall off, that is why it sticks hands.
Solving methods:
1. With higher violet ray strength
2. With more quality of photo initiating agent
3. With faster system of photo initiating agent
4. With light source of 265nm
七. Is UV glue poisonous? Why skin may inflamed and itchy after using UV glue?

UV glue is green, environment-friendly and economical products,no any organic solvent included. Solidification 100% solids glue, will not cause any degeneration harm to poison, cancer or pathogenesis to human body. no danger of any poisonous or~~!
The main ingredients of UV glue are oligomer of acrylate series and monomer of parts acrylate series. Acrylate monomer has certain irritation to our skin as it is volatile to some extent. When first contact, it will causes skin irritation if your skin directly contact with the glue or long exposure under the condition of high concentration and without proper protection, such as eyes red and swollen , measles rise on the body, or feel itch,etc, but those phenomenon won't happened again after a period of time.

Measurements:
1.Keep good ventilation
2. User must wear protection suit, glasses, mask, gloves or finger~!
3. Wash hands often, change gloves and clothes often, etc.
4. Flush with water once skin or anywhere of our body touch the glue, then wash away with soap water.
5. For the users with poor immunity, please eat antianaphylaxis drugs for around 2 weeks. For already allergic user, don’t scratch with hands so as not infect other part of body. Take orally antiallergic drugs or have antiallergic injection, the allergy will disappear very soon, no need worry.
6. For people with allergic body or quite poor immunity, better change other job post, no use UV glue.