About UVmodification

FAQs about UVmodification

• What kind of equipment is a UV cleaning surface modification system?

  It is also called "UV ozone cleaner," "UV cleaner," "UV ozone cleaner," "UV/O₃ cleaner," or "UV ozone cleaner.This equipment is designed for decomposition and removal of organic matter, surface modification, and hydrophilization at the main wavelengths of 184.9 nm and 253.7 nm.

• What is the basic structure?

  (1) UV Lamps (2) Light Source Unit（Light leakage cover、Reflective mirrors, etc.） (3) Power supply to control lamp lighting (4) Ozone Discharge Blower、duct hose These four items are the basic components.

• Does the energy differ depending on the wavelength?

  The shorter the wavelength, the higher the energy, especially at 184.9 nm, which is strong enough to break bonds in organic materials.

• What is the specific amount of energy at 184.9nm and 253.7nm?

  The wavelength at 184.9 nm is 647 KJ/mol and at 253.7 nm is 472 KJ/mol.

• What is the typical molecular binding energy?

  C-C 347.7
  O-O 138.9
  C=C 607.0
  O=O 490.4
  C-H 413.4
  O-H 462.8
  C-F 441.0
  H-F 563.2
  C-Cl 328.4
  H-Cl 431.8
  C-N 291.6
  N-H 390.8
  C-O 351.5
  Si-O 369.0

• How can I check the effectiveness of the program?

  It is common to use a contact angle meter to check wettability by dropping deionized water on the workpiece and measuring its angle.Other methods include a peel evaluation method called cross-cut and evaluation with inexpensive wetting reagents.

• What are the main consumable parts?

  The equipment can be used repeatedly by simply replacing the UV lamps periodically. The lamps use low-power, low-pressure mercury lamps, which are economical.

• How long is the life of a UV lamp?

  Low-pressure mercury lamps have a design life of 6,000 hours of continuous lighting. If the design life is exceeded, the capacity will decrease and should be replaced with a new one. The device is equipped with a totalizer meter for easy confirmation.

• What is the difference from excimer UV irradiation system?

  メリットは、１）Irradiation at high energy of 172nm　2）Instantaneous lighting　etc.

• What is ozone?

  It is an allotrope of oxygen consisting of three oxygen atoms.The molecular formula is O₃ and has a folded structure.It is a highly corrosive, toxic substance with a characteristic fishy, pungent odor and is present in very low concentrations in the atmosphere.Ozone has the second strongest oxidizing effect after fluorine, and is used for sterilization, virus inactivation, deodorization, decolorization, and removal of organic matter.

• How is ozone generated?

  Ozone generated by low-pressure mercury lamps is produced when the UV wavelength of 184.9 nm reacts with oxygen in the air.
  Ｏ₂　＋　ｈ_ν　→　Ｏ　＋　Ｏ
  Ｏ₂　＋　Ｏ　→　Ｏ₃

• How can I measure the ozone concentration generated?

  Many ozone concentration measurement devices, including devices that constantly measure ozone, are available from many manufacturers of measurement devices, but a simplified method is to use Kitagawa-type detector tubes.Consisting of a detector tube and gas sampler, ozone can be easily measured.

• How is the ozone generated treated?

  Ozone generated by low-pressure mercury lamps is produced when the UV wavelength of 184.9 nm reacts with oxygen in the air.Another UV wavelength of 253.7 nm, which is output simultaneously, forces ozone to decompose. The UV reaction with the oxygen concentration in the air (about 30%) and the fact that decomposition occurs simultaneously (compared to the high-pressure discharge method) means that ozone is not generated at high concentrations. The amount of ozone produced by 40-110W-class low-pressure mercury vapor lamps is several hundred milligrams/Hr, or about several dozen ppm in ozone concentration.The amount of ozone produced by a single lamp does not reach a concentration that would immediately cause serious harm to humans, but even a few dozen seconds in the room can cause a suffocating odor that can damage bronchial tubes and make people feel sick within a few minutes.Regarding the safety of ozone, there is a regulation that workers must work 8 hours a day in an environment with an ozone concentration of 0.1 ppm or less. (The Japan Society for Occupational Health "Recommendations on Permissible Concentrations (2004)") Methods to prevent the outflow of ozone to the outside are often used, such as the activated carbon adsorption method or special adsorption honeycomb filters.In the case of the amount of ozone generated from a single lamp, it can be reduced to a harmless concentration by bringing it into contact with activated carbon for a few seconds.

• There is no facility to exhaust ozone. What should I do?

  If there is no facility to exhaust ozone at the installation site, an ozone decomposition device can be installed to ensure safe use.They are called "ozone killers," "ozone decomposers," or "ozone decomposition units."

• What range of UV irradiance can be adjusted by adjusting the distance between the sample and the lamp or by dimming?

  The irradiance of short-wavelength ultraviolet light attenuates inversely proportional to the square of the distance. This is the reason why irradiation at short distances is advantageous when using UV light for each reaction.When used for surface treatment, irradiation distances of up to 10 to 30 mm are used in most cases.Conversely, irradiation at too close a distance will result in uneven illumination between lamps, so a distance of a few centimeters is appropriate.Standard low-pressure mercury vapor lamps are rarely equipped with an optical function because of the high cost of configuration. The addition of a two-stage adjustable function, which turns the power on in standby mode so that the illuminance is restored immediately, is sometimes incorporated in production facilities.