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  Characteristics of UV process>>
  Characteristics of plasma process
  Adhering/ Peeling/ Curing/ Drying
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Characteristics of UV process : Business
The UV system primarily consists of 4 parts.

(1)Light resources
Ultraviolet light used in UV process varies with the purpose of process. The most suitable type for each purpose is listed below.

UV lamp Application Wavelength
High-pressure mercury lamp Curing, drying and adhering 365nm
Metal halide lamp Curing, drying and adhering 365nm
Low-pressure mercury lamp for sterilizing Sterilizing 254nm
Low-pressure mercury lamp for cleaning and reforming Cleaning and reforming 185nm, 254nm
Excimer lamp Cleaning and reforming 172nm

Features of spectral energy distribution of various light sources.

(2)Irradiation equipments
Irradiation equipment, consisting of reflector and cooling device, could be designed to meet various purposes.

Shapes of reflectors
Light-concentrating type Parallel light type
Applying the focus point light Applying the diffused light
Cross section is in elliptical shape. The high-intensity ultraviolet lights will be generated when the focus point lights are used, while the comparatively uniform ultraviolet ones will be generated when the diffused rays are used. Cross section is paraboloid. The ultraviolet lights could irradiate uniformly a wide area of the object.

Types of reflectors and the low temperature curing system
Aluminum mirror Ultraviolet and heat lights are reflected effectively by using the ultrapure aluminum reflector, which has the property of high reflectivity.
Cold mirror The cold mirror is formed by coating a thin film of many kinds ofmental compounds onto the designed glass substrate. It can not only reflect the UV lights effectively, but also transmit the visible lights and infrared lights successfully, which are of nearly no use to UV curing.
Cold mirror
Cutoff filter of heat rays
It is necessary to use the cold mirror and the heat-ray cutoff filter at the same time in the curing process, which is proceeding at more lower temperature environment. In this process, the necessary ultraviolet lights pass through the heat-ray cutoff filter and the visible lights are reflected there.
Cold mirror
(Cutoff filter of heat rays)
This type is used in the process where the temperature should be prevented from rising. In this process, the temperature varies with the air volume and drops remarkably when the heat-ray cutoff filter is added into use.

** About the ozone **

In UV process, the short wavelength ultraviolet rays are useful but will generate the ozone. We proposed the following measures to deal with the ozone problem.

(1)Standard lamp + exhaust system (outdoor)
(2)Ozoneless lamp (this measure is recommended when the outdoor exhaust system could not be applied, though the efficiency of dealing with the ozone is getting lower with it.)

[[Influence on the living bodies]]
The influences on living bodies caused by different ozone densities are listed below.
Ozone density (ppm) Influences on living bodies
0.02 ~ 0.05 There is a peculiar smell. (Just a few seconds)
0.06 No influences on the ventilation function of the patients with chronic pulmonary disease
0.1 ~ 0.3 Nose and throat are irritated. (A few seconds ~ several tens of minutes)
The asthmatic patients are attacked by the disease more frequently.
0.23 More people working at the ozone-generating spot develop symptoms of chronic bronchitis. (Exposed for several hours)
0.6 ~ 0.8 Symptoms of coughing and difficult breathing are appeared. Furthermore, the patient's ventilation function is becoming weaker. (2 hours)
1 ~ 2 Tiredness and headache (1~2 hours)
10 Difficulty in breathing, pulmonary edema, and deep coma (several tens of minutes)
15 ~ 20 Existing the possibility of death from pulmonary edema (in about 2 hours)
1000ˆÈã In danger of death in several minutes

[[Environmental quality standard]]
▪Environmental quality standard:
Photochemical oxidant: no more than 0.06ppm per hour on average. This value is changed to be about 0.05ppm if expressed with ozone density.
▪Working environment standard (recommended permissible limit):
The working environment standard is defined as a density, under which there is no harmful influence on people's health even people keep working 6 hours per day.
Japan: 0.1ppm or 0.2g/m3
USA: 0.1ppm

▪Sato: Photosensitivity, Tokyo Publish (1983) (Japanese)
▪Japan Association for Working Environment Measurement, TLV of ACGIH chemical substance and environment factor (1990) (Japanese)
▪Isao Mizoguchi: The toxicity and safety of ozone, ? AR-77-4 (1977) (Japanese)
▪Public announcement No.47, Ministry of the Environment (1973) (Japanese)

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