About Melp

MELP Close Joint-Stock Company, an affiliate of the Scientific and Technical Park of St. Petersburg State Polytechnic University, was established in 1993. The Company specializes in the development and production of electrophysical devices. The core activity of CJSC MELP is related to ozone generation and application processes. We have developed a multipurpose ozone module comprising a flat gas-discharge reactor of unique design and a high-voltage impulse source. The ozone module operates on air and oxygen and may be used in ozonizers of various capacities and purposes. The module requires no water cooling, which is an obvious advantage when using small-capacity ozonizers (up to 100 g/hour). Currently, the Company is addressing the following areas of ozone technology application:

• Medicine – ozone sterilization and disinfection, and ozone therapy. The new model will sterilize a broader range of medical products in gas-permeable packages, such as, laparoscopes and other inflexible endoscopes, instruments for laparoscopic surgery, electrosurgical instruments, respiratory tubes, catheters, drainage tubes, probes, etc.
• Environmental protection – water treatment and preparation, air deodorization and disinfection
• Agriculture and food industry – decontamination of process equipment components, containers, packages, and raw food stuffs

Other aspects of MELP activity are related to development and implementation of:

• Bipolar air ion flow sources used for electrostatic charge neutralization and for indoor air quality control
• Devices of surface modification and treatment in low-temperature plasma of gas discharge at atmospheric pressure
• DC, AC, and impulse high voltage sources used in laser equipment, electrical filters, security alarm systems, and process technology

Surface treatment in low-temperature gas-discharge plasma unit

The method of treating the surfaces of various materials in a gas-discharge reactor to provide post-treatment of the surface or to change the surface structure is very efficient, as it is in the low-temperature gas-discharge plasma generating electrons, ions, active atomic particles, and radicals that can react with the molecules of impurities or parent material on the surface of this material. Besides, the surface layer molecules of the material are exposed to ultraviolet radiation and soft X-rays generated in the discharge cathode layer, and are destroyed by action of ion-ion and ion-electron emission. Discharges of different types, such as space discharge, corona discharge, and discharge on a dielectric surface (sliding discharge) can be used in the gas-discharge reactor. A space barrier discharge provides the highest degree of effect uniformity.

MELP have been tested for the following applications:

• Sterilization of flat items such as paper documents, money, sealed mail, and medical products (suture material or blood vessels)
• Carbon fiber surface modification prior to sintering with epoxy compound binding materials
• Surface post-treatment and modification for products used in microelectronics and semi-conductor engineering
• Post-treatment and modification of glass and films prior to metallization

Main technical characteristics of the plasma-treatment units made by ZAO MELP are as follows:

• Gas-discharge gap value: up to 15 mm
• Area of items to be treated: up to 0.5 square meters
• Voltage increase rate on electrodes: at least 1012 V/s
• Specific energy release density in gas-discharge space: abt. 4 W/square decimeters