شستشو در حمام اولتراسونیک یک فرآیند است که با استفاده از امواج مافوق صوت(معمولا بین20-400 کیلو هرتز) و حلال مناسب انجام می شود که در این آزمایشگاه از این تکنولوژی برای تمیز کردن توری الک ها استفاده می شود.فرآیند شستشو بین 3 تا 6 دقیقه بطول می انجامد.شستشو در حمام آلتراسونیک با استفاده از حباب کاویتاسیون ناشی از فشار فرکانس بالا امواج صوت به تحریک یه محیط مادی مثل آب انجام می گردد.همانطور که می دانید صوت برخلاف نور برای آنکه بتواند منتشر شود نیاز به یک محیط مادی دارد،انتشار امواج صوتی در محیط مادی بصورت انتقال ارتعاشی از یک ذره به ذره مجاور می باشد بنابراین از آب و یا حلال دیگر بسته به نوع آلودگی و قطعه کار استفاده می شود،چون آب حلال بسیار عالی،غیر سمی ، غیر قابل اشتعال و سازگار با محیط زیست.استفاده از مواد شوینده سازگار با قطعه کار میتواند در کاهش کشش سحطی آب مناسب باشد.
بطور کلی هدف این است که بطور کامل تمام آثار آلودگی محکم و بهم چسبیده بروی توری الک و در داخل حفره ها بدون صدمه زدن به ابعاد نامی حفره ها برطرف شود.


Ultrasonic Cleaning


ULTRASONIC CLEANING involves the use of high-frequency sound waves (above the upper range of human hearing, or about 18 kHz) to remove a variety of contaminants from parts immersed in aqueous media.  The contaminants can be dirt, oil, grease, buffing/polishing compounds, and mold release agents, just to name a few.  Materials that can be cleaned include metals, glass, ceramics, and so on.  Ultrasonic agitation can be used with a variety of cleaning agents: detailed information about these agents is available in the other articles on surface cleaning in this Section of the Handbook.

Typical applications found in the metals industry are removing chips and cutting oils from cutting and machining operations, removing buffing and polishing compounds prior to plating operations, and cleaning greases and sludge from rebuilt components for automotive and aircraft applications.

Ultrasonic cleaning is powerful enough to remove tough contaminants, yet gentle enough not to damage the substrate.  It provides excellent penetration and cleaning in the smallest crevices and between tightly spaced parts in a cleaning tank.

The use of ultrasonics in cleaning has become increasingly popular due to the restrictions on the use of chlorofluorocarbons such as 1,1,1-trichloroethane.  Because of these restrictions, many manufacturers and surface treaters are now using immersion cleaning technologies rather than solvent-based vapor degreasing.  The use of ultrasonics enables the cleaning of intricately shaped parts with an effectiveness that corresponds to that achieved by vapor degreasing.  Additional information about the regulation of surface cleaning chemicals is contained in the article “Environmental Regulation of Surface Engineering” in this Volume.  The article “Vapor Degreasing Alternatives” in this Volume includes descriptions of cleaning systems (some using ultrasonics) that have been designed to meet regulatory requirements while at the same time providing effective surface cleaning

In a process termed cavitation, micron-size bubbles form and grow due to alternating positive and negative pressure waves in a solution.  The bubbles subjected to these alternating pressure waves continue to grow until they reach resonant size.  Just prior to the bubble implosion (Fig. 1), there is a tremendous amount of energy stored inside the bubble itself.

Temperature inside a cavitating bubble can be extremely high, with pressures up to 500 atm.  The implosion event, when it occurs near a hard surface, changes the bubble into a jet about one-tenth the bubble size, which travels at speeds up to 400 km/hr toward the hard surface.  With the combination of pressure, temperature, and velocity, the jet frees contaminants from their bonds with the substrate.  Because of the inherently small size of the jet and the relatively large energy, ultrasonic cleaning has the ability to reach into small crevices and remove entrapped soils very effectively.

An excellent demonstration of this phenomenon is to take two flat glass microscope slides, put lipstick on a side of one, place the other slide over top, and wrap the slides with a rubber band.  When the slides are placed into an ultrasonic bath with nothing more than a mild detergent and hot water, within a few minutes the process of cavitation will work the lipstick out from between the slide assembly. It is the powerful scrubbing action and the extremely small size of the jet action that enable this to happen.

In order to produce the positive and negative pressure waves in the aqueous medium, a mechanical vibrating device is required.  Ultrasonic manufacturers make use of a diaphragm attached to high-frequency transducers.  The transducers, which vibrate at their resonant frequency due to a high-frequency electronic generator source, induce amplified vibration of the diaphragm.  This amplified vibration is the source of positive and negative pressure waves that propagate through the solution in the tank.  The operation is similar to the operation of a loudspeaker except that it occurs at higher frequencies.  When transmitted through water, these pressure waves create the cavitation processes.

The resonant frequency of the transducer determines the size and magnitude of the resonant bubbles.  Typically, ultrasonic transducers used in the cleaning industry range in frequency from 20 to 80 kHz.  The lower frequencies create larger bubbles with more energy, as can be seen by dipping a piece of heavy-duty aluminum foil in a tank.  The lower-frequency cleaners will tend to form larger dents, whereas higher-frequency cleaners form much smaller .dents


کالیبراسیون الک در این آزمایشگاه زیر نظر متخصصین این امر و با دقت فراوان انجام میپذیرد. لطفاً برای اطلاع از قیمت کالیبراسیون الک با خانم کلهر با شماره 61907-021 داخلی 303 تماس بگیرید.

دیدگاهتان را بنویسید

نشانی ایمیل شما منتشر نخواهد شد. بخش‌های موردنیاز علامت‌گذاری شده‌اند *