Ultrasonic Sealer for Plastic Humidity Indicator Case In packaging industry very few people selects using chemicals and tries to find alternative sealing methods. The way comes to ultrasonic sealing. Ultrasonic welding machine combines two thermoplastics into each other without using any chemicals. The ultrasonic welder has a power generator to create electrical signals then these signals are fed to ultrasonic convertor. This convertor is connected to the sonotrode and this sonotrode applies the ultrasound vibrations onto the plastic part. In this application Sonikel Ultrasonics, designed a special aluminum sonotrode for plastic plastic case of humidity indicator. The humidity indictor consist of 2 parts. These two parts are put under the ultrasonic plastic sealer and in a time shorter than 1 second, it has been sealed by ultrasonic vibrations.