The theory of ultrasonic.
 -It is a theory of conversion energy. Once using
  by the sound wave which is ranged about 20Khz
  that human being can't hear,its vertical
  movement is transformed as a movement energy.

 The difference between iron and ultrasonic
 -Iron : To stick by heat (It may be seperated
  by impact and gets the molcular structure fired)
 -Supersonic : When as many as 20,000 vibrations
  is diliverd to a plasti during 0.1~1 second,
  there are heats and melt the surface

 of the plastic and it allows to be sticky (The molcular structure is collapsed)
 (It never need a duplicate work in the future)

 Cmmercialized products-Eyes,noses,mouths and accessory of toys etc...(ABS,PE,PP..)

 Ultrasonic solder
 -It is able to get a strong adhesion without deformation or transformation quickly.
 -It also allows a working environment to be cleaned. And it brings a high
  productivity and a cost-down effects