Sign up for PlasticsToday newsletter
Sponsored By
NPE 2000 Showcase - Ultrasonic Welding, Assembly: High-precision weldingNPE 2000 Showcase - Ultrasonic Welding, Assembly: High-precision welding
September 26, 2000
4 Min Read
.svg?width=1280&auto=webp&quality=95&format=jpg&disable=upscale "Plastics Today")
In lightof the hot electrical trend in injection molding machines,it seems logical that assembly equipment should follow suit. Manymanufacturers at NPE were offering welders with servomotors insteadof pneumatics, pushing high precision as a benefit. It also appearedthat they were attempting to give plastics processors optionsfor joining previously difficult-to-weld materials and parts.
At Branson Ultrasonics' booth, three new welders were featuredwith servo power. The MC ultrasonic welder incorporates a servodrivenactuator under closed loop control, enabling parts molded fromlow-viscosity resins to be welded, such as nylon.
Spin welding also received a servo boost in the Model SWServo2.In this machine, which welds circular parts, servos control boththe spin and actuator downstroke.
In hot plate welding, servodriven holding fixtures were usedin Branson's third servo offering, the HV-15S hot plate welder.The Model HPS 152/152 hot plate welder showcased by Sonics &Materials is powered by a servomotor that enables parts with wallsas thin as 1 mm to be welded. Although not a servodriven unit,one hot plate welder from Dukane Ultrasonics contains a uniquefeature: a rack and pinion system ? reportedly the only onein the U.S. ? that synchronizes the two platens.
Of course, precision is possible with straight electrics also,say Sonics and Ultra Sonic Seal. Both companies presented assemblysystems with electric stepper motor transport to control the horn'sstopping point to a tolerance of ±.0003 inch. Sonics' versionis the ElectroPress ultrasonic plastics assembly system; UltraSonic Seal's press is called the EPM 2010.
Four companies introduced assembly methods for joining materialsor parts previously thought to be impossible, or at least difficult,to weld. For the first time, MS Plastic Welders offered hot airwelding for attaching dissimilar materials. The process has beenput to the test in the automotive industry, where metal air bagcovers or chrome-plated parts are joined to thermoplastics withoutdamaging the chrome like ultrasonics can.
Lasers also provide options for welding. Branson's IRAM (infraredassembly method) was reported as having the ability to join materialsnot possible with other welding technologies. So far, the companyreports that PC, acrylics, PS, ABS, and elastomers have all beenwelded successfully. This technology illuminates the entire weldingsurface simultaneously in 3 to 5 seconds.
For delicate parts, the Ultrasonic Lateral Actuator from Bransonoperates with a shear motion, joining thin parts that are toofragile to be assembled with a clunky plunge welder. Some largeparts and soft materials can be tough to assemble ultrasonicallyas well, so Dukane introduced a 15-kHz, 4000W ultrasonic welderfor solving this problem.
New technology from Sonics has enabled the bonding of unbackedcarpet to plastic. Designed for use with the Model EH 5020 vibrationwelder, the process includes tooling coated with a proprietarysubstance that grips the carpet.
A number of new ultrasonic systems were presented at NPE:
Branson's Series 40 configurable welding system incorporates a 900 or 2000 Series ultrasonic welder, Camco indexer, system controls, and operator loading station. A new addition to the 2000 Series, the 2000f, was also presented with digital programming of weld force, down speed, and step force during weld and hold cycles.
More digital electronics were to be found in Herrmann Ultrasonics' PS and HS Dialog digital control systems, available in 35 or 20 kHz.
Two new welders from Sonitek -- the S840 (900W) and S870 (1500W) -- have power supplies integrated into the stand, with front-panel controls.
Sonobond is offering 20- and 35-kHz machine builder's modules of its ultrasonic welder for integration into automated and custom equipment.
MS Plastic Welders presented a door panel assembly three-station shuttle machine that can weld multiple points with one power supply.
From Dukane, a 40-kHz platen thruster system for the automotive industry was presented, as well as the DPC III (dynamic process control) system. The latter comes with a 16-bit processor.
Stapla's K-1 welder, previously covered, sported a simplified controller that operates with just one dial.
Not to ignore vibration welding, Branson came out with threenew linear models. For the ergonomically inclined, the weldingsurface on the Model Mini II Ergo vibration welder can be adjustedto operator height. It also saves space with the smallest footprintin the industry at 3 by 4 ft., according to Branson. Another compactunit, the Model VW-4UH Ultra Hy-Line welder, includes a digitaldrive controller; its cousin, the M-Series Model M624H welder,uses a two-phase digital drive.
Dukane threw its hat in the ring of vibration welders as well,offering a new line of large-capacity units for large or irregularlyshaped parts in the appliance and automotive industries.
In spin welding, Dukane made available 3- and 5-hp models withan rpm range of 300 to 3500, while Ultra Sonic Seal showed itscompact low-torque LTR spin welder.
Thermal presses were also featured. Dukane's includes up tosix individually controlled temperature zones, and Sonitek's TSSeries HT Model heat staking system incorporates a heavy-dutyH frame with force capabilities up to 5026 lb.
You May Also Like
