EuroWire July 2015

News Technology

Ultrasonic welding the favoured method of assembly

A localised increase in temperature and interfacial slip breaks up oxides and surface films, permitting metal-to-metal contact at many points. Continued vibration causes further deformation of the points, increasing the contact area and essentially creating a weld without melting, and producing a metallurgical bond with high conductivity and tensile strength. The Wedge-Reed system uses a vertical vibrating reed, driven by a wedge-shaped coupler and transducer assembly perpen- dicular to the reed, allowing high clamp force without bending stress or stalling. Sonobond’s Dual Head SpliceRite TM features welding heads on both sides of the weld area, enabling it to provide one-pulse wire splicing of up to 100mm 2 in stranded bare copper wire and tinned wire to about 60mm 2 . Also available are a Dual Head Spot Welder, as well as Sonobond’s SonoWeld ® units, which can be custom-tooled to weld tinned wire to bare or coated terminals. Every Sonobond welder is equipped with a microprocessor controller that can program welds by height, energy or time, and store and recall up to 250 jobs. Additionally, all units have heat-treated, taper-lock tips that are capable of achieving up to 100,000 welds and that are easily replaceable without requiring machine readjustment or calibration. Sonobond’s equipment also offers automatic frequency control and overload protection, and can detect and prevent wrong-part or no-part activation. Sonobond Ultrasonics – UK Website : www.sonobondultrasonics.com

telecommunications, lighting, medical, automobile, marine and aerospace,” said Melissa Alleman, Sonobond Ultrasonics’ vice president. Ultrasonic welding has become a popular alternative to other methods of welding because it uses vibrational energy to disperse surface oxides and create galling on wire strands. This forms a solid-state metallurgical bond with high conductivity, producing the lowest resistance weld available. “Unlike resistance welding that generates high heat, in ultrasonic welding the metals do not melt, so there are no significant changes in the material properties, and the lower heat means no external water cooling is needed,” added Ms Alleman. Also, unlike soldering – which cannot be used if the temperature at the weld during use approaches the melting point of the solder – ultrasonic welding requires no flux or filler materials. Plus, ultrasonic welding uses much less time and energy than its alternatives. The ultrasonic welding process begins with a power supply that converts input line power into high frequency electrical power and transmits that energy to a transducer. The transducer transforms the electrical energy into vibratory energy, which is delivered to the welding area as sound waves, or ultrasonics. When the vibrating, shear forces of the ultrasonic waves are directed by the welding tip to the interface between two metals, which are held together under clamping force, internal stresses cause deformation where the materials are in contact.

With manufacturers using wire harnesses in increasingly challenging functional and environmental conditions, ultrasonic welding is becoming the favoured method of assembly, since it produces welds with high conductivity and tensile strength. In fact, it is estimated that at least two-thirds of the cabling used in today’s cars is ultrasonically welded. “Wire harnesses are like the central nervous systems for equipment in a wide variety of industries, including consumer electronics and appliances, data and

New powerful cable feeding systems Schleuniger has introduced the new PreFeeder 3300 and PreFeeder 4300 cable feeding systems. The systems distinguish themselves through simple design and ease of use. For easy reel handling and fast changeovers, all axes are electrically driven. Both the PreFeeder 3300 and PreFeeder 4300 use a shaftless design for easy loading and unloading of reels.

The PreFeeder 3300 is suitable for reels weighing up to 150kg (330lb) with

▲ ▲ The new PreFeeder 4300 cable feeding systems

a maximum diameter of 600mm (24") while the PreFeeder 4300 can handle reels weighing up to 400kg (880lb) with a maximum diameter of 900mm (36"). These powerful machines can increase production rates and economic efficiency. Schleuniger North America Inc – USA Website : www.schleuniger-na.com

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July 2015