Spot welding is quick and easy. There is no need to use any fluxes or filler metal to create a join by spot welding, and there is no dangerous open flame. Spot welding can be performed without any special skill.

The butt weld consists of joining of two pieces of metal together either on face or on edge. It is of two types namely upset butt welding and flash butt welding.

(i) It is a faster process. (ii) Preparation of weld surface is not required. (iii) Power requirement is less. (iv) Many dissimilar metals with different melting temperatures can be flash welded.

Advantages & Disadvantages of Resistance Welding

• Higher speeds, <.1 seconds for automotive spot welding, short process time.
• Excellent for sheet metal applications <1/4 inch.
• No filler metals or consumables required.
• Relatively safe due to low voltage requirements.
• Environmentally friendly clean process.

Disadvantages and defects of resistance welding Higher cost, a large investment costs. 2) large capacity, and the majority of single-phase welder, unbalanced load on the grid causing serious, must be connected to the grid larger capacity.

Resistance welding is the joining of metals by applying pressure and passing current for a length of time through the metal area which is to be joined. The key advantage of resistance welding is that no other materials are needed to create the bond, which makes this process extremely cost effective.

A limitation of ultrasonic welding is that with current technology, large joints cannot be welded in a single operation. In addition, specifically designed joint details are required. Ultrasonic vibrations can also damage electrical components, although the use of higher frequency equipment can reduce this damage.

Ultrasonic welding offers many advantages to assemblers. “It is more expensive than resistance welding machinery, but [less expensive] than lasers.” Ultrasonics is much more cost-effective in the long run due to many factors, such as tooling, energy consumption and joint quality.

Safety: Using ultrasonic welding equipment is extremely safe compared to other welding techniques. The ultrasonic energy is highly targeted, reducing the risk of dangers due to excess electrical energy.

Ultrasonic welding equipment has been in use for more than 40 years. Medical and scientific literature reports no documented health hazard from airborne industrial ultrasonic energy reaching an operator. Pacemakers are not affected by airborne ultrasonic energy, but may be affected by electromagnetic energy.

Ultrasonic welding offers some key advantages over other forms of welding:

• It saves time. It is much faster than traditional welding methods, as virtually no time is needed for drying or curing.
• It saves production costs.
• It produces a high-quality bond and a clean, tight seal.

ultrasonic welding of plastics – material suitability guide

These polymers generally are very efficient with regard to their ability to trans- mit ultrasonic vibrations, and can be welded under a wide range of force/amplitude combinations.

Only special type of high heat/cooling systems can be used to weld Teflon. Furthermore, most of these materials can be used in Ultrasonic or RF welding. Other materials such as PET, PETG, Open Celled Polyurethanes, LDPE/EVA, PEVA and some ABS plastics can also be used.

The purpose of this innovative process is to allow ultrasonic welding of plastic parts which have rubber overmolding and utilize the rubber for sealing and as a “live” axis. This design constraint requires designing a door which seals a compartment and needs to stay attached to the main unit at all times.

The maximum thickness can be that can be welded is 2.5mm. 7. Electric currents are passed is ultrasonic welding. Explanation: In ultrasonic welding method, the parts which are to be joined, are kept clamping to one another in between of supporting member and the welding tip.

Cold welding or contact welding is a solid-state welding process in which joining takes place without fusion or heating at the interface of the two parts to be welded. Cold welding was first recognized as a general materials phenomenon in the 1940s.