Seeing a need for custom-build ultrasonic welding machines, particularly for a variety of complex exterior and interior automotive components, Sefortek Inc., Stoney Creek, Ont., is now offering that service. The 11-yr old firm specializes in tooling and custom automation for the plastics industry.
Currently, the company is sourcing the electronics to build these machines from various vendors. However, Sefertek is very close to solidifying a partnership with one company. According to owner and engineer Nestor Segura, the company has the engineering know-how to design an ultrasonic welding machine for virtually any part, with different operations added as needed, including integrated vision inspection, for both the automotive and packaging industries.
One of the initial projects recently completed was for a Tier 1 supplier that needed a specialized welder for the Class A painted ABS exterior trim of the rear doors of a new compact sedan.Sefortek build an ultrasonic welder that could weld these painted parts, which required 14 welds, seamlessly. Key to this machine are two vision sensors—one for LH and one for RH nest. These sensors will detect the position and presence of clips and foam clips for water sealing—six each, in this case, two double-sided tapes, and six aluminum tab bends. The vision sensors can be enabled or disabled by the user. There are extra sensors in the nest—one for detecting plastic parts presence and one for aluminum chrome presence.
This ultrasonic welding system has three power generators. To switch the power generators from post-to-post, there are three Multiplexer cards on an auxiliary panel underneath the main panel. Multiplexers 1 and 2, each have five switches, while Multiplexer 3 has four. The welding is controlled by time. Amplitude can be left at 100% and users can just change the time to make a lower or higher post weld. Energy is used only as a guidance. An energy level can be set in order to ensure a complete weld has been made.
In this case, user interface is operated by two main users with passwords. Each has different types of access to the machine. The main user has full access to all screens, can change all set-ups, enable or disable the vision system, and can change sonic welding times. Other incorporated features include: a light fixture in the machine; a light curtain in front of the unit for safety purposes; two heat sinks that are height adjustable; and nests made of polyurethane with blue rubber strips which act as a protection that prevents any blemishes on the paint due to the sonic welding.