Welding & bonding.

Welding & Bonding

Living up to their advance billing notices for the show, several manufacturers unveiled entirely new technologies in the field of welding and bonding. Precise computer process control to ensure welding accuracy on these new, more sophisticated systems was a trend.

ORBITAL WELDING MOTION

A novel friction-welding process that uses an electromagnetic orbital drive to generate heat between thermoplastic parts was introduced by Vinton Inc., Henrietta, N.Y.

Known as the OmniWeld system, the process employs a fixed, fixtured plastic part matched with another part mounted on the mechanical, electromagnetic orbital drive, according to a Vinton spokesman. A microprocessor control monitors weld time, pressure, velocity, height and distance of the parts being welded, as well as providing statistical process control outputs.

The system creates heat friction by rubbing the two parts together in a controlled, constant-velocity circular motion, which raises the plastic parts to their melting point. An electromagnetically driven weld head drives the moving platen against the fixtured part. Motion is programmed to stop automatically after sufficient material is melted, allowing the melted plastic to solidify and form a permanent bond.

Maximum part size for the initial OmniWeld unit, known as the Vinton CV-12, is 10 x 10 in. The spokesman points out that the OmniWeld system is a distinct technology from spin welding or linear vibration welding. He says uniform velocity is established across the entire surface of the platens, adding that unsupported flexible walls can be easily joined because no wall is ever perpendicular to the "omni-directional" welding motion.

Base price for the CV-12 is $30,000. Options include a meltdown sensing system and a SPC data receiver. Vinton currently is developing a larger machine that also employs the OmniWeld technology. The CV-12 unit's opening between platens is 16 in., with a 16-in. platen travel distance. The unit has a max. clamp force of 1500 lb.

FOCUSED INFRARED WELDING

A new noncontact fusion bonding technique for welding thermoplastic, composite and TP elastomer parts that utilizes focused infrared heat technology was unveiled by Branson Ultrasonics Corp., Danbury, Conn.

According to Branson officials, the new welding process makes use of a reciprocating focused infrared heat reflected from a single quartz lamp. Lamps can be custom built, up to 10 ft in length, and can achieve melt temperatures of up to 1500 F. Two separate plastic parts can be fixtured above and below the heat source. A focused beam of infrared thermal radiation scans the plastic substrates, raising the material temperature and creating a melt without contacting the heat source. Once the cycle is completed, the two parts are clamped together.

Melt temperatures for the two fixtured parts can be individually controlled, which permits the assembly of thin- and thick-walled components, as well as accommodating the correct melt temperatures for unlike plastic parts. The temperature and intensity of the focused beam can be accurately monitored and adjusted during the welding cycle, providing the flexibility to weld various thermoplastic and composite materials.

The basic operations of the welding system can be automated or retrofitted into an existing fusion system. Base price for the unit is about $25,000. Branson says it plans to introduce different-size models in the coming months.

|GUARANTEED' QUALITY CONTROL

Herrmann Ultrasonics Inc., Schaumburg, Ill., introduced three new models in its modular Dialog ultrasonic welding line. A company executive said Herrmann "guarantees" the process and quality control of its PS, HS and Ultrasafe models, which have been recently introduced in North America, through its proprietary "millisecond" scan and control computer technology.

Controlled by a microprocessor, a part and process reference model is first established in the Dialog 2002 computer module, which is employed by all three units. The computer then automatically scans the welding operation of parts, making a reference measurement 1000 times a second, continually checking both the power distribution and joining velocity of the in-process work against the established reference model.

The Dialog computer can determine if there are any changes along the welding curve, and will automatically signal a fault message and reject a part that deviates from the established specifications. By making measurements 1000 times a second, the system continually monitors the entire welding cycle to ensure part quality and process consistency, rather than track only the power peak of the weld curve, thereby guaranteeing consistent results, according to the company.

To help ensure consistency, another technology feature on the Dialog units is fully automated, "locked-in" computer numerical control of every parameter in the welding operation. The computer module for the Dialog units also includes a "visualize to optimize" feature, which can automatically recognize changes or inconsistencies in the materials being welded. This feature reportedly allows the welding process to maintain a consistent curve as well as maximum power distribution by compensating for any quality deviations in the plastic being welded caused by excessive regrind content, impurities or moisture.

Base pricing for the new Dialog ultrasonic welders ranges from $18,000 to $30,000. Options include a modular rotary indexer and pick-and-place part-removal system, as well as a fast-change tooling system.

SERIES NETWORK CONTROLLER

A new computer network controller that permits a single workstation operator to communicate and monitor eight separate welding systems was introduced by the Ultrasonics Div. of Dukane Corp., St. Charles, Ill.

Known as the Dukane Multiplexer, the unit enables programmer access to the process and setup data of up to eight Dukane ultrasonic welding devices. The multiplexer box can be integrated into a customer's existing computer control system. A Dukane spokesman said the multiplexer organizes the data of a simultaneous multiheaded system on a single screen, allowing an operator to work with one computer display to help simplify welding modifications. He said the multiplexer permits an operator to treat a multihead system as a single machine, controlling various welders individually or in tandem. The multiplexer also incorporates an SPC software package.

Pricing for the multiplexer, which ranges between $995 and $1595, is determined by the number of serial ports selected by users (from two to eight, moving up in multiples of two).

WINDOW WELDER

A fully automatic system for thermally butt-welding all four corners of a PVC window frame simultaneously was shown by Technoplast International, Corrales, N.M. (representative for Technoplast of Austria). The S-Tech 400 has a 2-min cycle, is said to be accurate to 4 mils, and can weld two frames at once. Microprocessor control of welding-plate position and temperature includes servo positioning, clearly designed keyboard, and automatic program with 100-line memory. System price is about $100,000.

PHOTO : Technoplast system welds all four corners of one or two PVC window frames simultaneously under microprocessor control.