A piece of metal seems like the simplest, most straightforward of items, but when that single section of metal is combined with others by cutting, forming, welding and then heat treated, finished and tested, anything is possible. This approach is the guiding mantra for Alma, Michigan-based Merrill Fabricators.
|Whether it's transforming metal plates into valves that can precisely control millions of gallons of high-pressure petrochemicals, or into suspension components that provide accurate steering for trucks as big as buildings, Merrill Fabricators innately understands its customers' livelihoods, as well as their reputations, depend on the precision and performance of the company’s fabricated metal components.
A member of Merrill Technologies Group Company, Merrill Fabricators holds itself to the highest industry standards, and this means using the best equipment, technology, knowledge and expertise available especially when it comes to welding, the lifeblood of this company. Here’s a look at Merrill's approach and the part robotic welding automation is playing in the company’s ongoing success.
Figure 1 - Merrill's facility includes an AWS SENSE-accredited (Schools Excelling through National Skills Standards Education) welding school where workers can hone their skills. It is managed by one of Merrill's Certified Welding Inspectors (CWI) who is also a Certified Welding Educator (CWE).
Redefining Job Shop
When you hear the words job shop, images of a few fabricators working diligently in a couple of hundred square feet may first come to mind. As you stand on the floor of Merrill’s 400,000-square-foot facility, the term job shop takes on a whole new meaning.
The company serves nearly every industry where critical fabrication is essential. In the ever-expanding energy sector, including solar, wind, nuclear and fossil fuel, the company fabricates valve housings, pressure vessels, coolant tanks, processing chambers, and tower components. For its defense customers, armored vehicle components are the norm.
In mining and heavy equipment, employees – of which there are more than 300 companywide – work on large truck components, including suspension parts, booms, arms, gearboxes and frames. Additionally, the company’s products are used in aerospace, chemical processing, plastic injection, rail systems, food systems and robotics.
Precision from Start to Finish
From the day it opened its doors in 1974 Merrill has built uncompromising quality, precision and performance into every step of its manufacturing process.
This starts with the metal – selecting the right materials. Merrill Fabricators is experienced in working with nearly every type of metal imaginable, ranging from aluminum, A-36 and stainless, to nickel-based super-alloys like Hastelloy®, Waspaloy® and Inconel®, to specialty alloys such as Ferralium®. Every piece is thoroughly inspected upon its arrival, which helps the company to control the quality and integrity of finished pieces.
Merrill carries inventory of more common metals in square bars, square tubing, angle iron, channel, beam, ID/OD tube and solid diameters, allowing for quick fabrication of many pieces.
The next step in the process is cutting. The star of this step is a state-of-the-art multi-axis CNC gantry plasma and flame cutting machine, which has a 40 ft. x 120 ft. cutting area and cuts up to 10-inch thick plate to exacting tolerances in minutes.
“If there’s a way to weld metal, we do it,” says one of Merrill's welding engineers who is also a certified welding inspector (CWI). The company's capabilities include semiautomatic systems and multi-axis, programmable robotic welding installations that allow team members to guide welding directly from CAD/CAM data. These systems are partnered with weld positioners, welding manipulators or tank-turning rolls that can accommodate Merrill's wide range of projects. Welding processes run the full gamut – submerged arc (SAW), MIG (GMAW), TIG (GTAW), stick (SMAW) and flux-cored (FCAW).
Figure 2 – Hydraulic cylinder is repaired by robotic submerged arc welding (SAW) using 3/32-inch diameter Lincolnweld® L-50 solid wire electrode, Lincolnweld® 980 submerged arc flux and a FANUC ARC Mate® Robot Arm.
Merrill rounds outs its fabrication services with in house blasting and painting, ideal for when specialized parts require a specific coating.
A Closer Look at the Welding
Merrill Fabricators relies heavily on robotic welding. “Robots more efficiently and easily reach locations within a large, complicated project, such as a rock crusher or turbine housing,” the welding engineer adds. "They are precise and efficient, allowing us to meet deadlines and produce a higher-quality product."
Part of the company's robotic fleet includes four FANUC® ARC Mate® six-axis servo-robot units specifically designed for precise, high-speed welding and cutting. Two of these units are configured for submerged arc, which were among the first of these types of systems to be deployed in the United States. A third unit includes a FANUC® ServoTorch™ for aluminum and other soft welding wires and another is equipped for open arc MIG.
Two of these systems are powered with Lincoln Electric Power Wave® 455M units and two include Power Wave® 655R power sources for use on thicker materials.
Merrill’s fleet of Lincoln Electric welders also includes additional Power Wave® 455M packages for semiautomatic welding, a number of TIG welders and several copies of the Power Wave® S350, a rugged multi-process unit designed to deliver an extremely fast arc response. The S350 is loaded with more than 65 standard welding waveforms for optimized performance on almost any application.
The company has recently been testing a new Lincoln Electric Flextec™ 450, a multi-process welder that delivers up to 500 amps of welding power for construction and fabrication applications. It uses the latest inverter technology, which helps save on energy costs.
“We're looking at machines like the Flextec™ 450 that will allow us to increase our efficiency and cost savings, save on electricity and reduce our overall energy footprint,” the welding engineer says.
Figure 3 – Repair of hydraulic cylinder is complete. One continuous weld bead was created by 80 plus rotations of
Figure 4 – Robotic Submerged Arc welding (SAW) was used to build-up a large diameter cable drum using 3/32-inch diameter Lincolnweld® LA-100 solid wire electrode and Lincolnweld® 888 submerged arc flux.
No matter where you stand on the shop floor at Merrill Fabricators, you are consistently reminded that precision is the primary focus for this growing company. Every employee understands that their reputation, that of the company and of their customers, depends on the performance of the large components coming off of its floor.
“We’ve built our reputation by time and again delivering excellent products that perform over time. This is critical to us because we understand how important of a role these components play for our customers,” the welding engineer adds. “We never lose sight of that.”
Figure 5 - Merrill relies on Lincoln Electric welding consumables including UltraCore® gas-shielded flux-cored wire and SuperArc® MIG wire.