Splicing and Sewing Machine

Product Overview

A sheet metal splicing and sewing machine turns two sheets into one continuous panel. In a duct shop that is the step between cutting and forming: sheet is cut to width, the edges are joined, and only then is the panel rolled, folded or lock-formed into a duct section. Done by hand, that joint is slow and depends on who is holding the tool. Done on a machine, it is a repeatable pass along a rail.

The carriage does the work. It rides a rail above a long horizontal bed, driven by an electric motor, and travels the full length of the joint at an even rate. The rail keeps the seam straight; the drive keeps the closing pressure steady from the start of the joint to the end. That is what makes the tenth panel of a shift look like the first.

Setup is made with the handwheel. Turning it sets the working gap for the gauge on the bed, which is the adjustment an operator makes when moving between galvanized and stainless work, or between a light sheet and a heavy one. The control box sits within reach, so a run can be started and stopped without stepping away from the panel.

This is a floor-standing industrial unit, not a benchtop tool. It sits level in a fixed spot with clear approach at both ends, because a full-length sheet going in and a longer panel coming out take up more floor than the machine itself. Anchor and foundation details are settled with you against your own floor.

Coorig builds these units in Tianjin. As a sheet metal splicing machine supplier we build the machine around the material mix a shop actually runs, galvanized, stainless or both, before it is packed for export.

Key Features

• Rail-guided carriage. The seam-forming head runs on a rail the full length of the bed, so the joint follows a straight line instead of the operator's hand. Long seams stay parallel and evenly closed.
• Electric motor drive. The carriage is driven, not pushed. Travel stays even through a full-length pass, which takes the effort out of the job and keeps the joint consistent from the first panel of a shift to the last.
• Full-length working bed. The bed is long enough to sew a duct panel in a single pass rather than two shorter ones, so there is no second joint in the middle of a panel to line up, close or inspect.
• Handwheel gap adjustment. One handwheel sets the working gap for the gauge on the bed. Changing from galvanized to stainless, or from light to heavy sheet, becomes a visible, repeatable adjustment rather than a tooling change.
• Controls within reach. The control box is mounted on the machine beside the operator, so a run can be started, stopped and watched without stepping away from the panel.
• Floor-standing steel frame. The machine sits at working height on its own painted steel frame, with bare metal only where the sheet and the seam-forming head meet. It wipes down easily, and wear shows where it matters.

Material & Gauge Range

Galvanized sheet splicing for duct fabrication is where this machine spends most of its working life. The galvanized range covers light low-pressure work at the thin end and larger, stiffer duct sections at the top; the exact figures sit in the specifications table below. Stainless has a lower ceiling, and that limit comes from the material rather than from the drive: stainless work-hardens as it is formed and springs back more than galvanized, so the seam-forming head needs a tighter, more closely watched pass.

In practice, one machine carries a shop through a normal duct schedule. Light gauge for small rectangular runs and fittings, mid-gauge for standard supply and return duct, and the top of the galvanized range for larger panels where stiffness matters. Shops quoting both galvanized and stainless work, commercial kitchen extract for instance, do not need two machines to cover the schedule.

Gauge matters more than width at the joint. A seam between a light sheet and a heavy sheet closes unevenly, so keep both sides of a joint in the same gauge wherever the design allows. Where a thickness change cannot be avoided, run the joint at the setting for the heavier side and check the first panel before committing the rest of the batch.

Edge preparation is worth a minute of attention. Sheared edges that are square, burr-free and clean give the head an even line to follow; a ragged or twisted edge shows in the finished seam no matter how carefully the machine is set. Keep the bed clear of offcuts and swarf between panels, because a single chip under the sheet lifts the joint line.

Stainless rewards a test piece before a production run. Temper varies more between stainless suppliers than between galvanized suppliers, so sew a short offcut from the same sheet before the first full panel goes on the bed.

Technical Parameters

Seam Forming Sequence

1. Set the gap for the gauge. Turn the handwheel to the setting that matches the sheet on the bed. When the material or thickness changes, reset it before the first panel, not after.
2. Lay the sheets on the bed. Bring the two edges together in the position the seam profile requires, with both sheets flat and square to the rail. A panel that starts out of square finishes out of square.
3. Hold the panel steady. Keep the sheets from lifting or shifting as the carriage starts. On longer panels, a second pair of hands at the far end saves rework.
4. Position the carriage at the start of the joint. Bring the head to the beginning of the seam and check that it is centred over the joint line before the drive engages.
5. Run the seam. Start the motor drive and let the carriage travel the full length at its own rate. Do not push, hurry or hold back the head; even travel is what produces an even joint.
6. Inspect before the panel moves. Look along the finished seam for flatness and a closed line from end to end. A section that has not fully closed is far easier to deal with while the panel is still on the bed.
7. Clear the machine. Brush off the bed and the head, and check that the carriage has not picked up swarf, before the next panel goes on.

Applications in Duct Fabrication

• Long rectangular duct panels. A sheet metal splicing and sewing machine makes panels longer than a standard sheet possible, which is routine work in a shop cutting to a duct schedule rather than to sheet size.
• Plenum and plant-room casings. Large casings and plenum boxes need wide, stiff panels; joining two sheets gives the size without waiting for a special sheet order.
• Transitions, offsets and taper pieces. Where a fitting needs a panel that is wider at one end than the other, the joint is laid and sewn flat before the piece is formed.
• Stainless and kitchen extract work. Galvanized sheet splicing for duct fabrication is the everyday job, and the same bed takes stainless for commercial kitchen extract and other corrosion-resistant ductwork.
• Prefabrication shops on MEP contracts. Contractors running their own prefab shop turn coil-cut and standard sheet into project-sized panels under a roof, ahead of installation.
• Shops moving off hand seaming. Hammered and hand-locked joints vary with the operator and cost the shop a full-time pair of hands; a motor-driven carriage takes both the variation and the effort out of the job.

Who It's For

Four kinds of shop end up buying this machine. HVAC duct factories producing rectangular duct to a schedule need a dependable way to build panels wider or longer than a standard sheet, and they run it as the station between the shear and the forming equipment. MEP contractors with their own prefab shop use it so panels are joined under a roof rather than on site, where a long joint is awkward to handle and harder to keep straight. Stainless and specialist fabricators, working on commercial kitchen extract, laboratory and process ductwork, want a controlled motor-driven seam instead of hand work that depends on who is on shift. Equipment agents and distributors complete the picture: they look for a sheet metal splicing machine supplier whose range covers cutting, forming, folding and joining, so a duct shop can build a package from one source instead of three.

Care & Consumables

• Clean the bed between panels. Swarf under a sheet lifts the joint line, and a chip on the rail throws the carriage off its path. Brush down at every panel change and wipe the rail at the end of the shift.
• Keep the rail lightly lubricated. A thin film is enough. Too much collects dust and turns into grinding paste; too little and the carriage drags. Run the carriage by hand before switching on, and if it feels stiff, clean and relubricate first.
• Inspect the seam-forming head. Burrs, flats and material build-up show up in the seam before they show anywhere else. Look at the head whenever seam quality changes, and replace it as a matched set rather than one piece at a time.
• Reset the handwheel after every material change. The gap that suits one gauge will not suit the next. A setting left over from the previous job is the most common reason a seam fails to close.
• Protect the control box and cable. Keep the box dry, the cable clear of floor traffic and the connections tight. Electrical faults on a shop-floor machine usually start with a damaged cable rather than the control itself.
• Plan the spare before you need it. A worn head should not idle the machine while a replacement is on its way. Order the spare with the machine so it matches the build exactly.

Ordering & Delivery

1. Send the material mix. Tell us whether you run galvanized sheet, stainless or both, and the thickest gauge in each. That single answer decides the roll set and the working gap the machine is built around, and it is the first thing any sheet metal splicing machine supplier needs before quoting.
2. Confirm the power supply. The motor is rated at 1.5 kW, while voltage, phase and frequency have to match what your building actually supplies. Send the site specification rather than the standard for your region, because the two are not always the same.
3. Share the floor position. This is a floor-standing unit with a long bed. A sketch of where it will sit, and of how sheet is fed in and panels taken out, lets us confirm clearance and access before the machine is built.
4. Arrange lifting and placement. The machine ships as a heavy one-piece unit, so plan lifting gear at the unloading point and check the floor loading where it will stand. Tell us if access to the shop is restricted, because a narrow doorway changes the packing plan.
5. Agree packing, shipping terms and lead time. Give us the destination port and the terms you work on, and we will confirm the packing method, shipping arrangements and production lead time in writing before the order is placed. Final configuration is confirmed against your order before production starts.
6. Plan training and spares with the order. Ask about operator training, the documentation supplied with the machine and a spare seam-forming set to keep on the shelf. Arranging all three alongside the order is simpler than sorting them out after commissioning.

Splicing vs Seam Closing

• Two different moments in the build. This machine joins two flat sheets into one continuous panel before anything is formed. A vertical duct zipper closes the longitudinal seam of a duct that has already been rolled or folded to shape. One works on flat sheet, the other on a finished duct body, and neither can take over the other's job.
• Horizontal bed versus vertical seam. Here the panel lies flat on the 3000 mm bed while the driven carriage travels the joint. A seam closer stands the duct on end and runs down a vertical seam, typically on duct lengths of 1000-1530 mm.
• Same materials, different work. Both are built for the same galvanized and stainless sheet gauges, which is exactly why the two get mixed up when a shop is quoting new equipment. Sharing a gauge range says nothing about function: galvanized sheet splicing for duct fabrication and closing a formed duct seam are separate operations on the schedule.
• Buying the wrong one leaves the joint uncovered. A shop that orders a seam closer expecting to build long panels will still be hand-locking sheet. A shop that orders a sheet metal splicing and sewing machine to close duct seams will still be chasing longitudinal seams by hand at the end of the line.
• Most duct shops run both. Splicing sits upstream of forming, seam closing sits downstream of it, with folding or lock forming in between. They are complements rather than alternatives, so it is worth planning the second one while the first is being specified.
• Neither is a welding set. Both form the joint mechanically from the sheet itself, so there is no filler metal, no weld bead and nothing to grind back before the panel moves to the next station.
• Which one your shop needs. If the panel a job calls for is wider or longer than the sheet you can buy, the bottleneck is joining sheet and it is this machine. If formed ducts are leaving the shop with an open seam, the bottleneck is closing that seam and a vertical zipper is the machine you are missing.

Scale & Supply Capability

Tianjin Coorig Technology Co., Ltd. has been building sheet metal and MEP prefabrication equipment since 2004, with a team of around 200 people working from our own factory in Tianjin, China. In more than 20 years we have supplied buyers in over 35 countries — processing plants, mechanical installation contractors and agents — and we look after export, documentation and shipping as a one-stop service. A database of 3,000+ qualified suppliers, in-house quality control and our automated manufacturing systems keep build quality and delivery predictable. Reference work includes the Beijing Olympic Games, Egypt CBD, Guangzhou Baiyun Airport and BYD's European Center.

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