L-bar sealer buying guide

What to measure and decide before you ask for a quote: product size, output, film, seal area, electrical service, floor space, and support.

Updated October 2, 2026

Measure your products

Measure the length, width, and height of your smallest and largest products, in inches or millimeters. Note the weight and which side faces up. Note which way each one will travel through the machine. Flag anything fragile, loose, or odd-shaped, such as multipacks, soft goods, or round items.

The seal area of an L-bar sealer must be larger than the package plus film. Height matters as much as footprint. Many sealers and hooded chambers top out around 6 to 8 inches. The Sealer Sales SS-48ST takes products up to 6 in. tall, and the Clamco 6750EL up to 8 in.

Seal area specs are maximums, and you usually can’t use all of them at once. Heat Seal’s HDX-2000 sheet says you can’t use all its maximum product sizes at the same time. Send the supplier your actual product sizes and ask them to confirm.

Pick a seal area

There is no standard order for seal area sizes. Eastey model numbers list the side bar first. An EM2016 has a 20 in. side bar and a 16 in. front bar, and the EM1622 has a 22 in. front bar and a 16 in. side bar. Clamco lists the 6750EL seal bar as “cross x front”. Confirm which bar is which on every quote.

Choose a seal area that fits your largest product with room for the film to wrap over the top and sides. A seal area much larger than your products still works. But the machine costs more, takes more floor space, and is harder to load the same way each time. The roll width and bag length you choose set your film use, not the bar size. Common sizes:

Worked sizing example

Say your boxed product is 10 in. long × 8 in. wide × 3.5 in. high. It travels with the 10-inch side along the conveyor. This is an example request, not an equipment pick.

The Clamco 250C lists a 17 × 23-inch seal area, a 20-inch centerfold-film limit, and a 16 × 9-inch tunnel opening. Those numbers make it worth asking about for this example. They don’t prove a match. Have the supplier run the actual package and confirm all limits together. See combo systems for other setups.

Record the roll spec, product direction, settings, and approved sample in a setup sheet. Don’t buy from a footprint calculation alone.

Work out the output you need

Start from packages per day, not machine speed.

1. Write down how many finished packages you need per shift. Include your busiest season.
2. Divide by the minutes the machine will actually run, after breaks, changeovers, and film changes.
3. That is your required packs per minute. Buy a machine that reaches it at the low end of its rated range.

Example: 3,600 packages in a shift with 6 hours of real run time is 3,600 ÷ 360 = 10 packs per minute. That is above the 6 to 8 per minute Uline rates its H-2378 hand sealer for. It fits a semi-automatic machine.

Maker speed ratings assume ideal conditions. The Clamco 6750EL is rated up to 60 packs per minute. Clamco says speed is “dependent on package size, configuration, and film used.” Ask the supplier to time a run with your product. See machine types for typical speed ranges.

Choose your film

Before you buy, pick polyolefin, PVC, or polyethylene, and pick the gauge. The film affects seal settings, seal pad type, and ventilation. Then size the centerfold film. Use product width + height + 2 to 4 in., rounded up. Confirm the machine takes that film width. The shrink film guide covers all of this.

Check your electrical service

Small hand sealers plug into a standard 110 to 120 V outlet. The semi-automatic sealers we checked need their own circuit. Depending on model, that is 115 V at 15 to 20 A or 220 V at 10 to 15 A. Tunnels and larger combos often need 220 V. Larger tunnels often run on 220 V three-phase. Some are offered in single-phase or 480 V, so order the voltage your plant supplies.

Have an electrician check the whole installation against each machine’s circuit needs. Don’t assume separate machines can share a circuit just because their ratings add up. A fixed-resistance heater on 208 V instead of 240 V gives about 75% of its rated heat (208² ÷ 240²). Chromalox rates one heater 4 kW at 240 V and 3 kW at 208 V. So have your supply voltage checked and give it to the supplier. That heater math doesn’t show that a complete 240 V machine is approved to run on 208 V. Some automatic machines also need a little compressed air, such as 1 CFM at 80 psi for the Conflex E-250A. Get the requirements in writing and have an electrician check your panel before you order.

Plan the floor space

Measure the space for the sealer, tunnel, and conveyors in a line. Add room for the operator, film roll changes, and service access on both sides. Check doorway widths and the route from the loading dock. If the line connects to other equipment, note the conveyor heights at the infeed and outfeed. Ask the supplier for a layout drawing.

Ask about support

Get these answers in writing:

• What is included: sealer, tunnel, conveyors, options, manuals, starter film, and spare parts.
• Part numbers and prices for PTFE tape, seal pads, and the wire or knife.
• Warranty length and what it excludes.
• Who installs and trains, and whether that costs extra.
• How service works: phone support, response time, and travel charges.

Test before you accept

Packaging machine builders split acceptance into two tests. Douglas Machine builds automatic packaging machines. It describes a factory acceptance test (FAT) as a run at the maker’s plant before the machine ships. A site acceptance test (SAT) is run after installation, with your utilities, your line, and your operators. Douglas says both should ideally be in the contract before you sign the purchase order. Ask each supplier what acceptance testing they offer for your machine.

What to run, from Douglas’s FAT list:

• Your actual products and your film, not the maker’s test samples. Douglas says material differences can have “a significant impact on machine performance.”
• Your target rate, checked against the speed in the contract.
• A changeover for every product size in the contract.
• A check of guards and emergency stops. Also review the manuals, spare parts lists, and wiring diagrams.

Over a timed run, record the number of good packages and each reject and its cause. Also record the settings used and how long each changeover took. Douglas says a FAT should end with signed-off documents and a dated punch list of open items. It should also end with a shared definition of what “acceptance” means. Write that definition into the purchase order. Name the products, the film, the rate, how long the run lasts, and what counts as a good package.

The checklist below collects all of this in one place. To compare quotes, build an installed-cost comparison.