L-bar sealer vs. side sealer

An L-bar sealer is limited by its bar length. A side sealer has no bar limit, and continuous models run faster. Compare sizes, speeds, utilities, and cost.

Updated October 2, 2026

The short answer

• L-bar sealer: one L-shaped bar seals the side and the trailing end in one stroke. The package can’t be longer than the bar. Automatic models are rated up to about 35 to 60 packs per minute and list from about $30,000.
• Side sealer: wheels, belts, or a hot knife seal the side continuously while the product moves, and a cross seal cuts packages apart. No seal bar limits length, but each model lists a minimum length. Rated speeds run from about 35 to 200 packs per minute. New prices we found start around $49,000.

Move to a side sealer when products are longer than the bar or you run many lengths. Also move when you need more speed than an automatic L-bar gives. Conflex calls the side sealer “the next step up in production from the automatic L bar sealer”.

How each one seals

Both start with centerfold film, which closes one side of the package with its fold.

L-bar sealer. The product sits inside the folded film. One stroke of the L-shaped bar seals the open side and the trailing end. That end seal also closes the leading edge of the next package. Conflex describes it as “an ‘L’ shaped sealing system to fully envelope the product in film”. See how an L-bar sealer works.

Side sealer. The machine seals the open side as the product travels, forming a continuous tube of film. Conflex: it places “a seal along the ‘side’ of the package enclosing the product into a tube of shrink film. The tube of film is then sealed into individual packages using sensors and the cross seal.” Manufacturers use different side seal methods:

• Wheel. The TL-INT-20 uses a side sealing wheel.
• Belt. The Conflex AdvantEDGE uses a “Micro-V belt side sealer.”
• Hot knife. The Clamco 6800CS uses a “seal and trim knife.”

Side-by-side comparison

Speeds are manufacturer ratings for ideal conditions. Prices were seen on sellers’ sites September 29 and October 1, 2026, in US dollars, without tunnel, freight, or installation. Sources are in the sections below and in the cost guide.

On film, Conflex side sealers use “a center-folded roll of shrink film and an inverting head”. The SMIPack HS500E side sealer takes “centerfolded or flat film with film folder”. The Conflex E-250A L-bar lists a film centerfolder option. Conflex says both types produce “a waste tail of shrink film which is wound up.”

Package size limits

An L-bar sealer is limited by its seal area in both length and width. It is also limited by product height. A side sealer is limited by width, height, and a minimum length.

The bag must be larger than the product, so the largest package that fits is smaller than the seal bar. Clamco notes the 6750EL’s “seal area is dependent on overall product size.” Send samples of your largest and smallest products to the supplier.

Intermittent vs. continuous motion side sealers

Intermittent motion. The product stops while the cross seal closes, then moves on. Texwrap rates its intermittent ISS at “film and conveyor speeds of 100 feet per minute.” The TL-INT-20 is rated at over 35 products per minute.

Continuous motion. The cross seal travels with the product, so the product never stops. Some machines use a traveling seal bar and others use rotating seal heads. The Clamco 6800CS-HS uses a servo-driven “continuous box motion cross seal bar” rated up to 120 cycles per minute. Conflex rates its AdvantEDGE Rotary at up to 200 packages per minute and credits “the rotary seal head.” Conflex says continuous machines “will typically run faster as your product will never stop during the sealing process.”

Footprint and utilities

Sizes overlap. The larger side sealers are longer than automatic L-bars. Some side sealers need three-phase power. Others run on single-phase like an L-bar.

Add the shrink tunnel after either machine. Check your building’s electrical service before you buy. See electrical service.

Cost

The two new side sealer listings below cost more than the automatic L-bar listings we sampled. This small sample doesn’t show that every side sealer costs more.

• New, intermittent: US Packaging & Wrapping TL-INT-20 $48,828. Maripak IMPACK Pro 20 $63,980 on sale, rated at 60 cycles per minute.
• New, automatic L-bar for comparison: $30,091 to $46,280. See L-bar sealer prices.
• Used side sealers: a Shanklin HS-1 asked $12,500 and a Conflex FUSION asked $8,500, both on eBay with best offer. See buying used before you bid.

Prices are in US dollars, seen October 1, 2026 unless noted, without tunnel, freight, or installation.

When to choose a side sealer

Choose a side sealer when one of these is true:

1. Products are longer than an L-bar’s seal area. Long items such as molding or poster tubes don’t fit an L-bar’s seal area. PAC Machinery says the 6800CS-HS “eliminates the constraints of a fixed-length side seal.”
2. You run many product lengths. Conflex says a side sealer is “more flexible… when a user has several different sizes of products.”
3. You need more speed than an automatic L-bar gives. The automatic L-bar examples in this guide include ratings up to 60 packs per minute. That is not a speed limit for every L-bar on the market. Intermittent side sealers are rated in the same range, so look at continuous-motion models.

Stay with an L-bar sealer when products fit the seal area or floor space is tight. Also stay when your volume is under what an automatic L-bar can run. A semi-automatic L-bar costs a fraction of either automatic machine.

Where an I-bar sealer fits

An I-bar sealer is a single straight heated bar. The operator seals one side, turns the package, and seals the other. Then the operator shrinks it with a heat gun. One manufacturer’s I-bar manual lists seal lengths of 14 to 36 in. Uline rates its I-bar kits at 1 to 2 packages per minute.

An I-bar suits occasional, low-volume wrapping. An L-bar sealer makes the same package in one stroke. See I-bar sealer kits and shrink wrap machines for home and small business.

For conveyor-fed L-bar choices, see the three L-bar automation levels.