L bar sealers are designed to be used with centerfold shrink film sealing two open ends of material at once. With continued use, L-bar sealers will encounter problems and require maintenance and replacement parts. The type of sealing blade, the material used, and the material's thickness can impact the need for replacement parts.

For maintenance, the two most crucial elements are replacing the Teflon tape and cleaning the sealing area after use. The tape is the first line of defense to protect other parts and the sealing element. If black sealing residue is noticeable on the sealing blade or tape, cleaning with a damp cloth when the machine is unplugged is highly recommended. These simple steps can extend the life of sealing components and delay the need for part replacement. 

Eventually, parts will need to be replaced due to wear and tear. We suggest referencing the manufacturer’s machine user manual before replacing any parts. For the machines offered at U.S. Packaging & Wrapping, we have an L bar sealer troubleshooting guide. The following parts are standard, replaceable components in the L-bar sealers we offer. Some manufacturers may refer to the parts differently, or machines can have different components than those listed below.

WEARABLE PARTS

Fuses – Fuses keep excessive current from damaging the machine. Incoming power can surge from time to time, causing issues throughout the machine if it is strong enough. Fuses help protect the machine and can fail if a power surge occurs.

Teflon Tape - Provides a solid heat-proof surface for the micro knife to make contact to complete a seal. Teflon tape is typically placed on top of a sponge pad opposite the sealing element.

Seal Pad - The seal pad provides a surface for the micro knife to make contact. Commonly made from silicone, the seal pad provides cushion and ensures a complete seal is made. Over time, a groove can wear into the seal pad, preventing ideal seals.

Transit Channel – Sealers with a micro knife or sealing blade often have a transit channel to hold the sealing blade in place. Over time, the groove in the channel can wear out, causing the blade to slip out of place.

Micro knife/Sealing Blade – The micro knife is heated once the sealer is engaged. The L-shaped seal encloses products within shrink film before shrinking down. It sits inside the transit channel.

Corner Block – The corner block is located at the bend of the L in the sealer and features a groove for the sealing blade to fit into. With enough use, issues may arise with the corner block requiring replacement.

NON-WEARABLE PARTS

The manufacturer’s warranty often covers non-wearable parts. They are meant to last longer than wearable parts. Over time, they may need to be replaced due to wear and tear. If the parts require replacement before the warranty period, contact the company from which you purchased your machine to discuss warranty considerations.

Below are some non-wearable replacement parts.

Teflon Belt – The Teflon belt transports the product after the seal cycle is complete. With enough usage, they can wear out and need to be replaced.

Compensator Block – Located on each side of the sealing blade, compensators hold the seal in place. One side will have electrical wires to heat the sealing blade when engaged. This block can be broken or lose tension over time.

Contactors – Engage and disengage when the sealer is at the beginning of the seal cycle and when the machine is turned on. When these quit working, the sealer will not engage or stay engaged for too long. If this happens, discontinue the use of the machine until the part is replaced.

Power Switch – The switch is used for turning the machine on and off. It commonly needs to be replaced due to the operator bumping or knocking into the knob.

Sealing Timer – When the sealing bar is lowered, the seal timer measures the time it takes for the seal to be completed, and the bar disengages. If the seal timer fails, the seal will either not engage at all or remain engaged, potentially overheating the sealing area.

Micro Switch – When the sealing bar is initially lowered, the microswitch engages the sealing timer, initiating the seal cycle. Over time, the microswitch can wear out, preventing the seal timer from engaging.

The longevity of your L bar sealer can depend mainly on the quality of spare parts and the habit of replacing them at regular intervals. Costly downtime can be avoided, and you can lower maintenance costs by maintaining fresh parts.

It is essential to maintain a good supply of compatible parts in case of a breakdown, which could lead to production delays.

You can rely on U.S. Packaging & Wrapping when purchasing machines and parts. We can also help troubleshoot your machine.

Visit our website at uspackagingandwrapping.com or contact us at 1-800-441-5090.