What Are the Common Issues with Bag Making Machines? How to Maintain a New Machine Properly?

Running a new bag making machine can be frustrating. Small problems like bad seals or uneven bags can stop your whole production line. I will show you these common issues.

The most common issues for beginners are inconsistent bag length, weak or burnt seals¹, and film jamming or wrinkling². These are almost always caused by incorrect machine settings for temperature, speed, or film tension, which are easy to fix.

These problems are very common, so don't worry. The key is to understand how the machine's main parts work together. The film feeding system, the sealing bar, and the cutting knife must be perfectly synchronized. At BagMec®, we design our machines to be user-friendly. Our "Smart Tension Control" system, for example, helps automate one of the trickiest parts. But you still need to know the basics. A small adjustment can make a huge difference in your bag quality and production speed. Let's break down each problem so you can solve it quickly.

When you see these issues, you can trace them back to a few core areas. For inconsistent bag length³, the film feed roller might be slipping, or the length setting in the PLC is wrong. For poor seals, the problem is usually temperature. If it's too hot, the film burns. If it's too cold, it won’t stick together. Film jamming often happens when the film path is not straight or the tension is either too loose or too tight. Mastering these three areas will solve most of your initial challenges.

What to Do When Something Goes Wrong? Basic Troubleshooting and Emergency Fixes

Your machine suddenly stops. The first step is not to panic. A few simple checks can often get your production running again. Here is what to do.

When your machine stops, first press the emergency stop button for safety. Then, do a quick visual check for obvious problems like film tears or material running out. Next, look at the error code on the PLC HMI screen for specific guidance.

The First Response: Safety and a Quick Scan

Safety is always number one. Hitting the emergency stop button cuts power to the motors. This prevents any further damage to the machine and protects the operator. All our BagMec® machines are built to strict CE compliance standards, with easily accessible E-stop buttons.

Once the machine is safely stopped, walk around it. Look for the most common culprits:

• Is the film roll empty? It sounds simple, but it happens.
• Is there a tear or jam in the film path? Look at the rollers, the dancer arms, and the area around the sealing bar.
• Is there a pile-up of bags at the collection table? A full stacker can trigger a sensor to stop the machine.

This initial visual check solves a surprising number of problems without needing to open the control panel.

Using Your Machine's Brain: The PLC Interface

If the problem isn't obvious, your machine’s control panel is the next place to look. Our machines feature modern PLC touchscreens (HMIs) that provide clear information.

• Error Codes: The screen will usually display an error code or message. This is your best clue. For example, it might say "Sealing Bar Temperature Low" or "Film Feed Motor Fault."
• Manual Reference: Each BagMec® machine comes with a detailed manual. This manual has a full list of every error code and what it means. It also tells you the steps to fix it. Keep this manual near the machine.
• IoT-Ready Systems: Many of our newer models are IoT-enabled. This means we can offer remote diagnostics. With your permission, our engineers can log in to see the error history and help your team troubleshoot in real-time.

A Basic Troubleshooting Checklist

Most issues fall into a few categories. You can use a systematic approach to find the root cause. Here is a table to guide you through common faults and their fixes.

Problem Observed	Potential Cause	Simple Troubleshooting Step
Weak or Incomplete Bag Seals	Sealing temperature is too low.	Check the set temperature on the HMI. Increase it in small 5°C steps.
	Sealing pressure is not enough.	Adjust the pneumatic pressure setting. Make sure the air supply is correct.
	The sealing bar's Teflon tape is worn out.	Turn off the machine and inspect the tape. Replace it if it's burnt or torn.
Bags are Burnt or Melted at Seal	Sealing temperature is too high.	Lower the temperature on the HMI in 5°C steps.
	Dwell time (how long the bar presses) is too long.	Reduce the sealing dwell time setting in the PLC.
Bag Length is Too Long or Too Short	"Bag Length" parameter is set incorrectly.	Double-check the value entered in the PLC settings.
	The film is slipping on the feed roller.	Clean the rubber feed roller. Check the roller's pressure.
	The dancer arm is stuck.	Ensure the dancer arm assembly moves freely without obstruction.
Film Wrinkles Before Sealing	The film roll is not centered on the unwind stand.	Loosen the chucks, re-center the roll, and tighten them again.
	Tension is uneven across the film.	Adjust the unwind tension. Our "Smart Tension Control" helps, but manual tweaks are sometimes needed.

What Initial Maintenance Should Be Done on a New Machine? How to Prevent Early Wear

You just received your new machine. Doing the right things before you start full production will ensure it has a long, productive life. Let's look at the first steps.

On a new machine, first verify all bolts are tight, as they can loosen during shipping. Next, clean all surfaces and apply lubricant to points shown in the manual. Finally, conduct a slow initial test run to check alignment and timing.

The Post-Delivery Inspection is a Must

Your BagMec® machine passed our rigorous 5-stage inspection protocol before it left our factory. This includes a 72-hour continuous operation stress test. However, the journey to your facility can be rough. Vibration during shipping can sometimes loosen components.

Before you even plug it in:

1. Check for Shipping Damage: Inspect the machine for any dents, scratches, or broken parts. Report any damage to the logistics company and us immediately.
2. Tighten Key Bolts: Use a wrench to check the tightness of major structural bolts on the frame, motor mounts, and sealing assembly. Don't overtighten, just ensure they are snug.
3. Verify Electrical Connections: Open the main electrical cabinet and gently check that all terminal connections are secure. Make sure plugs and connectors are fully seated.

The Critical "First Clean and Lube"

Your machine is new, but it may have a light coating of protective oil or have collected dust during transit.

• Cleaning: Use a soft, dry cloth to wipe down all rollers, guides, and surfaces that the film will touch. This prevents any residue from transferring to your product.
• Lubrication: This is the most important step to prevent early wear. Your manual contains a detailed lubrication map and schedule. Before the first run, you must apply the correct lubricant to all specified points. Our high-carbon steel components and precision bearings depend on it.

The "First Run" Protocol: Slow and Steady

Don't start a new machine at full speed. A slow, methodical test run helps you spot any minor issues before they become big problems.

1. Dry Run (No Film): First, turn on the machine and run it at the slowest possible speed without any film. Watch the moving parts. Listen for any unusual sounds. Does the sealing bar move up and down smoothly? Does the cutter activate correctly?
2. Slow Run (With Film): Next, thread the film through the machine. Run it again at a very low speed (e.g., 20 bags per minute). This allows you to check:
   • Film Tracking: Is the film staying centered as it moves through the machine?
   • Sealing and Cutting Alignment: Does the sealing bar come down squarely on the film? Does the knife cut in the right place?

This slow run gives you a chance to make small alignment and timing adjustments. It's much easier to do this at 20 bags per minute than at 200.

Key Maintenance Tips: Lubrication, Cleaning, and Regular Inspection Schedule

Good maintenance is not just for fixing problems. It is a routine that prevents them. A simple, consistent schedule will keep your machine efficient and reliable for years.

A good maintenance plan has three key parts. First, daily cleaning of dust and plastic scraps. Second, weekly lubrication of all moving parts. Third, a monthly inspection of high-wear items like cutting blades, belts, and sealing tape.

Why a Schedule is Better Than a Reaction

Waiting for something to break is expensive. It leads to downtime, wasted material, and missed deadlines. Proactive maintenance is an investment that pays for itself. A well-maintained machine runs faster, produces higher quality bags, and lasts longer. Our machines are built for durability, with features like corrosion-resistant coatings for humid environments. But even the best-built machine needs regular care to perform at its peak.

This structured schedule will help you organize your maintenance tasks.

Tiered Maintenance Schedule: Daily, Weekly, and Monthly Tasks

We recommend breaking down your maintenance into manageable chunks. This ensures that critical tasks are not forgotten.

Daily Tasks (Takes 5-10 Minutes)

These are quick checks you should do at the beginning or end of every shift.

• Clean the machine: Use compressed air and a soft cloth to remove film dust and plastic pieces from around the sensors, rollers, and sealing area. Debris can cause sensor errors and jams.
• Wipe down the sealing bar: A clean bar transfers heat evenly. Use a brass brush or a rough cloth to gently remove any melted plastic residue. Do this when the bar is cool.
• Check the product path: Make sure there are no bags or scraps stuck in the cutting or stacking area.

Weekly Tasks (Takes 30-45 Minutes)

These tasks are a bit more involved but are critical for preventing wear and tear.

• Full Lubrication: Follow the lubrication chart in your manual. Apply grease or oil to all specified bearings, chains, and gears. This is the single most important thing you can do to extend the machine’s life.
• Inspect the Cutting Knife: Check the blade for any nicks or dullness. A sharp blade gives a clean cut and uses less force. Our high-carbon steel blades last a long time, but they still need to be checked.
• Inspect Teflon Tape/Sealing Pad: Look at the Teflon tape on the sealing jaw. If it's brown, peeling, or worn through, replace it. Worn tape leads to poor seals and forces you to use higher temperatures, which wastes energy.

Monthly and Quarterly Checks (Takes 1-2 Hours)

These are deeper inspections to catch problems before they start.

Frequency	Maintenance Task	Reason for Task	Relevant BagMec® Feature
Monthly	Check Drive Belts and Chains	Inspect for proper tension and signs of wear. Loose belts can cause timing issues.	Our machines use tensioning systems that are easy to access and adjust.
Monthly	Inspect Electrical Wiring	Look for any frayed or loose wires, especially around moving parts.	All our machines meet CE safety standards for secure and protected wiring.
Monthly	Test All Safety Features	Activate the emergency stop, light curtains, and safety guards to ensure they are working.	Operator safety is a core part of our design philosophy.
Monthly	Clean Air Filters	Clean or replace the filters on your pneumatic system's air supply. Dirty filters restrict airflow.	A clean air supply is essential for consistent sealing pressure.
Quarterly	Review PLC Diagnostic Logs	Check the machine's error log for recurring faults that may indicate a developing problem.	Our advanced HMIs log all errors with timestamps for easy tracking.
Quarterly	Calibrate Temperature Sensors	Use a calibrated external thermometer to check if the sealing bar's actual temperature matches the HMI display.	Accurate temperature is key for food-grade and medical packaging.
Quarterly	Full Mechanical Inspection	Do a more thorough check of all bolts, frame alignment, and bearings for any signs of long-term wear.	This is a miniature version of the 72-hour stress test we do at our factory.

Conclusion

Mastering your bag making machine is about understanding common problems and being disciplined with maintenance. Following these steps for troubleshooting and creating a regular cleaning and lubrication routine will prevent downtime, improve bag quality, and maximize your machine's long-term performance.

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