Philippe, based on your experience, what advice would you give to customers regarding the everyday handling of adhesives for packaging to ensure the best quality and safety of packaging?
Reducing risks and preventing problems from the beginning – in my opinion, this is the best and most convenient way to ensure product safety and quality for packaging. A proactive machine maintenance routine is central to this. Choosing the right equipment and hotmelt is an important lever as well.
What is part of such proactive maintenance routine? Is there anything you can do to increase the safety of operations and of the product packaging that does not imply a costly preparation or the use of additional resources?
Yes there is, absolutely. In my experience, every line manager can take five measures with an immediate positive effect:
Measure number one: Proactive maintenance starts by ensuring that the hotmelt is always stored in closed containers. This protects the adhesive from contamination, for example by dust, board fibers or water. Even though the contaminating particles are not visible when you look in the sack with adhesives, they must not be ignored; they cause quality issues after the adhesive has been melted in the tank.
Measure number two: In case the tank is filled manually, always use a clean metal or plastic scoop. Spilled adhesive should never be put back into the containers or tanks – this would mean a risk of contamination.
Measure number three: For improved bonding, keep the tank topped up a little and refill it regularly. This helps to minimize variations in tank and adhesive temperature and improves bonding. Also ensure that the hotmelt tank is not overfilled.
Measure number four: Use the stand-by mode, if you know the line is not scheduled to run for a period greater than four hours. This helps to prevent degradation and ensures the melting unit is available when needed. In case of a stoppage greater than 72 hours, it is best to turn the melter off.
And finally: Control the coat weight and the positioning of the adhesive beads; this will help to eliminate the build-up of adhesive in the machine. It also ensures that the excess of adhesive is not being applied to the packaging material.
If you follow these simple rules, you will need to clean and maintain your machines less often. You will also prolong the life of your machine parts. Although you can’t avoid cleaning completely, you can minimize it considerably this way.
Let us have a closer look on the cleaning itself. What is your advice on this matter?
When talking about cleaning cycles, we have to distinguish between the melter and the surface of the machine.
Melter cleaning is necessary when you change the adhesive; this can have a severe impact on the performance of the new adhesive technology running in the system. Melter cleaning should also be part of the annual service of the system.
When it comes to the machine surface, as a minimum, cleaning should be part of the weekly maintenance. I would strongly advise the removal of all sort of adhesive build-up on the guiderails, compression plates or bars.
In a nutshell: A clean machine is the cornerstone of a safe product. Clean machines are the result of proactive maintenance, cleaning or a combination of both. Ensuring this offers great rewards for a relatively small, low-cost effort.
What are further advantages of regular and thorough cleaning? Is there anything beyond product safety?
Definitely: Proper cleaning minimizes machine downtime. If you clean your machines properly, you will spend less time cleaning overall.
Improved packaging quality is a further argument. Thorough cleaning avoids build-up on the nozzle, leading to adhesive beads that are cleaner and more precise. This increases the quality of the finished packaging, as it avoids bonding failures, for example.
Longer machine life is another result of good cleaning – it reduces the need for costly spare parts or new equipment.
Let’s shift the topic from measures to means: What about operator safety with cleaners? Common knowledge says cleaners might be harmful for human health, especially if exposed to them regularly over a long period of time. What can be done to minimize health risks?
First and foremost: Workers should use gloves, protective goggles, proper work wear and follow the rules of handling as given by the manufacturer of the machine and the adhesive.
Normally, tank cleaning agents are not harmful at room temperature. However, they are applied at temperatures over 100°C, which means you should avoid direct skin contact to prevent skin burns.
Surface cleaners vary when it comes to health risks. Users should check the information in the CLP section of the label.