When considering plastic tube sealing for your products, there are different types of sealing options you can look at. What you choose will very much depend on the nature of your product and type of plastic tubing material you are using.
MSD plastic tube filling machinery come with a choice of hot-air sealing, ultrasonic sealing, impulse sealing or hot-jaw sealing processes. When making your decision you need to be careful to match the type of tube you are using with the correct tube sealing equipment to ensure a complete, safe seal that remains strong and durable throughout the life and use of the product.
Depending on your choice of plastic tube material, it will behave in a certain way that lends itself to a particular type of sealing process. For example, the type of plastic seal that works well for a polyethylene tube with a mono layer will not work quite so well for a different tube type with a multi-layer structure.
Two of the most popular plastic tube sealing methods currently in use today are: hot air plastic tube sealers and ultrasonic plastic tube sealers.
Probably the most common choice for plastic tube sealing is using hot air tube sealing machinery. How the process works is that the machine generates hot air that is passed into the open end of the plastic tube. The walls of the plastic tube are heated up enough by the hot air to allow the plastic to become soft and more pliable. Once the plastic tube material is soft enough, a set of sealing jaws are then triggered to grip the end of the tube and weld the open end closed by being clamped tightly together, leaving a strong well-bonded seal.
One of the primary appeals about hot air plastic tube sealing is the fact that the process is so fast. This means that production speeds are not slowed down by the sealing process so that productivity remains high.
Another good reason why hot air plastic sealing is such a popular choice is because it works very well with a whole range of different plastic and laminate tube types. Hot air plastic tube sealing machinery works very well with LDPE, MDPE, HDPE, and PP materials, plus it works with Mono layer or multi-layer with or without EVOH barrier protection without issue.
In truth, there are not too many disadvantages with choosing hot air plastic tube sealing as long as you are using a suitable type of plastic material for your tubes. The only slight technical hitch found with this method of sealing is the need for specific hot air nozzles that are sized to fit each diameter tube that needs to be filled and sealed. There will be a cost to factor in with the need to change parts for the tube sealing run.
Ultrasonic tube sealing is also a popular choice for plastic tube sealing. Ultrasonic tube sealers are more suited for small volume runs, but are a great alternative where hot air sealing isn’t possible.
Plastic tube sealing is done through the use of the high frequency vibration of an ultrasonic sealing horn. The vibrating process generates enough heat within the tube wall to soften the material. The open tube end is then clamped closed under pressure from the sealing horn and anvil – a combination that leaves a very strong seal.
This choice of plastic tube sealing is easy to use and has the added advantage of not needing any custom-made parts to operate. The only disadvantage would be that it is a slower process than a hot air solution, at around five tubes per minute.