If you know some basic crafting skills, then you should be familiar with hand-held hot glue guns. A hot melt machine operates on the same principles, but made on an industrial scale, and it’s increasing in popularity in the adhesive market every year.
The hot melt machine became mainstream in the packaging industry in the 1960s and is now a standard piece of equipment. It is used for carton closing, sealing and pallet stabilization.
Because of its ease of use, functionality and ability to handle different types of adhesives, it's perfect for bonding all types of materials. It not only has a high heat and humidity resistance, but it can also tolerate temperatures as low as 40 degrees Celsius.
Tankless hot melt systems
As packers are always looking for new ways to reduce waste and increase production, manufacturers continue to develop innovative new designs for hot melt systems. Tankless hot melts, like the Graco hot melt systems, are now taking over industrial applications. Considering their advantages, it's easy to see why.
Traditional tank-based systems have several drawbacks, due to the way the adhesive is handled and heated. These include:
Messy manual filling — when operators must add adhesive from boxes or bags to the melter tank, the results are often messy.
Danger of adhesive running out — because they must be continually refilled, there is always the issue of a device running out and halting production.
Overfilling by operator — to cut back on filling time, operators sometimes fill tanks to capacity, even if it means leaving the lid off to accommodate more adhesive. This increases the risk of the system becoming contaminated by airborne materials, which can cause clogging and damage the system. Overfilling can also result in broken tank lids, usually at the start of a shift when an operator attempts to open a tank and finds it glued shut.
Thermal shock during refilling — when adding a significant amount of new adhesive to the tank, it can dramatically lower the temperature. The melter must melt this new adhesive and bring it to the optimum temperature before use. Sometimes, when adding adhesive at a high temperature while it is going through a cycle, it may cause it not to bond with the rest, leading to product waste and rejects.
The need for a bigger tank — some manufacturers, just to avoid having to fill a tank frequently, will buy a larger model than required. An oversized tank increases the amount of adhesive at a given temperature, which can result in thermal degradation and excessive power consumption. Instead, the choice of machine should be based on speed, volume and the melt rate needed.
A tankless system solves these problems by reducing operator interaction because it automatically adds small amounts of adhesive as needed. This melt-on-demand system only melts what is required when it is needed. This decreases adhesive degradation from temperature variations and ensures that contamination by airborne materials won’t occur.
Choosing the best tankless hot melt system
When considering your options for a tankless hot melt system, Graco dispensing equipment like the Graco InvisiPac is a great option. Every hot melt system will have the essential features of separate storage containers from the heating elements, hoses, specialized glue guns and nozzles.
To find what makes each one different, look at their components more closely.
Storage size
Depending on your production needs, make sure the storage tank has enough capacity to suit the job.
Vacuum feed
The solid-state melt is routed through a vacuum tube from the storage tank to the melt chamber. Ensure the system has vacuum delivery and is made from quality materials
Melt chamber
The melt chamber is designed to melt only when needed, reducing char build up and downtime that is due to maintenance. How fast it can melt adhesive for use will make a big difference in production. Higher-grade models are made from higher-quality materials which cut down heating time and make it safer to operate.
Pump
Once heated, the adhesive is moved to the glue gun using a pump. The quality of the materials in a pump can make a difference to the flow rate and lifespan of a device. For instance, the Graco InvisiPac system is made from durable components that are heat resistant, with a built-in filter to prevent clogging.
Hose
The hose also plays a part in transferring the adhesive from the melt chamber to the glue gun. The hose should be well-insulated for safety and efficiency. Poor quality hoses can cause hot spots which lead to char.
Glue gun
InvisiPac demonstrates its strengths with a new free-flow design that prevents clogging. Ensure you have the right nozzle. Graco nozzle sizes come in sizes ranging from .008 to .024, giving you a more extensive choice than competing models.
Extra features like a touchscreen, downloadable data tracking, adhesive consumption tracking and power management can all enhance the operator’s experience.