Each adhesive has specific properties. Even if hot melt adhesives look the same, that doesn't mean they have the same chemical structure.

2 reasons why mixing is not recommended

1. Clogging of hoses and hot melt glue guns

Suppose you change from a hot melt adhesive that is used at 150-170°C to one that is used at 130-150°C. What happens if you mix new hot melt glue into the old glue in the glue tank?

First of all, because the temperature in the melt tank is too high, the newly added hot melt adhesive will carbonize.

Secondly, when hot melt adhesive is heated above its use temperature, the viscosity will decrease - the glue will become very thin. Thin hot melt glue will flow out faster because it flows better, while thicker old glue will stay in the melt tank and cause carbonization.

Carbonized hot melt adhesive will not be noticed immediately, but once molding begins, it will adhere to any location in the glue spray system, causing serious consequences. Hot melt hoses and glue guns may become clogged.

2. Cause poor bonding effect

If the temperature setting is wrong and the viscosity is too high, the hot melt adhesive will be too viscous and too little of the hot melt adhesive will be sprayed. Conversely, if the viscosity is too low, it will be too thin and too much hot melt adhesive will be sprayed. And due to different opening times, too long or too short time for hot melt glue to set may also lead to poor bonding.

Therefore, never mix different hot melt glues!

Mixing two or more different hot melt adhesives

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Carbonization, clogging (difficult to clean)

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Increased downtime (impacts production)

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In severe cases, the glue gun and hot melt hose need to be replaced.

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Increase production costs