Adhesive Knowledge

What's the reason on hot melt adhesive for color shading

If you often use hot melt glue, you will find one problem,in fact,it is not a real problem,the color grading is allways with you for one same model,same formula.Why?

The problem maybe:

1) The color grading of materials.
2) The temperature of machine is not homothermal
3) The cold water of groove is even.
...
So,even for one same item with same formula, sometimes lead to color grading ,but don't worry about it,the performance will not been impacted,you can use it as normally.