If this bond fragile can be judged from the following four aspects: 1, to observe the analysis of bonding surfaces if found mainly in a surface of the glue on the glue surface, this phenomenon did not penetrate into another surface, the opening time is too short. This glue phenomenon can be improved by coating glue or glue temperature increase sometimes, these two methods need to be used at the same time; if the adherends surfaces too cool may also need to preheat the adherend. 2, if observed two surface are indicated in the glue, curing time is disturbed or curing hot melt adhesive is too slow, then the need to replace the hot melt adhesive curing faster 3, on the surface of the treated adherend, such as film, on the surface, the permeability is not good. The glue can be improved by the use of temperature increase; glue; speed up the two surface of the adhesive; the most fundamental is to choose and cover Film, hot melt type glazing material good affinity. 4, surface treating agent corresponding to the first treatment. If through the analysis of these four methods is still not ideal. At this time, you need to consider is the adherends surfaces have no change, if there is damage that is off the surface strength of the adherend is too low. If no damage surface is required to consider changing adhesive use.