Causes and countermeasures of glue leakage in injection molding machine production

During the production of the injection molding machine, when the product is produced due to leakage of glue due to some reasons, the heating ring is wrapped by molten glue. With the extension of the production time, the heating ring is damaged, and the hidden danger of poor quality of the product is produced. The serious leakage of glue covers the entire barrel; This causes a great waste of cost and maintenance time;
Glue leakage during production 1
During production, the nozzle (also called nozzle head) and the gate sleeve of the mold shall be concentric, and the two spherical surfaces shall be closely matched, otherwise glue leakage will occur. Generally, the radius of the two spherical surfaces is required to be the same, but the spherical diameter of the nozzle is slightly smaller than the gate sleeve 0.5~1mm, and the coaxiality tolerance of the two shall be guaranteed to be less than 0.25~0.3.
The following is an analysis of several causes of glue leakage:
Glue leakage during production 2
1. The mold has no locating ring or the locating ring does not match the forming machine. When installing the mold, the mold glue inlet hole and the gun barrel nozzle are not on the coaxiality, and there is a little deviation in the position. Every the first mock examination is produced during production, there is a little glue leakage. Compared with the same parts of the product, there is no obvious change, but as the production time lengthens, the glue leakage will accumulate more and more, and finally the glue leakage will slowly wrap the heating ring;
Mold locating ring 3
2. The fixing screw of the nozzle turret is loose, so that the nozzle of the barrel and the mold gate are not on the same axis. When the nozzle is against the mold gate during production, there is a little deviation in the position. Every the first mock examination is produced during production, there is a little glue leakage. Compared with the same products, there is no obvious change, but with the increase of production time, the glue leakage will be more and more accumulated, and finally the glue leakage will slowly wrap the heating ring;
Fixed upper and lower left and right screws 4 of nozzle turret
3. The mold gate sleeve is damaged. During production, the nozzle and the mold gate sleeve can not fit closely together. Each time the glue is injected, a small amount of molten glue will flow out of the mold. With the extension of production time, the glue leakage will become more and more tired. Finally, the glue leakage will slowly wrap the heating ring;
Mold sprue sleeve 5
4. The nozzle mouth is damaged. During production, the nozzle mouth and the mold sprue sleeve can not fit closely together. Each time the glue is injected, a small amount of molten glue will flow out of the mold. With the extension of production time, the glue leakage will become more and more tired, and finally the glue leakage will slowly wrap the heating ring;
Nozzle 6
5. The R angle of the mold gate sleeve and the nozzle does not match. During production, there will be a gap between the nozzle mouth and the mold gate sleeve at the close joint. Each time the glue is injected, a small amount of molten glue will flow out of the mold. As the production time increases, the glue leakage will become more and more tired
For the above leakage, the following countermeasures are proposed:
1. It is suggested that all molds should be equipped with locating rings. Although the absence of locating rings will save its cost, the absence of locating rings will not only lead to the potential of glue leakage, but also prolong the time of changing the mold. The cost of damaging the heating ring caused by one glue leakage can save the investment of locating rings;
2. Timely check the reasons for the loosening of the fastening screws of the fort and tighten them; Corresponding confirmation method: before production, hold the gun barrel firing table and move forward. When touching the mold, feel whether the nozzle is on the same coaxiality with the mold gate sleeve, or use thin paper to pad at the mold rubber mouth. After the nozzle touches the mold, exit to see whether the paper hole is consistent with the nozzle hole;
3. Due to the damage of the mold gate sleeve and nozzle mouth, the temporary countermeasures are as follows: cushion the mold gate sleeve with soft metal, such as copper sheet, the nozzle forward meets the copper sheet, and then back off. After drilling at the nozzle mouth, place the copper sheet on the mold rubber mouth sleeve again according to the last holding position, and use the nozzle to hold the production; Permanent countermeasures: the corresponding sprue sleeve or nozzle shall be polished again to make the R angle of the sprue sleeve and the nozzle on the turret flat contact production;
4. If the rubber leakage is caused by the mismatch of the R angle of the gate sleeve or nozzle, replace the gate sleeve or nozzle to keep the R angle of the gate sleeve and nozzle consistent;