Dongguan Jieyang Machinery Co., LtdDongguan Jieyang Machinery Co., Ltd


Basic knowledge of injection molding machinery

201 Published by Sabrina wang Aug 15,2020

1. The problem of cracking after screen printing on the spherical surface.  Due to the stress on the product surface, cracking after screen printing. Increase the mold temperature and reduce the stress; annealing can be used to eliminate the stress.
2. Glasses frame, the nozzle edge is easy to break.  The injection pressure and holding pressure are large, and the residual internal stress on the nozzle side causes the product to break easily. Reduce the injection pressure and holding pressure as much as possible, and appropriately increase the mold temperature to solve it.  
3. Electrical enclosure, four assembly pillars, bursting problem when screwing.  Because the pillars have water lines, the product assembly pillars are easy to burst. Increase the exhaust of the mold, appropriately increase the mold temperature, and accelerate the injection speed to reduce the water trapping Line. 
4. Product deformation problems.  Product deformation is mainly caused by unbalanced heat shrinkage, or product deformation due to the internal stress of the product itself. 
5. The bubble problem of transparent PC case. Insufficient drying of the raw materials; uneven glue thickness in the product, poor mold exhaust, and easy decomposition of the raw materials may cause product bubbles.  Fully dry the raw materials, increase the mold exhaust, and minimize the uneven thickness of the glue. 
6. Copiers, the problem of magnetic materials. High mold temperature and fast injection method should be used. 
7. Product encapsulation, shrinkage of nozzle. Poor mold venting, slow injection speed, insufficient holding pressure and time, can all cause nozzle shrinkage.  Increase mold exhaust, appropriately increase injection speed, increase holding pressure and time.  
8. The internal stress of the product causes the product to burst after being placed for a period of time. Due to the residual stress in the product, the product bursts due to the stress after being placed for a period of time.  Increase the mold temperature during beer molding and reduce the injection pressure to eliminate the product stress. The product can be annealed to eliminate the stress. 
9. When black color masterbatch is used for ABS material, the product is easy to break and peel. It is the reason that too much toner is used in the color masterbatch pigment, which causes the product to peel. Replace the masterbatch pigment.  
10. A 180 ton 14 oz machine, the product comes out of four CD boxes totaling 120 grams, the appearance is good, there is no peak, but one of them weighs 2 grams, why? The mold products are out of four. Due to the imbalance of the mold injection, one of the products is full of plastic, dense, and weighs 2 grams.  
11. A 100-ton hydraulic toggle press has been used for three years. After the mold is locked, it often fails to open. It is due to the abrasion of the elbow of the machine, which causes the mold opening to be unbalanced, so after the mold is locked, it will often fail to open.  12. A 7 oz machine has been used for two years, and the glue injection is unstable. Lack of glue, change the oil seal and glue head, the system pressure is also stable, it will not work. Due to the abrasion or damage of the screw, the return material is uneven, so there will be instability in the injection. 
13. A 150-ton new machine beer PP nozzle material for half a year, the fastest melting time was 3 seconds, but now it takes 6 seconds. Due to the wear of the screw, the material return is slow. 
14. When a master is debugging a product, there is a lack of glue, the speed or pressure rises a little, the product does not respond, and if it rises a little, the batch will be peaked? The clamping mechanism of the machine is worn out, causing a gap in the clamping, so there will be a flare. 
15. One machine has been used for two years, and the temperature in the middle of the barrel is too high during beer, so it is useless when the power is turned off. As the screw becomes rough due to wear and tear, heat is generated by friction during the plastic feeding, which makes the temperature of the barrel high.  There are more than a dozen new and old machines in a factory, and the oil seal often leaks. Excessive oil temperature makes the oil seal easy to age and damage, and oil leakage; the cylinder core is worn, causing the oil seal to be scratched and leaking.