Why does flash occur during the injection molding process

With the development of society and technology, the application range of metal insert injection products has become more and more extensive, and the demand is increasing. There are often some problems in the injection molding process of metal inserts. The author has already introduced why the injection molded product lacks glue and its treatment methods. This article describes why flash defects occur in product processing. Flashing, also known as flashing, overflowing, draping, etc., mostly occurs at the opening and closing positions of the mold. If the flashing is not resolved in time, it will be further enlarged, resulting in partial collapse of the imprinting mold, causing damage. The flash of the insert gap and the ejector pin hole will also cause the product to be stuck on the mold and affect the demolding. 1. Equipment (1) The real clamping force of the machine is insufficient. (2) The mold clamping device is not well adjusted, the toggle mechanism is not straight, and the left and right or up and down molds are not balanced, and the mold parallelism cannot be achieved. (3) The mold itself is poorly parallel or is not installed in parallel. Or the template is not parallel, or the tension rod is unevenly distributed and deformed (4) The check ring is worn seriously; the spring nozzle spring is invalid; the barrel or screw is worn too much; the inlet cooling system fails to cause 'bridging' phenomenon ; The set injection volume of the barrel is insufficient, the cushion is too small, etc., and it needs to be repaired or replaced in time. Second, the mold (1) The accuracy of the mold parting surface is poor. (2) The mold design is unreasonable. 3. Process (1) The injection pressure is too high or the injection speed is too fast. The injection speed and injection time should be adjusted according to the thickness of the product. (2) Excessive feeding volume causes flash. This situation should be resolved by extending the injection time or holding time. (3) Too high temperature of the barrel and nozzle or too high mold temperature will reduce the viscosity of the plastic, increase the fluidity, and cause flash when the mold enters the mold smoothly. 4. In terms of raw materials (1) If the plastic viscosity is too high or too low, flash may appear. (2) When the size of the plastic raw materials is not uniform, the feeding amount will change, the parts may be dissatisfied, or flash. [Related recommendation] Learn more: 精の corporate culture Learn more: Continuous improvement and innovation are the key factors for the survival of stamping companies Learn more: Why most stamping factories are unwilling to quote foreign trade companies