What happened to the bottle embryo in the injection molding machine?
Technological aspects(1) the injection pressure is too high or the injection speed is too fast. Because of the high pressure and high speed, the opening force of the mold increases, causing the overflow. According to the thickness of the product to adjust the injection speed and injection time, the thin products should be filled with high speed, no longer into the note; thick products should be used at low speed mold filling, and let the epidermis in the final pressure before reaching the general fixed.(2) excessive feed, resulting in flying edge. It is worth noting that not to prevent the depression and to inject too many molten material, so that the depression may not be "filling", while the "flying edge" will appear. This is done by extending the injection time or holding time.(3) the temperature of the cylinder, nozzle is too high, or the mold temperature is too high, will reduce the viscosity of plastic, liquidity increased, in the case of smooth die, resulting in flying edge.
Mold aspects(1) the accuracy of parting surface is poor. The movable plate (such as the middle plate) is deformed and warped; foreign parts are stuck on the parting surface or the projecting edge of the die frame is provided with a sharp skid; the old mold is fatigued and collapsed due to the extrusion of the front wing.(2) the die design is unreasonable. The opened position of the mold cavity and deviation, will make the injection mold has unilateral tension, caused by flash; plastic flow is good, such as polyethylene, polypropylene, nylon and so on in the molten state, the viscosity is low, easy to enter the activity or fixed gap, high precision mold manufacturing requirements; in the next should as far as possible placed in the center on the premise of not affecting the product quality of symmetric integrity, WIP thick parts into the material, can prevent side Queliao side with flash; when forming holes or near the central product, used in hole arranged on the side gate, the injection pressure is large, if this part of the support insufficient clamping force force mode is not a slight warping caused by flash, such as mold side with movable member, the side of the projection area is also affected by the molding pressure, if the bearing capacity is not enough Will cause flash; the sliding core with poor accuracy or fixed core and cavity mounting position offset caused flash; cavity venting, in parting surface without exhaust groove or vent groove is too light or too deep or too large by obstruction will cause the edge to fly; the mold cavity should pay attention to the rational design of the diversion Gate Road, otherwise it will cause the filling uneven stress caused flash
Raw material(1) plastic viscosity is too high or too low, may appear flying edge. The low viscosity of plastics such as nylon, polyethylene, polypropylene, it should improve the clamping force; plastic absorbent plastic or water sensitive will greatly reduce the flow viscosity at high temperature, increase the possibility of flash, the plastic must be completely dry; adding plastic viscosity of renewable materials too much too fall, when necessary to add stranded components. Plastic viscosity is too high, the flow resistance increases, resulting in large back pressure, so that the cavity pressure increases, resulting in lack of clamping force and resulting in flying edge.(2) when the size of the plastic raw material is uneven, the quantity of the feeding material can be changed, and the part or the dissatisfied part or the edge of the fly can not be changed.
(1) the actual clamping force of the machine is insufficient. When choosing an injection molding machine, the rated clamping force of the machine must be higher than the tension formed by the longitudinal projection area of the injection molding product, otherwise it will cause bulging and flying edges.(2) the clamping device for regulating the poor, not straight or toggle mechanism, or the upper and lower mold is not balanced, mould parallelism cannot reach a phenomenon caused by unilateral side mold is screwed tightly while the other side does not close the case, when the injection will appear flash.(3) the mold itself is of poor parallelism, or it is not parallel, or the template is not parallel, or the tie rod is uneven distribution of force and uneven deformation, these will cause the mold is not close, resulting in flying edge.(4) stopping ring wear; nozzle spring spring failure; barrel screw or excessive wear; inlet cooling system caused by the failure of "bridge" phenomenon; the feeding amount of the barrel setting lack of buffer is too small and so may cause flash appears repeatedly, must be timely repair or replacement of parts.
