When processing Copper Nut Injection Nut Embedded Parts, how can we prevent the copper nut from deformation or displacement by optimizing the process parameters?
Release Time : 2025-04-28
In copper nut injection nut embedded parts processing, the deformation or displacement of copper nuts will seriously affect the product quality. Reasonable optimization of process parameters is the key to solving this problem. The following describes methods to prevent copper nuts from deformation or displacement from multiple process parameter perspectives.
The temperature during the injection molding process directly affects the fluidity of the plastic and the stability of the copper nut. If the barrel temperature is too high, the viscosity of the plastic melt will decrease and the fluidity will increase, but too high a temperature will cause the plastic to generate a large impact force when filling the mold, which may cause the copper nut to shift; at the same time, high temperature may also cause the copper nut to soften and deform due to heat conduction. If the barrel temperature is too low, the plastic melt has poor fluidity, making it difficult to evenly fill the mold, and it is easy to generate a large extrusion force, which will also cause the copper nut to shift. Therefore, it is necessary to accurately set the temperature of each section of the barrel according to the characteristics of the plastic material. Usually, the preliminary temperature range can be obtained through the trial mold, and then fine-tuned and optimized in combination with the material and size of the copper nut. For example, for polycarbonate (PC) materials, the temperature of the front section of the barrel can be controlled at 280-300℃, 270-290℃ in the middle section, and 250-270℃ in the rear section to ensure that the plastic fills the mold smoothly with appropriate fluidity and reduce the impact on the copper nut.
If the injection pressure is too high, the plastic melt is injected into the mold cavity at a high speed, and the strong impact force can easily cause the copper nut to shift; if the pressure is too low, the plastic cannot fully fill the mold, resulting in insufficient product size or material shortage, affecting the bonding strength between the copper nut and the plastic, and indirectly causing the copper nut to be unstable. In actual processing, the injection pressure should be set in stages according to the mold structure, plastic melt characteristics and product size. Generally speaking, in the early stage of injection molding, a low pressure can be used for slow filling to initially position the copper nut; as the plastic melt gradually fills the mold cavity, the pressure is appropriately increased to maintain the pressure to ensure the quality of product molding. For example, for small copper nut injection nut embedded parts processing, the injection pressure can be set to 60-80MPa and the holding pressure to 40-60MPa. Through reasonable changes in pressure, the copper nut can be prevented from being displaced due to excessive impact while ensuring good plastic filling.
If the injection speed is too fast, the plastic melt will flow turbulently in the mold cavity, which will generate a large turbulent force and easily push the copper nut to shift; if the speed is too slow, the plastic melt may cool down in advance during the filling process, resulting in insufficient filling and affecting product quality. The optimization of injection speed requires comprehensive consideration of mold structure, gate size and plastic properties. For thin-walled molds or complex structure molds, segmented injection speed can be used. In the early stage of filling, the speed is smoothly pushed forward at a lower speed to prevent the copper nut from shifting; in the later stage of filling, the speed is appropriately increased to ensure that the plastic quickly fills the cavity. For example, when filling thin-wall copper nut injection nut embedded parts processing, the initial injection speed can be set to 30-50mm/s. When the cavity is filled to about 80%, the speed is increased to 60-80mm/s. Through precise speed control, the uniform filling of plastic and the stable fixation of copper nut can be achieved.
If the holding time is too short, the plastic is not fully compacted in the mold cavity, and the product shrinks greatly after cooling, which will cause gaps around the copper nut and cause it to shift; if the holding time is too long, it will increase the production cycle, reduce production efficiency, and may also cause the copper nut to deform due to long-term pressure. Cooling time is also critical. If the cooling time is insufficient, the plastic is not completely solidified and is easy to deform during demolding, affecting the fixation of the copper nut; if the cooling time is too long, it will also extend the production cycle. Reasonable holding time and cooling time need to be determined through experiments. Generally, the holding time can be set to 10-20s, and the cooling time can be adjusted between 20-40s according to the product wall thickness and plastic material. For example, for copper nut injection nut embedded parts processing with a wall thickness of 2mm, the holding time is 15s and the cooling time is 30s, which can fully solidify the plastic and ensure the stable position of the copper nut.
The mold temperature has an important influence on the cooling speed and molding quality of the plastic. If the mold temperature is too high, the plastic cools slowly, and it is easy to shrink and deform during the cooling process, causing the copper nut to shift; if the mold temperature is too low, the plastic cools too quickly, the fluidity becomes poor, and defects such as weld marks may occur, affecting the product strength and the fixing effect of the copper nut. To ensure the stability of the mold temperature, a thermostat can be used to heat or cool the mold to control the mold temperature within a suitable range. For example, for ABS plastic, the mold temperature can be controlled at 40-60℃, so that the plastic cools slowly and evenly in the mold, ensuring that the copper nut is tightly combined with the plastic and does not shift.
Pre-treating the copper nut and optimizing the positioning method before injection molding can effectively prevent its deformation or shift. Roughening the surface of the copper nut, such as sandblasting and knurling, can increase the friction between the copper nut and the plastic and improve the bonding strength; designing precise positioning structures in the mold, such as positioning pins and slots, can ensure that the copper nut remains in a fixed position during the injection molding process. In addition, the copper nut can be embedded by applying appropriate pre-tightening force to keep it in a stable state before injection molding, reducing the possibility of displacement during the injection molding process.
During the copper nut injection nut embedded parts processing, a real-time monitoring system is established to monitor and adjust the process parameters in real time. The injection molding pressure, temperature, speed and other parameters are collected in real time by sensors and compared with the preset values. Once an abnormality is found, the process parameters are adjusted in time. At the same time, the molds and equipment are regularly inspected and maintained to ensure their accuracy and stability, avoid fluctuations in process parameters due to mold wear or equipment failure, and effectively prevent the copper nut from deforming or shifting during processing.