A brief analysis of bottle cap mold designprocess secrets all know.

2018-05-14 People Reading

Now with the development of economy in our country, the use of high precision plastic mould and the number increasing, and the user requirements for the use of plastic mold is becoming more and more high, in this paper, the mold design of plastic bottle cap, shows the process method and the common quality problems, and puts forward some more reasonable solution, in order to improve the efficiency of the use of plastic bottle cap mould, improve the overall quality of the plastic bottle cap.


Lack of material


Generally in the process of plastic processing, because of the mold cavity filled with dissatisfaction, resulting in the appearance of the parts and the design of the phenomenon called lack of materials.


(1) equipment method


There are many technological factors that lead to the shortage of plastic parts. The most important reason is that the filling pressure is small, the injection time is short and the mold temperature is low. Filling pressure hour, the injection molding machine in the injection molding, can cause the pressure of the cavity, the plastic is difficult to fill the entire cavity, resulting in the missing parts; Short injection time can also cause plastic not fully filling the cavity, resulting in the missing parts. Low mold temperature will accelerate the solidification of plastic and reduce liquid liquidity. It will also cause plastic to be unable to fill the entire cavity, resulting in lack of material.


(2) equipment reasons


The main reason for the equipment shortage is the nozzle part, which is usually blocked by the nozzle. The general method is to clean the nozzle. Nozzle leakage can also lead to lack of material, such failure generally needs to replace the nozzle.


(3) mould reason


Generally caused by mold inside the exhaust not unobstructed, due to the accumulation of air in cavity can't discharge, will cause the plastic filling quantity is not enough, which leads to lack of material, the measures is to reduce plastic filling speed or increase the vent on the mould.


Due to hot runner block or plastic melt due to unbalanced flow material flow is not smooth, cause the lack of material, general measures is to improve the lack of material products corresponding to the temperature of hot water the flow path, and use the delicate and clean raw material.


flash


Generally, it occurs in the parting position of the mold, such as the parting surface of the mould, the coordination position of the sliding block, the side gap of the insert, and the pore of the putter. When the overflow problem is not solved in time, it will be expanded. The spillage of insert side gap and putter hole will cause the plastic parts to be stuck on the mold, which will affect the parting.


(1) process method


Generally due to the injection molding machine injection pressure too much or the speed of the injection molding. Due to the high pressure in the mold cavity, the tension of the mould increases the phenomenon of overflow. The general solution is to extend the injection molding time and time.


(2) equipment


The machine itself is not enough. Mould can't normal compaction, which generally when choosing injection molding machine model, the calibration of the machine rated generally must be greater than the injection mould clamping force von berg systeme axial cross-sectional area formed by tension when injection, otherwise will cause demoulding, form a flash. When the injection molding machine is not properly adjusted, it will result in the flanging phenomenon due to the insufficient parallelism of the mold itself.


(3) mould reason


Generally, due to the unreasonable design of the mold, this problem is difficult to solve, and the mold needs to be redesigned.


shrink


Plastic shrinkage is mainly due to the contraction of the volume, the surface material of the wall thickness is pulled in, and after cooling, there is a dent in the finished surface. Shrinkage is the surface of the finished product of the most adverse phenomena, mostly dry wall thickness.


(1) process method


Injection molding machine injection molding speed and pressure maintaining time is less, make plastic illiquid, first into the mold cavity plastic cooling fast, not enough pressure maintaining time for feeding, general solution measures is to use a higher injection pressure.


(2) mould reason


Plastic bottle cap mould inside the exhaust not unobstructed, can also lead to cavity with excess air cannot be ruled out, also takes less feeding of plastic, parts of shrinkage is larger, the general measures for the mold maintenance and increase the vent.