are you still trying to find a expert partner for your two shot injection molding project ? here is the right place and click here for more details. Asia Billion have the capacity for two shot injection molding , bi-injection over molding and insert injection molding capacity for all difference size from small one to big size. this project is for our Germany customer , it is used for some electrical inspection equipment, the material is PC/ABS with TPU over molding. bright design and very smart for different usage. Asia Billion just make the mold and then export to our customer side for mass production.
two shot injection molding
Core surface finish:
PC/ABS + TPU
Cavity surface finish:
No of Cavities:
Type of gating:
Pin point gate and sub gate
Lead time for T1
Mold base steel:
Place of Origin
1. 2+2 cavities two shot plastic injection molding project
2. UV resistance , V0 grade flammability and Good toughness
3. competitive mold cost comparing customers local supplier to save at least 40%
4. High requirement for appearance features
5. Difficult flash control for TPU over moulding
Asia Billion advantages in this project:
help customer optimize the design by DFM ( design for manufacturing & design for money ) to help them save the invest
fast lead time , high quality and competitive price
local customer service when we transfer the mold to customer side within 3 years guarantee
Asia Billion injection mould tooling plant:
Asia Billion tooling Certifications and Quality Control:
How to control the flash and burr problem in the two-color plastic injection molding ?
The reason is that there are too many types of burrs, and the influencing factors are even more square. See the four elements of injection molding: mold, machine, plastic materials, molding parameters, and then expand these four elements. Then there are at least dozens of factors that affect the burr. As long as they are sorted out and sorted out one by one, it is not difficult to solve them. Follow Asia Billion today to discuss the issue of batching in injection molding!
1. How to judge the glitch caused by the mold problem ?
First, remove the pressure of the machine, and adjust the V/P switching position to make a short shot. Because the cavity pressure is the smallest when shooting short shots, if there is a burr in any local position of the short shot, emphasize the local part. The problem of the mold needs to be confirmed by the mold. Depending on the burr of the broken surface, confirm whether the mold core has collapsed angle and sag, whether there is any damage to the corner when polishing or drying, whether the mold core is deformed, whether the template is deformed, whether the slider is retracted, and whether the mold is retracted. If it is not fit, the insert is loose or not in place. For burrs in the thimble or the inserted position, it is necessary to confirm whether the gap is too large due to wear. The burrs caused by the mold problem are more intuitive, and the problem is immediately repaired.
2. How to judge the glitch caused by the machine problem ?
For short shots or shrinkage samples, if the entire parting surface is burred, in addition to checking the mold, the machine should also be inspected. Manually open and close the mold, first observe the pressure gauge, confirm whether the mold thickness adjustment meets the requirements of the clamping force, if not, re-adjust the mold thickness. In addition, in the process of adjusting the machine, if the mold temperature has a large change in the lift, it is necessary to re-confirm the clamping force, because the thermal expansion and contraction of the mold or the change of the mold thickness, but only for the crankshaft type Taiwan, direct pressure machine will not have this problem.
If the mold thickness is adjusted, there are burrs on the parting surface, and it is necessary to re-approve whether the machine tonnage is too small and the clamping force is insufficient. One method for calculating the clamping force required for mold theory is to refer to the data of the mold flow analysis; the other method is to use the empirical formula to follow up the projected area calculation of the vertical mold opening direction of the product.
If there is no problem with the clamping force, the burr of the parting surface may be caused by the unbalance of the machine. In this case, the burrs will be fixedly distributed on the same side of the machine, and the machine needs to be repaired and corrected.
3. How to analyze and solve the glitch caused by improper setting of molding parameters?
The five elements of the molding parameters (temperature, pressure, time, speed, metering) almost always lead to the occurrence of burrs, sometimes caused by one factor, sometimes caused by multiple factors. It seems complicated. In fact, all the burrs caused by the setting of the molding parameters can be attributed to the pressure. When the injection pressure exceeds the clamping force set by the machine or the local bearing strength, the burr will be produced.
(1) The V/P switching is too late.
Generally, when the glue is just running through the entire structure of the product, it is ideal to switch the pressure. The switching is late, the cavity pressure rises sharply, and the pressure is excessive, it is prone to burrs, and even the product is deformed, and the size is too large. , sticking mold, top injury and other issues.
(2) The injection speed is too fast.
The glue injection process is the same as the unlocking mode of the machine. The speed setting generally follows the principle of “slow-fast-slow”, especially the tipping speed of the end, and the excessive speed impact, so that the pressure of the cavity quickly reaches the peak. If the mold gap is too large or the clamping force is insufficient, burrs will appear.
(3) The holding pressure is too high or the holding pressure is too fast.
Excessive holding pressure or too fast holding speed will quickly squeeze the plastic into the cavity during the pressure holding process, resulting in a sudden rise in the cavity pressure, excessive pressure, and burrs around the gate or even the entire analysis surface. More serious will lead to expansion. When the product structure allows, set a small pressure (less than 10%) and a short holding time in the first stage of pressure holding (products with a thickness of 1.5mm or more can be set for about 0.5 seconds) for buffering. The transition of V/P switching can play a very good role in preventing burrs. The setting of the holding pressure generally follows a principle: the position of the plastic melt in the cavity is low first, and the position is high after the temperature is high. The position with low temperature is generally distributed in the last stage of filling, the position with thinner thickness and the parting surface. Therefore, the holding pressure of the front part should not be set too high. Try to use the holding pressure in the back part to solve the local shrinkage problem. Or size issues. When adjusting the machine, the pressure setting is gradually increased from low to high. It is recommended to increase the cycle by 5%-10% until a reasonable pressure value is found.
4. Glitch caused by excessive temperature of plastic melt
When the temperature of the plastic melt is too high, the viscosity will gradually decrease, the fluidity will become better, the clamping force required per unit area will increase, and if the local gap of the mold is too large or the clamping force is insufficient, burrs will appear. . The cause of the actual temperature rise of the plastic melt is also multi-faceted. The temperature of the material tube is set too high, the molten rubber is too large, the screw is too thick, the cycle is too long, the back pressure is too large, and the rotation speed is too fast, which will lead to plastic. An increase in temperature or a direct decrease in viscosity. When the product has burrs, these parameters should be checked in time.
5. Glitch caused by plastic properties
PA, PP, POM, these crystalline plastics, their characteristics determine their super high fluidity, the requirements for mold gap and machine clamping force are much higher than the general non-crystalline plastic, to prevent burrs, in Open mold evaluation, machine and mold should be fully considered, control the mold gap; when the machine tonnage selection, also to make a preliminary estimate, or according to the mold flow analysis of the clamping force value for reference.
Asia Billion will add two more points for your reference:
(1) In the preliminary evaluation of mold opening, fully evaluate the distribution of gates, and make qualified products with the lowest injection pressure as much as possible; combined with the characteristics of plastic materials, fully evaluate the structure and strength of various parts of the mold, and properly control Good mold clearance, prevention of burrs in advance in the mold opening stage, it will be easier to repair after the mold is opened.
(2) In the production process, the burrs caused by any cause need to be solved in time. It is a small matter to waste manpower to process, causing more damage to the mold, and then repairing and repairing, which will only cause a vicious circle.
Asia Billion is an expertize two shot injection molding company and toolmaker. each year we made more than 100 sets 2k, 3k, bi-injection over molding and insert over molding tools. our main mold maker had worked with us when we start the company , so our quality , lead time and customer service is very good and stable.If you have any over moulding project, please give me you 2d .3d drawings, mold specifications and some other what you want, we will give our best price and solutions for you.