Metal insert plastic over mold for the electronic music instrument. It is a handle for the percussion instrument and exported to USA. Stainless steel insert over molding the engineering nylon plastic material.
Project details as below :
Electronic over mold
Core surface finish:
MT special texture
Stainless steel and Nylon resign
Cavity surface finish:
MT special texture
No of Cavities:
1 x 2 cavities
H13 with heat treatment
Type of gating:
H13 with heat treatment
Lead time for FOT:
Mold base steel:
Mold Price Totally:
1） Metal insert over molding for the electronic music instrument
2) Special custom made Mold tech texture
3) Part weight control and control the central of gravity in order to have good sound
4) Good toughness decorative pattern both of the metal insert and plastic over molded part
Asia Billion is a professional electronic over mold and plastic molding manufacture in Shenzhen south of China, we are ISO 9001 certified and accord to the TS 16949 standard to control our manufacturing process. Around a quarter of our project are over mold, so we are the expert for the over mold and over molding projects. Please contact us freely for you project.
Asia Billion electronic over mold making process:
Asia Billion electronic over mold making Engineering and Project control Capacity:
Mold Workshop Overview:
Advantages of small gates for electronic over molding project introduction:
The gate is a critical section of the gating system. Except for the main channel gate, most gates are the smallest cross-sectional area in the gating system. The value is generally only 3% to 9% of the cross-sectional area of the runner. .
For plastic melts that obey the Newtonian flow law, because of the viscosity independent of the shear rate, a large gate cross-sectional area can reduce the flow resistance and increase the melt flow rate, which is advantageous for both filling and forming quality.
For most plastic melts that do not obey the Newtonian flow law, it is often possible to increase the melt shear rate by reducing the cross-sectional area of the gate. The shear heat will cause the appearance of the melt. A significant drop in viscosity may be more favorable for filling the mold than a large cross-section gate.
As for the pressure drop caused by increasing the flow resistance when molding with a small gate, it can be compensated by a method of increasing the injection pressure within a certain range.
In general, when using a small gate for electronic plastic injection over molding project, it has the following advantages.
1. There is a large pressure difference between the front and rear ends of the small gate, which can effectively increase the shear rate of the melt and generate a large shear heat, which leads to a decrease in the apparent viscosity of the melt and an increase in fluidity. Conducive to filling the mold.
This feature of small gates is for thin-walled articles or products with fine patterns and plastics that are sensitive to shear rate, such as polyethylene (PE), polypropylene (PP), polystyrene (PS), etc. Both have great benefits.
2. During the injection molding process, the pressure-holding and shrinking stage generally continues until the melt at the gate is frozen, otherwise the melt in the cavity will flow back outside the cavity.
If the gate size is large, the pressure-holding time will continue for a long time, so it is possible to increase the degree of orientation and flow deformation of the macromolecule, causing a large shrinkage in the product, especially near the gate. Stress causes the product to eventually warp.
If a small gate is used, it is possible to adjust the volume of the small gate by trial or repair, so that the melt at the gate is frozen during the pressure keeping process, thereby properly controlling the feeding time and avoiding the above phenomenon.
3. Due to the small volume of the small gate and fast freezing, when the certain products are produced, it is not necessary to completely cure the inside of the product after the small gate is frozen. As long as the external solidified layer has sufficient strength and rigidity, the product can be demolded. Thereby shortening the molding cycle and improving production efficiency.
4. If a small gate is used in a multi-cavity non-equilibrium casting system, the flow resistance of the gate to the plastic melt will be much greater than the flow resistance of the multi-melt of the split runner, so it is possible to After filling the flow path and establishing sufficient pressure, each cavity can be filled at approximately the same time.
Therefore, the small gate can balance the feed rate of each cavity in the multi-cavity cavity, which is beneficial to the balance of the pouring system.
5. If a larger gate is used to shape the product, in the case of high surface quality requirements, it is often necessary to post-process the product with appropriate tools or machine tools to remove the gate scar, especially when the gate is too large. The grout must also be removed by sawing, cutting, etc. However, this can be avoided by using a small gate.
For example, small gate aggregates can be quickly removed by hand or automatically removed using a special mold structure during demolding. In addition, the scar after the small gate is small, generally does not require or only need a slight finishing work.
to sum up
Therefore, the use of a small gate not only facilitates the detachment of the gluing system from the article, but also facilitates the trimming of the article.
It should be noted, however, that although small gates have all of the above advantages, too small gates can cause large flow resistance, resulting in prolonged feed filling time. Therefore, it is not advisable to use small gate molding for certain plastic melts (such as polyformats and polysulfones) whose high viscosity or shear rate has little effect on apparent viscosity.
In addition, when molding large products, attention should also be paid to magnifying the cross-sectional area of the gate. Sometimes it is even necessary to enlarge the height of the gate section to the maximum thickness of the product to improve the fluidity of the melt.
In addition to the above, for a product having a large wall thickness and a large shrinkage ratio, a sufficient feeding time is generally required, so in this case, the gate cross-sectional area cannot be designed too small.