Jug Mould

　　
In the production of die casting, the mold often encounters the defense methods of the pouring system, the overflow system, the runner, the inner gate, and the overflow groove.

　　
1. Pouring system, overflow system

① The diameter of the pressure chamber should be selected according to the required specific pressure and the fullness of the pressure chamber. At the same time, the deviation of the inner diameter of the sprue sleeve should be appropriately enlarged by a few more than the deviation of the pressure chamber diameter, so as to avoid The internal diameter is different from the axis, causing the punch to jam or wear serious problems, and the wall thickness of the crate mould sleeve should not be too thin. The length of the sprue sleeve should generally be less than the ejection lead of the injection punch, so that the paint can escape from the pressure chamber.

② The inner hole of the pressure chamber and the sprue sleeve should be finely ground after heat treatment, and then ground along the axis. The surface roughness is less than or equal to Ra0.2μm.

③ The diverter and the cavity forming the paint have a recessed depth equal to the depth of the runner, and its diameter matches the inner diameter of the sprue sleeve, with a 5° slope along the demolding direction. When a coating-introduction sprue is used, the fullness of the pressure chamber can be increased because the effective length of the pressure chamber is shortened.

　　
2. Requirements for the mold runner

① The entrance of the runner for cold horizontal molds should generally be located at a position above 2/3 of the inner diameter of the upper part of the pressure chamber to prevent the molten metal in the pressure chamber from entering the runner prematurely under the action of gravity and starting to solidify in advance.

② The cross-sectional area of ??the runner should be gradually reduced from the sprue to the inner gate. In order to expand the cross-section, negative pressure will appear when the molten metal flows through, which can easily inhale gas on the parting surface and increase the flow of molten metal. The vortex in the air. Generally, the cross section at the exit is 10-30% smaller than that at the entrance.

③ The runner should have a certain length and depth. The purpose of maintaining a certain length is to stabilize the flow and guide. If the depth is not enough, the molten metal will cool down quickly, and if the depth is too deep, the condensation will be too slow, which will affect the productivity and increase the amount of recycled material.

④ The cross-sectional area of ??the runner should be greater than the cross-sectional area of ??the inner gate to ensure the speed of the molten metal. The cross-sectional area of ??the main runner should be larger than the cross-sectional area of ??each branch runner.

⑤ The two sides of the bottom of the runner should be rounded to avoid early cracks. The two sides can be inclined at about 5°. The surface roughness of the runner part is less than or equal to Ra0.4μm.

　　
3. Inner gate

① The parting surface should not be closed immediately after molten metal is injected into the mold, and the overflow groove and exhaust groove should not impact the core directly. After the molten metal enters the mold, the flow direction is as far as possible along the cast ribs and fins, and fills from the thick wall to the thin wall.

② When selecting the position of the inner gate, make the molten metal flow as short as possible. When using multiple internal gates, it is necessary to prevent several molten metal from converging and impacting each other after entering the mold, resulting in defects such as vortex entrapment and oxidation inclusion.

③ The thickness of the inner gate of the thin-walled parts should be appropriately smaller to ensure the necessary filling speed, and the setting of the inner gate should be easy to cut, and the casting body should not be damaged (eat meat).

　　
4. Overflow tank

① The overflow groove should be easy to remove from the casting, and try not to damage the casting body.

② When opening an exhaust groove on the overflow groove, pay attention to the position of the overflow port to avoid premature blockage of the exhaust groove and make the exhaust groove inoperative.

③ There should not be several overflow openings or a very wide and thick overflow opening on the same overflow groove, so as to prevent the cold liquid, slag, gas, paint, etc. in the molten metal from returning to the cavity from the overflow groove , Resulting in casting defects.

Flower pot mould

The mold steel materials processed by the mold parts have high hardness, which requires the mold processing equipment to have thermal stability and high reliability.

For complex cavities and multi-functional composite molds, as the shape of the part becomes more complex, the design and manufacturing level of the mold must be improved. Multiple grooves and multiple materials are formed in a set of molds or assembled into a multi-functional composite of components The mold requires a large amount of processing programming, a high-deep cavity comprehensive cutting ability and high stability, which increases the processing difficulty.
 
The machining quality of mold parts includes machining accuracy and surface quality: machining accuracy is the degree of conformity between the three geometric parameters of the actual size, shape, and position of the surface of the processed part with the ideal geometric parameters required by the drawing; the deviation of the actual geometric parameters of the part from the ideal geometric parameters The value is called machining error.
Machining accuracy and machining error are both terms to evaluate the geometric parameters of the machined surface. Machining accuracy is measured by tolerance grade, the smaller the grade value, the higher its accuracy; the processing error is expressed by a numerical value, the larger the value, the greater the error. High machining accuracy means small machining error, and vice versa; the actual parameters obtained by any machining method will not be absolutely accurate. From the perspective of the function of the part, as long as the machining error is within the tolerance range required by the part drawing, the machining is considered guaranteed Accuracy.

The quality of the machine depends on the machining quality of the parts and the assembly quality of the machine. The machining quality of the parts includes the machining accuracy and the surface quality. The machining accuracy refers to the actual geometric parameters (size, shape and position) and the ideal geometry after the machining The degree to which the parameters match. The difference between them is called machining error. The size of the machining error reflects the level of machining accuracy. The greater the error, the lower the machining accuracy, and the smaller the error, the higher the machining accuracy; the main aspects that affect the machining accuracy: dimensional accuracy, the degree of conformity between the actual size of the processed part and the center of the tolerance zone of the part size.

The injection cycle time is as short as possible under the premise

The injection cycle time is as short as possible under the premise of ensuring product quality. The shorter the injection cycle time, the more the production quantity, the lower the manufacturing cost per unit product. Injection cycle time includes: injection time, holding pressure time, cooling time (melting time), mold opening time, ejection time (including dwell time), door opening time, pickup time, door closing time, and mold clamping time (special The situation also includes the forward/backward time of the shooting stage and the time of spraying release agent).

The most important methods to shorten the injection cycle time are: reduce the wall thickness of the plastic part/runner size (to shorten the cooling time), reduce the opening and closing distance/thimble stroke, quickly take out the product, manipulator operation, and accelerate the speed of opening/closing the safety door , Reduce the phenomenon of plastic parts sticking to the mold, correctly choose the cooling time, reasonably set the opening/closing speed and the ejector speed/number of times.


"Scrap is the biggest waste." If there is a high defect rate, a large amount of scrap or a return phenomenon in the injection molding production process, the loss of raw materials, electricity, labor, and equipment (excluding other costs) will be very high. Big.

If mold maintenance is not done in place, mold failures will often occur during the production process, and frequent production stops will be required for maintenance. This will affect the smooth production and the stability of the quality of rubber parts, and will cause economic losses to the enterprise (such as mold repairs) Costs, plastic materials/power consumption, labor costs, loss of machine shutdown, etc.)

Plastic mold processing is basically divided into static mold and movable mold. The one with sprue sleeve on the side of the injection head processed by the plastic injection mold is a static mold. The static mold generally consists of a sprue sleeve, a backing plate, and a template. A simple mold can also use a thicker template instead of a backing plate. Up. Plastic mold processing sprue sleeves are generally standard parts, and it is not recommended to cancel unless there are special reasons. The use of sprue sleeves for plastic mold processing is conducive to mold installation and easy replacement, without self-polishing. Plastic mold processing Some special mold sprue sleeves can be drilled out or cut by taper line cutting. When part of the mold must be demolded from the static mold, the static mold release mechanism must be added. The structure of the movable mold for plastic mold processing is generally a movable template, a movable mold backing plate, a demolding mechanism, and a mold foot and a fixed plate for the installation.

In addition to the stripping rod, there is also a return rod in the demolding mechanism. In the injection molding part of the plastic shell, a spring must be added to realize functions such as automatic demolding. The basic structure of the mold is also indispensable for plastic shell injection processing, as well as guide posts, cooling water holes, and runners. Of course, the inclined guide mold also has inclined guide boxes, inclined guide posts, etc. When designing a mold for a product, the plastic shell injection molding process must first set the basic structural dimensions of the mold to prepare materials to speed up the mold manufacturing. Plastic shell injection molding complex products should first draw the product picture, and then determine the size of the mold.

The gate is directly related to the beauty of the plastic part. If the gate design is not good, defects are likely to occur. It is easy to produce snake-like flow when the plastic shell is sprayed without any obstruction. Plastic shell spraying should also be designed for overflow and exhaust for products with high requirements. The ejector pin can be used at the overflow, and there should be no overflow flash on the template, so as not to affect the life of the mold. There are also more and more software for plastic shell spraying design molds, and most of them rarely use pencils to draw mold drawings.

Plastic mold processing is basically divided into static mold

Plastic mold processing is basically divided into static mold and movable mold. The one with sprue sleeve on the side of the injection head processed by the plastic injection mold is a static mold. The static mold generally consists of a sprue sleeve, a backing plate, and a template. A simple mold can also use a thicker template instead of a backing plate. Up. Plastic mold processing sprue sleeves are generally standard parts, and it is not recommended to cancel unless there are special reasons. The use of sprue sleeves for plastic mold processing is conducive to mold installation and easy replacement, without self-polishing. Plastic mold processing Some special mold sprue sleeves can be drilled out or cut by taper line cutting. When part of the mold must be demolded from the static mold, the static mold release mechanism must be added. The structure of the movable mold for plastic mold processing is generally a movable template, a movable mold backing plate, a demolding mechanism, and a mold foot and a fixed plate for the installation.

In addition to the stripping rod, there is also a return rod in the demolding mechanism. In the injection molding part of the plastic shell, a spring must be added to realize functions such as automatic demolding. The basic structure of the mold is also indispensable for plastic shell injection processing, as well as guide posts, cooling water holes, and runners. Of course, the inclined guide mold also has inclined guide boxes, inclined guide posts, etc. When designing a mold for a product, the plastic shell injection molding process must first set the basic structural dimensions of the mold to prepare materials to speed up the mold manufacturing. Plastic shell injection molding complex products should first draw the product picture, and then determine the size of the mold.

The gate is directly related to the beauty of the plastic part. If the gate design is not good, defects are likely to occur. It is easy to produce snake-like flow when the plastic shell is sprayed without any obstruction. Plastic shell spraying should also be designed for overflow and exhaust for products with high requirements. The ejector pin can be used at the overflow, and there should be no overflow flash on the template, so as not to affect the life of the mold. There are also more and more software for plastic shell spraying design molds, and most of them rarely use pencils to draw mold drawings.

crate mould

Plastic injection molding is one of the most common methods for mass production of plastic products. Examples include chairs, disposable tableware, crates, toys, consumer electronics housings, Lego blocks, etc.

The injection molding machine consists of three main parts-injection unit, plastic injection mold and fixture. The barrel heats the plastic particles. These molten plastics will move forward in the barrel through the screw system. Once completely melted, it will be "injected" into the mold cavity and formed. It will cool and harden to form a plastic part.

Injection molding automates the mass production process. One injection may result in the production of many parts, depending on your mold design. There are many types of molds that can further increase the productivity of a single injection of molten plastic, such as laminated molds, tandem molds, and multiple cavitation molds.

When we choose mass production, we will definitely support predictability, efficiency and less troubleshooting. Plastic injection molding is undoubtedly an established manufacturing method. High-precision engineering plastic materials can be bought on the market to advanced injection molding machines to meet different manufacturing requirements.

Mass production using injection molds is very useful for achieving higher efficiency. Once the design is designed for a specific purpose according to the customer's choice, the molding process will not take long. This makes it more effective in mass production and also more effective in terms of yield.

It has enhanced strength.

It is very common to use additives such as glass fibers in plastic materials. These highly engineered composite plastic materials have the durability of their raw materials. And, there are thousands of different types of materials on the market to meet different needs.

Most importantly, the density of the plastic when it is just molded makes it stronger. There is a great need for durable parts in the market, and plastic injection molding provides you with a lot of flexibility that other molding processes cannot provide.