Plastic mold design and manufacturing personnel should carefully carry out mold design according to the above basis and requirements provided by customers. During mold design, the above contents should be specified one by one and expressed in the form of drawings and technical documents. Then let's learn about the detailed operation of the general procedures for plastic mold design and manufacturing!

1, plastic mold design and manufacturing diagram and actual analysis and digestion

 

In the plastic mold design and manufacturing, first of all, the product map or the actual detailed analysis and digestion, its content includes

 

1) product geometry

 

2) Product dimensions, tolerances and design standards;

 

3) Product technical requirements (technical conditions);

 

4) The name and variety of the plastic used in the product;

 

5) Product surface requirements.

 

2. Determination of injection machine model

 

The determination of the specifications of the injection machine mainly depends on the size of the plastic products and the production batch. When selecting the injection machine, the designer mainly considers the plasticization rate, injection volume, clamping force, installation mold production area (distance between the rods of the injection machine), volume rate, extrusion form and extrusion length. If the customer provides the model or specification of the injection machine that has been used, the designer should compare its parameters, and if it is too scared to meet the requirements, it should be replaced with the customer.

 

3. Determination of the number of cavities and cavity arrangement

 

The determination of the number of cavities mainly depends on the projected area of the product, the geometric shape (with or without side cores), and the accuracy of the product. It is then determined by economic efficiency. The number of cavities is mainly determined based on the following factors:

 

1) Product weight and injection volume of injection machine

 

2) Product projection area and injection machine locking force

 

3) The external dimensions of the mold and the effective area of the injection machine mounting bracket mold (the distance between the rods of the injection machine)

 

4) Product accuracy

 

5) Product color

 

6) Whether the product has side core and its treatment method

 

7) Product production batch (monthly batch or annual batch).

 

8) Economic benefits; (output per type)

 

Some of these factors in the design and manufacture of plastic molds are mutually restricted. When determining the design plan, it is necessary to coordinate to meet its main conditions. After determining the number of cavities, place the cavity, that is, place the cavity position. The cavity arrangement involves the mold size, the design of the gating system, the balance of the gating system, the design of the core slider mechanism, the design of the plug-in and the core, and the design of the heat exchange system. These problems also involve the selection of the parting surface and the gate position. Necessary adjustments need to be made in the specific design process to achieve a relatively complete design.

 

4. Determination of parting surface

 

Some foreign product maps also specify the parting surface, but many mold designs are determined by mold designers. In general, the separation surface on one plane is easy to handle, so special care may be required when touching the separation surface of the three-dimensional portion. The choice of its parting surface should follow the following principles;

 

1) For products that do not affect the appearance of the product, especially for products that have clear requirements on the appearance, attention should be paid to the effect of typing on the appearance.

 

2) Helps to ensure product accuracy

 

3) is conducive to mold processing

 

4) Conducive to the design of gating system, exhaust system and cooling system

 

5) It is beneficial to demolding the product, keeping the cut product, and leaving the product on the movable mold side when opening the mold;

 

6) Easy installation of metal plug

 

5. Determination of side parting and core pulling mechanism

 

When designing the side separation mechanism, please ensure safety and reliability, and try to avoid interference with the ejection mechanism. Otherwise, set the reflow mechanism in the mold.

 

6, Design of Gating System

 

The design of the gating system includes the selection of the main runner, the determination of the cross-sectional shape and size of the runner, the selection of the gate position, the determination of the gate form and the cross-sectional size of the gate. When using a point gate, in order to ensure that the shunt falls off, the gate discharge device must first pay attention to the selection of the gate position when designing the gating system. The selection of the gate position is directly related to the quality of the product and the smooth injection process. Gate location selection please follow the following principles

 

1) the gate position should be selected as far as possible on the parting surface, in order to facilitate the mold processing and use of the gate cleaning;

 

2) The distance between the gate position and each part of the cavity is as consistent as possible to make the flow shorter.

 

3) When the gate position is when the plastic flows into the cavity, it should be ensured that it is opposite to the wider and wall-thick part of the cavity to facilitate the injection of the plastic

 

4) When flowing into the cavity, avoid direct collision of plastic with the cavity wall, core and plug-in. In this way, the plastic can quickly flow into the various parts of the cavity, preventing the core and insert deformation.

 

5) Avoid weld lines in the product and avoid weld lines in unimportant parts of the product;

 

6) Gate position and plastic inflow direction, when the plastic flows into the cavity, it should flow evenly along the parallel direction of the cavity, which is conducive to the discharge of gas in the cavity;

 

7) The gate should be set at the part where the sealing is easy to remove, and try not to affect the appearance of the product.

 

The above is the plastic mold design and manufacture of the general procedures for detailed operation, if you need to know more, you can contact us at any time!