Making Molds Well: Key Factors You Can’t Ignore

For a business, competition among businesses is a competition of technology.

The technology used in molding is also crucial for the success of the enterprise.

Mold has a direct impact on both the quality of products and production efficiency.

It is recommended to stay informed about the latest advancements in mold technology.

Mold can be a powerful tool in winning the competition.

Here are some design suggestions.

For creating a high-quality product, these are the main factors to consider:

  • (1) Raw materials;
  • (2) Product optimization design;
  • (3) Optimization design of mold;
  • (4) Stamping process

Compared to a poor mold, a good mold can have a production efficiency increase of 3-5 times. To create a mold with high production efficiency, the following factors are crucial:

  • (1) Mold material;
  • (2) Technology;
  • (3) Computer aided system;
  • (4) New processing equipment;
  • (5) Mold design and design ideas.

The fifth point is the most important and crucial.

A. Optimal Design

Every product has multiple design options, but the optimal design requires the designer to have extensive practical experience.

An optimal design takes into account all factors, including the properties of materials (as different materials require different mold design), the product’s structural complexity, the parameters of the pressing process, the selection of mold steel, and the mold’s durability, among others.

B. Spatial Simulation Method

Mold designers possess strong spatial imagination skills, meaning they can envision various design options while holding the product in their mind. They can consider the relationships between parts and the optimal arrangement of processes.

To find the best design, various options should be designed, compared, and screened. Then, the most reasonable design should be selected and simulated using the spatial simulation method. The designer can imagine the molding process in their mind and identify any potential problems, which can also be simulated on a computer.

By listing and correcting these issues during the redesign, unnecessary waste can be reduced, the mold manufacturing time can be shortened, and production efficiency can be improved.

Inadequate consideration of factors during the design process can result in defects in the final product, which may require multiple corrections before being scrapped. Unsuccessful designs can waste a significant amount of time and resources.

C. Innovative Mindset

Designers possess a mindset of continuous innovation and are not afraid to present their unique design concepts. They don’t let the teachings of past mentors restrict their creativity. Some design techniques of the past may become obsolete, and some outdated design ideas may need to be revised.

With technology constantly advancing and evolving, designers must stay updated and be open to new technologies. To achieve this, they must engage in continuous exploration and experimentation in their work practices. For example, mold experts don’t simply rely on theory but also gain hands-on experience.

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In the pursuit of design innovation, it’s essential to bring mold designers together to collaborate and learn from each other. Alone, one person’s capabilities are limited, but as a team, they can achieve greater results. Mold design is a crucial aspect of the process and requires a collaborative effort.

1. Stamping dies can be classified into three categories based on their structure: single engineering die, composite die, and continuous die.

Single engineering and composite dies require more human intervention, which is not economically efficient. On the other hand, continuous dies offer high-efficiency mass production of a large number of products.

To design high-speed and precise continuous stamping dies, it’s essential to monitor and control the production of all products processed through stamping. During the design process of continuous dies, consideration must be given to the module spacing, processing accuracy of parts, assembly accuracy, fitting accuracy, and interference to achieve automatic mass production.

2. Modular Design Approach:

The design of a stamping die can be divided into two parts: the common elements and the elements that vary based on the product.

Common elements can be standardized or normalized, while elements that vary based on the product are more challenging to standardize.

3. Formwork Composition and Specification:

Formwork Composition

The composition of stamping dies can vary based on the type and structure of the dies and can be divided into two categories: forward configuration structure and reverse configuration structure. The forward configuration structure is the most commonly used and the reverse configuration structure is mainly used for drawing forming dies or special dies.

4. Formwork Design:

The main components of continuous molds include the punch fixing plate, pressing plate, and mother template. The structural design of the molds can take one of three forms, depending on the accuracy of the stamped products, production volume, processing equipment and method, and maintenance requirements: integral type, yoke type, and inlay type.

Continuous die design technology

5. Modular Design:

1. Mold Alignment Unit

The mold alignment unit, also known as the mold blade alignment guide device, is used to maintain the alignment of the upper and lower molds and reduce preparation time. Depending on the requirements of product accuracy, production quantity, and other factors, mold alignment units can be classified into five main types:

(1) Unguided Type

(2) External Guidance Type

(3) External and Internal Guidance

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(4) External and Internal Guidance

(5) Internally Guided

  1. Guide Injection and Sleeve Unit

There are two types of mold guiding methods and accessories: external guidance (mold base type or main guiding) and internal guidance (auxiliary guiding). The use of a combination of external and internal guidance is highly demanded for precision molds.

3. Pressing Bolt and Spring Unit

When selecting the pressing spring unit, it is important to consider the following factors:

  • Ensure that the spring has the correct free length and necessary compression.
  • Determine if it is necessary to adjust the initial spring compression (pre-compression) or load.
  • Evaluate the ease of mold assembly and maintenance.
  • Consider the relationship between the length of the punch or pressing bolt.
  • Ensure safety, so that the spring does not fly out in the event of a break.

4. Guide Pin Unit (Positioning for Strip Feeding Direction)

(1) Guide Pin Unit: The main function of the guide pin is to ensure accurate feeding pitch during continuous stamping processing. There are two types of guide units for stamping dies: indirect (guide pin used alone) and direct (guide pin installed inside the punch).

(2) Guide Pin Assembly: The guide pin is assembled in the same manner as a punching punch, by being installed on the punch fixing plate and restrained by a spring.

(3) Additional Guide Pin Installation: The guide pin can also be installed in the form of a pressing plate.

It is essential to ensure that the guide pin protrudes from the pressing plate to the required level and to facilitate the handling of the processed material when the mold rises. Hence, it is crucial to consider the rigidity and design of the guiding form of the pressing plate.

(4) The guide pin unit comes in a direct type, which is mounted on the punch and primarily used for contour punching (blanking) or edge cutting in drawing engineering. Its positioning is based on the product’s hole and the inner diameter of the drawn part.

5. Guide unit

6. Lifting and jacking unit

7. Fixed pin list

8. Pressing plate unit

9. Error detection unit

10. Waste cutting unit

11. Height stop block unit

6. Design of main mold components:

1. Standard Parts and Specifications

In selecting standard specifications for molds, the following factors should be considered:

When there are no limitations on the specification content, it is advisable to choose the highest level.

The standard number should be adopted as a principle.

If the standard parts of the mold do not have the required size, the nearest one should be used for processing.

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2. Punch Design

The punch can be divided into three parts based on its function:

The cutting edge tip, which processes the material (the cutting edge can have an irregular, square, or round shape).

The contact part with the punch fixing plate (the fixing part or the handle part can have an irregular, square, or circular cross-section shape).

The connecting part (the middle part) between the blade and the handle.

3. Design of Punch Fixing Plate

The thickness of the punch fixing plate is determined by the size of the die and the load it will bear, typically 30-40% of the punch length. The length of the punch guide portion should be one or five times greater than the diameter of the punch.

4. Design of Guide Pin (Punch)

The diameter of the guide portion of the guide pin (punch) and the gap between the material guide hole are designed based on the thickness of the material, as well as the amount of protrusion from the pressing plate.

The shape of the leading end of the guide pin can be broadly classified into two types: shell shape and conical shape (push-pull shape).

5. Countermeasures for Punch Side Pressure

In stamping, the ideal state is for the punch to bear an equal load on both the left and right sides, resulting in no lateral pressure.

When the punch experiences lateral pressure, it can cause the upper and lower dies to become offset in the transverse direction, resulting in an uneven gap between the dies and affecting the accuracy of the stamping process.

6. Design of the Pressing Plate

The purpose of the pressing plate is to separate the material from the punch and to guide the smaller punch. Its design elements can vary significantly depending on its function.

There are two types of thickness and selection criteria for the pressing plate, based on product design: movable and fixed pressing plates.

7. Design of the Back Pressure Plate

During the stamping process, the main components (punch, pressing plate, and master die) will only experience surface pressure.

If the punching pressure exceeds the surface pressure, it is necessary to use a back pressure plate.

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