10 manufacturing processes for molds from design to test molds

I. Acceptance of the mandate

A mandate for forming plastic parts is usually submitted by the designers of the parts and the content is as follows:

1. A certified drawing of a regularly manufactured part, indicating the number of plastics used, transparency, etc.

2. Instructions or technical requirements for plastic parts.

3. Production yields.

4. Samples of plastic parts.

Usually, a mold design task is proposed by a plastic parts worker based on the task of forming plastic parts, and mold designers use the formed plastic parts task and mold design task to design molds.

II. Collection, analysis and digestion of raw materials

Collect and collate information on component design, forming processes, forming equipment, machining and special processing for use in the design of molds.

1. To digest the plastic parts diagram, understand the uses of the parts, analyze the process nature, dimensional accuracy and other technical requirements of plastic parts. For example, what are the requirements for the outer shape, color transparency, and use performance of plastic parts, whether the geometric structure, slope, and embedding of plastic parts are reasonable, the degree of permissibility of forming defects such as weld marks and shrinking holes, and whether there are after-treatments such as paint, plating, glue, and drilling. Select the largest dimensional accuracy of plastic parts and analyze it to see whether the estimated forming tolerance is lower than the tolerance of plastic parts, and whether the required plastic parts can be molded. In addition, we need to understand the plasticization and molding process parameters of plastics.

2. Digest the process information and analyze whether the requirements of the forming method, equipment model, material specifications, mold structure type and other requirements set out in the process task paper are appropriate and can be implemented.

The moulding material should meet the strength requirements of plastic parts, have good fluidity, uniformity and uniformity, and thermal stability. Depending on the purpose of the plastic parts, the moulding material should meet the requirements of dyeing, metal plating, decorative properties, necessary elasticity and plasticity, transparent or conversely reflective properties, bonding or welding.

3. Determine a forming method

Use direct pressure, cast pressure or injection.

5. Specific structural programmes

(1) Determining mold type

Examples are pressing molds (open, semi-closed, closed), cast pressing mold, injection mold, etc.

III. The factors affecting the mold structure and the individual mold systems are many and complex:

1. The moulding arrangement. According to the geometry and structural characteristics of the plastic parts, the dimensional accuracy requirements, the batch size, the ease of mold manufacturing, the mold cost, etc., the number of mold cavities and the way they are arranged.

2. Determine the morphology. The position of the forming surface should be conducive to mold processing, exhaust, de-modeling and molding operations, and the surface quality of plastic parts.

3. Determine the pouring system (shape, position, size of main pouring channels, sub-pouring channels and filling channels) and the exhaust system (means of exhaust, placement, size of exhaust tanks).

4. Select the topping mode (top rod, top tube, pushboard, combined topping), decide on the side recess treatment method, and the spooling mode.

5. Determine the mode of cooling and heating and the shape, position of the heating cooling chute and the place where the heating element is installed.

6. Based on mold materials, strength calculations or empirical data, determine the thickness and shape of mold parts, the shape structure and the position of all connections, positioning and steering parts.

7. Determine the structural form of the main moulded parts and structural parts.

8. Consider the strength of the parts of the mold and calculate the working size of the moulded parts.

If the above problems are solved, the structural form of the mold will naturally be solved. At this time, we should begin to draw a sketch of the mold structure in order to prepare for the formal drawing.

IV. Drawing mold diagrams

Drawing is required in accordance with national drawing standards, but it is also required to combine factory standards with factory custom drawings not stipulated by the state.

Under the process diagram, it is best to mark the component number, name, material, material shrinkage rate, drawing ratio, etc. The process is usually drawn on the mold assembly diagram.

1. Draw a general assembly structure diagram

Draw the general assembly diagram as much as possible in a 1: 1 ratio, beginning with the moulding, and the main view is drawn at the same time as the other views.

5. The mold assembly diagram shall include the following contents:

1. Part structure of mold molding

2. The structural form of the pouring system and the exhaust system.

3. Form surfaces and ways of forming parts.

4. Form structure and all connectors, positioning and orientation of the moving parts.

5. The height size of the annotated cavity (not strong, as needed) and the total size of the mold.

6. Auxiliary tools (removal tool, correction tool, etc.).

7. In order, write out the serial numbers of all parts and fill out the detailed form.

8. Label technical requirements and instructions for use.

VI. The technical requirements of the mold assembly diagram are:

1. Performance requirements for molds for certain systems. Examples include assembly requirements for roofing systems and spool pumping structures.

2. Requirements for the mold assembly process. For example, the fitting gap of the fitting surface of the parting surface after the mold assembly should be no more than 0.05mm on the mold and the following flatness requirements, and indicate the size determined by the assembly and the requirements for the size.

3. Mold use, method of assembly.

4. Antioxidation treatment, mold numbering, engraving, marking, oil sealing, safekeeping, etc. requirements.

5. Requirements relating to test models and inspections.

VII. Draw a diagram of all parts

The order in which the parts diagram is decomposed from the mold assembly diagram should be: first inside, after outside, first complex, after simple, first formed parts, and then structural parts.

1. Graphical requirements: Be sure to draw in proportion and allow for zooming or shrinking. The view was chosen reasonably, projected correctly and arranged properly. In order to make the processing patent number easy to understand and easy to assemble, the graphics are as consistent as possible with the general assembly diagram, and the graphics should be clear.

2. The marking dimensions need to be uniform, centralized, orderly and complete. The order of marking dimensions is: first mark the main part dimensions and mold slope, then mark the co-ordinated dimensions, and then mark the entire dimensions. On the drawings of non-main parts, specify the co-ordinated dimensions first and the full dimensions later.

3. The surface roughness. Mark the most applied degree of roughness in the upper right corner of the drawing, as indicated " The balance is 3.2. " Other roughness symbols are marked separately on each surface of the part.

4. Other contents, such as part name, mold number, material plate number, heat treatment and hardness requirements, surface treatment, graphic proportions, free-scale machining accuracy, technical instructions, etc., must be correctly filled in.

VIII. Editing, reviewing, drawing, and sending photos

A. The content of self-proofreading is:

1. Relationship of molds and their parts to plastic sheeting

Whether the material, hardness, dimensional accuracy, structure, etc. of the mold and mold parts meet the requirements of the plastic parts drawings.

2. In the area of plastic components
3. Whether the flow of plastic material flow, shrinking pores, melting marks, cracks, de-molded slope, etc. affect the use performance, dimensional accuracy, surface quality and other requirements of plastic parts. Are there any deficiencies in the pattern design, whether the machining is simple, and whether the contracting rate of the forming material is correctly selected.

3. In the area of moulding equipment

The amount of injection, the injection pressure, the locking force is enough, whether there are problems with the installation of the mold, the southern core of the plastic parts, and the demobilization, and whether the nozzle of the syringe is in proper contact with the muzzle glove.

5. Design drawings

1). Is the placement of each mold part in the assembly diagram appropriate, clearly represented, and any omissions?

3). Parts Main parts, moulded parts working dimensions and matching dimensions. The size figures should be correct and should not be altered by the producer.

4). Check the view position of all part drawings and assembly drawings, whether the projection is correct, whether drawing conforms to the national specifications, and whether dimensions are missing.

6. Calibrating nuclear processing performance

Whether the geometry of all parts, the drawing method, the dimensions, etc. are conducive to machining.

7. Main operating dimensions of reconciliation aids

B. Professional proofreading is carried out according to the designer's self-proofreading project in principle; However, emphasis should be placed on structural principles, process performance and operational safety.

C. The drawing of the bottom to the designer proofreading signature, the customary practice is by the tool manufacturing unit technical personnel review, countersign, check the manufacturing process, and then can be sent to the sun.

D.. Write manufacturing process cards

A tool manufacturing unit technician writes a manufacturing process card and prepares it for machining.

IX. Mold testing and modification

Although when selecting forming materials and forming equipment, mold design is carried out under the pre-evisioned process conditions, people's understanding is often imperfect, so after the mold processing is completed, a test mold test must be carried out to see how good the molded parts are. A discovery is always made later, and a modification is made to eliminate the error.

X. Preparation of information for archiving

After the mold has been tested, if it is not used for a while, it should be completely wiped away decomposition residue, dust, oil, etc., coated with butter or other rust-proof oil or rust-proof agents, and closed in a storage place for storage.

le and thin.

Slide Processing Process

1, First, the milling machine grinds six sides, 2 grinds six faces to the size requirements, 3 the milling machines grinding stand, 4 The shaft is carefully milled to the size requirements and fitted with the spool position, 5 The milling machine processes the slope, ensuring that the slant is consistent with the pressure tightening block, leaving a residual amount to fly the mold, 6 The drill for water and the shallow guide hole, the slender guide hole is 1 mm larger than the guide column and inverts the angle, and the gradient of the sliding guide hole should be 2 degrees smaller than the slower side of the slider. Squeezed column holes can also be reprocessed with the mold shelf after they have flown the mold and attached the mold, depending on the different circumstances.

The precise control of the transmission valve can basically eliminate the lag and enhance the repeatability of all functions.