Plastic mould design the last five steps!
Plastic mould design the last five steps!
First, the technical requirements of the mold assembly drawing
1. Performance requirements for certain systems of the mold. For example, the assembly requirements for the ejector system and the slider core structure.
2. Requirements for the mold assembly process. For example, the fitting gap of the mating surface of the parting surface after the mold is assembled should be no more than 0.05 mm, the parallelism of the upper and lower parts of the mold, and the size determined by the assembly and the requirement for the size are indicated.
3. Mold use, assembly and disassembly methods.
4. Anti-oxidation treatment, mold number, lettering, marking, oil seal, storage and other requirements.
5. Requirements for test and inspection.
Second, draw all parts map
The order of drawing the parts drawing from the mold assembly drawing should be: first inside and then outside, first complicated and then simple, first forming parts, then structural parts.
1. Graphics requirements: Be sure to draw in proportions, allowing you to zoom in or out. The view selection is reasonable, the projection is correct, and the layout is proper. In order to make the processing patent number easy to understand and easy to assemble, the graphics should be as consistent as possible with the final assembly drawing, and the graphics should be clear.
2. Dimensioning requirements are uniform, centralized, orderly, and complete. The order of dimensioning is: first mark the main part size and the draft angle, then mark the fit size, and then mark the full size. Mark the fit size on the non-main part drawing and mark the full size.
3. Surface roughness. Mark the roughness of the most applied type in the upper right corner of the drawing, as marked "Others 3.2." Other roughness symbols are marked on each surface of the part.
4. Other contents, such as part name, mold drawing number, material grade, heat treatment and hardness requirements, surface treatment, graphic scale, free-size machining accuracy, technical description, etc. must be correctly filled out.
Third, proofreading, reviewing, drawing, sending sun
(1) The content of self-proofing is:
1. The relationship between molds and their parts and plastic parts drawings
Whether the material, hardness, dimensional accuracy, structure, etc. of the mold and mold parts meet the requirements of the plastic parts drawings.
2. Plastic parts
Whether the flow, shrinkage, weld line, crack, and draft of the plastic material affect the performance, dimensional accuracy, and surface quality of the plastic parts. Whether the pattern design is insufficient or not, whether the processing is simple or not, and whether the shrinkage rate of the molding material is selected correctly.
3. Forming equipment
The injection volume, plastic injection moulding pressure, and clamping force are insufficient. The mold is installed, the core of the plastic part is released, and there is no problem with the mold release. Whether the nozzle of the injection machine and the mouthpiece are in proper contact.
4. Mold structure
1). Whether the position of the parting surface and the precision of the finishing meet the requirements, will there be any flashing, and whether the plastic part can be left on the side of the mold with the ejector device after the mold is opened.
2). Is the demoulding method correct? Is the size, position and quantity of the promotion rod and the push tube appropriate? Will the push plate be caught by the core and will not cause the molded part to be scratched.
3). Mold temperature adjustment. The power and quantity of the heater; whether the flow line position, size and quantity of the cooling medium are suitable.
4). The method of processing the undercut of the plastic part, whether the mechanism for removing the concave side is appropriate, for example, whether the slider and the push rod in the core pulling mechanism of the inclined guide column interfere with each other.
5). The position of the pouring and exhaust system is appropriate.
5. Design drawings
1). Is the placement of each mold part on the assembly drawing appropriate? Is it clear whether there is any omission?
2). The part number, name, number of production, part internal or outsourced on the parts drawing, whether it is standard or non-standard parts, the precision of the part processing, the correction processing and the margin of the high-precision size of the molded plastic parts Whether the material of the mold part, heat treatment, surface treatment, surface finishing degree is marked, and the description is clear.
3). The main parts of the parts, the working dimensions of the molded parts and the matching dimensions. The size figures should be correct and should not be converted by the manufacturer.
4). Check the view position of all parts drawing and assembly drawing, whether the projection is correct, whether the drawing conforms to the national standard of drawing, and whether there is any missing size.
6. Check processing performance
(All parts geometry, view drawing, size label, etc. is beneficial for processing)
7. The main working size of the recalculation aid
(2) Professional proofreading is carried out in principle according to the designer's self-calibration project; however, it should focus on structural principles, process performance and operational safety.
When drawing, first digest the graphics, draw according to the requirements of the national standard, fill in all the dimensions and technical requirements. Self-school and sign after the description.
(3). Submit the prepared base map to the designer for proofreading. The customary practice is to review the technical personnel of the tool manufacturing unit, sign and check the manufacturing process, and then send the sun.
(4). Writing manufacturing process cards
The manufacturing process card is written by the tool manufacturing unit technician and is ready for processing.
In the manufacturing process of the mold parts, the inspection should be strengthened, and the focus of the inspection should be on the dimensional accuracy. After the mold assembly is completed, the inspector performs the inspection according to the mold inspection table. The main thing is to check whether the performance of the mold parts is good. Only in this way can the quality of the mold be manufactured.
Fourth, try and repair
Although the mold design is carried out under the expected process conditions when selecting molding materials and molding equipment, people's understanding is often imperfect. Therefore, after the mold processing is completed, the mold test must be carried out to see the molded parts. How is the quality? It is always found that after the erroneous repairs are carried out.
There are many types of defects in plastic parts, and the reasons are also very complicated. There are mold reasons and process conditions, and the two tend to be together. Before the mold is repaired, it should be carefully analyzed according to the actual situation of the defective parts of the plastic parts, and the remedy method should be proposed after finding out the cause of the defects of the plastic parts. Since the molding conditions are easy to change, it is common practice to change the molding conditions first, and when the molding conditions cannot be solved, the mold is considered to be repaired.
Repairing the mold should be more cautious, not very sure not to act rashly. The reason is that once the mold conditions are changed, it is impossible to make major modifications and restore the original condition.
Five,Organize data for archiving
After the mold has been tested, if it is not used for a while, it should be completely wiped off the mold residue, dust, oil, etc., coated with butter or other anti-rust oil or rust inhibitor, and kept in a storage place.
The technical data generated during the period from the start of the design of the mold to the successful processing of the mold, such as the task book, the workpiece drawing, the technical specification, the mold assembly drawing, the mold part drawing, the base drawing, the mold design specification, and the inspection record. Tables, test mold repair records, etc., according to regulations, systematically sorted, bound, numbered for archiving. This seems cumbersome to do, but it is useful to design new molds for future repairs.
This is Plastic mould design the last five steps!