The whole process from mold design to trial mode
1. Proofreading, reviewing, drawing, and drying
(1) 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, injection pressure, and clamping force are insufficient. The installation of the mold, the south core of the plastic part, and the mold release have no problem. 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 finishing can meet the needs, 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) A method of processing the undercut of the plastic part, whether the mechanism for removing the undercut 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, production quantity, part internal or outsourced on the parts drawing, whether it is standard or non-standard parts, the matching processing precision of the parts, 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) Working parts and matching dimensions of main parts and molded parts. 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
Whether the geometry of all parts, view drawing, size mark, etc. is beneficial to processing
(7) The main working size of the recalculation aid
1) 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.
2) Digest the graphics first, draw according to the national standard requirements, 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.
(8) Writing a manufacturing process card
1) The manufacturing process card is written by the technician of the tool manufacturing unit and is ready for processing.
2) In the manufacturing process of the mold parts, the inspection should be strengthened, and the inspection focus 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 mold manufacturing quality be guaranteed.
Second, draw the mold map
It is required to draw according to the national drawing standard, but it also requires the combination of factory standards and factory customary methods not specified by the state. Before drawing the master assembly drawing, the process drawing should be drawn and conformed to the requirements of the parts drawing and process data. The size guaranteed by the next process shall be marked with the words "process size" on the drawing. If, after the molding, no other machining is performed except for the repair of the burrs, the process diagram is exactly the same as the workpiece drawing. It is best to mark the part number, name, material, material shrinkage rate, drawing ratio, etc. under the process diagram. Usually the process picture is on the mold assembly drawing.
1. Draw the assembly structure diagram
Draw the final assembly drawing as much as possible with a 1:1 ratio, starting with the cavity and drawing the main view at the same time as the other views.
(1) The mold assembly drawing should include the following contents:
1) Mold forming part structure
2) The structural form of the gating system and the exhaust system.
3) Parting surface and parting mode.
4) Outline structure and position of all connectors, positioning and guides.
5) Mark the cavity height dimension (not required, as needed) and the overall size of the mold.
6) Auxiliary tools (removing tools, correction tools, etc.).
7) Program all the part numbers in order and fill out the schedule.
8) Mark technical requirements and instructions for use.
(2) Technical requirements for the assembly drawing of the mold:
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 bonding surface of the parting surface after the mold is assembled should be no more than the parallelism requirement of the upper and lower sides of the mold of 0.05 mm, and the size determined by the assembly and the requirement for the size are pointed out.
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.
2. Draw all parts drawings
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 proportion, 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) The 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 ratio, free-size machining accuracy, technical description, etc. must be correctly filled out.
Third, 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 found that always afterwards, the erroneous revision is performed.
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.
Whether the performance of the parts is good, only in this way can the quality of the mold manufacturing.
Fourth, organize the 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.
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