Before drawing master assembly drawing, process drawing should be drawn and conformed to requirements of part drawing, process data. Size guaranteed by next process shall be marked with words "process size" on drawing. If no other machining is performed after molding except for repair of burrs, process diagram is exactly the same as workpiece drawing.
It is best to mark part number, name, material, material shrinkage rate, drawing ratio, etc. under process diagram. Usually process picture is on moulding process drawing.
Draw final assembly drawing as much as possible with a ratio of 1:1, starting with cavity and drawing the main view at the same time as other views.
Moulding process drawing should include the following:
Mold forming part structure
Structure of gating system and exhaust system.
Parting surface and parting mode.
Outline structure and position of all connectors, positioning and guides.
Mark cavity height dimension (not required, as needed) and overall dimensions of mold.
Auxiliary tools (pickup tool, calibration tool, etc.).
All part numbers are programmed in order and schedule is filled out.
Mark technical requirements and instructions for use.
Technical requirements for moulding process drawing:
Performance requirements for certain systems of molds. For example, assembly requirements for ejector system and slider core structure.
Requirements for moulding process process. For example, fitting gap of mating surface of parting surface after mold is assembled should be no more than parallelism requirement of upper and lower sides of mold of 0.05 mm, and size determined by assembly and requirement for size are pointed out.
Mold use, assembly and disassembly methods.
Anti-oxidation treatment, mold number, lettering, marking, oil seal, storage and other requirements.
Requirements for test and inspection.
Order of parts drawing from moulding process drawing should be: inside first and then outside, complicated first and then simple, forming parts first and then structural parts.
Requirements are as follows:

Be sure to draw on scale, allowing you to zoom in or out. Reasonable view selection, correct projection, and proper layout. In order to make processing patent number easy to understand and easy to assemble, graphics should be as consistent as possible with final assembly drawing, and graphics should be clear.
Dimensioning requirements are uniform, centralized, orderly, complete
Order of dimensioning is: first mark main part size and draft angle, then mark fit size, and then mark full size. Mark fit size on non-main part drawing and mark full size then.

Mark roughness of the most applied type in upper right corner of drawing, as marked "Others 3.2". Other roughness symbols are marked on each surface of part.

For example, 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.

 

Relationship between molds, its parts and injection molded parts drawings
Whether material, hardness, dimensional accuracy, structure, etc. of mold and injection molded parts meet requirements of mold parts drawings.

Whether flow, shrinkage, weld line, crack, and draft of plastic material affect performance, dimensional accuracy, and surface quality of mold parts. Whether pattern design is insufficient or not, whether processing is simple or not, and whether shrinkage rate of molding material is selected correctly.

Whether Injection volume, injection pressure, and clamping force are sufficient or not. Whether installation of mold, core of mold parts, and mold release have problem or not. Whether nozzle of injection machine and mouthpiece are in proper contact.

Whether position of parting surface and precision of finishing meet the requirements, will there be any flashing, and whether mold parts can be left on the side of mold with ejector device after mold is opened.
Is demoulding method correct? Is size, position and quantity of promotion rod and push tube appropriate? Will push plate be caught by core and will not cause mold parts to be scratched.
Mold temperature adjustment. Power and quantity of heater; whether flow line position, size and quantity of cooling medium are suitable.
Method of processing undercut of plastic part, whether mechanism for removing concave side is appropriate, for example, whether slider and push rod in core pulling mechanism of inclined guide column interfere with each other.
Position of pouring and exhaust system is appropriate.

Whether placement of each injection molded parts on assembly drawing is appropriate, whether it is clear or not, whether it is missing;
Part number, name, production quantity, part internal or outsourced, parts are standard or non-standard parts, part processing precision, correction processing and margin of high-precision size of injection molded parts, mold parts. Whether material, heat treatment, surface treatment, surface finishing degree is marked, and description is clear.
Main parts, working dimensions of mold parts and matching dimensions. Size figures should be correct and should not be converted by manufacturer.
Check view position of all parts drawing and assembly drawing, whether projection is correct, whether drawing conforms to national standard of drawing, and whether there is any missing size.

Whether geometry of all parts, view drawing, size mark is beneficial to processing

In principle, professional proofreading is carried out according to designer's self-calibration project; however, it should focus on structural principles, process performance and operational safety. When drawing, first digest graphics, draw according to requirements of national standard, fill in all dimensions and technical requirements. Self-correction and sign after description.
Base drawing is handed over to designer for proofreading. Customary practice is to review technical personnel of injection molding companies, sign and check moulding process, and then send out.

Manufacturing process card is written by injection molding companies technician and is ready for processing.
In the manufacturing process of mold parts, inspection should be strengthened, and focus of inspection should be on dimensional accuracy. After moulding process is completed, inspector performs inspection according to mold inspection table. Main thing is to check whether performance of mold parts is good. Only in this way can moulding process quality be guaranteed.

 

Although molding design is carried out under expected process conditions when selecting molding materials and molding equipment, people's understanding is often imperfect. Therefore, after moulding process is completed, mold test must be carried out to see mold parts. How is quality?
There are many types of defects in injection molded parts, and reasons are also very complicated. There are mold reasons and process conditions, and these two tend to be together.
Before mold is repaired, it should be carefully analyzed according to actual situation of defective parts of injection molded parts, and remedy method should be proposed after finding out cause of defects of injection molded parts. Since molding conditions are easy to change, it is common practice to change molding conditions first, and when molding conditions cannot be solved, mold is considered to be repaired.
Repairing mold should be more cautious, please donot act rashly if not very sure. Reason is that once mold conditions are changed, it is impossible to make major modifications and restore original condition.
Whether performance of parts is good, only in this way can determine quality of mould manufacturing.

 

After mold has been tested, if it is not used for a while, it should be completely wiped off mold residue, dust, oil, coated with butter, anti-rust oil or rust inhibitor, and kept in a storage place.
Technical data generated during period from start of design of mold to successful processing of mold, such as task book, workpiece drawing, technical specification, moulding process drawing, mold part drawing, base drawing, molding design specification, inspection record, tables, test mold repair records should be systematically sorted, bound, numbered for archiving according to regulations. This seems cumbersome, but it is useful to design new molds for future repairs.