A DFM report, standing for Design for Manufacturing Report, serves as a bridge between moldmakers and clients, is an important basis for communication between mold engineers and client product engineers. Especially when a product is still immature, a DFM report can help optimize product structure, leading to more rational mold design, cost-effective mold manufacturing, smoother and more efficient injection molding production. Therefore, a well-prepared DFM report is crucial before mold construction and is a key indicator of a designer's skill.

Every company has different PPT templates, but a good PPT doesn't necessarily guarantee a good DFM. If product design is mature and data quality is high, then mold DFM can be simpler; simply using line drawing screenshots to clearly convey information will suffice. For products with numerous issues, you should identify relevant issues based on your own experience, provide reasonable solutions, then make optimizations based on customer feedback. To produce a good DFM report, a mold designer must have extensive design experience and be deeply familiar with product functions, structural design, and mold structure. They should propose effective modification plans based on product structure and functions. This simplifies mold structure and addresses potential product vulnerabilities, ultimately gaining customer approval while also saving costs.

A good DFM report, regardless of specific template used, generally includes following key points.

 

DFM Report Cover:
Indicate client name, project name, and name of product being analyzed. You may also include information such as report preparer and phone number.

 

 

First, complete product information, including material, such as commonly used materials for automotive interior and exterior trim (PP, PE, PP-TD20, PP-TD40, PP+EPDM-TD20, PP+GF30/GF35, PA6+GF30, etc.). It's best to discuss material brand with customer in advance, or consult with plastic pellet manufacturer for recommendations and confirmation. Obtain material property sheet, recommended molding parameters, UDB data, and theoretical shrinkage. This information must be confirmed during Design for Material (DFM) review.
Product color, dimensions, and weight are standard information. The key focus is on product's surface finish. In most interior and exterior trim products, main body will feature a leather-grained finish, such as geometric or three-dimensional. These appearance requirements determine product's A-side, specifically draft angle, mold material selection, and pre-etching polish requirements. Other center console components utilize processes such as electroplating, water transfer printing, spray painting, high-gloss coating, and IMD, requiring specific confirmation of mold material selection and specific product structural design requirements.

 

Mold information must clearly indicate shrinkage data, also known as shrinkage reduction. Depending on product structure, determine whether mold should be enlarged in equal proportions or in varying lengths and widths. Mold layout information includes number of cavities and mold structure (two-plate mold with large sprue, three-plate mold, hot runner mold, reverse mold, etc.). For hot runner molds, indicate type of hot nozzle: single nozzle, point gate, needle valve, needle valve with wide-dip, needle valve with side-injection, etc.
Mold steel material information primarily specifies A/B plate material and steel mill information. S50C is generally selected for mold frame. Requirements for cavity, core, and slide surface should be specified. If graining is present, indicate grain number and depth.
Mold information includes production-related machine matching and injection molding cycle information, which should be determined based on mold dimensions and professional calculations.

 

Correctly match injection molds to injection molding machines with this calculation!
Fully Automatic Calculation Model for Injection Molding Cycle V0

Detailed descriptions of parting lines typically occupy several pages of report. For products with complex structures, a simple flat parting is not possible. Therefore, ejection direction must be determined based on product structure. PL line contour is extracted and displayed as a bold red line. Parting lines generated by removing inserts or sliders, especially on exterior surface, must be detailed and illustrated with screenshots. No omissions should be made, and customer must confirm each one. This will serve as a basis for subsequent product proofing and acceptance.
Also, selection of PL line must take into account boundary of grain pattern on leather-grained parts. These details can be determined in conjunction with grain pattern supplier in the early stages. For localized protrusions and dense mesh (such as door speaker covers), separate inserts can be created. Parting lines of inserts also require customer confirmation.

 

For automotive front molds, a 2° draft angle is generally recommended for appearance. For leather texture, a draft angle of 5° to 7° is recommended, with a minimum of 5°. If draft angle is insufficient, notify customer promptly. For automotive interior and exterior trim, typical mold frame width for rear molds is 1mm at larger end and 0.7° to 0.8mm at smaller end.
Mold ejector layout is crucial for smooth product ejection and proper production. When ejection and cooling conflict, prioritize ejection, then optimize water flow. For automotive molds, a straight ejector is generally preferred. If there is room for ejector pins, a D12 or larger ejector pin is recommended. Ejector blocks are preferred.
 

 

This type of analysis requires CAE mold flow analysis results. That is, before analyzing and outputting a DFM report, a mold flow analysis of product must be completed first or simultaneously. Select relevant analysis results and include them in report, along with a textual explanation. For example, if product has 3mm Z-direction warpage, identify risk points or provide pre-deformation solutions. Obtain customer approval for weld line descriptions and provide optimization suggestions. Sink mark analysis, analysis results explained, and professional solutions for localized glue leakage to eliminate sink mark effects.

 

Wall thickness of dark red area of product is too thick, which may cause shrinkage.

 

Wall thickness of product here is too large. It is recommended to reduce glue along red line on product surface in red circle.

Date stamp, date table, product information, mold cavity number, etc.
Function: Used to understand product's production date, project name, and other information
Design points:
(1) Important! All characters on product are reversed on mold!
(2) Date stamp should be placed in normal direction of product surface, protruding from inner mold by 0.2, i.e., 0.2 on product. A through hole should be made at the bottom of date stamp so that it may need to be removed later.
(3) Date table and product information are engraved directly on mold. Character height is generally 2-3mm and depth is about 0.2, i.e., 0.2 on product. There should be no ejector pins in the date table and engraving.
(4) Generally, molds with multiple cavities should be designed with cavity numbers to distinguish them, so as to facilitate later mold modification. Design points are same as those for date table. Cavity numbers can be engraved on ejector pins.

 

At this point, a Design for Modification (DFM) report is analyzed and summarized, can be submitted to customer for approval. Upon receipt of customer's approved mold DFM, subsequent mold design and mold design review will be conducted based on this report. Once review is passed, mold production will officially begin according to customer's "Mold Opening and Processing Instructions."