What is shape flow analysis

Form flow analysis can save your plastic injection molding design

The secret to a high-quality injection-molded plastic part is a flawless shape - one that produces consistent pieces over and over again. So what is the key to a flawless mold? In addition to a strong initial design, shape flow analysis is your secret weapon.It is an indispensable component of any plastic injection molding design project. MFA software comes at a price, but its impact on shape quality, product performance, and appearance and production ROI is undeniable. Read on to learn how that one tool can literally save your shape design.

Photo source: Jason Bailey of Moldflow Plastics Advisers

What is shape flow analysis?

Mold Flow Analysis (MFA) software simulates plastic flow so you can improve mold design and create the highest quality products possible. This analysis provides a virtual sneak peek as the chosen material fills the cavities of a mold and highlights potential areas of concern. Digital simulation of this process in front Cutting the tool allows changes to be made early on, ultimately saving money and optimizing results.

When should mold flow analysis be used?

MFA should be performed before tool production starts. Software can be used to evaluate the mold design to ensure that it will produce the most consistent, high quality parts from each cavity of the tool. A virtual model of the mold is created, and using the known data and characteristics of the selected material, the software can predict how the material will flow into the mold and cavities. Various data points can be assessed including pressure, fill time and melt temperature. This enables the process to be optimized before tool production begins.

Is the analysis necessary for every application?

The short answer: not necessarily. Just because MFA is an available resource doesn't mean it should be used for every project. The following factors will help determine whether to use MFA for a particular application:

Product geometry
Complex geometries are most likely to benefit from analysis because they are more complicated and the flow is less predictable than with a simpler geometric design.

Tolerance requirements
Similar to complex geometry, tight tolerances benefit from pre-tool analysis to ensure that a product meets specifications with the selected materials and tool design.

Project area
This is where the cost eligibility comes into play. The size and scope of the project should be large enough to justify the cost and manpower to perform proper analysis.

Advantages of the mold flow analysis

MFA has several advantages, including:

  • Solve wall thickness problems

  • Optimize gate location

  • Fill mold cavities consistently and evenly

  • Discover weaknesses in design geometry

  • Avoid costly tool defects and rework

  • Improvement in manufacturability

  • Reduce the time to market

  • Improve efficiency and quality

  • Discover potential visual defects, including air traps, sink marks, and weld lines

  • Evaluate different material options before production to choose the best material

  • View customer and supplier data to support your design or request changes

MFA software options

Our recommendation is to work with an experienced contract manufacturer to guide you through the Design for Manufacturing (DFM) process from start to finish. Find a manufacturing partner who has the know-how and experience to do the flow analysis for you Should you decide by yourself, here are some existing software options:

Autodesk Simulation Moldflow

A leader in this category, Autodesk developed its Moldflow software back in 1987. The Autodesk website is bursting with useful simulation tutorial videos. Software updates are released consistently and new versions come out every year.


Moldex3D flow

Via their website: Moldex3D is the world's leading CAE product for the plastic injection molding industry.With best-in-class analysis technology, Moldex3D can help you realize the widest range of injection molding processes and optimize product designs and manufacturing options.In addition, the high level of compatibility and adaptability offers users immediate connection to CAD-CAD systems, creating a flexible, simulation-controlled design platform.