August 2007 Rapid Prototyping Consortium. Changing the way plastics parts and molds are analyzed and optimized

August 2007 Rapid

Prototyping Consortium

Changing the way plastics

parts and molds are

analyzed and optimized

Jonathan Toy

Engineering Services Manager Moldflow Corporation

DESIGN SOLUTIONS

DESIGN SOLUTIONS

Part Design

Mold Design

Production

Injection Molding Process

Primary Problem - Islands of Automation

“Islands of Automation” adds cost and creates quality and process efficiency problems

DESIGN SOLUTIONS

OEM/Erie

Problem:

Cycle times were longer than expected.

Solution:

SAVINGS ACHIEVED MPI/3D, MPI/FLOW, AND MPI/COOL Analyses identified

thick/chunky areas, then through optimization of the part design and cooling system design, cycle times were

reduced by 53%!

Annual savings of 25,000 US$

in cycle time reduction

INDUSTRY: Automotive

PRODUCT:Cowl Screen End Cap

INDUSTRY: Automotive

DESIGN SOLUTIONS

Airmate Electrical Co.,Ltd

Problem:

unbalanced flow

Great amount of warpage

Solution & Benefits:

Design changing of runner system

Warpage reduced by 45% Cycle time reduced by 35%

Clamping force reduced to 150 tons

Solved difficult assembly

problem, machine cost

reduced by at least 50%!

INDUSTRY: Household appliances PRODUCT: Box fan housing

INDUSTRY: Household appliances PRODUCT: Box fan housing

DESIGN SOLUTIONS

INDUSTRY: Electric Switches PRODUCT: Dimmer housing

INDUSTRY: Electric Switches PRODUCT: Dimmer housing

A coil should be mounted in a DIN rail housing. In older, similar products, a configuration with 4 little stakes and 3 springs is used for the fixture.

For a new universal dimmer, the proven fixture geometry was copied, and a

simulation seemed unnecessary. However, the nominal wall thickness of the base plate had changed.

Mr. Patrick Meeus of Niko, performing Moldflow MPI simulations on every new plastic product, decided to do the simulation anyway.

The MPI simulation showed that short shots would appear in the stakes and springs, due to the changes in the base plate. This was not expected. By optimizing wall

thicknesses this problem was resolved before the mold was cut in steel.

Lower mold cost - the

mold was right from the

start!

Shorter time-to-market!

DESIGN SOLUTIONS

Moldflow Corporation

Founded 1978 – Melbourne, Australia

Acquired C-Mold 2000

Global Operations (Development,

Sales, Support)

Global Partners (Design, Research,

Manufacturing, Hardware)

Global Customers (8,000+ in 70

countries)

DESIGN SOLUTIONS Air Outlet Water Tank Radiator Inlet Water Tank Vehicle Engine

Radiator

Water Tank

DESIGN SOLUTIONS

First failure

Stress level

about 50% of the tensile strength

Internal pressure load case

Weld Line

Courtesy Valeo

DESIGN SOLUTIONS

Interfaces to Structural CAE – Overview

Historical method of analyzing plastic parts in

Structural CAE:

Generic & isotropic material data

Stress-free initial state of plastic

Original CAD geometry

New method (using data from the MPI

interface):

Grade-specific & anisotropic material properties

Process-induced material anisotropic data (for

fiber-filled materials)

Account for residual stresses

DESIGN SOLUTIONS

3D Model Interface Details

Data exported for a 3D mesh

Unfilled Materials

Elastic modulus, Shear modulus & Poisson’s ratio from Material database

Coefficient of thermal expansion (CTE) from Material database

Elemental (for each 3D tetrahedral element) initial stress values

Fiber-filled Materials

Elemental Elastic modulus, Shear modulus & Poisson’s ratio

Elemental CTE

Elemental equivalent pressures

DESIGN SOLUTIONS

Residual stresses and part deformations to be included in all parts of this model

Droptest of entire phone Droptest simulation of the whole Phone in ABAQUS/Explicit

Trend – Virtually Simulate Entire Assembly

DESIGN SOLUTIONS

Trend – Virtually Simulate Entire Assembly

Traditional stress analysis:

σ_{vonmises=14.4 MPa}

Fully integrated analysis:

σ_{vonmises=35.9 MPa}

Fully integrated analysis:

σ_{vonmises=80.1 MPa}

Traditional stress analysis:

σ_vonmises=17.2 MPa Integration Fiber orientation Shrinkage Flow Dynamic Stress Courtesy Nokia

DESIGN SOLUTIONS

Graco Children’s Products

Problem:

Weld line anticipated to be in the top of the bridge area is expected to

cause the base to fail during crash testing.

Solution:

The initial proposed solution was to add flow leaders to move the weld line off the top of the bridge area. Flow and stress analyses deemed the

flow leaders unnecessary, saving a 7% part weight increase.

Prototype parts performed well in crash testing!

SAVINGS ACHIEVED WITH MPI/FLOW AND MPI/ANSYS INTERFACE

Problem:

Weld line anticipated to be in the top of the bridge area is expected to

cause the base to fail during crash testing.

Solution:

The initial proposed solution was to add flow leaders to move the weld line off the top of the bridge area.

Flow and stress analyses deemed the flow leaders unnecessary, saving a 7% part weight increase.

Prototype parts performed well in crash testing!

SAVINGS ACHIEVED WITH MPI/FLOW AND MPI/ANSYS INTERFACE

Annual savings of 115,000 US$

in material alone

INDUSTRY: Children’s Products PRODUCT: Car Seat Base

INDUSTRY: Children’s Products PRODUCT: Car Seat Base

DESIGN SOLUTIONS

Model / Mesh Types

DESIGN SOLUTIONS

DESIGN SOLUTIONS

Moldflow Product Families

Moldflow Plastics Advisers

Directional

Simulation Tool

Targeted at Preliminary Part & Mold Design

Part Adviser

Mold Adviser

Answers fundamental manufacturing questions

Will the part fill?

Where are weld

lines and air traps?

Which material?

Where should gates

be located?

Wall Thickness?

DESIGN SOLUTIONS

Moldflow Product Families

Moldflow Plastics Insight

Definitive

Simulation Tool

Industry Best

Breadth & Depth

World’s most popular

in-depth injection molding

simulation software

DESIGN SOLUTIONS

Solution Depth

MPI/Flow

Predicts the flow of plastic throughout the injection molding cycle to ensure quality parts and optimized process. Covers Insert-Molding and 2-Shot Molding.

MPI/Cool

Mold cooling analysis optimizes mold and cooling circuit design to achieve uniform component cooling within the minimum cycle time.

MPI/Warp

Predicts and controls the shrinkage and warpage of plastic parts, ensuring parts are fit for purpose.

DESIGN SOLUTIONS

Solution Depth

MPI/MuCell

Microcellular (MuCell®) injection molding is a process in which a supercritical fluid (SCF) such as carbon dioxide (CO2) or nitrogen (N2) is mixed with molten polymer and injected into the mold to produce microcellular foam.

MPI/Optim

MPI/Optim allows you to perform an injection molding machine-specific analysis which takes into account the actual machine response time, maximum injection velocity, and the number of steps that can be programmed for

velocity and pressure profiles on the machine controller.

MPI/Birefringence

Birefringence is an optical defect that typically manifests as double images and is therefore undesirable in optical lens applications. 3D Birefringence analysis is an add-on option to 3D Warp to predict such occurrences.

DESIGN SOLUTIONS

Solution Depth

MPI/Gas

Optimization of the design and production of Gas Injection Molded (GIM) components.

MPI/Co-Injection

Predicts the injection molding of 2 thermoplastic polymers, and their distribution through the part thickness.

MPI/Injection Compression

Predicts the flow of plastic throughout the injection molding cycle and the effects of the compression process.

DESIGN SOLUTIONS

Solution Depth

MPI/Reactive Molding

Predicts the flow and cure of thermoset plastic to ensure quality parts and optimized process.

MPI/Microchip Encapsulation

Extends Reactive Molding to examine microchip encapsulation, wire sweep and paddle shift.

MPI/Underfill Encapsulation

Extends Reactive Molding to examine the underfill (flip-chip) encapsulation process.

DESIGN SOLUTIONS

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DESIGN SOLUTIONS

Moldflow Communicator (MC)

Results viewer

Anyone can use it

Share Moldflow results

with colleagues around the world

Supports

MPI 6.1 MPA 8

Reads Moldflow results file FREE DOWNLOAD!