Alcore Aluminum Tooling Conversion Via Composite Manufacturing

Senior Design Fall 2010, University of Delaware

Department of Mechanical Engineering

Zachary Melrose, Thomas Mulrooney, Kyle Steelmen, Brian Traylor

Introduction VARTM Process LIMS Simulation

Permeability Tool Assembly Validation

Project Description Alcore is one of the world’s leaders in providing lightweight structural

honeycomb materials for use in many industries. Alcore utilizes 5-axis

CNC machining and specialized aluminum tooling to create complex but

precise core materials for their customers. Our project is to create an

efficient process to convert one of Alcore’s current aluminum tools into a

composite material tool.

5 axis mill

cutting head

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Aluminum Tool

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[Justin B. Alms, Nuno

Correia, Suresh G. Advani

and Edu Ruiz.

Experimental Procedures

to Run Longitudinal

Injections to Measure

Unsaturated Permeability

of LCM Reinforcements]

Vacuum Assisted Resin Transfer Molding (VARTM) will be the process

utilized to form the composite tool.

Tool Fusion 3A/3B will be the resin used in the VARTM process.

Part must be cured in an autoclave to complete the VARTM process and to

ensure dimensional integrity.

The LIMS software displays resin flow as a function of time for a

given part.

LIMS simulations aide in the proper placement of injection and

vacuum lines.

Reveals dry spots, areas where resin flow is absent.

Our LIMS analysis will depict a variety of resin flow situations for

Airtech’s Toolfusion 3 resin.

Figure (5) below, Toolfusion’s viscosity curves are

depicted at different temperatures correlating with

their respective pot life.

Figure (4) above, LIMS simulation at with

injection and vacuum lines placed at the

center of the part. Part is completely filled

in 3.3 hrs.

Figure (2) left, Cross-Section of

part undergoing VARTM

Results

Figure (1) below, Aluminum Part

illustration

Figure (6)

Project Scope Create a negative part by laying composite on the aluminum tool via

VARTM

Final part will be made by using the VARTM process with the negative

part as the parent mold.

Needs and Wants Reusable- Up to 100 uses

Versatile- Adaptable to different part

geometries

Dimensional Stability- 1/100 inch

Durability- Resistant to damage

Cost- Affordability of the system

Light Weight

Simple Design- Expedite production

Compatibility- With supporting Structure

To ensure the dimensions of the composite part

match the dimensions of the original aluminum tool

within the allowed tolerance, the two surfaces will be

compared

Using a high precision optical scanner ,we can

obtain an accurate graphical representation of the

composite part to compare to the original CAD Model

To test the deflection of the tool under load, the tool

will be subjected to elastic deformations up to the

tolerance limit to determine the maximum load.

The final weight of the part will be compared to the

aluminum tool, and using the NIOSH Lifting

Equation, we can determine the improvements in

materials handing ease.

Figure (3) right, Glass fiber

VARTM . The plastic bag

creates an airtight vacuum on

the aluminum part allowing for

the resin to flow over the glass

fiber.

During VARTM practice runs, our team experienced

low vacuum pressure due to leaks because of the

parts complex geometry.

Our team decided to manufacture and assemble 3

separate pieces to eliminate these bagging issues

while still maintaining the tool’s dimensional stability.

Figure 9 shows the completed tool with all three

pieces assembled.

Figure 4 shows how the resin will flow with the worst case scenario

parameters.

Pressure is set at 20 in. Hg. significantly lower than expected value.

Viscosity is set at 650 cps, 200 cps higher than that of our resin.

Thickness is set at .2 in. the maximum thickness that our team will use.

Resin Flow Front

Injection Inlet

Vacuum Outlet

Figure (9) above

VARTM Negative of

Surface

Infuse Side Panels

Infuse Positive tooling

surface within negative from

prior step

Final Construction

Composite Mold Replica

Flip over tooling surface, and

assembly with adhesives

Original Mold