JEC COMPOSITES MAGAZINE - Issue #70 - January/February 2012 - 53

Table 5: Weight comparison between aluminium tray arm and tray arms made with LNP Thermocomp* EC006PXQ and EC008PXQ compounds

6061 and 19% compared to die-cast aluminium for a release quantity of 1,000 parts.

Tray arm material
Machined aluminium EC006PXQ EC008PXQ

Tray arm material 0.2425 0.1315 0.1364

Weight reduction compared to Al tray arm (%)

Conclusions
In this study, LNP* Thermocomp* materials based on Ultem PEI resin and containing 40% and 30% carbon fibre reinforcement were evaluated in a food tray arm application proof of concept to validate that engineering thermoplastic composites can successfully replace metals in various applications. To maximize part performance, it might be necessary to redesign the part to accommodate the difference in mechanical behaviour between metals and plastic compounds. If designed properly, parts made with high-modulus, high-strength engineering thermoplastic compounds could be excellent alternatives to metal parts, providing the benefits of weight reduction (and, consequently, carbon emissions reduction), cost savings and design flexibility. n
* Trademarks of SABIC Innovative Plastics IP B.V. More information: www.sabic-ip.com References 1. American Airlines website: www.aa.com/i18n/amrcorp/newsroom/fuel-smart.jsp 2. U.S. Environmental Protection Agency website: www.epa.gov/otaq/climate/420f05001.htm#calculating

46 44

Tray arms made with EC008PXQ material will provide better stiffness and lower deflection with great load-bearing capacity, while tray arms made with EC006PXQ material will provide even greater load-bearing capacity with some compromise in stiffness and deflection.

Weight savings and cost reduction
The thermoplastic composite tray arms made with the EC006PXQ and EC008PXQ compounds will not only help deliver excellent performance, but also provide significant weight savings and cost benefits. Table 5 shows the individual weight of the closed-end, spider-rib tray arms made with the EC006PXQ and EC008PXQ materials, as well as the weight of a dual-rib, open-ended aluminium tray arm of similar size and shape. The data indicates that the tray arms made with the EC006PXQ and EC008EXQ materials result in a 46% and 44% weight saving, respectively, as compared to the machined aluminium tray arms. For an airline with approximately 600 planes having 200 seats per plane on average, this weight reduction translates to 0.5 million gallons of fuel saved and 9.9 million lbs of CO2 eliminated per year1,2. Table 6 shows the relative cost per tray arm made with EC008PXQ material and different grades of aluminium for release quantities of 5,000 and 10,000 parts. These are normalized costs based on estimates provided by Vaupell. Using the EC008PXQ compound will result in a 77% cost saving compared to aluminium 7075, 73% compared to aluminium
Table 6: Cost comparison between an aluminium tray arm and tray arms made with LNP Thermocomp EC008PXQ compound for release quantities of 5,000 and 10,000 parts

Relative cost/part Tray arm material Maximum stress
Al 7075 Al 6061 Stress in the rib/core intersection

$1.00 $0.86

$1.00 $0.85

Al 380 (die cast)

$0.30 $0.25

$0.28 $0.23

EC008PXQ

No70 January - February 2012 /

jec composites magazine 53

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JEC COMPOSITES MAGAZINE - Issue #70 - January/February 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #70 - January/February 2012