1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2010 03 04 Revised See Summary of Revisions J. Souza, SA 2006 09 29 Revised Inserted 3.0; Deleted 3.1, 3.2, 3.3, 3.10 & 4 1996 02 08 Activated J.D. Rehkopf L.R. Gullen Printed copies are uncontrolled Copyright 2010, Ford Global Technologies, L
2、LC Page 1 of 8 COMPOSITE, FUEL TANK HIGH DENSITY WSL-M98D29-A POLYETHYLENE (PE-HD), LINEAR LOW DENSITY POLYETHYLENE (PE-LLD) TIE LAYERS, ETHYLENE VINYL ALCOHOL (E/VAL) BARRIER 1. SCOPE The material defined by this specification is a thermoplastic blow molded composite based on high molecular weight
3、PE-HD, E/VAL and PE-LLD tie layers (Figure 1). This specification defines a composite material used in manufacturing of blow molded fuel tanks and similar articles. The composite consists of a coextruded and blow molded high density polyethylene, barrier layer of ethylene/vinyl alcohol and tie layer
4、s of linear low density polyethylene, and has excellent chemical resistance and low fuel permeation characteristics. 2. APPLICATION This specification was released originally for materials used for composite fuel tanks which meet CARB/EPA Clean Air Act Requirements in Passenger Car and Truck Applica
5、tions. 3. REQUIREMENTS 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.1.1 All requirements of this specification, identified by symbol (s), shall be met with data
6、 representing 3 sigma values. 3.4 MOLDED TEST SPECIMEN 3.4.1 Preparation of Test Specimens The following tests shall be performed on test specimens cut (in accordance with the ISO methods specified) from blow molded fuel tanks. Specimens are tested with the as-molded thickness of the fuel tank and a
7、re not machined to meet the thickness requirements of the Standard Test Methods except where necessary for fixturing. Greater variation in test values can be anticipated when evaluating materials that are thinner than recommended by an applicable Industry Standard/Test Method. The following dimensio
8、ns are required: A. 150 min x 20/10 +/- 0.2 mm (Tensile Bar, ISO 527) B. 80 x 10 +/- 0.2 mm (Flexure Bar, ISO 178) C. 60 x 10/3, r = 15 mm (Tensile Impact Bar, ISO 8256) ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 2
9、 of 8 3.4.2 Density 0.940 - 0.960 (ISO 1183, Method A) g/cm33.4.3 Tensile Properties (ISO 527, 50 mm/minute test speed, 150 min x 20/10 +/- 0.2 mm specimen) 3.4.3.1 Tensile Strength at 20 MPa Yield, min (Test Method according to para 3.4.3)3.4.3.2 Elongation at Yield, min 10% (Test Method according
10、to para 3.4.3)3.4.3.3 Elongation at Break of 25% E/VAL Layer, min (Test Method according to para 3.4.3, noting that E/VAL layer typically fractures before PE layers) 3.4.3.4 Elongation at Break of 40% PE-HD Layer, min (Test Method according to para 3.4.3, reflecting first fracture of one of the PE-H
11、D layers) Note: Yield is defined as the first point on the engineering stress-strain curve at which the stress does not increase with increasing strain. Break of E/VAL layer (para 3.4.3.3) can be detected by an audible cracking sound. Break of PE-HD layer (para 3.4.3.4) is the first fracture of the
12、regrind or PE-HD layers. 3.4.4 Flexural Modulus, min 750 MPa (ISO 178, 80 x 10 +/- 0.2 mm specimen, 2 mm/minute test speed, 64 mm support span) 3.4.5 Tensile Impact Strength, min (ISO 8256, 60 x 10/3, r = 15 mm specimen / ASTM D1822 Type L) 3.4.5.1 At 23 +/- 2 C, min 100 kJ/m2 / 200 kJ/m23.4.5.2 At
13、-40 +/- 2 C, min 30 kJ/m2 /175 J/m23.4.6 Heat Deflection Temperature, min (ISO 75, 120 x 10 +/- 0.2 mm specimen, 0.32 +/- 0.01 mm deflection) 3.4.6.1 At 1.82 MPa 35 C ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 3 of
14、 8 3.4.7 Heat Aging Performance (ISO 188, except 150 +/- 50 air changes/ h, 1000 h at 120 +/- 2 C. Unaged property values shall be determined at the time of the aged properties determination) 3.4.7.1 Tensile Strength at +/- 25% change Yield (Test Method per para 3.4.3.1) 3.4.7.2 Tensile Impact Stren
15、gth 80 kJ/m2min at 23 C, max and +/- 50% (Test Method per para change max 3.4.5.1) 3.4.8 Adhesion Strength, min 3 N/mm (FLTM BO 101-06, T-Peel test, 127 x 12.7 mm specimen, 50 mm/min) 3.4.9 Resistance to Fuel (ISO 1817, complete immersion in fuel at 40 +/- 2 C for 1000 h) Testing is to be completed
16、within 30 minutes after the coupons have been removed from the fuel. Coupons should be wrapped in aluminum foil as long as practical between removal and testing to minimize drying. The following requirements shall be met for: Fuel C +15% Methanol 3.4.9.1 Tensile Strength at 16 MPa Yield, min (Test M
17、ethod per para 3.4.3.1) 3.4.9.2 Elongation at Yield, min 10% (Test Method per para 3.4.3.2) 3.4.9.3 Adhesion Strength, min 2 N/mm (Test Method per para 3.4.8) In addition, there shall be no evidence of delamination after fuel soak. 3.4.10 Fuel Swell (ASTM D 471, 75 x 25 mm specimen, immersed in Fuel
18、 C +15% Methanol at 40 +/- 2 C for 1000 h) 3.4.10.1 Linear Swell, max 8% 3.4.10.2 Weight Gain, max 15% ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 4 of 8 3.5 FLAMMABILITY (ISO 3795) Burn Rate, max 100 mm/minute The
19、specimen size required for material approval is 355 x 100 +/- 0.1 mm, with an as-molded thickness close to 3 mm (the min allowable tank wall thickness). The specimen should have a relatively smooth surface. 3.6 ENVIRONMENTAL STRESS CRACKING RESISTANCE (ASTM D 1693, Sample Type A F50, 10% Igepal at 5
20、0 +/- 0.5 C) Across Flow 1000 h min Specimen dimensions to be as specified in the ASTM procedure. Tank coupons which are thicker than this specification are to be milled or ground down on the inner HDPE surface to the proper thickness. Notch is to be applied to the exterior HDPE surface (see Figure
21、1.). 3.7 E/VAL BARRIER LAYER, % of total composite 2 - 5% Thickness Or Specified on Engineering Drawing 3.8 TIE LAYER, % of total composite thickness 1.5 +/- 0.75% (on each side of E/VAL barrier layer) 3.9 REGRIND Regrind material from production sources of WSL-M98D29-A fuel tank material. The regri
22、nd material may only be used in the second-most exterior layer of the composite, on the exterior side of the outer tie layer (see Figure 1). 3.9.1 Regrind Layer Thickness, % of total 45% fuel tank wall thickness, max 3.9.2 Agglomerate Particle Size of E/VAL Within Regrind (blow molded part) (Visual
23、Standard) Note: Agglomerate E/VAL particle size and shape are significant characteristics. Using a microtome, obtain thin sections ( 40 micrometer thick) of the composite structure and mount on glass slides using Canada Balsam. View at 350 - 500 x magnification using an optical microscope which has
24、a calibrated scale. E/VAL particles appear dark and may be more distinct if stained with iodine solution prior to microtoming. E/VAL particles in the regrind layer must be uniformly dispersed (Compare with Visual Master provided in the Control Plan). Max dimension of agglomerate E/VAL particles 15 m
25、icrometer (Compare with Visual Master provided in the Control Plan) ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 5 of 8 5. GENERAL INFORMATION The information given below is provided for clarification and assistance
26、in meeting the requirements of this specification. 5.1 SHEAR MODULUS AT 23 C 400 - 700 MPa (ASTM D 4065, 0.1% stain, fixed frequency of 1 Hz) Additionally, a Shear Modulus vs. Temperature curve is to be plotted over -50 to +100 C at 5 C intervals min. The curve should be within the tolerance range s
27、hown on page 8 of this specification. 5.2 TENSILE STRENGTH AT BREAK, min For Record (ISO 527, 50 mm/min test speed, 150 min x 20/10 +/- 0.2 mm specimen) Break is complete fracture of the entire composite specimen. 5.3 RESISTANCE TO FUEL (ISO 1817, complete immersion in fuel at 40 +/- 2 C for 1000 h)
28、 Testing is to be completed within 30 minutes after the coupons have been removed from the fuel. Coupons should be wrapped in aluminum foil as long as practical between removal and testing to minimize drying. The following requirements shall be met for: Fuel C +15% Methanol 5.3.1 Tensile Strength at
29、 Break, min For Record (Test Method per para 5.2) 5.4 HEAT DEFLECTION TEMPERATURE, min (ISO 75, 120 x 10 +/- 0.2 mm specimen, 0.32 +/- 0.01 mm deflection) 5.4.1 At 0.45 MPa 50 C 5.5 COEFFICIENT OF LINEAR THERMAL EXPANSION (ASTM E 831 TMA, temperature range -30 C to +30 C) PE-HD 11-19 x 10-5/C Tie La
30、yer 10 x 10-5/C E/VAL 5 x 10-5/C 5.6 RAW MATERIALS The raw materials (PE-HD, E/VAL, and PE-LLD - based tie layer), which are formulated to comprise the blow molded composite fuel tank material, are controlled in the Control Plan. The Control Plan is on file at the materials activity in the manufactu
31、ring plant. 5.7 RECYCLING CODE PE-HD,PE-LLD,E/VAL ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 6 of 8 PE-HD w/ carbon blackRegrind (optional)PE-HDE/VAL BarrierTie LayerTie LayerFIGURE 1 ENGINEERING MATERIAL SPECIFICA
32、TIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 7 of 8 ENGINEERING MATERIAL SPECIFICATIONWSL-M98D29-APrinted copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 8 of 8 6. SUMMARY OF REVISIONS 2010 03 04 Revised Item 3.4.2 Density lower limit Added ASTM D1822 methodology to 3.4.5 Tensile Impact Strength, min Added 10% Igepal concentration to 3.6 Environmental Stress Cracking Resistance Changed No cracking to F50, 10% Igepal, Across Flow to specify to 3.6 Environmental Stress Cracking Resistance
