Performance of Corrugated Pipe Manufactured with Recycled Polyethylene Content (2011)

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F-1 A P P E N D I X F Proposed Draft Standard for Recycled Content Containing HDPE Resin Formulations for Corrugated Pipe Made to AASHTO Standard M252-Recycled

F-2 DRAFT ____________________________________________________________ Draft Standard Specification for RECYCLED CONTAINING HDPE FOR CORRUGATED PIPE MADE TO AASHTO STANDARD M252-RECYCLED AASHTO Draft Standard XXX-XX ____________________________________________________________ 1. SCOPE 1.1 This specification covers the quality of HDPE resin formulations containing recycled HDPE that are intended for use in AASHTO M252–Recycled approved corrugated drainage pipe for subsurface drainage applications, sizes 75- to 250- mm diameter (3-10 in.). 1.2 The recycled polyethylene may be either post-commercial or post-industrial. 1.3 This specification presents a set of properties and test frequencies to be met for the resin. 1.4 This specification can be used by suppliers of resin containing recycled PE as part of manufacturing quality control (MQC), or by pipe manufacturers or independent bodies as manufacturing quality assurance (MQA). ______________________________________________________________________ 2. REFERENCED DOCUMENTS 2.1 ASTM Standards: D638, Test Method for Tensile Properties of Plastics D792, Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement D1238, Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer D1505, Test Method for Density of Plastics by the Density-Gradient Technique D3895, Standard Test Method for Oxidative-Induction Time of Polyolefins by Differential Scanning Calorimetry D4218, Test Method for Determination of Carbon Black Content in Polyethylene Compounds By the Muffle-Furnace Technique D4703, Practice for Compression Molding Thermoplastic Materials into Test Specimens, Plaques, or Sheets D5630, Test Method for Ash Content in Plastics F2136, Standard Test Method for Notched, Constant Ligament-Stress (NCLS) Test to Determine Slow-Crack-Growth Resistance of HDPE Resins or HDPE Corrugated Pipe

F-3 ______________________________________________________________________ 3. TERMINOLOGY 3.1 Mixed-Color PCR-HDPE – Post-Consumer Recycled HDPE that is composed of mostly colored detergent bottles. 3.2 Natural PCR-HDPE – Post-Consumer Recycled HDPE that is composed of milk bottles. 3.3 Post-Consumer Recycled HDPE (PCR-HDPE) – Polyethylene that has been discarded by consumers after use, then collected, cleaned, and washed. The density is greater than 0.940 g/cm3 and typical sources include primarily bottles and some bags. 3.4 PCR-HDPE Regrind – Post-Consumer Recycled HDPE that has been cleaned, washed and ground into plastic chips. 3.5 Post-Industrial Recycled HDPE (PIR-HDPE) - Polyethylene that has been obtained for recycling from industrial sources. This may include industrial scrap, rejected parts, or surplus goods. 3.6 Reprocessed PCR-HDPE - Post-Consumer Recycled HDPE that has been cleaned, washed, melt-filtered, and pelletized. Commonly known as “Repro.” ______________________________________________________________________ 4. REQUIRED PROPERTIES 4.1 The required properties for corrugated pipe resins containing recycled HDPE are given in Table 1. Specific details of the tests are found in Section 7. Table 1. Required properties for M252 resins containing recycled HDPE. Property Test Method Sample Specified Value Frequency Density ASTM D1505 ASTM D792 Pellets/Plaque 0.948a g/cm 1 per shift Melt Index ASTM D1238 190°C/2.16 Kg Pellets/Plaque <1.0 g/10 min 1 per shift % Volatiles 175°C/1 Hour Pelletsb <0.2 % Certifyc % Carbon Black ASTM D4218 Pellets/Plaque 2-4 % 1 per shift % Ash ASTM D5603 Pellets/Plaque <0.75 % 1 per shift

F-4 % PP DSC Section 7.6 Plaque <7.5 % 1 per lotd Yield Stress ASTM D638e Plaque >3500 psi 1 per lot Break Strain ASTM D638f Plaque >150 % 1 per lot NCLS Stress Crack Test ASTM F2136 Plaque >20 hrs 1 per lot OIT ASTM D3895 Pellets/Plaque >25 ming 1 per lot a Correct for carbon black by Dcor = D – 0.0044C, where C is % carbon black. b Tested on pellet samples before melt blending. c Manufacturer will provide a certificate stating their material will lose less than 0.2% of its weight when a 2.000 ± 0.100 g sample is heated at 350ºF for 1 hour. d A production lot is defined as either a truckload, or one compartment of a railcar. Its weight is generally between 40,000 and 50,000 lbs. e Strain rate shall be 2.0 in. per minute, assume 1.3 in. gage. f Assume 2.0” gage length. gA common additive package that meets this requirement is 1000 ppm Irganox 1010 plus 500 ppm Irgaphos 168, or an equivalent. ______________________________________________________________________ 5. SAMPLING 5.1 A production lot shall be considered as a truckload or shipping container full of 1,500 lb boxes of resin, or one compartment of a railcar. The weight is normally between 40,000 and 50,000 lbs. 5.2 Sample a truckload by obtaining 0.5 lb of material from each of eight boxes, for a total of 4 lbs of resin. This is about every fourth box. Combine the eight samples to form a lot sample. 5.3 Sample a compartment of a railcar by obtaining 2 lb from the top and 2 lb from the bottom of the compartment. Combine the two samples to form a lot sample. Therefore, each railcar will have four lot samples for evaluation. 5.4 The entire lot sample shall be dry blended before sample preparation. A convenient way to do this is by hand in a 5-gallon plastic pail. 5.5 The lot sample shall be divided into two; one for immediate testing and the other for validation testing, should the need arise. The back-up sample shall be kept for 90 days after the resin is sold. 5.6 Clearly label the sample and include a traceable production number and a date. ______________________________________________________________________ 6. SAMPLE PREPARATION

F-5 6.1 Homogenize about 2 lb (900 g) of material by melt blending, preferably with a twin screw laboratory extruder. A two roll mill is also acceptable. 6.2 The blended material shall be compression molded into plaques according to ASTM D4703, with the use of a 15°C/min. cooling rate. 6.3 The plaques shall be 1.9- 0.08-mm (0.075- 0.003-in.) thick for tensile and NCLS testing. 6.4 Allow the plaques to equilibrate at standard laboratory conditions (72°F, 50% RH) for at least 12 hours before they are tested. ______________________________________________________________________ 7. TEST METHODS 7.1 Test Conditions – Unless otherwise specified in the test methods or in this specification, conduct tests at the standard laboratory temperature of 23 2°C (73.4 3.6°F). 7.2 Density – Test methods ASTM D1505 or D792 are acceptable. Make three separate determinations using separate pellets or separate portions of a plaque. The plaque thickness shall be 1.9 0.08 mm (0.075 .003 in.). Calculate and report the average and standard deviation from the mean. Correct the density value for % carbon black by subtracting 0.0044 g/cm3 for each percent of carbon black. 7.3 Melt Index – Test method ASTM D1238, using Condition 190/2.16. Make duplicate determinations on either pellets or a plaque and calculate the average. 7.4 % Volatiles – This test shall be performed in aluminum pans that have been heated at 350°F (177°C) until they obtain a constant weight. 7.4.1 Test duplicate samples. 7.4.2 Weigh 2.000 ± 0.100 g of pellets or a plaque to an accuracy of three places past the decimal point into an aluminum pan. 7.4.3 Place the pan in a forced-air recirculating oven preheated and stabilized to 350 ± 5°F (177 2°C) for a period of 1 hour. 7.4.4 Remove the pan and let it completely cool to room temperature in a desiccator. 7.4.5 Reweigh the pan and calculate the percentage weight loss of the sample. Report the average to the nearest 0.01%. 7.5 % Ash - Test method ASTM D5630, Procedure B. 7.5.1 Sample size shall be 2 g.

F-6 7.5.2 Heat for 5 minutes at 800°C. 7.5.3 Test triplicate samples. 7.6 % Polypropylene 7.6.1 A melting curve shall be generated by differential scanning calorimetry (DSC) at a heating rate of 10°C/min from room temperature to 200°C. See Figure 1. Figure 1. DSC curve of HDPE containing PP generated. 7.6.2 Expand the curve to a range that includes the end of the HDPE peak and the complete PP peak. See Figure 2. Figure 2. DSC curve of HDPE containing PP expanded. 7.6.3 Integrate the curve from a flat point before the PP melting to a point where the PP curve returns to baseline. -4 -3 -2 -1 0 H ea t F lo w (W /g) 20 40 60 80 100 120 140 160 180 200 Temperature (°C)Exo Up Universal V4.5A TA Instruments 162.84°C 150.59°C 2.568J/g 142.71°C -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 H ea t F lo w (W /g) 130 140 150 160 170 180 Temperature (°C)Exo Up Universal V4.5A TA Instruments

F-7 7.6.4 The point where the HDPE melt returns to baseline will be marked. The end of the HDPE melt and the beginning of the PP melt will not necessarily be the same point . 7.6.5 Record the HDPE end-of-melt temperature and the PP heat of fusion in J/g. 7.6.6 Calculate the theoretical heat of fusion for 100% polypropylene for the portion of the PP melting curve that does not overlap with HDPE by: Y = -0.035X 2 + 8.851X – 475.6 (1) Where: X = HDPE end-of-melt temperature (°C) And Y = H f of 100% PP not overlapped with HDPE. For X = 142.7, Y = 74.7 J/g. 7.6.7 Calculate the percentage PP by: %PP = H f sample/ H f 100% PP x 100 (2) For H f sample = 2.57 J/g, %PP = 3.4 % 7.6.8 Test two specimens from different parts of the molded plaque and report the average. 7.7 Yield Stress/Break Strain – Test by ASTM Method D638, with a Type IV dumbbell at 2”/min crosshead speed. 7.7.1 Test five specimens, individually measured for thickness. 7.7.2 2.0-in. gage length, use crosshead to follow displacement. 7.7.3 Report five results, average, and standard deviation. 7.8 NCLS Stress- Crack Test – Test 1.9-mm plaque for slow crack growth with ASTM F2136 with a notch depth of 20% of the test specimen thickness and under an applied load of 4100 kPa (600 psi). 7.8.1 Test five replicates and report the average and standard deviation. 7.9 Oxidative Induction Time (OIT) – Test by ASTM D3895 at 200°C in oxygen in duplicate and report the average time. ___________________________________________________________________ 8. RETEST AND REJECTION

F-8 8.1 If any failure occurs, the material shall be retested to establish conformity in accordance to the specified property. A second failed result will result in rejection of the lot for the purposes of this specification. ______________________________________________________________________ 9. CERTIFICATION 9.1 Upon request of the purchaser in the contract or order, a manufacturer’s certification that the material was manufactured and tested in accordance with this specification, together with a report of the test results, shall be furnished at the time of shipment.