3D printing with special materials Graduation Project 2 An-Najah National University Bachelor’s degree in Mechatronics Engineering Students: Supervisor: Saleh Amer  Mohammad Odeh Mohammad Sabra Dr. Bahaa Shaqour Definition and Overview 3D printing, or additive manufacturing, involves creating objects layer by layer from a digital model. This process contrasts with traditional subtractive manufacturing by allowing for more intricate designs and reduced material waste. History of 3D Printing Technology The origins of 3D printing trace back to the 1980s with Charles Hull's invention of stereolithography. Over the years, various techniques and materials have evolved, expanding the technology's applications across numerous industries. Materials Used in 3D Printing 3D printing uses materials like PLA, ABS, TPU, and metals, each affecting strength and flexibility. The document highlights TPU with foaming agents for lightweight, flexible prints. Parts of project Testing of special material(loaded with foaming agent) Mechanical testing setup Printer chamber temperature control TPU loaded with foaming agent (Colorfabb varioshore) VarioShore TPU is a lightweight, soft-touch material with variable shore hardness (92A to 55A) achieved by adjusting printing temperature and flow. It foams between 200–250 °C, expanding up to 1.6× to reduce density and increase softness. Shore hardness Shore hardness : a measure of a material's resistance to indentation, commonly used for polymers like rubber and plastics. Samples Preparation for µCT imaging and Mechanical testing To Prepare the samples we used design of experiment method based on several factors as shown in the figure. Factor A is Temperature, Factor B is speed and Factor C is layer Hight. Quality assessment Visual observation X-Ray Tomography Mechanical testing Visual observation Is to inspect the printed samples for any defects , we took Xray CT images for the samples at sesame in Jordan by using the Beats beam line which is a hard Xray µCT Procedure At first we calibrate the Lense for the desired resolution, then we calibrate the approximate center of rotation, after that we place the sample in front of the Lense to start taking photos of the samples µCT results and analysis As we see in the figure the bubbles formation varies based on the printing parameters And as we see in the figure at the bottom which is the average porosity for the µCT images by the MATLAB code Mechanical testing In our project, we used the ISO 7743 standard to test how rubber behaves under compression. This standard basically tells you how to run the test and what size the samples should be — usually around 29.5 mm wide and 12.5 mm thick. Sticking to the standard helps us get results that are consistent and easy to compare. Whin the sample is tested as we see in the following curve we have an elastic region which if the load is removed the samples will return to its original shape, but if we get to the plastic deformation zone the sample won't get back to its original shape after removing the load. Compression testing curve for differents Shore This graph shows how different rubber materials behave when we press on them, depending on their Shore hardness — that’s basically how hard or soft they are. The x-axis is strain (how much the material gets squished), and the y-axis is stress (how much force we apply). You can see that the harder the material (like Shore 70A), the more pressure it takes to compress it. It resists better, so its curve goes higher. Softer materials, like Shore 50A, compress more easily — their curve stays lower because they don’t need as much force to deform. So overall, this compression test curve helps us see how each type reacts under pressure. Unversial testing machine We built a simple machine to see how strong our 3D-printed. It’s made from some 3D-printed parts, a stepper motor, and a load cell that measures force. The plan was to run the test like this: we put the sample between two plates one stays fix while the other moves as the motor turns the power screw. When the moving part moves, it squeezes the sample, and the sensor shows us how much force it takes until the sample starts to deform. But because of the current situation in the country, we couldn’t get the PCB board, so we couldn’t run the test the way it was planned. Universal testing setup We built our testing machine following a DIY guide, printing the parts ourselves and ordering most electronics from AliExpress since local options were limited or pricey. It took about a month to get everything. After assembling the mechanical parts, we started on the electronics but missed the motor’s microcontroller. We ordered it, but it arrived late due to the situation in the country. When we got it, programming didn’t work right, so we sent the PCB design to the university lab. They found some mistakes, we fixed them, and the PCB was made just before the lockdown. Sadly, we couldn’t pick it up in time. Heating system Chamber temperature is critical in Fused Filament Fabrication (FFF) 3D printing. Impacts print quality, mechanical properties, and dimensional accuracy. Key benefits: Reduces warping and shrinkage. Enhances interlayer adhesion. Improves surface finish and strength. Content: Enclosure: Fireproof, dustproof cover (75x65x55 cm) to maintain stable temperature. Heater: 220V 500W integrated heater with fan for uniform heat distribution. NTC Thermistor: 10kΩ sensor for precise temperature monitoring (±1°C accuracy). Arduino Uno SMD R3: Controls heater via PID and ON/OFF logic. Solid-State Relay (SSR): Safely switches heater on/off. – Implementation Steps The electrical circuit was connected according to the approved schematic. The system was installed inside the enclosed printing chamber. The system was powered up and all components were working properly. The control code was uploaded to the Arduino Nano board. The system was tested at different temperatures (30°C and 40°C). The performance was monitored to ensure efficiency. 30°C was found to be optimal for printing. When 30°C was reached, the system automatically shuts down to maintain thermal stability. – Arduino Setup Set the target temperature to 30°C. Adjust the hysteresis to adjust the stability. Connect an NTC 10K temperature sensor to pin A0 to read data. Connect an SSR to the digital pin D9 to control the heater. The Arduino Uno was powered via a USB cable connected to the computer. ON/OFF control In the ON/OFF control system, the setpoint was set at 30°C. The temperature reached the desired value within 40 seconds, but exceeded 31°C due to residual heat in the heater after it was disconnected. When the setpoint was raised to 40°C, the system took approximately 110 seconds to reach it, showing slower response at higher temperatures. on off 30 Temperature(C) 2.02 4.03 6.05 8.06 10.08 12.09 14.11 16.12 18.14 20.149999999999999 22.17 24.19 26.2 28.22 30.23 32.25 34.270000000000003 36.28 38.299999999999997 40.31 42.33 44.34 46.36 48.38 50.39 52.41 54.42 56.44 58.45 60.47 62.48 64.5 66.510000000000005 68.53 70.55 72.56 74.58 76.59 78.61 80.63 82.64 84.66 86.67 88.69 90.71 92.72 94.74 96.75 98.77 100.79 102.8 104.82 106.83 108.85 110.86 112.88 114.9 116.91 118.93 120.94 122.96 124.98 126.99 129.01 131.02000000000001 133.04 135.06 137.07 139.09 141.1 143.12 145.13 147.15 149.16999999999999 151.18 153.19999999999999 155.21 157.22999999999999 159.25 161.26 163.28 165.3 167.31 169.33 171.34 173.36 175.37 177.39 179.41 181.42 183.44 185.45 187.47 189.49 191.5 193.52 195.53 197.55 199.57 201.58 203.6 205.61 207.63 209.64 211.66 213.68 215.69 217.71 219.72 221.74 223.76 225.77 227.79 229.8 231.82 233.84 235.85 237.87 239.88 241.9 243.91 245.93 247.95 25.13 25.31 25.67 25.94 26.3 26.66 27.11 27.56 27.93 28.29 28.66 29.12 29.48 29.85 30.13 30.51 30.69 30.88 30.97 31.07 31.16 30.97 30.97 31.07 30.97 30.97 30.88 30.88 30.69 30.6 30.51 30.6 30.51 30.41 30.41 30.41 30.23 30.13 30.13 30.13 30.04 29.95 29.95 30.04 30.13 30.23 30.23 30.13 30.23 30.13 30.13 30.04 30.32 30.04 30.04 30.04 30.04 30.13 30.13 30.13 30.13 30.13 30.13 30.04 30.13 30.04 30.04 29.95 29.95 30.04 30.04 30.04 30.04 30.23 30.13 30.13 30.04 30.04 30.04 30.04 29.95 30.04 30.13 30.13 30.13 30.13 30.13 30.13 30.13 30.13 29.95 30.04 30.13 30.04 30.04 30.04 30.13 30.04 30.13 30.04 30.13 30.04 30.04 30.04 30.04 30.04 30.04 29.95 30.13 30.04 30.13 30.13 29.95 30.13 30.04 30.04 29.95 30.04 30.04 30.13 30.04 30.04 30.04 Time(S) Temp C on off 40 2.02 4.03 6.05 8.06 10.08 12.09 14.11 16.12 18.14 20.16 22.17 24.19 26.2 28.22 30.23 32.25 34.270000000000003 36.28 38.299999999999997 40.31 42.33 44.34 46.36 48.37 50.39 52.4 54.42 56.44 58.45 60.47 62.48 64.5 66.510000000000005 68.53 70.540000000000006 72.56 74.569999999999993 76.59 78.61 80.62 82.64 84.65 86.67 88.68 90.7 92.71 94.73 96.75 98.76 100.78 102.79 104.81 106.82 108.84 110.86 112.87 114.89 116.9 118.92 120.93 122.95 124.96 126.98 129 131.01 133.03 135.04 137.06 139.08000000000001 141.09 143.11000000000001 145.12 147.13999999999999 149.15 151.16999999999999 153.19 155.19999999999999 157.22 159.22999999999999 161.25 163.26 165.28 167.3 169.31 171.33 173.34 175.36 177.37 179.39 181.41 183.42 185.44 187.45 189.47 191.48 193.5 195.52 197.53 199.55 201.56 203.58 205.59 207.61 209.63 211.64 213.66 215.67 217.69 219.7 221.72 223.74 225.75 227.77 229.78 231.8 233.81 235.83 237.85 239.86 241.88 243.89 245.91 247.92 249.94 251.96 253.97 255.99 258 260.02 262.02999999999997 264.05 266.07 268.08 270.10000000000002 272.11 274.13 276.14 278.16000000000003 280.17 282.19 284.20999999999998 286.22000000000003 288.24 290.25 292.27 294.2900000 0000002 296.3 298.32 300.33 302.35000000000002 304.36 306.38 308.39999999999998 310.41000000000003 312.43 314.44 316.45999999999998 318.47000000000003 320.49 322.51 324.52 326.54000000000002 328.55 330.57 332.58 334.6 336.61 338.63 340.65 342.66 344.68 346.69 348.71 350.73 352.74 354.76 356.77 358.79 360.8 362.82 364.83 366.85 368.87 370.88 372.9 374.91 376.93 378.95 380.96 382.98 384.99 387.01 389.02 391.04 393.06 395.07 397.09 399.1 401.12 403.13 405.15 407.17 409.18 411.2 413.21 415.23 417.24 419.26 421.27 423.29 425.31 427.32 429.34 431.35 433.37 435.39 437.4 439.42 441.43 443.45 445.46 447.48 449.5 451.51 453.53 455.54 457.56 459.58 461.59 463.61 26.66 26.66 27.02 27.29 27.47 27.93 28.29 28.75 29.02 29.48 29.85 30.13 30.6 30.97 31.26 31.82 31.92 32.39 32.68 33.06 33.450000000000003 33.840000000000003 34.130000000000003 34.42 34.619999999999997 35.01 35.21 35.51 35.81 35.909999999999997 36.21 36.409999999999997 36.51 36.82 36.92 37.22 37.43 37.53 37.74 37.840000000000003 38.049999999999997 38.15 38.36 38.46 38.57 38.78 38.99 39.090000000000003 39.200000000000003 39.409999999999997 39.520000000000003 39.520000000000003 39.840000000000003 39.840000000000003 39.94 40.049999999999997 40.159999999999997 39.94 39.94 39.94 39.729999999999997 39.729999999999997 39.729999999999997 39.729999999999997 39.840000000000003 39.94 39.94 40.049999999999997 39.94 40.049999999999997 40.049999999999997 40.049999999999997 39.840000000000003 39.729999999999997 39.729999999999997 39.729999999999997 39.619999999999997 39.729999999999997 39.840000000000003 39.840000000000003 40.049999999999997 40.049999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.840000000000003 39.94 39.840000000000003 39.94 39.94 40.049999999999997 40.049999999999997 40.049999999999997 39.94 39.94 39.729999999999997 39.619999999999997 39.729999999999997 39.619999999999997 39.84 0000000000003 39.840000000000003 40.159999999999997 40.049999999999997 40.159999999999997 40.159999999999997 40.049999999999997 39.94 39.840000000000003 39.729999999999997 39.619999999999997 39.840000000000003 39.729999999999997 39.729999999999997 40.049999999999997 40.049999999999997 40.159999999999997 40.049999999999997 39.94 39.94 39.840000000000003 39.840000000000003 39.840000000000003 39.840000000000003 39.840000000000003 40.049999999999997 40.049999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.94 39.840000000000003 39.840000000000003 39.840000000000003 39.840000000000003 39.94 40.049999999999997 40.049999999999997 40.159999999999997 40.159999999999997 39.94 39.94 39.840000000000003 39.840000000000003 39.729999999999997 39.840000000000003 39.94 40.049999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.840000000000003 39.840000000000003 39.619999999999997 39.729999999999997 39.729999999999997 39.840000000000003 39.840000000000003 40.049999999999997 40.159999999999997 40.159999999999997 40.159999999999997 40.049999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.840000000000003 39.840000000000003 39.840000000000003 40.159999999999997 40.159999999999997 40.049999999999997 40.049999999999997 40.049999999999997 39.94 39.840000000000003 39.840000000000003 39.729999999999997 39.94 39.94 40.049999999999997 40.049999999999997 40.26 40.049999999999997 40.049999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.729999999999997 39.840000000000003 39.840000000000003 40.049999999999997 40.159999999999997 40.159999999999997 40.159999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.729999999999997 39.729999999999997 39.729999999999997 39.94 39.94 40.159999999999997 40.159999999999997 40.26 40.049999999999997 39.729999999999997 39.840000000000003 39.729999999999997 39.729999999999997 39.840000000000003 39.94 39.94 40.159999999999997 40.159999999999997 40.159999999999997 40.049999999999997 39.94 39.840000000000003 39.840000000000003 39.729999999999997 39.840000000000003 39.94 ON/OFF control The system is in equilibrium at 40°C. When the chamber door is opened, the temperature drops to about 35°C and stabilizes. When the door is closed, the system returns to equilibrium at 40°C. on off 40 with disturbance Temperature(C) 2.02 4.03 6.05 8.06 10.08 12.09 14.11 16.12 18.14 20.16 22.17 24.19 26.2 28.22 30.23 32.25 34.270000000000003 36.28 38.299999999999997 40.31 42.33 44.34 46.36 48.37 50.39 52.4 54.42 56.44 58.45 60.47 62.48 64.5 66.510000000000005 68.53 70.540000000000006 72.56 74.569999999999993 76.59 78.61 80.62 82 .64 84.65 86.67 88.68 90.7 92.72 94.73 96.75 98.76 100.78 102.79 104.81 106.82 108.84 110.86 112.87 114.89 116.9 118.92 120.93 122.95 124.97 126.98 129 131.01 133.03 135.05000000000001 137.06 139.08000000000001 141.09 143.11000000000001 145.12 147.13999999999999 149.16 151.16999999999999 153.19 155.19999999999999 157.22 159.22999999999999 161.25 163.27000000000001 165.28 167.3 169.31 171.33 173.34 175.36 177.38 179.39 181.41 183.42 185.44 187.45 189.47 191.49 193.5 195.52 197.53 199.55 201.56 203.58 205.6 207.61 209.63 211.64 213.66 215.67 217.69 219.71 221.72 223.74 225.75 227.77 229.78 231.8 233.82 235.83 237.85 239.86 241.88 243.89 245.91 247.93 249.94 251.96 253.97 255.99 258 260.02 262.04000000000002 264.05 266.07 268.08 270.10000000000002 272.11 274.13 276.14 278.16000000000003 280.18 282.19 284.20999999999998 286.22000000000003 288.24 290.25 292.27 294.29000000000002 296.3 298.32 300.33 302.35000000000002 304.36 306.38 308.39 310.41000000000003 312.42 314.44 316.45999999999998 318.47000000000003 320.49 322.5 324.52 326.52999999999997 328.55 330.57 332.58 334.6 336.61 338.63 340.64 342.66 344.67 346.69 348.7 350.72 352.74 354.75 356.77 358.78 360.8 362.81 364.83 366.84 368.86 370.88 372.89 374.91 376.92 378.94 380.95 382.97 384 .98 387 389.02 391.03 393.05 395.06 397.08 399.09 401.11 403.13 405.14 407.16 409.17 411.19 413.2 415.22 417.23 419.25 421.26 423.28 425.3 427.31 429.33 431.34 433.36 435.37 437.39 439.4 441.42 443.44 445.45 447.47 449.48 451.5 453.51 455.53 457.54 459.56 461.58 463.59 465.61 467.62 469.64 471.65 473.67 475.68 477.7 479.72 481.73 483.75 485.76 487.78 489.79 491.81 493.82 495.84 497.86 499.87 501.89 503.9 505.92 507.93 509.95 511.96 513.98 516 518.01 520.03 522.04 524.05999999999995 526.07000000000005 528.09 530.1 532.12 534.13 536.15 538.16999999999996 540.17999999999995 542.20000000000005 544.21 546.23 548.24 550.26 552.27 554.29 556.30999999999995 558.32000000000005 560.34 562.35 564.37 566.38 568.4 570.41 572.42999999999995 574.45000000000005 576.46 578.48 580.49 582.51 584.52 586.5 4 588.55999999999995 590.57000000000005 592.59 594.6 596.62 598.63 600.65 602.66 604.67999999999995 606.70000000000005 608.71 610.73 612.74 614.76 616.78 618.79 620.80999999999995 622.82000000000005 624.84 626.85 628.87 630.89 632.9 634.91999999999996 636.92999999999995 638.95000000000005 640.96 642.98 645 647.01 649.03 651.04 653.05999999999995 655.07000000000005 657.09 659.1 661.12 663.14 665.15 667.17 26.21 26.39 26.75 27.11 27.56 28.11 28.47 28.93 29.39 29.85 30.23 30.6 31.07 31.44 32.01 32.299999999999997 32.68 33.06 33.35 33.840000000000003 34.229999999999997 34.42 34.82 35.21 35.409999999999997 35.61 35.909999999999997 36.21 36.51 36.82 37.119999999999997 37.33 37.53 37.74 37.94 38.15 38.36 38.57 38.67 38.880000000000003 39.090000000000003 39.090000000000003 39.409999999999997 39.520000000000003 39.619999999999997 39.840000000000003 39.94 40.159999999999997 40.049999999999997 40.26 40.049999999999997 40.049999999999997 39.94 39.729999999999997 39.619999999999997 39.729999999999997 39.729999999999997 39.729999999999997 39.840000000000003 39.840000000000003 39.94 40.159999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.94 39.94 39.729999999999997 39.729999999999997 39.729999999999997 39.619999999999997 39.729999999999997 39.840000000000003 40.049999999999997 40.159999999999997 40.159999999999997 40.26 40.049999999999997 39.94 39.840000000000003 39.619999999999997 39.840000000000003 39.729999999999997 39.840000000000003 39.94 40.049999999999997 40.159999999999997 40.26 40.159999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.729999999999997 39.619999999999997 39.840000000000003 39.94 40.049999999999997 40.159999999999997 40.159999999999997 40.159999999999997 40.049999999999997 39.94 39.840000000000003 39.729999999999997 39.729999999999997 39.729999999999997 39.840000000000003 39.94 39.94 40.159999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.94 39.840000000000003 39.840000000000003 39.729999999999997 39.840000000000003 39.840000000000003 39.94 40.049999999999997 40.159999999999997 40.159999999999997 40.049999999999997 40.049999999999997 39.840000000000003 39.729999999999997 39.619999999999997 39.619999999999997 39.299999999999997 38.99 38.67 38.57 38.36 38.25 38.15 37.94 37.840000000000003 37.74 37.630000000000003 37.43 37.33 37.22 37.020000000000003 36.82 36.71 36.61 36.409999999999997 36.51 36.409999999999997 36.31 36.11 36.11 36.01 36.01 35.909999999999997 35.909999999999997 35.909999999999997 35.909999999999997 35.81 35.909999999999997 35.81 35.71 35.71 35.71 35.61 35.61 35.51 35.51 35.409999999999997 35.51 35.409999999999997 35.31 35.31 35.31 35.31 35.21 35.21 35.11 35.11 34.909999999999997 35.01 35.01 34.909999999999997 34.909999999999997 35.01 34.909999999999997 34.82 34.909999999999997 34.909999999999997 34.909999999999997 35.01 35.01 35.01 34.82 34.909999999999997 34.909999999999997 34.909999999999997 34.909999999999997 34.909999999999997 34.72 34.72 34.72 34.82 34.72 34.82 34.909999999999997 34.909999999999997 34.909999999999997 34.82 34.909999999999997 35.01 34.909999999999997 35.01 35.01 35.01 35.21 35.11 35.11 35.21 35.21 35.21 35.21 35.21 35.31 35.21 35.21 35.21 35.31 35.21 35.11 35.01 35.01 34.909999999999997 34.82 34.909999999999997 34.72 34.72 34.82 34.72 34.72 34.72 34.72 34.619999999999997 34.619999999999997 34.520000000000003 34.619999999999997 34.42 34.520000000000003 34.520000000000003 34.520000000000003 34.619999999999997 34.619999999999997 34.619999999999997 34.72 34.619999999999997 34.520000000000003 34.520000000000003 34.520000000000003 34.520000000000003 34.520000000000003 34.520000000000003 34.42 34.42 34.42 34.42 34.520000000000003 34.619999999999997 34.909999999999997 35.01 35.31 35.51 35.909999999999997 36.01 36.409999999999997 36.82 37.020000000000003 37.33 37.43 37.630000000000003 37.94 38.15 38.36 38.46 38.78 38.880000000000003 39.090000000000003 39.409999999999997 39.409999999999997 39.729999999999997 39.94 40.049999999999997 40.159999999999997 40.26 40.369999999999997 40.159999999999997 40.159999999999997 39.94 39.729999999999997 39.520000000000003 39.619999999999997 39.729999999999997 39.840000000000003 39.840000000000003 39.94 40.159999999999997 40.159999999999997 40.159999999999997 39.94 40.049999999999997 39.94 39.840000000000003 39.840000000000003 39.729999999999997 39.94 39.94 40.049999999999997 40.049999999999997 40.159999999999997 40.159999999999997 40.049999999999997 39.94 39.94 39.729999999999997 39.840000000000003 39.729999999999997 39.94 40.049999999999997 40.159999999999997 40.049999999999997 Time(S) Temp C PID control After experimenting with ON/OFF control, we used a PID system via the Arduino library, but encountered problems. We switched to a hybrid control system that starts with ON/OFF and then transitions to PID via PWM. We adjusted the PID parameters experimentally to achieve a fast response without overshoot. When testing the disturbance by opening the chamber door at 40°C, the temperature dropped to 33°C, then gradually returned to a steady state after the door was closed, as shown in Figures This table shows the performance of a temperature control system under different conditions, using two control methods. Condition Overshoot (%) Settling Time (s) Rise Time (s) ON/OFF 30°C 3.8 110 20 ON/OFF 40°C 0.4 185 84 ON/OFF 40°C w/ Disturbance 1.3 107 75 PID 30°C 3.7 95 29 PID 40°C w/ Disturbance 3.0 173 55 General Notes: ON/OFF Performance: More stable at higher temperatures (40°C) with less overshoot, but slower response. PID Performance: Provides faster response in some situations, but may be less stable under disturbances. Disturbances: Impact the performance of both systems, but their effect on the PID is more pronounced in the increased settling time. Print sample of ASA material With heating system Without heating system Conclusion We improved the chamber temperature using PID to keep it stable. Building the testing machine was challenging but taught us a lot — especially problem-solving and teamwork. Compression testing will help us understand how our flexible, foam-like TPU material holds up under pressure, which is key for real-world use. µCT imaging helped us to understand how the bubble formation and distribution accrues in the material Future work Improving chamber temperature control accuracy by using multiple sensors and an advanced PID system to reduce temperature variation. Perform mor testing on the material such as taking CT images while applying compression and tension loads Completing the testing machine by connecting all the electrical components to the pcb and calibrating the device. Enhancing the safety by adding a ventilation system with HEPA/activated carbon filters to reduce harmful emissions. we dedicate this work to our families and our people in Palestine and to all those who love us as well Thank you for listening. Your questions ? image1.bin image2.gif image3.png image4.jpeg image5.png image6.png image7.png image8.png image9.jpeg image10.png image11.png image12.jpeg image13.jpg image14.png image15.png image16.png image17.jpg image18.png image19.jpeg image20.png image21.png image22.jpeg image23.png image24.jpg image25.png image26.png image27.jpeg image28.jpeg image29.jpeg image30.jpeg image31.jpeg image32.jpeg /docProps/thumbnail.jpeg