1. 1 Improvement of X-Ray Protection Properties of 3D Spacer Fabric by lead powder printing Dariush Semnani, Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran

2. 2 HIGH LIGHT POITS X-Ray Risks Definitions Materials and Expriments Results and discussion Conclusion

3. 3 X-Ray and Risks X-ray was discovered in 1895 by German physicist (Roentgen) and was so named because their nature was unknown at the time. Unlike ordinary light, these rays were invisible, but they traveled in straight lines and affected photographic film. in the same way as light. On the other hand, they were much more penetrating than light and could easily pass through the human body, wood, quite thick pieces of metal and other opaque objects. X-ray is a form of radiant energy, like light or radio waves. Unlike lights, x-ray can penetrate the body which allows a radiologist to produce picture of internal structures. As other medical procedures, X-ray is safe in care usage. Risks for Radiologists and Inspectors

4. 4 The aim of present research Radiologists have to wear special covers. Heavy. Uncomforted to protect. Problems in operations specially in warm weather. Quality controller specialists who control welded parts of vessels, pipe lines and structures. They should be protected against X-ray radiation. Using lead covers in site of construction is unlike because of those of heavy weight and low flexibility In this research, it is tried to make low weight and flexible 3D spacer fabric contained lead particles for making a good protective fabric against X-ray radiation.

5. 5 The aim of present research Radiologists have to wear special covers. Heavy. Uncomforted to protect. Problems in operations specially in warm weather.

6. 6 The aim of present research Quality controller specialists who control welded parts of vessels, pipe lines and structures. They should be protected against X-ray radiation. Using lead covers in site of construction is unlike because of those of heavy weight and low flexibility

7. 7 The aim of present research In this research, it is tried to make low weight and flexible 3D spacer fabric contained lead particles for making a good protective fabric against X-ray radiation.

8. 8 Previous attempts Many researchers have been tried to make new protector products against dangerous radiations Most of those researches have been concerned in treatment process of cotton fabrics to prevent pass of UV radiation. Other attempt was done for heat protection None of them are applicable in preparation of X-ray protection properties of fabric. There is a patent about cloth protective against X-ray in both covering and face protection. Applicable in industry and radiography by using rigid lead sheets. These regular products can be protective against radiation but they are heavy and very rigid.

9. 9 Methodology Spacer fabrics could be 3D structures with free spaces. Made from two layers of warp knitted fabrics and crossed filaments between those layers. Produced on Rachel machine with two needle bars. Spacer fabrics have been improved for using in military, medical, sports and industrial applications.

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11. 11 Methodology Spacer fabrics can be produced in different thicknesses of 20 to 60 millimeters. Shape of fabric and its properties depend on crossed filaments arrangement in fabric. Monofilaments, staple, fantasy, metal, glass and high modulus yarns could be used for spacer fabric. Suitable 3D structure of fabric as a spacer could be compact structure of fabric in both sides with long under laps. Pore structure of inner space of fabric could be made form textured or filament yarns crossed between fabric layers.

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13. 13 Methodology Spacer fabric was produced from Polyester yarn. The test area was 5cm×5cm with weight of 0.9 grams and density of 1.38 (gr/cm3). Lead powder was used to make the spacer fabric as a protective barrier against X-ray. The used lead was code no. 19210, 207.2 gr/mol molecular weight of 0.99 assays from MERC Company. To stick lead particles into spacer fabric a suitable binder was needed. The used binder was HELIZARIN FWT2003 from BASFAKTIENGESELLESCHAFT Company (60 gr/l). This binder was acrylic dispersion solution with white color and solvable in water during printing process. The binder was unsolvable in stabilizer after setting time. The used binder is dilute. Therefore, to stick the lead on the surface, viscosity should be increased. To increase viscosity of binder a little dry synthetic binder of PVA was added to the HELIZARIN. The lead powder has been applied for different samples from 0 to 100 percent of weight of lead and binder mixture.

14. 14 Samples specifications of different lead powder weight percent Pick up (%) Dry time (min) Stab. temp. (°c) Lead % Binder (gr/lit) 10010145-1502060Sample1 10010145-1503060Sample2 10010145-1504060Sample3 10010145-1505060Sample4 10010145-1507560Sample5 10010145-15010060Sample6 –– 060Raw fab.

15. 15 Methodology In this study, image analysis technique was used to investigate effect of X-ray passing from the samples in difference conditions of radiation intensities. Different intensities of X-ray were transited from all of samples by radiology X-ray apparatus while there was sensitive film of radiography behinds of samples. The negatives were prepared and scanned by high resolution of 1200 dpi with uniform backlight. In image processing technique the grayscales have been used to recognize effect of X-ray on negative film. Black and white images were two boundary scales for demonstrating the X-ray effect. The histogram of image pixel intensities could define effect of increasing the lead particles in composite sample as increasing the intensities of image pixels toward light part. In this research, different conditions of X-ray currency intensity and voltage were used. All of the samples were experienced in constant distance of 20 cm from X-ray source.

16. 16 Figure 1: samples of radiography images of fabric composites with a) less, b) medium and c) high value of lead. abc

17. 17 Methodology To study the pass of ray through produced composite samples, negative films of experienced samples with different conditions of X-ray radiation were scanned and analyzed by image processing technique. Dark pixels referred to parts of X-ray passed from fabric sample and the others referred to lead particle parts of fabric as protective parts against X-ray. The histograms of negative films images for composite samples with different lead percent had one pick. For composites with more percent of lead the pick of histogram was near to the light part as intensity of 220-255 (high protective parts) and in composites with less lead percent, pick of histogram was near to dark part with intensity of 0-40 (low protective part). Histograms of negative film images did not present such a normal distribution. They were similar to Gamma distribution. Whereas Gamma distribution had been assumed as phenomena distribution with coefficient of Gamma distribution. In sample size of image with more than 500000 pixels, the distribution is near to "t" distribution of Gamma. The specific variance of samples was acceptable estimation of "t" distribution variance to describe regularity of lead particles distribution in the composite samples.

18. 18 Results The X-ray radiography images were taken from the composite samples in different conditions of X-ray source. condition I: 4mA, 35kV and 70cm condition II: 2.4mA, 35kV and 100cm, condition III: 10mA, 40kV and 70cm, the negative images of the samples were black even the lead plate because of the very high intensity of X-ray source. Therefore, only conditions I and II were considered. Condition III is a critical X radiation which may not occurred in actual situation, generally.

19. 19 Results of mean and variance of negative image pixels intensities (condition I variationMeanSample 9.499934.4839Raw fabric 29.7196143.1738Sample1(20%lead) 41.7115167.9652Sample2(30%lead) 30.9976228.5498Sample3(40%lead) 11.7230241.4836Sample4(50%lead) 12.9021239.9836Sample5(75%lead) 5.2005241.3727Sample6(100%lead) 0.3040241.9001Lead plate

20. 20 Results of mean and variance of negative image pixels intensities (condition II variationmean Sample 9.499934.4839Raw fabric 41.7115167.9652Sample 1(20%lead) 11.7230241.4836Sample 2(30%lead) 1.0753230.4457Sample3(40%lead) 0.3040241.9001Lead plate

21. 21 (a) (b) (c) (d) (e) (a) (b) (c) The histograms of negative images for samples a) 20% lead, b) 50% lead,c)100% lead. The histograms of negative images for samples a) raw fabric, b) 20% lead, c) 50% lead, d) 100% lead and e) lead plate. Increasing lead content

22. 22 Results From 20% to 50% lead component, samples were improved for X-ray protection ability More lead component did not present noticeable protection. Inspection of samples images showed that X-ray was passed via cross lapped filament of inner space of spacer fabric, where no lead particles were located in filament. 50% lead component generated filled inner space of fabric with lead particles which caused the most protection against X-ray. More than 50% lead components could not improve protection ability of composite. The variation of lead particles in composite samples was very noticeable for most of the samples with less than 40% lead component. The variation of lead particles was decreased for samples with more than 50% lead component. The sample with 40% lead components presented acceptable protection ability against X- ray sample with 40% lead component presented very low variation and high mean intensities in negative film. Therefore, the composite sample with 40% lead component was suitable as protective composite for condition I of low intensity source of X-ray.

23. 23 Conclusion Radiologist and x-ray technologists have to wear special covers of lead sheets to protect themselves. This matter leads to many problems in specialists operations in the warm situations. Different samples of fabric composite with different percent of lead component were produced using deep printing procedure of lead and binder mixture. After That, Protection ability of samples against X-ray was investigated using image analysis technique on negative images of samples taken from three different X-ray conditions of sources. Composites 3D fabric with 50% and 40% lead components were suitable barrier for protection against the high and low X-ray sources, respectively. The uniformity of lead particles in sample with 50% lead component was optimum.