The Effect of Radiation Sterilization on the Stress-Strain Properties of Non-Woven Materials -Based on Polypropylene

2020 ◽  
Vol 992 ◽  
pp. 403-408
Author(s):  
Elvina R. Rakhmatullina ◽  
M.S. Lisanevich ◽  
Rezeda Yu. Galimzyanova ◽  
Yu.N. Khakimullin

Non-woven materials are widely used for the manufacture of disposable medical clothing and underwear. Radiation is widely used to sterilize single-use medical devices. The paper analyzes the effect of ionizing radiation at absorbed doses of 0-60 kGy on the stress-strain properties of medical non-woven spanmelt material based on polypropylene obtained by blow-molding technology. It has been established that ionizing radiation significantly reduces the breaking load and elongation in the machine and cross directions of the web. For this type of material, the most critical is the decrease in strength in the cross direction of the web, primarily because the level of strength in the cross direction of spanmelt materials is generally low. Sterilization by ionizing radiation further reduces strength and leads to the fact that non-woven materials irradiated with an absorbed dose of 50-60 kGy are close to unacceptable values in accordance with the requirements of EN 13975-2011.

2021 ◽  
Vol 899 ◽  
pp. 172-178
Author(s):  
Rezeda Yu. Galimzyanova ◽  
Maria S. Lisanevich ◽  
Yuri N. Khakimullin

Radiation sterilization is widely used to sterilize nonwoven SMS medical products. SMS materials have improved filtering and barrier properties, low bacteriopermeability and, due to these properties, are indispensable for medicine. They are used to make such important health care products as disposable surgical clothing and underwear. As a result of the research carried out, the effect of gamma and electron radiation, in the range of absorbed doses from 15 to 25 kGy, on the strength characteristics of nonwoven SMS materials based on polypropylene with a surface density of 35, 40, 50 g/cm2 was studied. It has been established that the strength characteristics (tensile strength, tensile strength, and tear strength) of nonwoven materials decrease after exposure to ionizing radiation. The higher the density of the material, the more its characteristics decrease after radiation sterilization. It was also found that gamma radiation, due to its nature, has a stronger effect on nonwoven materials based on polypropylene, and leads to a stronger decrease in strength characteristics. In general, for products sterilized by ionizing radiation and made from SMS materials, it is important to control the strength characteristics, primarily, the tensile strength in the transverse direction of the web stuff.


2021 ◽  
Vol 2124 (1) ◽  
pp. 012024
Author(s):  
M S Lisanevich ◽  
R Yu Galimzyanova ◽  
V V Ivanov

Abstract At the moment, there is a wide range of bulky nonwovens for various purposes on the market. One of the important areas of using such materials is healthcare. In particular, bulky nonwoven materials are intended for the manufacture of wound dressings, evacuation kits for newborns. Disposable medical devices of this kind are usually subjected to radiation sterilization. As is known from earlier studies, radiation sterilization significantly affects the performance of nonwovens. In this regard, for nonwoven materials for medical use, an important characteristic is the stability of indicators after exposure to radiation sterilization. As a result of the study of bulk nonwovens Holofiber ® after radiation radiation in the dose range from 20-60 kGy, there were no significant changes in operational performance. The stiffness increased by an average of 3-10%. The stiffness indicators after ionizing radiation according to GOST 24684 also meet the requirements. The value of electrification increased due to an increase in the static field under the action of ionizing radiation. It is worth noting that the values of electrification are within the norm established by GOST 32995. The breaking load varies from 1-5%. Thus, non-woven materials Holofiber ® PROFI, article P 35191, Holofiber ® SOFT, article P 5197, Holofiber ® SOFT, article P 5200 are recommended for the production of medical devices.


2021 ◽  
Vol 2124 (1) ◽  
pp. 012015
Author(s):  
R Yu Galimzyanova ◽  
M S Lisanevich ◽  
Yu N Khakimullin

Abstract The effect of electron radiation on the physical and mechanical properties of Sontara nonwoven fabric produced using spunlace technology has been studied. The initial raw material for the manufacture of materials using this technology, as a rule, are viscose, polyester, polypropylene and cellulose fibers. Such nonwovens are highly breathable and are therefore used in disposable surgical gowns and suits. Since radiation can be used to sterilize disposable surgical gowns, it is important to assess the resistance to ionizing radiation. It was found that the Sontara brand material is resistant to the effects of ionizing radiation - the physical and mechanical characteristics of the material (breaking load and relative elongation) in the longitudinal and transverse directions of the web do not significantly change when irradiated with absorbed doses up to 60 kGy. It should also be noted that a cloth with a basis weight of 68 g/m2 has a significant smell of strength after radiation sterilization.


2019 ◽  
Vol 822 ◽  
pp. 355-361
Author(s):  
M.S. Lisanevich ◽  
Rezeda Yu. Galimzyanova ◽  
Elvina P. Rakhmatullina ◽  
Yu.N. Khakimullin ◽  
Ildar N. Musin ◽  
...  

While producing polymers as well as during their processing, a certain amount of stabilizers is introduced into the product, which should ensure polymer properties saving during processing and those of polymer products during storage and operation. However, in cases where medical products based on polypropylene are subjected to radiation sterilization, there are not enough stabilizers in it to save their characteristics during operation. In this regard, we made an assessment of the influence of processing conditions on the properties of polypropylene with a different set of stabilizers in the manufacture of products based on it, in order to assess the degree of influence of each technological operation, including the effects of ionizing radiation during sterilization. Processing and radiation exposure are shown to affect the properties of polypropylene. Nevertheless, the effect of ionizing radiation with an absorbed dose of 40-60 kGy exceeds the negative effect of thermo-oxidative breakdown greatly during the extrusion of PP. Polypropylene containing organophosphorus stabilizers (brand PP 1562R) is more susceptible to breakdown. This is indicated by low values of oxidation induction time, breakdown initial temperature, as well as high values of MFI after exposure to electron radiation. PP brand PP H350FF/1 whose stabilizing complex contains phenol-phosphite antioxidants is more resistant to breakdown during processing and sterilization. For both brands under study, it is apparently necessary to increase the content of stabilizing additives in order to save the properties at the level of the original unexposed material.


1985 ◽  
Vol 48 (12) ◽  
pp. 1016-1018 ◽  
Author(s):  
W. B. VAN DER RIET ◽  
W. H. VAN DER WALT

Radiation inactivation of the ascospores of three strains (M 68–79), NRRL 1125 and NRRL 2614) of the heat resistant mold Byssochlamys fulva suspended in apple juice, was investigated. Whereas the ascospores of strain M 68–79 were significantly more sensitive to ionizing radiation, those of strains NRRL 1125 and NRRL 2614 did not differ significantly from one another in this respect. High numbers of ascospores of the more resistant strains required an absorbed dose of approximately 7.2 kGy (95% confidence interval 6.7 to 7.9 kGy) for inactivation; a decimal reduction dose (D10) of approximately 1.2 kGy was estimated for these strains. Ascospores of strain NRRL 2614 were confirmed as more radiation resistant when a small proportion survived an absorbed dose of 5 kGy and spoiled apple juice within a 3-month storage period. Although it was possible to inactivate B. fulva ascospores at absorbed doses of <10 kGy, it is probable that flavor impairment of apple juice, as well as cost currently limit the feasibility of this process.


2020 ◽  
Vol 64 (11) ◽  
pp. 127-134
Author(s):  
Maria S. Lisanevich ◽  
◽  
Reseda Yu. Galimzyanova ◽  
Ildar N. Musin ◽  
◽  
...  

Currently, there is a tendency for a significant increase in production and expansion of areas of application of nonwoven materials (NM), which are used in almost all areas of human life. Such properties of NMs as hydrophilicity or hydrophobicity, air permeability, good barrier and strength indicators at a relative low cost allow them to be effectively used for medical purposes. Nonwovens for medical use (NMMN) are considered. The most important stage in the final processing of medical devices made of NM is radiation sterilization. The influence of the absorbed dose and the type of ionizing radiation on the properties of NMMN of various designs: obtained by spunlace technology, by spunbond-meltblown-spunbond technology, and laminated nonwoven material has been studied. As a result of the conducted research, it was recommended: to sterilize NM with an electron beam, to control the consumer properties of medical devices from NM to check the quality of products after sterilization by assessing the change in the strength index with elongation, additionally to assess for laminated NM – water resistance, spunlace – absorption. In the production of nonwoven materials, various polymers are used, which have correspondingly different resistance to radiation sterilization. Some materials, for example, based on polypropylene, degrade when exposed to radiation, and the level of technical characteristics of the material is significantly reduced. It is also possible for autooxidative reactions initiated by radiation to occur in polymers, which can continue for a long time after irradiation of articles. To use these materials in radiation sterilized medical devices, it is necessary to have an understanding of the effect of ionizing radiation in a wide range of sterilizing doses on the materials used in these devices.


1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.


Author(s):  
S. Schumann ◽  
U. Eberlein ◽  
C. Lapa ◽  
J. Müller ◽  
S. Serfling ◽  
...  

Abstract Purpose One therapy option for prostate cancer patients with bone metastases is the use of [223Ra]RaCl2. The α-emitter 223Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [223Ra]RaCl2. Methods Multiple blood samples from nine prostate cancer patients were collected before and after administration of [223Ra]RaCl2, up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h – 4 weeks after administration), the α-track frequency remained elevated. Conclusion The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.


2002 ◽  
Vol 45 (spe) ◽  
pp. 115-118
Author(s):  
Nicole Colas-Linhart

In nuclear medicine, radiation absorbed dose estimates calculated by standard models at the whole body or organ are very low. At cellular level, however, the heterogeneity of radionuclide distributions of radiation dose patterns may be significant. We present here absorbed doses at cellular level and evaluate their possible impact on the usually assumed risk/benefit relationships in nuclear medicine studies. The absorbed dose values calculated are surprisingly high, and are difficult to interpret. In the present study, we show calculated doses at the cellular level and discuss possible biological consequences, for two radiopharmaceuticals labelled with technetium-99m: human serum albumin microspheres used for pulmonary scintigrapies and HMPAO used to labelled leukocytes.


In this paper after mentioning the clinical radiation fields of 20 keV-450 MeV/u, they are characterized by the number of particles and their energy. Particle energy is the quantity that determines radiation penetration at the depth at which the tumor is situated (Fig. 1). The number of particles (or beam intensity) is the second major quantity that assures the administration of the absorbed dose in the tumor. The first application shows the radiation levels planned for various radiation fields. Prior to interacting with the medium, the intensity (or energy fluence rate) allows the determination of energy density, energy, power and relativistic force. In the interaction process, it determines the absorbed dose, kerma and exposure. Non-ionizing radiations in the EM spectrum are used as negative energy waves to accelerate particles charged into special installations called particle accelerators. The particles extracted from the accelerator are the source of the corpuscular radiation for high-energy radiotherapy. Of these, light particle beams (electrons and photons) for radiotherapy are generated by betatron, linac, microtron, and synchrotron and heavy particle beams (protons and heavy ions) are generated by cyclotron, isochronous cyclotron, synchro-cyclotron and synchrotron. The ionization dosimetry method used is the ionization chamber for both indirectly ionizing radiation (photons and neutrons) and for directly ionizing radiation (electrons, protons and carbon ions). Because the necessary energies for hadrons therapy are relatively high, 50-250 MeV for protons and 100-450 MeV/u for carbon ions, the alternative to replace non-ionizing radiation with relativistic laser radiation for generating clinical corpuscular radiation through radiation pressure acceleration mechanism (RPA) is presented.


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