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1

Studies on the Gases Emission of Moulding and Core Sands with an Inorganic Binder Containing a Relaxation Additive

Bobrowski A., Żymankowska-Kumon S., Kaczmarska K., Drożyński D., Grabowska B.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 2

19--25

EN

The paper presents the results of an investigation of the gases emission of moulding sands with an inorganic (geopolymer) binder with a relaxation additive, whose main task is to reduce the final (residual) strength and improves knocking-out properties of moulding sand. The moulding sand without a relaxation additive was the reference point. The research was carried out using in accordance with the procedure developed at the Faculty of Foundry Engineering of AGH - University of Science and Technology, on the patented stand for determining gas emissions. Quantification of BTEX compounds was performed involving gas chromatography method (GC).The study showed that the introduction of relaxation additive has no negative impact on gas emissions - both in terms of the total amount of gases generated, as well as emissions of BTEX compounds. Among the BTEX compounds, only benzene is emitted from the tested moulding sands. Its emission is associated with the introduction a small amount of an organic hardener from the group of esters.

2

Structural Studies (FTIR, XRD) of Sodium Carboxymethyl Cellulose Modified Bentonite

Cukrowicz S., Grabowski B., Kaczmarska K., Bobrowski A., Sitarz M., Tyliszczak B.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

119--125

EN

The study investigates the effect of the organic compound representing the cellulose derivative - sodium salt of carboxymethyl cellulose (CMC/Na) on the structure of the main component of bentonite (B) - montmorillonite (MMT). Structural analysis revealed that the CMC/Na of different viscosity interacts with the mineral only via surface adsorption, causing at the same time partial or full delamination of its layered structure. This was confirmed by the XRD diffraction tests. Such polymer destructive influence on the structure of the modified main component of the bentonite limits the use of its composites as an independent binder in moulding sand technology, but does not exclude it from acting as an additive being a lustrous carbon carrier. According to the IR spectra of the B/CMC/Na materials, it can be stated that the interaction between the organic and inorganic parts is based on the formation of hydrogen bonds. That kind of the interpretation applies especially to the MMT modified in the bentonite with a lower viscosity polymer. The characteristics of the main IR absorption bands for composites with a higher viscosity polymer indicates the formation of less stable structures suggesting the random nature of the hydrogen bonds formation.

3

Influence of the Atmosphere on the Type of Evolved Gases from Phenolic Binders

Żymankowska-Kumon S., Kaczmarska K., Grabowska B., Bobrowski A., Cukrowicz S.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 1

31--36

EN

The problem of harmful casting resins has been present in foundries for many years. Manufacturers are introducing new products that contain in their composition environmentally and eco-friendly ingredients. Unfortunately, not all types of technology can be used, sometimes environmental benefits are disproportionate to the quality of castings and their price. In the foundry industry, the most popular binders are based on organic compounds (often carcinogenic) and other harmful substances. Due to strict legal regulations regarding environmental protection, as well as care for the foundry's workers' comfort - their occurrence should be reduce to a minimum. These compounds often behave also depending on the conditions of use (temperature, atmosphere). The application of various methods of thermal analysis and spectroscopic methods allows to verify the mechanism of resin decomposition process in relation to conditions in the form in both inert and oxidizing atmosphere. For analysis the resins from cold-box technology, were used TG–DTG–DSC, Py-GC/MS methods and specified the course of changes occurring in combination of different atmosphere.

4

Study of Thermal Degradation of Starch-Based Binder by TG-DTG-DSC, Py-GC/MS and DRIFTS

Kaczmarska K., Żymankowska-Kumon S., Grabowska B., Bobrowski A., Cukrowicz S.

Archives of Foundry Engineering

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2019

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iss. 4

21--26

EN

This paper focuses on the thermal behavior of the starch-based binder (Albertine F/1 by Hüttenes-Albertus) used in foundry technology of molding sand. The analysis of the course of decomposition of the starch material under controlled heating in the temperature range of 25- 1100°C was conducted. Thermal analysis methods (TG-DTG-DSC), pyrolysis gas chromatography coupled with mass spectrometry (Py- GC/MS) and diffuse reflectance spectroscopy (DRIFT) were used. The application of various methods of thermal analysis and spectroscopic methods allows to verify the binder decomposition process in relation to conditions in the form in both inert and oxidizing atmosphere. It was confirmed that the binder decomposition is a complex multistage process. The identification of CO2 formation at set temperature range indicated the progressive process of decomposition. A qualitative evaluation of pyrolysis products was carried out and the course of structural changes occurring in the presence of oxygen was determined based on thermo-analytical investigations the temperature of the beginning of binder degradation in set condition was determined. It was noticed that, significant intensification of Albertine F/1 sample decomposition with formation of more degradation products took place at temperatures above 550ºC. Aromatic hydrocarbons were identified at 1100ºC.

5

Studies of Poly(Acrylic Acid-co-Maleic Acid) Sodium Salt Intercalated Montmorillonite

Grabowska B., Cukrowicz S., Kurleto-Kozioł Ż., Kaczmarska K., Drożyński D., Sitarz M., Bobrowski A.

Archives of Foundry Engineering

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2019

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iss. 4

67--75

EN

The intercalation into interlayer spaces of montmorillonite (MMT), obtained from natural calcium bentonite, was investigated. Modification of MMT was performed by the poly(acrylic acid-co-maleic acid) sodium salt (co-MA/AA). Efficiency of modification of MMT by sodium salt co-MA/AA was assessed by the infrared spectroscopic methods (FTIR), X-ray diffraction method (XRD) and spectrophotometry UV-Vis. It was found, that MMT can be relatively simply modified with omitting the preliminary organofilisation – by introducing hydrogel chains of maleic acid-acrylic acid copolymer in a form of sodium salt into interlayer galleries. A successful intercalation by sodium salt of the above mentioned copolymer was confirmed by the powder X-ray diffraction (shifting the reflex (001) originated from the montmorillonite phase indicating an increase of interlayer distances) as well as by the infrared spectroscopy (occurring of vibrations characteristic for the introduced organic macromolecules). The performed modification causes an increase of the ion exchange ability which allows to assume that the developed hybrid composite: MMT-/maleic acid-acrylic acid copolymer (MMT-co- MA/AA) can find the application as a binding material in the moulding sands technology. In addition, modified montmorillonites indicate an increased ability for ion exchanges at higher temperatures (TG-DTG, UV-Vis). MMT modified by sodium salt of maleic acid-acrylic acid copolymer indicates a significant shifting of the loss of the ion exchange ability in the direction of the higher temperature range (500–700°C).

6

Thermal Deformation of Moulding and Core Sands with an Inorganic Binder Containing a Relaxation Additive

Bobrowski A., Drożyński D., Jakubski J., Szumera M., Kaczmarska K., Grabowska B.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 4

93--98

EN

The paper presents the results of an investigation of the thermal deformation of moulding sands with an inorganic (geopolymer) binder with a relaxation additive, whose main task is to reduce the final (residual) strength and improves knocking-out properties of moulding sand. The moulding sand without a relaxation additive was the reference point. The research was carried out using the hot-distortion method (DMA apparatus from Multiserw-Morek). The results were combined with linear deformation studies with determination of the linear expansion factor (Netzsch DIL 402C dilatometer). The study showed that the introduction of relaxation additive has a positive effect on the thermal stability of moulding sand by limiting the measured deformation value, in relation to the moulding sand without additive. In addition, a relaxation additive slightly changes the course of the dilatometric curve. Change in the linear dimension of the moulding sand sample with the relaxation additive differs by only 0.05%, in comparison to the moulding sand without additive.

7

Influence of Carbon Fibers Addition on Selected Properties of Microwave-Cured Moulding Sand Bonded with BioCo2 Binder

Grabowska B., Kaczmarska K., Cukrowicz S., Drożyński D., Żymankowska-Kumon S., Bobrowski A., Gawluk B.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

152--160

EN

It was found that the addition of carbon fibers (CFs) does not affect the crosslinking process in the microwave radiation (800 W, 2.45 GHz) of the BioCo2 binder, which is a water solution of poly(acrylic acid) and dextrin (PAA/D). It has influence on BioCo2 thermal properties. The CFs addition improves the thermostability of a binder and leads to the reduction of gas products quantity generated in the temperature range of 300-1100°C (TG-DTG, Py-GC/MS). Moreover, it causes the emission of harmful decomposition products such as benzene, toluene, xylene and styrene to be registered in a higher temperatures (above 700°C). BioCo2 binder without CFs addition is characterized by the emission of these substances in the lower temperature range. This indicates the positive effect of carbon fibers presence on the amount of released harmful products. The selected technological tests (permeability, friability, bending strength, tensile strength) have shown that the moulding sand with the 0.3 parts by weight carbon fibers addition displays the worst properties. The addition of 0.1 parts by weight of CFs is sufficient to obtain a beneficial effect on the analyzed moulding sands properties. The reduction of harmful substances at the higher temperatures can also be observed.

8

Effect of Silicate Modifier on the Emission of Harmful Compounds from Phenolic Resin used in Cold-Box Technology

Żymankowska-Kumon S., Bobrowski A., Drożyński D., Grabowska B., Kaczmarska K.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

151--156

EN

In many foundries, the requirements placed on castings production have risen mainly over the few years. Further trends in recent years have been the ever increasing level of automation and introduction of new alloys, especially composites. On the other hand, the foundry environment has become increasingly difficult because is used many organic binders. Environmental regulations will be further tightened up. These processes are pursued at national, European and global level. Conformity with emission limits is becoming increasingly difficult. The problem is emission of aromatic hydrocarbons, phenol, odours and other harmful compounds to environment. The main purpose of many companies is reduction of this toxins. The new cold-box systems (based on phenolic resins) try to reduce the emission by introducing into the resin structure silicate modifiers. Research presented of this article evaluate the effectiveness of these methods. The results show comparison of two resins ("without" and "with" silicate modifier) for assessment of emission of harmful aromatic hydrocarbons and phenol.

9

Analysis of Structural Changes in Starch- Aluminosilicate Binder and Molding Sand with its Participation after Physical Curing

Kaczmarska K., Grabowska B., Cukrowicz S., Bobrowski A., Żymankowska-Kumon S.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

138--143

EN

The organo-inorganic commercial binder Albertine F/1 (Hüttenes-Albertus) constituting the starch-aluminosilicate mixture was directed to structural studies. The paper presents a detailed structural analysis of the binder before and after exposure to physical curing agents (microwaves, high temperature) based on the results of infrared spectroscopy studies (FTIR). An analysis of structural changes taking place in the binder system with the quartz matrix was also carried out. Based on the course of the obtained IR spectra, it was found that during the exposure on physical agents there are structural changes within the hydroxyl groups in the polymeric starch chains and silanol groups derived from aluminosilicate as well as in the quartz matrix (SiO2). The curing of the molding sand takes place due to the evaporation of the solvent water and the formation of intramolecular and intermolecular cross-linking hydrogen bonds. Type and amount of hydrogen bonds presence in cured molding sand have an impact on selected properties of molding sand. Results indicates that for molding sand with Albertine F/1 during conventional heating a more extensive network of hydrogen bonds is created.

10

Badania strukturalne (FTIR, DRIFT) skrobi eteryfikowanej CMS-Na0,6 pod kątem zastosowania w technologii mas formierskich

Kaczmarska K., Grabowska B.

Prace Instytutu Odlewnictwa

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2017

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Vol. 57, no. 2

137--149

PL

Do badań strukturalnych (FTIR) i termoanalitycznych (DRIFT) skierowano modyfikowaną skrobię w postaci soli sodowej karboksymetyloskrobi (CMS-Na0,6) w formie w yjściowej stanowiącej roztwór koloidalny oraz w postaci usieciowanej na drodze fizycznej (temperatura, promieniowanie mikrofalowe). Zmodyfikowaną skrobię CMS-Na0,6 otrzymano na drodze eteryfikacji skrobi ziemniaczanej. W pierwszej części artykułu przedstawiono analizę strukturalną CMS-Na0,6 przed i po usieciowaniu czynnikami fizycznymi w oparciu o wyniki badań spektroskopii w podczerwieni (FTIR) uzyskanych techniką transmisyjną. W drugiej części ustalono zmiany strukturalne w eteryfikowanej skrobi, stosując technikę spektroskopii rozproszonego odbicia w zakresie średniej podczerwieni (DRIFT), rejestrując widma on-line w zakresie temperatury 25−500°C. Na podstawie przebiegów otrzymanych widm IR stwierdzono, że podczas działania czynników fizycznych (temperatura, promieniowanie mikrofalowe) dochodzi do usieciowania koloidu CMS-Na0,6 wskutek całkowitego odparowania wody rozpuszczalnikowej, a dalej dehydratacji i utworzenia wewnątrzcząsteczkowych i międzycząsteczkowych sieciujących wiązań wodorowych. Metodą spektroskopową DRIFT ustalono postęp termicznego rozkładu, jakiemu CMS-Na0,6 podlegał podczas kontrolowanego wzrostu temperatury w zakresie 25−500°C. Ustalono, że proces degradacji termicznej rozpoczyna się już w temperaturze 280°C. Przeprowadzona analiza otrzymanych wyników badań strukturalnych stanowi dopełnienie prac badawczych w zakresie zastosowania eteryfikowanej skrobi jako spoiwa w technologii mas formierskich.

EN

Structural (FTIR) and thermo-analytic (DRIFT) studies were conducted on modified starch in the form of sodium salt of carboxymethyl starch (CMS-Na0.6) in the initial state, i.e. a colloidal solution, and in a cross-linked form prepared by physical means (temperature, microwave radiation). Modified starch CMS-Na0.6 was obtained by way of etherification of potato starch. The first part of the article presents the structural analysis of CMS-Na0.6 before and after cross-linking by means of physical factors based on the results of infrared spectroscopy tests (FTIR) obtained with the use of the transmission technique. The second part identifies the structural changes in the etherified starch with the use of Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT), recording the spectra in the temperature range of 25−500°C. Based on the courses of the obtained IR spectra, it was established that during the operation of physical factors (temperature, microwave radiation), cross-linking of the colloid CMS-Na0.6 was observed as a result of total evaporation of the solvent water and next dehydration and formation of intra- and intermolecular cross-linking hydrogen bonds. The spectroscopic method DRIFT was applied to determine the progress of the thermal decomposition of CMS-Na0.6 during a controlled temperature increase in the range of 25−500°C. It was established that the process of thermal degradation begins already at 280°C. The performed analysis of the obtained structural test results constitutes a complementation of the research conducted in the scope of applying etherified starch as a binder in moulding sand technology.

11

Welcome to the Journal of Casting and Materials Engineering

Grabowska B., Górny M., Brzeziński M., Jakubski J., Bobrowski A., Kaczmarska K.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 1

1

12

TG-DTG-DSC, FTIR, DRIFT, and Py-GC-MS Studies of Thermal Decomposition for Poly(sodium acrylate)/Dextrin (PAANa/D) – New Binder BioCo3

Grabowska B., Kaczmarska K., Bobrowski A., Żymankowska-Kumon S., Kurleto-Kozioł Ż.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 1

27--32

EN

TG-DTG-DSC, FTIR, DRIFT, and Py-GC-MS studies have been conducted to determine the effect of the thermal decomposition conditions and structure of foundry binder BioCo3 in the form of a composition poly(sodium acrylate)/dextrin (PAANa/D) on the progress of degradation in terms of processes occurring in foundry sands in contact with liquid metal. TG-DTG-DSC curves of the composition allowed us to determine the temperature range in which they do not undergo degradation, by which they do not lose their binding properties. With temperature increasing, physical and chemical changes occur that are related to the evaporation of solvent water (20–110°C), followed by the release of constitution water, and finally intermolecular dehydration (110–230°C). In this temperature range, processes that are mainly reversible take place. Within a temperature range of 450–826°C, polymer chains are decomposed, including the decomposition of side chains. Within a temperature range of 399–663°C, polymer composition decomposition can be observed (FTIR, DRIFT), and gas products are generated from this destruction (Py-GC-MS).

13

TG/DTG/DTA, FTIR and GC/MS Studies of Oil Sand for Artistic and Precision Foundry with the Emission of Gases Assessment

Bobrowski A., Żymankowska-Kumon S., Drożyński D., Grabowska B., Kaczmarska K.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

25--30

EN

The paper presents the results of thermoanalytical studies by TG/DTG/DTA, FTIR and GC/MS for the oil sand used in art and precision foundry. On the basis of course of DTG and DTA curves the characteristic temperature points for thermal effects accompanying the thermal decomposition reactions were determined. This results were linked with structural changes occurred in sample. It has been shown that the highest weight loss of the sample at temperatures of about 320°C is associated with destruction of C-H bonds (FTIR). In addition, a large volume of gases and high amounts of compounds from the BTEX group are generated when liquid metal interacts with oil sand. The results show, that compared to other molding sands used in foundry, this material is characterized by the highest gaseous emissions and the highest harmfulness, because benzene emissions per kilogram of oil sand are more than 7 times higher than molding sand with furan and phenolic binders and green sand with bentonite and lustrous carbon carrier.

14

Studies on the Gases Emission under High Temperature Condition from Moulding Sands Bonded by Modified Starch CMS-Na

Kaczmarska K., Bobrowski A., Żymankowska-Kumon S., Grabowska B.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 1

79--82

EN

Emission of gases under high temperature after pouring molten metal into moulds, which contain the organic binder or other additives (solvents or curing agent), may be an important factor influencing both on the quality of the produced castings, and on the state of environment. Therefore, a comprehensive studies of the emitted gases would allow to determine restrictions on the use of the moulding sands in foundry technologies, eg. the probability of occurrence of casting defects, and identify the gaseous pollutants emitted to the environment. The aim of the research presented in this paper was to determine the amount of gases that are released at high temperatures from moulding sands bonded by biopolymer binder and the quantitative assessment of the emitted pollutants with particular emphasis on chemical compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The water-soluble modified potato starch as a sodium carboxymethyl starch with low (CMS-NaL) or high (CMS-NaH) degree of substitution was a binder in the tested moulding sands. A tests of gases emission level were conducted according to the procedure developed at the Faculty of Foundry Engineering (AGH University of Science and Technology) involving gas chromatography method (GC). The obtained results of the determination of amount of BTEX compounds generated during the decomposition process of starch binders showed lower emission of aromatic hydrocarbons in comparison with binder based on resin Kaltharz U404 with the acidic curing agent commonly used in the foundries.

15

Polymer Binder BioCo3 with Silicates and its Application to Microwave-Cured Moulding Sand

Grabowska B., Kaczmarska K., Bobrowski A., Drożyński D., Żymankowska-Kumon S., Cukrowicz S.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

51--60

EN

The effects of silica additive (Poraver) on selected properties of BioCo3 binder in form of an aqueous poly(sodium acrylate) and dextrin (PAANa/D) binder were determined. Based on the results of the thermoanalytical studies (TG-DTG, FTIR, Py-GC/MS), it was found that the silica additive results in the increase of the thermostability of the BioCo3 binder and its contribution does not affect the increase in the level of emissions of organic destruction products. Compounds from group of aromatic hydrocarbons are only generated in the third set temperature range (420-838°C). The addition of silicate into the moulding sand with BioCo3 causes also the formation of a hydrogen bonds network with its share in the microwave radiation field and they are mainly responsible for maintaining the cross-linked structures in the mineral matrix system. As a consequence, the microwave curing process in the presence of Poraver leads to improved strength properties of the moulding sand […]. The addition of Poraver's silica to moulding sand did not alter the permeability of the moulding sand samples, and consequently reduced their friability. Microstructure investigations (SEM) of microwave-cured samples have confirmed that heterogeneous sand grains are bonded to one another through a binder film (bridges).

16

Detection of nitrates(V) and sulfates(VI) by UV-Vis spectrophotometry method in used green sand bonded by bentonite with modified starch addition

Grabowska B., Kurleto-Kozioł Ż., Szymański Ł., Kaczmarska K., Bobrowski A.

Metallurgy and Foundry Engineering

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2016

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Vol. 42, no. 4

203--211

EN

The research results (SEM, UV-Vis) that contain a part of the work connected with determining the influence of a modified starch addition on the physical and chemical property changes of green sands (including the emission levels of harmful substances from the used molding sands formed as a result of the liquid metal pouring of molds) are presented in this paper. A surface analysis (SEM) was performed for the fresh molding sands and used molding sands with and without modified starch samples. On the bases of the received microscopic images, the impact of the temperature factor on the morphology of the molding sand samples after the liquid metal pouring process are assessed. In the second part of the performed work on the UV-Vis research, eluates from two used molding sands (green sand [sand number 1] and green sand with the addition of a modified starch [sand number 2]) were tested for nitrate and sulfate content. In order to determine whether the level of nitrate and sulfate elusion from the used molding sands is permissible, the received results were compared with the Minister of Environment’s regulations concerning the requirements of surface waters used for supplying the population with potable water.

PL

W artykule przedstawiono wyniki badań (SEM, UV-Vis), wchodzących w zakres prac związanych z określeniem wpływu dodatku modyfikatu skrobiowego na zmianę właściwości fizycznych i chemicznych mas wiązanych bentonitem, w tym na poziom wydzielania substancji szkodliwych ze zużytych mas powstałych w procesie zalewania formy ciekłym metalem. Analizę powierzchniową (SEM) przeprowadzono dla próbek klasycznych mas świeżych i zużytych bez dodatku i z dodatkiem modyfikatu skrobiowego. Na podstawie otrzymanych zdjęć mikroskopowych oceniono wpływ czynnika temperatury na morfologię próbek masy po procesie zalewania formy ciekłym metalem. W drugiej części wykonanych prac badaniom UV-Vis na zawartość azotanów(V) i siarczanów( VI) poddano eluaty przygotowane z udziałem dwóch mas zużytych, tj.: klasycznej masy formierskiej (masa I) oraz klasycznej masy formierskiej z dodatkiem modyfikatu skrobiowego (masa II). W celu określenia poziomu wymywalności azotanów(V) i siarczanów(VI) ze zużytych mas otrzymane wyniki porównano z obowiązującym Rozporządzeniem Ministra Środowiska z dnia 27 listopada 2002 r. w sprawie wymagań, jakim powinny odpowiadać wody powierzchniowe wykorzystywane do zaopatrzenia ludności w wodę przeznaczoną do spożycia.

17

Crosslink the Novel Group of Polymeric Binders BioCo by the UV-radiation

Grabowska B., Kaczmarska K., Bobrowski A., Kurleto-Kozioł Ż, Szymański Ł.

Archives of Foundry Engineering

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2016

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Vol. 16, iss. 2

85--88

EN

The spectroscopic FT-IR and FT-Raman methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands (as a novel group binders BioCo). The cross-linking was performed by physical agent, applying the UV-radiation. The results of structural studies (IR, Raman) confirm the overlapping of the process of cross-linking polymer composition PAA/CMS-Na in UV radiation. Taking into account the ingredients and structure of the polymeric composition can also refer to a curing process in a binder - mineral matrix mixture. In the system of binder-mineral matrix under the influence of ultraviolet radiation is also observed effect of binding. However, the bonding process does not occur in the entire volume of the investigated system, but only on the surface, which gives some possibilities for application in the use of UV curing surface of cores, and also to cure sand moulds in 3D printing technology.

18

Właściwości kompozycji poli(kwas akrylowy)/modyfikowana skrobia stosowanej jako nowe spoiwo polimerowe

Grabowska B., Pilch-Pitera B., Kaczmarska K., Trzebicka B., Mendrek B., Drożyński D., Łątka P.

Polimery

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2015

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T. 60, nr 3

179--185

PL

Zbadano stabilność wybranych właściwości fizykochemicznych nowych, ekologicznych spoiw polimerowych w postaci wodorozcieńczalnych kompozycji poli(kwas akrylowy)/sól sodowa karboksymetyloskrobi (PAA/CMS-Na). Wodną kompozycję PAA/CMS-Na przechowywano w zamkniętych naczyniach w temp. 10 °C. Podczas trzymiesięcznego przechowywania badano zmiany zabarwienia, lepkości, kąta zwilżania szkła kwarcowego, struktury oraz rozkładu wymiarów cząstek spoiwa i na tej podstawie dokonano wstępnej oceny stabilności kompozycji. Sporządzono i utwardzono masy formierskie z udziałem wodnej kompozycji PAA/CMS-Na i określono ich wytrzymałość na zginanie. Stwierdzono, że w założonym czasie przechowywania, w warunkach zbliżonych do panujących w odlewni, nowe spoiwo nie traci właściwości wiążących ziarna piasku osnowy w masie formierskiej.

EN

The selected physicochemical properties of water-thinnable poly(acrylic acid)/sodiumsalt of carboxymethyl starch (PAA/CMS-Na) compositions — new environmentally friendly polymer binding agents — were investigated as a function of time. The aqueous composition PAA/CMS-Na was stored in closed vessels in a cooling chamber at 10 °C. During the three-month storage period the changes of coloration, viscosity, wetting angle on quartz glass, structure and size distribution of the binding agent particles were studied. On this basis, the stability of the binder properties was preliminarily evaluated. Additionally, the moulding sands containing an aqueous composition PAA/CMS-Naas a binder (stored for a week or three months) were prepared, hardened and subjected to the bending strength tests. It was found, that after three months of storage under conditions resembling those found in a foundry the new binder did not lose its properties as a binding agent for the moulding sand.

19

Structural construction of hardeners with different hardening rates intended for geopolimer binder systems used for the preparation of moulding sands

Bobrowski A., Grabowska B., Kaczmarska K.

Metallurgy and Foundry Engineering

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2015

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Vol. 41, no. 3

115--121

EN

The paper presents the results of structural investigations of hardeners with different hardening rate for geopolymer binder system Geopol, manufactured by the Sand-Team Company. Studies have shown that these hardeners have similar chemical structures and that the hardening rate of the binder depends on the proper selection of the proportions of the respective components.

PL

W artykule przedstawiono wyniki badań strukturalnych serii utwardzaczy o różnej szybkości utwardzania przeznaczonych dla spoiwa geopolimerowego produkcji firmy Sand Team. Przeprowadzone badania wykazały, że utwardzacze mają zbliżoną strukturę chemiczną, a szybkość utwardzania zależy od doboru właściwych proporcji poszczególnych składników.

20

Analysis of selected technological properties of green sands with starch-based additives

Drożyński D., Kurleto Ż., Kaczmarska K., Grabowska B.

Metallurgy and Foundry Engineering

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2015

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Vol. 41, no. 2

65--70

EN

This paper presents the results of determining the effect of the addition of native starch and mineral-starch mixes on selected technological properties of sands. The study was carried out on the permeability, compressive strength, and wear resistance of molding. Green sand with bentonite and silica sand was compared to green sand with the addition of Superior Standard native starch or the addition of a mineral-starch composition in the form of binder Albertine F/1. The main difference in applied starch materials is the characteristic property of native starch which is insoluble in cold water. Therefore, it was difficult to bond water added to molding sand during mixing of the ingredients in this case. However, the Albertine F/1 starch-based binder is a mixture of starch and aluminosilicates, whereas the bonding of water added into molding sand during ingredient mixing is more efficient.

PL

W artykule przedstawiono wyniki przeprowadzonych badań, które miały na celu określenie wpływu dodatku skrobi natywnej i mieszanek skrobiowo-mineralnych do klasycznych mas formier- skich na ich wybrane właściwości technologiczne. Przeprowadzone zostały badania dotyczące przepuszczalności, wytrzymałości na ściskanie oraz osypliwości mas formierskich. Masę wyjściową stanowiła masa z bentonitem na osnowie piasku kwarcowego, którą porównano z masami z dodatkiem skrobi natywnej Superior Standard oraz z dodatkiem komercyjnego spoiwa skrobiowo-mineralnego Albertine F/1. Cechą różnicującą zastosowanych materiałów skrobiowych jest to, że skrobia natywna nie rozpuszcza się w zimnej wodzie, więc w jej przypadku utrudnione jest wiązanie wody wprowadzonej do masy podczas mieszania składników. Natomiast spoiwo skrobiowe Albertine F/1 jest mieszaniną skrobi i glinokrzemianów, dzięki czemu wiązanie wody wprowadzonej do masy podczas mieszania składników okazuje się bardziej wydajne.