Modeling the curing behavior of a toughened hot curing epoxide adhesive during the paint drying process

2020 ◽  
Vol 234 (5) ◽  
pp. 406-414
Author(s):  
M Griese ◽  
N Günther ◽  
E Stammen ◽  
K Dilger
Keyword(s):  
Numerical Data ◽  
Dip Coating ◽  
Drying Process ◽  
Scanning Calorimetry ◽  
Curing Behavior ◽  
Adhesive Layers ◽  
Model Free ◽  
Body In White ◽  
Paint Drying ◽  
Structural Adhesive

Lightweight body-in-white is often based on a mix of materials that causes problems in the production process. More specifically, the paint oven process after cathodic dip-coating can lead to damaged adhesive layers due to mismatches in thermal expansion of the materials. The understanding of the curing behavior of the structural adhesive cured in this oven process is of crucial interest to determine the damaging in numerical analyses. Therefore, the curing behavior of a one-component toughened hot curing structural adhesive is modeled using three model-based and a model-free approach as well as experimental data from differential scanning calorimetry. After the parameter identification of the models, the parameters are validated using an oven-process-like temperature profile to compare experimental and numerical data.

scholarly journals Flexible Nanocomposites Based on Polydimethylsiloxane Matrices with DNA-Modified Graphene Filler: Curing Behavior by Differential Scanning Calorimetry

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2301 ◽  
Author(s):  
Elisa Toto ◽  
Susanna Laurenzi ◽  
Maria Gabriella Santonicola
Keyword(s):  
Differential Scanning Calorimetry ◽  
Deoxyribonucleic Acid ◽  
Isoconversional Methods ◽  
Activation Energies ◽  
Scanning Calorimetry ◽  
Curing Behavior ◽  
Model Free ◽  
Lower Viscosity ◽  
Modified Graphene

Novel silicone-based nanocomposites with varied elastic properties were prepared by blending standard polydimethylsiloxane (PDMS) with a lower viscosity component (hydroxyl-terminated PDMS) and integrating a graphene nanoplatelets (GNP) filler modified by strands of deoxyribonucleic acid (DNA). The curing behavior of these nanocomposites was studied by dynamic and isothermal differential scanning calorimetry. The activation energies of the polymerization reactions were determined using the Kissinger method and two model-free isoconversional approaches, the Ozawa–Flynn–Wall and the Kissinger–Akahira–Sunose methods. Results show that the complex trend of the curing behavior can be described using the isoconversional methods, unveiling lower activation energies for the nanocomposites with standard PDMS matrices. The role of the DNA modification of graphene on the curing behavior is also demonstrated. The curing reactions of the nanocomposites with the PDMS matrix are favored by the presence of the GNP–DNA filler. PDMS/PDMS–OH blends generate softer nanocomposites with hardness and reduced elastic modulus that can be tuned by varying the amount of the filler.

Crystallization kinetics mechanism investigation of sol–gel-derived NaYF4:(Yb,Er) up-converting phosphors

CrystEngComm ◽  
2017 ◽  
Vol 19 (34) ◽  
pp. 4992-5000 ◽  
Author(s):  
C. Bartha ◽  
C. E. Secu ◽  
E. Matei ◽  
M. Secu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystallization Kinetics ◽  
Sol Gel ◽  
Model Fitting ◽  
Crystallization Mechanism ◽  
Differential Scanning Calorimetry Analysis ◽  
Scanning Calorimetry ◽  
Model Free

The crystallization mechanism of sol–gel-derived NaYF4:(Yb,Er) up-converting phosphors has been studied by differential scanning calorimetry analysis using both model-free and model fitting approaches.

scholarly journals Freeze versus Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material

2021 ◽  
Author(s):  
Aleksandra A. Jovanović ◽  
Steva M. Lević ◽  
Vladimir B. Pavlovic ◽  
Smilja B. Markovic ◽  
Rada V. Pjanovic ◽  
...  
Keyword(s):  
Spray Drying ◽  
Dry Weight ◽  
Drying Process ◽  
Scanning Calorimetry ◽  
Coating Agent ◽  
Microwave Assisted ◽  
Freeze Dried ◽  
Wild Thyme ◽  
The Impact ◽  
Spray Dried

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drug in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration, heat-, ultrasound-, and microwave-assisted extractions. Higher powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53-75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation distinguished from others by higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process affected mainly position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray dried formulations compared to freeze dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151-223 µm) compared to small microspheres (~8 µm) in spray-dried powder.

scholarly journals Heat Curing Behavior of Light-cured Composite Resins Investigated by Dynamic Differential Scanning Calorimetry

1990 ◽  
Vol 9 (2) ◽  
pp. 153-162,228 ◽  
Author(s):  
Seiji BAN ◽  
Yosifumi TAKAHASHI ◽  
Hiroaki TANASE ◽  
Jiro HASEGAWA
Keyword(s):  
Differential Scanning Calorimetry ◽  
Composite Resins ◽  
Scanning Calorimetry ◽  
Curing Behavior ◽  
Heat Curing

A numerical simulation of a line-type paint drying furnace

2019 ◽  
Vol 30 (5) ◽  
pp. 2639-2653
Author(s):  
Jongrak Choi ◽  
Giyeob Yang ◽  
Nahmkeon Hur
Keyword(s):  
Numerical Results ◽  
Drying Process ◽  
Drying Time ◽  
Content Type ◽  
Hot Air ◽  
Air Supply ◽  
Nozzle Configuration ◽  
Paint Drying ◽  
Line Type

Purpose Paint drying is a very important process in an industry where shorter drying time for productivity and lower energy consumption for production cost are required while maintaining the product’s painting quality. In the present study, a drying process in a line-type paint drying furnace equipped with nozzles for hot air supply and moving conveyer belt to dry painted automotive parts is numerically simulated for the flow and heat transfer inside the furnace to evaluate the quality of the drying or baking at the end of the drying process in a production line. Design/methodology/approach A baking window for a specific paint is used for judging the local degree of baking (DOB) of the painted parts, which can be useful to identify under-baked or over-baked locations of the painted parts, and hence the quality of the baking process. Findings Numerical results of a time history of temperatures at two monitoring points on the painted parts were obtained and compared to the measured data in an actual furnace and showed good agreement. Three types of paints were considered in the present study and numerical results showed different drying characteristics. In addition to the original furnace nozzle configuration, two more furnace nozzle configurations with different numbers, direction and speed of hot air supply were simulated to improve the furnace’s drying performance. As a result, a newly suggested nozzle configuration with quick drying paint can give us a remarkable improvement in surface averaged DOB compared to the original nozzle configuration with original paint. Originality/value The present simulation technique and DOB methodology can be used for the optimal design of a drying furnace.

Effect of Soy Protein on Kinetics of Polyurethane Formation

2010 ◽  
Vol 160-162 ◽  
pp. 1712-1715
Author(s):  
Guang Heng Wang
Keyword(s):  
Soy Protein ◽  
Soy Protein Isolate ◽  
Kissinger Method ◽  
Toluene Diisocyanate ◽  
Polymerization Reaction ◽  
Dibutyltin Dilaurate ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Model Free ◽  
Kinetics Of

The polymerization reaction kinetics of biodegradable polyurethane extended with soy protein isolate (SPI) with dibutyltin dilaurate (DBTDL) as the curing catalyst was studied by means of non-isothermal differential scanning calorimetry (DSC). Model-free methods, Kissinger method and Ozawa method, were applied for analyzing the DSC data. The Ea and lnA obtained from Kissinger method for catalyzed reaction between toluene diisocyanate (TDI) and Polyoxypropyleneglycol (PPG) are 60.80 kJ•mol-1 and 12.09, and for catalyzed reaction among TDI, PPG, and SPI they were 65.91 kJ•mol-1and 14.04. Similarly the Ea obtained from Ozawa method for catalyzed reaction between TDI and PPG and catalyzed reaction among TDI, PPG, and SPI were 63.49 kJ•mol-1 and 64.78 kJ•mol-1, respectively. The results showed that, the incorporation of a small amount of SPI into polyurethane did not affect the reaction kinetic strongly, but increases the reaction activation energy Ea and lnA.

Complementarity of Atom Probe, Small Angle Scattering and Differential Scanning Calorimetry for the Study of Precipitation in Aluminium Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 926-932 ◽  
Author(s):  
Frédéric de Geuser ◽  
Thomas Dorin ◽  
Williams Lefebvre ◽  
Baptiste Gault ◽  
Alexis Deschamps
Keyword(s):  
Differential Scanning Calorimetry ◽  
Small Angle ◽  
Atom Probe Tomography ◽  
Aluminium Alloys ◽  
Atom Probe ◽  
Small Angle Scattering ◽  
Precipitation Behavior ◽  
Scanning Calorimetry ◽  
Model Free ◽  
Angle Scattering

Two examples of precipitation studies (in Al-Li-Cu and Al-Li-Mg alloys) are shown to demonstrate the complementarity of atom probe tomography, small-angle-scattering and differential scanning calorimetry for precipitation studies. It will be used to unravel an unexpected two-step precipitation behavior of T1in Al-Li-Cu and to ascertain precipitates size in Al-Li-Mg. through a model free comparison between atom probe and SAXS.

Ellipsometric Imaging of Drying Sol-Gel Films

1988 ◽  
Vol 121 ◽  
Author(s):  
Alan J. Hurd ◽  
C. Jeffrey Brinker
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Drying Process ◽  
Imaging Ellipsometry ◽  
Withdrawal Velocity ◽  
Coated Film ◽  
Sol Gel Films ◽  
Physical And Chemical ◽  
Dip Coated Films

ABSTRACTAlthough controlled dip-coating is an established way to apply high quality uniform coatings, the details of the coating and drying process have not been deeply studied. Depending on the physical and chemical state of the sol and the parameters of dipping (dipping angle and speed), a variety of thicknesses and porosities can be achieved [1]. For optical coatings, the refractive index and optical thickness can thereby be controlled.We have developed a method to view the drying front of a dip-coated film using broad beam ellipsometry [2], or “ellipsometric imaging.” In dip-coated films we take full advantage of the fact that a steady state is quickly reached where the drying line velocity matches the withdrawal velocity; however, the technique might also be used in unsteady situations such as spin coating. Imaging ellipsometry makes it possible to measure the refractive index and thickness profiles of both wet and dry films point-by-point in an entire image at once. These profiles provide important clues as to the relative importance of gravity, evaporation and other phenomena.

Sign in / Sign up

Export Citation Format

Share Document