scholarly journals Investigations on the execution and evaluation of the Pummel test for polyvinyl butyral based interlayers

2020 ◽  
Vol 5 (3) ◽  
pp. 371-396
Author(s):  
Miriam Schuster ◽  
Jens Schneider ◽  
Tuong An Nguyen
Keyword(s):  
Film Surface ◽  
Polyvinyl Butyral ◽  
Test Method ◽  
Structural Element ◽  
Binary Images ◽  
Free Film ◽  
Safety Glass ◽  
High Adhesion ◽  
Adhesion Level ◽  
Pull Tests

Abstract Laminated safety glass (LSG) is increasingly used as structural element in buildings. Of central importance for safety are the adhesion and the residual load-bearing capacity in the post fractured state. In literature a large number of tests to assess adhesion is mentioned. These include, e.g. peel tests, through-cracked-tensile/-bending tests, VW-pull tests and compressive shear tests. However, especially in industry, the Pummel test is widespread for determining the quality of adhesion in LSG with polyvinyl butyral based interlayers. This test method proves to be simple and quick to carry out: The laminate is stored at − 18 °C and then completely destroyed at room temperature with hammer blows. The adhesion level (0–10) is determined by visually comparing the adhering glass fragments with reference pictures or with the help of diagrams and tables which indicate the Pummel value as a function of the free film surface. Pummel value 0 is to be interpreted as no adhesion and Pummel value 10 as very high adhesion. Due to the lack of standardization, the execution and evaluation is very much dependent on the test institution and executive person. This paper shows different Pummel classifications that can currently be found on the market. Subsequently, approaches to the automatization and standardization of the execution and especially the evaluation of the Pummel test are shown. Three image evaluation methods in Matlab are presented, discussed and compared: (1) analysis of binary images, (2) statistical evaluation of the greyscale images and (3) texture analysis using co-occurrence matrices.

scholarly journals Coatings with recycled polyvinyl butyral on polyester and polyamide mono- and multifilament yarns

2021 ◽  
Author(s):  
Rike Brendgen ◽  
Carsten Graßmann ◽  
Thomas Grethe ◽  
Boris Mahltig ◽  
Anne Schwarz-Pfeiffer
Keyword(s):  
Mechanical Properties ◽  
Chemical Resistance ◽  
Crosslinking Agent ◽  
Polyvinyl Butyral ◽  
Polymer Dispersion ◽  
Safety Glass ◽  
Enhanced Properties ◽  
Multifilament Yarns ◽  
Textile Coating ◽  
Recycled Material

AbstractPolyvinyl butyral is used in safety glass interlayers, mainly in car windshields. Legislative regulations require a recycling of cars after their lifetime and therefore also their safety glass. This causes the availability of recycled polyvinyl butyrate (r-PVB) originated from safety glass interlayers. Due to deteriorated optical properties, such as the transparency, and unknown amounts of plasticizers, it is challenging to reuse the recycled material in new windshields. Therefore, it is of particular interest to find new fields of application for r-PVB, such as the usage as a textile coating. In this research, r-PVB was investigated as a material for yarn coating. Polyester and polyamide mono- and multifilament yarns were coated continuously with solely a polymer dispersion and with mixtures of crosslinking agent and polymer dispersion. Crosslinked r-PVB coatings showed enhanced properties toward abrasion and chemical resistance. Coatings without the crosslinking agent showed a diminished abrasion resistance and could be washed off with ethanol. Mechanical properties of the monofilaments were influenced by the r-PVB coating in general. However, varying concentrations of the crosslinking agent did not affect the mechanical properties.

scholarly journals Physical Structure Induced Hydrophobicity Analyzed from Electrospinning and Coating Polyvinyl Butyral Films

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Shuo Chen ◽  
Guo-Sai Liu ◽  
Hong-Wei He ◽  
Cheng-Feng Zhou ◽  
Xu Yan ◽  
...  
Keyword(s):  
Surface Structure ◽  
Critical Role ◽  
Film Surface ◽  
Polyvinyl Butyral ◽  
Physical Structure ◽  
Surface Wettability ◽  
Practical Applications ◽  
Physical Surface ◽  
Film Forming ◽  
Surface Morphologies

Surface wettability of a film plays a critical role in its practical applications. To control the surface wettability, modification on the physical surface structures has been a useful method. In this paper, we reported the controlling physical surface structure of polyvinyl butyral (PVB) films by different film-forming methods, spin-coating, bar-coating, and electrospinning. The wettability of these PVB films was examined, and the surface morphologies and roughness were investigated. The results indicated that coating PVB films were hydrophilic, while electrospun films were hydrophobic. The physical surface structure was the key role on the interesting transition of their surface wettability. Theoretical analyses on these results found that the coating PVB films showed different mechanism with electrospun ones. These results may help to find the way to control the PVB film surface wettability and then guide for applications.

Viscoelastic Properties of PVB Interlayer for Laminated Glass Structures Used in Building Reconstructions

2019 ◽  
Vol 808 ◽  
pp. 115-122
Author(s):  
Miroslav Vokáč ◽  
Tomáš Hána ◽  
Klára V. Machalická ◽  
Martina Eliášová
Keyword(s):  
Viscoelastic Properties ◽  
Thermoplastic Polyurethane ◽  
Maxwell Model ◽  
Polyvinyl Butyral ◽  
Laminated Glass ◽  
Building Structures ◽  
Structural Element ◽  
Stress Strain ◽  
Existing Building ◽  
Material Parameters

Laminated glass is a structural element used extensively in a reconstruction of existing building structures because of its transparency and simplicity. When using laminated glass as a glass staircase, balustrades, transparent flooring, facades or other structural elements, it is advisable to consider the shear interaction of individual glass panes in the cross-section. A conservative approach where the glass panes shear interaction is not considered, is uneconomical. This interaction depends on the properties of polymeric interlayers used in lamination process. Various commercial products based on PVB (polyvinyl butyral), EVA (ethylene vinyl acetate), ionomer, or thermoplastic polyurethane (TPU) are used. Stiffness of polymers depends on temperature and duration of a load. Interlayers exhibit the viscoelastic properties and temperature dependency usually described by the generalized Maxwell model and WLF model (Williams-Landel-Ferry). Parameters of these models are the most effectively determined by Dynamic Mechanical Thermal Analysis (DMTA), where the material is cyclically loaded at different frequencies and temperatures. Material parameters were found by DMTA in shear for PVB type of interlayer Trosifol® BG R20. In addition, the experimental quasi-static loading tests in shear were performed at different loading rates and at various temperatures. These experimental stress-strain diagrams were compared to the theoretical stress-strain relations obtained from Maxwell model with material parameters based on DMTA testing. All tests were performed in Klokner Institute CTU in Prague.

Synthesis, properties and application in polyvinyl butyral of spirooxazine photochromic compounds

2019 ◽  
Vol 48 (5) ◽  
pp. 421-430 ◽  
Author(s):  
Liemei Yuan ◽  
Gang Cai ◽  
Jun Gao
Keyword(s):  
Thermal Stability ◽  
Fatigue Resistance ◽  
Polyvinyl Butyral ◽  
Ring Closure ◽  
Content Type ◽  
Safety Glass ◽  
Synthesis Properties ◽  
Covalently Linked ◽  
Fading Rate ◽  
Photochromic Materials

Purpose The purpose of this paper is to evaluate the effect of antioxidant 2,6-di-tert-butyl-p-methylphenol (BHT) on the thermal stability and fatigue resistance of spirooxazine and then study the properties of photochromic polyvinyl butyral resin (PVB) films. Design/methodology/approach BHT was introduced into the spirooxazine system by blending and covalent bonding. The properties of spirooxazine solutions and photochromic PVB films were studied. Findings The thermal stability and fatigue resistance of spirooxazine covalently linked (BHT-SO) or mixed (BHT/SO) with BHT were higher than the system without BHT, and BHT-SO was the better one. But acidic substance would greatly impair the fatigue resistance of spirooxazine. The optimum addition amount of BHT-SO2 to PVB was 2.5 per cent, and the minimum limit was 0.01 per cent. The fading kinetic and fatigue resistance of film were similar to the solution and better. Plasticizer could accelerate the fading rate and strengthen the mechanical properties of photochromic film but had no effect on the fatigue resistance. Research limitations/implications Spirooxazine could be grafted onto the PVB chain to make the ring closure fading reaction slower. Practical implications In addition to the wide application prospects of photochromic materials in decoration, optical storage, etc., the photochromic PVB film in the car safety glass can absorb sunlight and turn blue, then fade to colorless when the sunlight disappears, making the interior environment more comfortable. Originality/value The introduction of BHT into the spirooxazine system not only exerts its ability to capture free radicals, but its bulky volume also increases the resistance of the ring closure, making the fading process slower.

Instability of a non-wetting film with interfacial viscous stress

1995 ◽  
Vol 298 ◽  
pp. 287-309 ◽  
Author(s):  
David A. Edwards ◽  
Alexander Oron
Keyword(s):  
Stability Analysis ◽  
Solid Wall ◽  
Nonlinear Partial Differential Equations ◽  
Three Dimensional ◽  
Film Surface ◽  
Extreme Case ◽  
Interfacial Stress ◽  
Nonlinear Stability Analysis ◽  
Free Film ◽  
Wetting Film

The destabilization of a thin three-dimensional non-wetting film above a solid wall is examined for the special case in which surfactant is adsorbed onto the free surface of the film. Attention is restricted to the case of a Newtonian surface, with surfactant displaying rapid surface diffusion or exhibiting small Marangoni number, such that the dominant intrinsic interfacial stress is of a purely viscous origin. A surface-excess force approach is adopted for the purpose of incorporating into the analysis the attractive/repulsive dispersive forces acting between the solid wall and the film. Three coupled nonlinear partial differential equations are obtained that describe the ‘large-wavelength’ spatio-temporal evolution of the free film surface following a small initial disturbance. These equations are shown to reduce to results in the literature in the limit of zero interfacial viscosities. Employing linear stability analysis, an explicit dispersion equation is obtained relating the growth coefficient to interfacial viscosities. It is found, at least in the linear regime, that the sum of interfacial shear and dilatational viscosities – and not each separately – imparts a damping effect that in the most extreme case is four-fold relative to the case of no interfacial viscosities. Nonlinear stability analysis in the limiting case of a two-dimensional film indicates that interfacial viscosities may strongly hinder the onset of instability through large interfacial stresses that arise in the vicinity of trough and crest regions of the film.

Effects of Compound Formulation on the Adhesion of Rubber to Brass-Plated Steel Cord

1984 ◽  
Vol 57 (5) ◽  
pp. 855-878 ◽  
Author(s):  
Yasuhiro Ishikawa
Keyword(s):  
Stearic Acid ◽  
Zinc Level ◽  
Cobalt Salt ◽  
High Adhesion ◽  
High Sulfur Content ◽  
Level 3 ◽  
Brass Surface ◽  
Steel Cord ◽  
Adhesion Level ◽  
High Level

Abstract Implications for cord adhesion from this study are as follows: 1) In the low-adhesion compounds containing low cobalt naphthenate and sulfur levels, adhesion increases with decreasing cobalt naphthenate:sulfur ratio, at a given amount of cobalt naphthenate. 2) Under mild curing condition (160°C, 20 min), high-adhesion compounds, containing high cobalt naphthenate and sulfur level, do not show a decrease in adhesion, even if the cobalt naphthenate:sulfur ratio is increased. However, after overcuring (160°C, 60 min), adhesion loss is encountered with increasing cobalt naphthenate:sulfur ratios, at a given cobalt naphthenate level. 3) A high level of unaged adhesion can be obtained if products with a combination of low cobalt and high sulfur content are formed on the brass surface. This condition obtains if the compound contains large amounts of cobalt salt and sulfur and a small ratio of cobalt salt to sulfur. 4) With a high-adhesion compound, the unaged adhesion is rather insensitive to the amount of accelerator. 5) After humidity aging, the adhesion of a high-adhesion compound varies depending upon the amounts of sulfur and accelerator. Compounds containing small amounts of sulfur show a decrease in adhesion with increasing amounts of the accelerator. However, compounds containing large amounts of sulfur maintain high adhesion, even with large amounts of accelerator. 6) For unaged adhesion, only a slight influence is observed by varying the amount of stearic acid. After humidity aging, however, compounds containing larger amounts of stearic acid show a decrease in adhesion, especially in the presence of large amounts of cobalt naphthenate. 7) Compounds which promote the formation of ZnO on the surface during bonding maintain a high adhesion level after humidity aging. This is similar to the effect of using a cord plated with brass containing a higher zinc level.

Densification kinetics of glass films constrained on rigid substrates

1995 ◽  
Vol 10 (5) ◽  
pp. 1321-1326 ◽  
Author(s):  
Jaecheol Bang ◽  
Guo-Quan Lu
Keyword(s):  
Polyvinyl Butyral ◽  
Silica Content ◽  
Free Standing ◽  
Free Film ◽  
Lift Off ◽  
Free Films ◽  
Mylar Sheet ◽  
Blade Casting ◽  
Kinetics Of

The kinetics of constrained-film sintering were studied in a borosilicate glass (BSG) + silica system because of their applications in microelectronic packaging technologies. Samples with a silica content by 20% by volume were prepared from slurries of powder mixtures in a commercial polyvinyl butyral (PVB) binder solution. Constrained films about 0.2 mm thick were formed by doctor-blade casting the slurries on silicon wafers. Free-standing films about 0.6 mm thick were also produced by casting the slurries on a treated mylar sheet for easy lift-off. Sintering experiments were carried out in a hot stage at temperatures between 715 °C and 775 °C. Shrinkage profiles of the free and constrained (shrinkage in thickness only) films were determined in situ using a custom-designed optical system. The densification rates measured in the constrained films were slower than those in the free films. However, the substrate constraint had no effect on the activation energy of densification which was found equal to 385 ± 10 kJ/mol, the same for both free and constrained films. A relation between the constrained-film and free-film densification profiles was derived using the viscous analogy for the constitutive equations of a porous sintering body.

Predicting and comparing the fire performance of a small-scale composite structure

2021 ◽  
Vol 12 (3) ◽  
pp. 72
Author(s):  
Burak Kaan Cirpici
Keyword(s):  
Composite Structures ◽  
Test Method ◽  
Scale Model ◽  
Small Scale ◽  
Fire Performance ◽  
Fire Testing ◽  
Structural Element ◽  
Scaled Model ◽  
Steel Columns ◽  
Reduced Scale

The purpose of this paper is to investigate a strategy for the fire testing of reduced scale structural models which will help engineers design safer structures and reduce the loss from fires. The concept of this work is how composite frame floor arrangements, beam-column connections might be modelled at a small scale suitable for fire testing. Testing full-scale is expensive, besides the testing of scaled model produces reasonable results which help us to understand the failure mechanism and all significant thermo-structural responses involved in a fire. Thermal effects within a structural element generate fire curve, thermal input and structural displacement output, in other words cause and impact. Dimensional analysis, which is a condition for dynamic similarity between prototype and model, can be achieved when all the dimensionless groups are set equal for both model and prototype. On the other hand, scaling rules are used to decide how much insulating material will be used on a structure. 5-storey composite building with composite floors and steel columns has been modelled at small scale with 1/5. The obtained results from various parametric investigations show that the reduced scale model fire test method would be a feasible way to investigate the fire performance of composite structures.

scholarly journals A Quantitative Method to Determine the Orientation of Collagen Fibers in the Dermis

2002 ◽  
Vol 50 (11) ◽  
pp. 1469-1474 ◽  
Author(s):  
Maril L. Noorlander ◽  
Paris Melis ◽  
Ard Jonker ◽  
Cornelis J.F. Van Noorden
Keyword(s):  
Collagen Fibers ◽  
Experimental Setting ◽  
Structural Element ◽  
Microscopic Method ◽  
Binary Images ◽  
Skin Stretching ◽  
The Mean ◽  
Cryostat Sections ◽  
Picrosirius Red ◽  
Control Skin

We have developed a quantitative microscopic method to determine changes in the orientation of collagen fibers in the dermis resulting from mechanical stress. The method is based on the use of picrosirius red-stained cryostat sections of piglet skin in which collagen fibers reflect light strongly when epipolarization microscopy is used. Digital images of sections were converted into binary images that were analyzed quantitatively on the basis of the length of the collagen fibers in the plane of the section as a measure for the orientation of the fibers. The length of the fibers was expressed in pixels and the mean length of the 10 longest fibers in the image was taken as the parameter for the orientation of the fibers. To test the procedure in an experimental setting, we used skin after 0 and 30 min of skin stretching. The orientation of the fibers in sections of control skin differed significantly from the orientation of fibers in sections of skin that was stretched mechanically for 30 min [76 ± 15 ( n = 5) vs 132 ± 36 ( n = 5)]. The method described here is a relatively simple way to determine (changes in) the orientation of individual collagen fibers in connective tissue and can also be applied for analysis of the orientation of any other structural element in tissues so long as a representative binary image can be created.

A Comparison of the Complex Wettability between Locust and Moth Wing

2015 ◽  
Vol 1095 ◽  
pp. 593-597
Author(s):  
Gang Sun ◽  
Yan Fang
Keyword(s):  
Contact Angle ◽  
Wing Surface ◽  
Baxter Equation ◽  
Structural Element ◽  
Sliding Angle ◽  
High Adhesion ◽  
Material Element ◽  
Infrared Spectrometer ◽  
Transport Channels ◽  
Functional Interface

The microstructure, hydrophobicity and chemical composition of the locust and moth wing surfaces were investigated by a scanning electron microscope (SEM), a contact angle meter and a Fourier transform infrared spectrometer (FT-IR). The hydrophobicity models were established on the basis of the Cassie-Baxter equation. The locust and moth wing surfaces are composed of naturally hydrophobic materials, but exhibit different complex wettability. The locust wing surface is of extremely high adhesion (sliding angle>180°) and superhydrophobicity (contact angle 151.5~157.3°), while the moth wing surface is of low adhesion (sliding angle 1~3°) and superhydrophobicity (contact angle 150.5~155.6°). The complex wettability of the wing surfaces ascribes to the cooperative effect of material element and structural element. The locust and moth wings can be potentially used as biomimetic templates for design and preparation of novel functional interface and no-loss microfluidic transport channels.

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