Strength of Bonded Joints of Polypropylene after Radiation Cross-Linking

2015 ◽  
Vol 1120-1121 ◽  
pp. 1167-1170
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polypropylene (PP). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polypropylene. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66 and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PP were achieved. The strength of bonded joints after irradiation was increased up to 450 % compared to untreated material. A similar trend was observed even for surface energy.

2014 ◽  
Vol 1025-1026 ◽  
pp. 251-255 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.


2015 ◽  
Vol 752-753 ◽  
pp. 378-381
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Bonded joints at elevated temperature (60 °C) were tested. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for improvement of adhesive properties and increased the strength of bonded joints of PC at elevated temperature (60 °C). Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, 99, 132, 165 and 198 kGy were irradiated. The best results were achieved by irradiation at doses of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 10 % and surface energy up to 30 % compared to untreated material.


2017 ◽  
Vol 1142 ◽  
pp. 188-193
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Ales Mizera ◽  
Martin Reznicek ◽  
...  

In this study there was compared the effect of different methods of modification (modification by plasma treatment and ionizing beta radiation) on the surface properties (contact angle of wetting and surface free energy) and on the final strength of bonded joints of selected types thermoplastics (low density polyethylene and polycarbonate). At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance.


2014 ◽  
Vol 1025-1026 ◽  
pp. 615-620 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.


2015 ◽  
Vol 752-753 ◽  
pp. 342-345
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  

In this study there was found that radiation cross-linking increased the surface energy of high-density polyethylene (HDPE), and low-density polyethylene (LDPE). Surface energy affects the wettability of the surface and is very important for creating of high-quality bonded joints. The measurement results indicated that radiation cross-linking was a very effective tool for the improvement of adhesive properties and increased the surface energy of selected polyolefins. Surfaces of selected materials with ionizing beta radiation with doses of 0, 33, 66, 99, 132, 165, and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 165 kGy. The surface energy after irradiation was increased up to 100 % compared to untreated material.


2013 ◽  
Vol 586 ◽  
pp. 79-82 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Martin Ovsik ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  

At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. In comparison with conventional joining methods (riveting, welding and screwing) provides bonding new combination of options and allows obtaining special shapes and properties which cannot be created by conventional methods of coupling. For the formation of quality bonded joint it is important that the adhesive bonding surface is well wetting. Wettability is characterized by the contact angle of wetting. The liquid must have a lower surface tension than the solid in order to be able to wetting the solid substance. This article describes the effect of beta irradiation on the contact angle of wetting, on the surface energy and on the final strength of bonded joints of HDPE.


1992 ◽  
Vol 266 ◽  
Author(s):  
Daniel T. Quillin ◽  
Daniel F. Caulfield ◽  
James A. Koutsky

AbstractIn addition to its use in recycled paper products, recovered lignocellulosic fiber can be used as a reinforcement filler in composites with polyolefins. However, problems in both processing and product performance are often caused by the incompatibilities of surface energies between hydrophilic cellulose and non-polar polyolefin. This poor match in surface polarities is detrimental to strong adhesive bonding between olefin and cellulose. This work examines the effect of surface energy on the adhesion properties of polypropylene and cellulose. In particular, three materials accepted as paper-sizing agents were used to change the cellulosic fiber's surface energy to make it more compatible withthe surface energy of polypropylene.Cellulose fibers were treated by various methods with (1) alkyl ketene dimer, (2) alkenyl succinic anhydride, and (3) stearic acid and were characterized by their surface energies as determined by single fiber wettability measurements using the Wilhelmy technique. These measurements are discussed in detail. Results from these measurments can be related to differences in adhesion between treated cellulose and polypropylene, which can be measured by internal bond tests on hot-pressed composite sheets.Results indicate that the use of sizing agents reduces the acid/base (hydrogen bonding) character of the cellulose surface. Interactions involving hydrogen bonding are important in cellulose/modified-polypropylene composites. Reduction of these interactions appears to lead to a corresponding reduction in adhesion between cellulose and polypropylene.


Aviation ◽  
2005 ◽  
Vol 9 (2) ◽  
pp. 24-28
Author(s):  
Petr Kachlík ◽  
Josef Klement

Riveting and adhesive bonding are common joining technology in aircraft engineering. A hybrid joining such as rivet‐bonding brings together the benefits of both basic techniques whilst minimising some of their shortcomings. These technologies have been present mastered sufficiently, and their characteristics are well known. Due to different influences in aircraft service (weather, location of aircraft operation, air composition, contact with fuel or hydraulic fluid), a degradation of the characteristics of joints is well noticed. This research was focused on the ageing of rivet‐bonded joints with a polyurethane adhesive and blind rivets and the influence of ageing on the properties of joints. Ageing according EN 2243–5 was carried out in hot/wet conditions, salt mist, hydraulic fluid, and fuel. Thermal cycling was used as a resource of ageing.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1863 ◽  
Author(s):  
David Manas ◽  
Martin Bednarik ◽  
Ales Mizera ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
...  

Bonding is increasingly being used, and it is an ever-evolving method for creating unbreakable bonds. The strength of adhesive bonds determines, to a significant extent, the possible applications of this technology and is influenced by many factors. In addition to the type of adhesive used, the characteristics of the surface layers play a significant role; therefore, significant attention is paid to their adjustment and modification. Radiation crosslinking is one of the most important methods for modifying polymer properties. Currently, the most frequently used type of radiation for polymer crosslinking is beta minus (β−) radiation, which affects not only mechanical but also surface properties, chemical and temperature resistance, and surface layer characteristics of polymers. This study investigated the effect of β− radiation on the surface layer properties of low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP) and the effects of surface-layer modification on the ultimate tensile strength of bonded joints. Based on the results, we concluded that β− radiation significantly changes the properties of the tested surface layers, increases the surface energy, and improves the adhesiveness of bonds. Consequently, the final strength of the LDPE, HDPE, and PP bonds increases significantly.


2011 ◽  
Vol 57 (No. 4) ◽  
pp. 153-162 ◽  
Author(s):  
M. Müller

Adhesive bonding technology is successfully applied partly in the primary production, partly in the renovation in various fields of human activities. This fact emphasizes the importance of the partial factors research, which influence is essential for the quality, reliability and necessarily the usable life of bonded joints. The mechanical preparation of bonded surface is a varied process which influences directly the resultant bonded joint quality. The aim of the bonded surface mechanical preparation is the adhesion improvement in the adhesive – adherend interface. For mechanical preparation we use tools of defined cutting edge, by means of which we get the uniform surface texture, e.g. by milling. On the contrary such methods are more often used when the uniform surface cannot be reached. Shot blasting and grinding are significant representatives of these methods. The manual grinding can be significantly applied mainly in the agriculture. The absence of connected areas availability for the mechanical tooling and impossibility of their work clamping are the reasons for that. The breakwater in the sprinkler cistern restricting the liquid motion is the example.


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