scholarly journals Effect of incorrect mix ratio on strength of two component adhesive Butt-Joints tested at elevated temperature

2018 ◽  
Vol 244 ◽  
pp. 01019
Author(s):  
Jakub Szabelski
Keyword(s):  
Elevated Temperature ◽  
Material Properties ◽  
Mixed Type ◽  
Epoxy Adhesive ◽  
Future Research ◽  
Butt Joints ◽  
Adhesive Material ◽  
Epoxy Adhesives ◽  
Two Component ◽  
The Impact

The aim of this study was to determine the impact of the incorrect mix ratio on the strength of joints bonded with a commercial epoxy adhesive compo-sition. The performance of cold-cured as well as accelerated cured butt joints was monitored at elevated temperature conditions. The obtained data was subjected to statistical analysis to show the correlation between joint strength at high temperature and incorrect mix ratio. The degradation of adhesive material properties with increase of hardener ratio in adhesive material was observed, as well as the change in failure type from mixed type to clearly cohesive (for inadequate volume of harde-ner) or adhesive (for excessive amount of hardener). Surprisingly insufficiency of hardener doesn’t affect the strength of joint in such manner. General recommend-dation were drawn for the preparation of two-component epoxy adhesives for joints to be used in elevated temperature, particularly when uncertainty regarding the correct resin/hardener mix ratio and future research was planned.

Adhesion and Cure Mechanism Studies for Advanced Lidded Flip Chip Applications

2013 ◽  
Vol 2013 (1) ◽  
pp. 000298-000302 ◽  
Author(s):  
Lyndon J. Larson ◽  
Kristen E. Steinbrecher
Keyword(s):  
Material Properties ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Adhesive Material ◽  
Ceramic Components ◽  
Cure Mechanism ◽  
Technology Nodes ◽  
The Impact ◽  
Package Reliability ◽  
Complex Arrangement

As packages utilizing the next technology nodes increase in power density and end-customers demand more functionality per device, many designs are facing thermo-mechanical and reliability challenges at an unprecedented level. Area array flip chip packages have become the package of choice for many of these advanced devices. These flip chip packages often require a complex arrangement of polymeric, metal, and ceramic components to work together in order to provide such performance, and maintain that performance for a given set of conditions and durations. One important aspect of this symbiosis is the design of the heat dissipation aspects of the package and how it is integrated with the electromechanical aspects of the package –in particular the adhesive technology used for coupling these two components. In this paper, the adhesive material properties are characterized along with the impact on the assembly process as well as on the package reliability.

scholarly journals Comparative Study on the Impact Wedge-Peel Performance of Epoxy-Based Structural Adhesives Modified with Different Toughening Agents

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1549
Author(s):  
Gyeong-Seok Chae ◽  
Hee-Woong Park ◽  
Jung-Hyun Lee ◽  
Seunghan Shin
Keyword(s):  
Shear Strength ◽  
Automotive Industry ◽  
Impact Resistance ◽  
High Energy ◽  
Epoxy Adhesive ◽  
Absorbed Energy ◽  
Structural Adhesives ◽  
Epoxy Adhesives ◽  
The Impact ◽  
Modified Epoxy

Epoxy adhesives are widely used in various industries because of their high heat and chemical resistance, high cohesion, and minimal shrinkage. Recently, epoxy adhesives have been applied in the automotive industry as structural adhesives for lightweight vehicles. However, the brittleness of the epoxy is an obstacle for this application, since the automotive industry requires epoxy-based structural adhesives to have a high level of high-speed impact resistance. Hence, we used phenol-terminated polyurethane (PTPU) as a toughening agent for epoxy adhesives and compared the results with those that were obtained with carboxyl-terminated butadiene acrylonitrile copolymer (CTBN). The high-energy impact resistance of the epoxy adhesives was measured by the impact wedge-peel (IWP) test, and the shear strength was measured by the single lap joint test. As a result, the 20 wt % PTPU-modified epoxy adhesive showed remarkably higher total absorbed energy (25.8 J) during the IWP test and shear strength (32.3 MPa) as compared with the control epoxy adhesive (4.1 J and 20.6 MPa, respectively). In particular, the total absorbed energy of the PTPU-modified epoxy adhesive was much larger than that of the CTBN-modified epoxy adhesive (5.8 J). When more than 10 wt % PTPU was added, the modified epoxy adhesives showed stable crack growth and effectively transferred external stress to the substrate. These results were explained by changes in the glass transition temperature, crosslinking density, and morphology due to the toughening agents.

scholarly journals Recent Advances on Thermally Conductive Adhesive in Electronic Packaging: A Review

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3337
Author(s):  
Md. Abdul Alim ◽  
Mohd Zulkifly Abdullah ◽  
Mohd Sharizal Abdul Aziz ◽  
R. Kamarudin ◽  
Prem Gunnasegaran
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Electronic Packaging ◽  
Epoxy Adhesive ◽  
Conductive Adhesive ◽  
Future Research ◽  
Epoxy Adhesives ◽  
Recent Advances ◽  
Thermally Conductive ◽  
Conductive Fillers

The application of epoxy adhesive is widespread in electronic packaging. Epoxy adhesives can be integrated with various types of nanoparticles for enhancing thermal conductivity. The joints with thermally conductive adhesive (TCA) are preferred for research and advances in thermal management. Many studies have been conducted to increase the thermal conductivity of epoxy-based TCAs by conductive fillers. This paper reviews and summarizes recent advances of these available fillers in TCAs that contribute to electronic packaging. It also covers the challenges of using the filler as a nano-composite. Moreover, the review reveals a broad scope for future research, particularly on thermal management by nanoparticles and improving bonding strength in electronic packaging.

The Strength of Joints Combining Adhesives With Bolts (Case Where Adherends Are Pipe Flanges of Which the Interfaces Are Bonded Partially)

1999 ◽  
Author(s):  
Masahiro Yoneno ◽  
Toshiyuki Sawa ◽  
Tomoya Ishihara ◽  
Hiroshi Kawamura
Keyword(s):  
Material Properties ◽  
Joint Strength ◽  
Epoxy Adhesive ◽  
Theory Of Elasticity ◽  
Clamping Force ◽  
Adhesive Material ◽  
Bonding Force ◽  
Sealing Performance ◽  
Bonding Area ◽  
Circle Diameter

Abstract The stresses of joints combining the bonding force of adhesives with the clamping force of bolts is analyzed using axisymmetrical theory of elasticity and FEM, when an internal pressure is applied to the combination joint in which two pipe flanges are clamped together by bolts and nuts with an initial clamping force after being joined by anaerobic sealant. The anaerobic sealant is applied at the interfaces partially instead of formed gaskets in pipe flange connections. In the numerical calculations, the effect of the bonding area and position and Young’s modulus of sealant (epoxy adhesive) on the contact stress at the interfaces are clarified. In addition, using the interface stress distribution, the strength of the combination joint is predicted. Experiments are performed and the analytical results are consistent with the experimental results concerning the variation in axial bolt force and the strength of combination joints. It is found that the joint strength changes as the bolt pitch circle diameter, the bonding position and the area, the initial clamping force and the adhesive material properties change. Furthermore, it is seen that the sealing performance of such combination joints in which the interfaces are bonded partially is improved over that of pipe flange connection with metallic gaskets.

Evaluation of kinetic parameter and mechanical Properties of biobased Epoxy Adhesives in Wood-based Composites for Automotive Applications

2020 ◽  
pp. 095440702096190
Author(s):  
A Aniol ◽  
T Grosse ◽  
F Fischer ◽  
S Böhm
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Paper Industry ◽  
Waste Product ◽  
Epoxy Adhesive ◽  
Sustainable Construction ◽  
Kinetic Behavior ◽  
Scanning Calorimetry ◽  
Automotive Components ◽  
Epoxy Adhesives

The relevance of sustainable structural materials is increasing in automotive components for sustainable construction. The sustainable material wood in particular can be used due to the very good specific mechanical material properties and has a high potential to be used as a structural material in hybrid constructions for the automotive components as an veneer laminate with modified epoxy adhesives. The material properties depend strongly on the interface between the capillary structure of the wood and the epoxy adhesive and also on the curing properties at the manufacturing process. In this study an epoxy adhesive (DGEBA) was copolymerized with lignosulphonate, a biobased waste product from the pulp and paper industry, as a sustainable coupling agent and the kinetic behavior of the macromolecular curing reactions and mechanical properties were characterized for wooden automotive components. The composites were characterized by differential scanning calorimetry (DSC) to investigate the curing kinetics of the biomodified adhesive. Subsequent a laminated veneer lumber was manufactured with beech veneer of 1 mm thickness. The mechanical properties of the composite structure were characterized by tensile tests, bending tests and tensile shear tests. The results show a significant improvement of the manufacturing time due to the kinetic behavior and the mechanical properties for structural components in the automotive industry.

scholarly journals Rigid and Flexible Double Shear Lap Adhesive Joint at Elevated Temperature—An Experimental Study

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2873
Author(s):  
Klaudia Śliwa-Wieczorek ◽  
Bogusław Zając
Keyword(s):  
Elevated Temperature ◽  
Adhesive Joint ◽  
Load Capacity ◽  
Structural Response ◽  
Adhesive Layer ◽  
Visual Assessment ◽  
Epoxy Adhesive ◽  
Shear Tests ◽  
Partial Load ◽  
The Impact

Double lap adhesive connections made of Sika® PS and Monolith EP2579-1 were studied experimentally in shear tests. The destructive shear tests were conducted under a quasi-static load at 20 °C and 80 °C. The aim was to study the impact of elevated temperature on the load capacity of the joint and make a comparative analysis of the results for two types of adhesives: polyurethane Sika® PS (flexible) and epoxy Monolit EP 2579-1 (rigid). The impact of adhesive layer thickness (t = 1, 2 and 4 mm) on the structural response of the joint was tested in two temperature ranges. A distinct impact of the temperature on the joint deformability was noticed. A visual assessment of the joint failure was performed and the initiation and form of failure was described. At 20 °C, the ultimate loading for epoxy adhesive joint depending on the joint thickness (t) was greater than for the polyurethane joint by, respectively, 282% for t = 1 mm, 88% for t = 2 mm and 279% for t = 4 mm. It was proved that the temperature increases to 80 °C in case of both adhesives reduces the mean destructive force in comparison with the measurements made at 20 °C. For the Sika® PS (PUR two-component polyurethane) adhesive, the greatest load capacity decrease was measured for the joint of thickness t = 2 mm (55%), and in case of the epoxy adhesive for the joint of thickness t = 4 mm (89%). It was found that after reaching the destructive force the flexible joints retain a partial load capacity contrary to the rigid joints.

scholarly journals Experimental Research on Load Capacity, Treatment of Adhesively Bonded Surface and Failure Process of Structural T-joint

2016 ◽  
Vol 64 (2) ◽  
pp. 473-479
Author(s):  
Miroslav Müller
Keyword(s):  
Surface Treatment ◽  
Mechanical Treatment ◽  
Load Capacity ◽  
Failure Process ◽  
Adhesive Bond ◽  
T Joints ◽  
Limit Values ◽  
Epoxy Adhesives ◽  
Two Component ◽  
The Impact

In this paper the mechanical behaviour of structural two-component epoxy adhesives in T-joints is experimentally investigated. The aim of this study is to analyse the impact of the adhesive bonded surface treatment on the maximum force required to cause destruction, i.e. bearing capacity of T-joints bonded with various adhesives. Experimental results showed that the type of the adhesive affected the limit values of a force required for the destruction of the adhesive bond. The effect of the bonded surface treatment was also confirmed. From the results of experiment it was proved on five tested two-component epoxy adhesives that the negative effect of the peeling forces can be reduced by mechanical treatment of the adhesive bonded surface e.g. blasting. When there is applied an unsuitable mechanical treatment of adhesive bonded surface, the decrease of the force required for the destruction of the bond was up to about 98%.

Impact Strength of Filled Polymer Materials

2017 ◽  
Vol 883 ◽  
pp. 46-50
Author(s):  
Miroslav Müller ◽  
Petr Valášek
Keyword(s):  
Impact Strength ◽  
Dynamic Loading ◽  
Constructional Material ◽  
Epoxy Adhesive ◽  
Polymer Materials ◽  
Significant Group ◽  
Two Component ◽  
Recycled Plastics ◽  
The Impact ◽  
Positive Effect

Polymers rank among a significant group of technical materials. One of requirements for this constructional material is to have enough resistance to a dynamic loading. Especially in the area of connecting the materials reactoplastics are used, which are distinguished for a low resistance to the dynamic loading. One solution for increasing an impact strength is filling the reactoplastics, i.e. a formation of polymer composites. The aim of the research was to evaluate an impact strength of various polymer materials (composites filled with different types of a filler, structural two-component epoxies, mixed recycled plastics, PPO – polyphenyle oxide and PS – polystyrene). The Dynstat method CSN 64 0611 was chosen for the evaluation of the impact strength. Reactoplastics matrix on the basis of two-component epoxy adhesive with high liquidity and an increased speed of a hardening GER reaches low values of the impact strength (2.54 ± 0.30 kJ·m-2). It is evident from the experimental results the positive effect of aluminium microparticles GER MFAI (3.26 ± 0.35 kJ·m-2), glass beads GR B134 (2.83 ± 0.29 kJ·m-2) and microfibres of polyamide from the process of tyre recovery GER MPA (3.92 ± 0.25 kJ·m-2) on the impact strength. The results of this experiments show the possibility of the modification of the relative fragile epoxy resin with the filler, which increases the impact strength.

Self-Compassion and Quality of Life in Adults Who Stutter

2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd
Keyword(s):  
Quality Of Life ◽  
Social Connectedness ◽  
The Self ◽  
Future Research ◽  
Self Compassion ◽  
Adults Who Stutter ◽  
And Gender ◽  
Relationship Of ◽  
The Impact

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.

Pengaruh Lintas Budaya Pada Pemasaran Internasional Dengan Pendekatan Perilaku Konsumen

2017 ◽  
Vol 1 (2) ◽  
pp. 168-176
Author(s):  
Endy Gunanto ◽  
Yenni Kurnia Gusti
Keyword(s):  
Consumer Behavior ◽  
Marketing Strategy ◽  
Consumer Culture ◽  
International Organization ◽  
Future Research ◽  
Special Issue ◽  
Cross Culture ◽  
Several Variables ◽  
Cultural Orientations ◽  
The Impact

In this article we present a conceptual of the effect of cross culture on consumer behavior incorporating the impact of globalization. This conceptual idea shows that culture inûuences various domains of consumer behavior directly as well as through international organization to implement marketing strategy. The conceptual identify several factors such as norm and value in the community, several variables and also depicts the impact of other environmental factors and marketing strategy elements on consumer behavior. We also identify categories of consumer culture orientation resulting from globalization. Highlights of each of the several other articles included in this special issue in Asia region. We conclude with the contributions of the articles in terms of the consumer cultural orientations and identify directions for future research.

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