Strength of Adhesives in a lap joint
Shear force refers to any internal force which acts in a perpendicular direction on a substance to its extension. For example air pressure along an air plane wing (Krenk, 2007). Compression test involves a measuring instrument such as leak-down tester used in determining internal condition of combustion engines; it’s done by compressing air into the cylinder and recording the rate at which air is leaking out.eg testing the condition of racing cars engines and other engines of vehicles with high performance (Chang, 2000). Double lap configuration refers to configuration of different timbers using PVA.
Advantages of PVA
- Toxicity; its non toxic which can be handled without any danger but not healthy for consumption. It doesn’t have gassy fumes thus no need of ventilation in rooms which are closed or during cold days.
- Drying time; PVA dries up quickly. Normally, if applied in little amount it makes a thin coat which takes less than 30mins to dry up. For heavier applications it can take a lot of time of about 24hrs with other conditions being applied such as pressure.
- Reversible; its easily reversed using water. It implies that a material is attached using PVA, it can be removed using water such as in archival purposes (Merrick, 2005).
- Clean up; it can be cleaned up easily using soap and water without applying other toxic thinners. When dry, it can be removed by peel ding without causing damage to the surface.
- Characteristics of PVA
- PVA particles when dry they have microscopic appearances which are similar.
- Dry PVA particles are similar and significantly increase in size during nonionic contrast suspension.
- When each PVA group is measured and parameters compared using software program in a microcomputer, they present a non-consistent histogram.
- Initially their particles were obtained through rasping Avalon block.
- Their particles are related to fluid viscosity effect or their behavior in solution. This makes them to be compressible and flexible in nature.
- Characteristics of resin based adhesives
- Durability; resin based adhesives are more durable compared to other adhesives such as synthetic
- Resin based adhesives made of cement are more superior to those of glass and zinc phosphate.
- They temporarily form synthetic adhesives when polyvinyl acetate is suspended.
- Most of resin based adhesives are derived from polymers where adhesives of good properties are shown.
- Resin based has strong adhesion forces which makes them more durable compared to other forms of adhesives (Vlieger, 1995).
- Resin based adhesives appears in different forms such water based and cement based adhesives.
- Advantages of Resin Based Adhesives
- Inflammable; resin based do not contain flammable solvents which makes them friendly to human beings.
- They don’t wear and are resistant to shrinkage when they have dried up.
- Resins based are of high quality compared to other forms of adhesives.
- Their different forms such water based are eco-friendly due to their non toxic nature.
- They are moisture resistant.
Double lap configuration is configured using access of light weight where adhesive forces are required in joining their respective wireless controller LAN. In conclusion, PVA particles are non uniform which have weak farces of adhesion. This affects the lap joints making them appear very weak. Resin based is known to be more durable making the relationship between lap joints stronger.
Chang, J. Y. (2000). Biopolymers, PVA hydrogels, anionic polymerisation, nanocomposites. Berlin: Springer.
Merrick, M. J. (2005). The behaviour of PVA adhesives in chairs. S.l.: Furniture Industry Research Association.
Krenk, S. (2007). Beam theory stresses in an adhesive lapjoint. Roskilde, Denmark: Risø National Laboratory.
Vlieger, H. (1995). Results of uniaxial and biaxial tests on riveted fuselage lapjoint specimens. Amsterdam: National Aerospace Laboratory NLR.