AS - Graphics - Types Of Adhesives

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AS-Level ­ Graphics ­ Adhesives
An adhesive is a mixture in a liquid or semi-liquid state that adheres or bonds items together. .
Adhesives may come from either natural or synthetic sources. The types of materials that can be
bonded are vast but they are especially useful for bonding thin materials.
The earliest known date for a simple glue is 200,000 BC and for a compound glue 70,000 BC.
The oldest adhesive is dated about 200,000 BC, it was made from spear stone flakes glued to wood
with birch-bark-tar.
The use of compound glues to haft stone spears into wood dates back to round 70,000 BC. Evidence
for this has been found in Sibudu Cave, South Africa and the compound glues used were made from
plant gum and red ochre. The Tyrolean Iceman had weapons fixed together with the aid of glue.
In the late 19th century in Switzerland, casein was first used as wood glue. Today, it is seen to be
used to glue grocery bags.
Types of Adhesives
Non-Reactive Adhesives:
Drying Adhesive:
There are two types of adhesives that harden by drying: solvent based adhesives and polymer
dispersion adhesives, also known as emulsion adhesives. Solvent based adhesives are mixture of
ingredients which is usually polymers dissolved in a solvent. As the solvent evaporates, the adhesive
hardens. Depending on the chemical composition of the adhesive, they will adhere to different
materials to greater or lesser degrees.
Polymer dispersion adhesives are milky-white dispersions often based on polyvinyl acetate (PVAc).
Used extensively in the woodworking and packaging industries. Also used with fabrics and fabric-
based components, and in engineered products such as loudspeaker cones.
Pressure Sensitive Adhesive:
Pressure sensitive adhesives (PSA) form a bond by the application of light pressure to marry the
adhesive with the adhered. They are designed with a balance between flow and resistance to flow.
Made By Richard Francis -

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The bond forms because the adhesive is soft enough to flow (i.e. "wet") the adhered. The bond has
strength because the adhesive is hard enough to resist flow when stress is applied to the bond.
Contact Adhesives
Contact adhesives are used in strong bonds with high shear-resistance like laminates, such as
bonding Formica to a wooden counter, and in footwear, as in attaching outsoles to uppers.…read more

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Synthetic adhesives
Synthetic adhesives are based on elastomers, thermoplastics, emulsions, and thermosets.
Glues for Different Materials
You have the simple wood glue but there is so much more to it than that. There are many different
types, such as:
- urea-formaldehyde resin adhesives feature low cost
- Resorcinol-formaldehyde resin glue is very strong and durable
- phenol formaldehyde resin is commonly used for making plywood.
- Traditionally, animal glues were ubiquitous, especially hide glue, which is still used in
lutherie and restoration.…read more

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- Epoxy adhesives, perhaps the strongest of all adhesives, is used to build planes, vehicles and
sports equipment
- Hot-melt adhesive is a solid adhesive made from thermoplastic resins. It comes in a solid or
semi-solid form and does not need to be mixed with an organic solvent.
- Cyanoacrylate, better known as super glue, is a water-resistant plastic adhesive that is
known to bond well with metals amongst other things; it does not, however, work well with smooth
glass.…read more


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