+ Submit your article here

Types of Glue

7/11/2012 1:04:55 PM | by Anonymous

Glue

In the past, the term glue was only used in reference to protein colloids that had be prepared animal flesh. However, in today’s date, any substance that is glue like and has the ability stick one material to another can also be referred to as glue. The meaning of glue has also been extended to any fluid adhesive that has the ability to join two materials. There are several adhesive substances in the market today that are used to join different types of materials be it wood, metal, plastic or paper. By definition, an adhesive is a substance that usually comes in the liquid or semi liquid form and has the capability to adhere or bond items together. They can either be made from natural or man-made sources. These substances are able to join two materials either by evaporating the solvent or through the chemical reactions that occur between two or more substances. They are also very useful in joining thin materials such as paper or plastic. One disadvantage of using these substances can be the fact that they require time to ‘cure’ which means that they take time before a joint is formed, unlike other joining processes where a joint can be formed almost instantly. The earliest glue known to mankind occurred in 200,000 BC.

 

Adhesives or glue can be classified into several groups according to their method of adhesion, substances that make them up or their application. The basics of classifying adhesives can be according to reactive, non-reactive adhesives which evaluates if the adhesive has a chemical reaction in order to join two items together, or by determining if the adhesive is made of raw natural material or synthetic.

 

Non-reactive adhesives

Drying adhesives

Drying adhesives do not cause any chemical reaction in order to join two items together. They simply wait for the solvent present in them to evaporate before a bond is formed between the items to be joined. Substances such as white glue, contact adhesive and rubber cement can be classified as drying adhesives. The chemical composition of the adhesive determines if it would form a strong bond between the two items to be joined.

 

Contact adhesives

These adhesives also belong to the non-reactive category of adhesives as they do not cause any chemical reactions. Such adhesives aid in the construction of bonds that are required to withstand high levels of shear-resistance, for example joining the outsoles of footwear to the uppers. Natural rubber is one example of a material commonly used as a contact adhesive. To create bonds using these adhesives, the substance is applied to both surfaces that are required to be joined together and left to dry for a few minutes before the two surfaces are held together to join. In some cases, the adhesive may require up to 24 hours to dry before the surfaces can be joined. Once the surfaces are held together, the adhesive forms a bond almost immediately without requiring much pressure to hold the two items together thus omitting the need for clamps.

 

Reactive adhesives

Multi-part adhesives

These adhesives require two or more components to be mixed together in order to join materials together. The components may not have any adhesives properties on their own, but when mixed with the right components, they can possess great adhesive properties. One example of such adhesives can be the combination of polyester resin and polyurethane resin. These adhesives can also either be solvent-based or solvent-less which leave each of the mixture with different properties from the others. For those that make use of a solvent, the solvent dries up during the curing process.

 

Natural adhesives

Often referred to as bioadhesives, these substances are made from organic sources such as vegetable starch or animal tissue. A common example such adhesives can be flour mixed with water. This mixture has adhesive properties and can be used to join lightweight items such as papers.

 

Synthetic adhesives

Based on man-made substances such as thermoplastics, these adhesives can make use of either a mixture of man-made and natural substances or be purely based on synthetic substances. Some examples of thermosetting adhesives can be epoxy, acrylic polymers and polyurethane.

Are you sourcing for a product or service?

Do you need a quotation?