| An adhesive is a substance that is used to | | | | this group. These are two chemicals that are |
| fix or bond two surfaces together. They come | | | | not adhesive until they are mixed together; |
| from very small powered substances to | | | | then they rapidly solidify into a chemical |
| incredibly strong. Adhesives can be natural | | | | bond that is very difficult to separate on a |
| or synthetic but more commonly are the | | | | flat surface. |
| latter, man made glues produced for anything | | | | |
| from household repairs to industrial bonding. | | | | Hot or 'thermoplastic' adhesives are the type |
| | | | often found in workshops and are what many of |
| The original adhesives were natural, plant | | | | us used in school. They are often loaded in a |
| resins or animal substances. Ancient | | | | solid state into a glue gun which heats the |
| Egyptians used animal glues and Native | | | | substance, letting it run onto the surface |
| Americans used rendered buffalo hooves. | | | | that needs it. The surface is pressed against |
| Natural adhesives are usually classed | | | | the desired object and generally left under |
| together and are separate from synthetic ones | | | | light pressure until the glue has cooled. |
| which themselves come in a variety of forms. | | | | Upon cooling the two surfaces should be very |
| The cheapest and weakest are usually simple | | | | difficult to separate. |
| solvents that evaporate and leave a adhesive | | | | |
| bond, basically drying out, like the white | | | | The glues used on masking tape are pressure |
| glue used by younger children in crafts that | | | | sensitive and form a bond when pressed into |
| can be painted onto a surface. | | | | place, but can be peeled away at a later |
| | | | date. They also come in more permanent forms |
| A fairly common form of adhesive is reactive; | | | | that are used in safety labels and sound |
| the well known two part epoxy comes under | | | | dampening seals among other things. |