Question

What is the Adhesive - What is an adhesive??

Accepted Answer

This term can refer both to a property of materials that makes them capable of adhesion  i e  an adhesive material is able to create a bond with another material  and to any material that is capable of holding two surfaces together by surface attachment  i e  an adhesive is the substance that is used to create a bond between two materials   Adhesives can also be referred to using the terms    glue        cement        mucilage     or    paste                Compared to other techniques used to join two surfaces or materials together  e g  sewing  mechanical fastening  thermal bonding etc   adhesives can be used to join a much wider range of materials together  can distribute stress across the joint more efficiently  reducing the chances of joint failure   offer a more aesthetic design and provide opportunities for greater flexibility of design  and tend to be much more cost effective  and time efficient  than other methods                                      There are many  many  many different types of adhesives  although they are typically categorised in one of two ways  They may be grouped by origin into    natural adhesives     made from organic sources  such as vegetable starch  natural resins  or animals     sometimes known as    bioadhesives     and    synthetic adhesives     made from man-made materials  such as polymers     this group includes emulsion adhesives  thermoplastic adhesives  and thermosetting adhesives              More commonly  adhesives are grouped by their method of adhesion and then organised into    reactive adhesives     require a chemical reaction to form an adhesive bond  and    non-reactive adhesives     don't require a physical change to form an adhesive bond  although they may undergo a physical change in order to form a bond              Reactive adhesives are further divided into    multi-part adhesives     where the chemical reaction takes place between two or more components  usually a base resin and a hardener curing agent  that are mixed together to create an adhesive bond  and    one-part adhesives     where the chemical reaction takes place between the adhesive and an external energy source  such as radiation  e g  UV Light   heat  or moisture              Examples of non-reactive adhesives include drying adhesives  contact adhesives  hot melt adhesives  and pressure sensitive adhesives  Drying adhesives create an adhesive bond via evaporation and can be either solvent-based adhesives  components of an adhesive are dissolved in a solvent  which evaporates and leaves the components behind  or emulsion adhesives  the components of an adhesive are dispersed throughout a liquid  such as water  which evaporates and leaves the components behind   Contact adhesives are similar but must be applied to both of the surfaces that are to be stuck together and time allowed for the adhesive to dry  via evaporation   before the two surfaces are pushed together to form an instant adhesive bond  Hot melt adhesives are thermoplastics that are heated and applied in molten form so that an adhesive bond is formed as they cool down and solidify  While other adhesives  sometimes known collectively as    structural adhesives     create an adhesive bond once they have hardened via chemical or physical processes  e g  via chemical reaction  evaporation  or cooling   pressure sensitive adhesives are    tacky    under normal conditions and require only the pressure of a finger or hand to form an adhesive bond  through intermolecular interactions between the adhesive and the adherend              At Label Planet  all of our products are   self-adhesive labels    which means that they are all made with pressure sensitive adhesives             Here is the Harvard-style citation to use if you would like to reference this definition of the word adhesive     Label Planet  2016    What is an adhesive    Adhesive Definition    Available at  https   www labelplanet co uk glossary adhesive   Accessed  January 1  2023

Affinity - What is affinity?

Definition of AFFINITY: