Amazing Glue properties How do it actually work see the principle behind it?

Amazing Glue properties

Introduction

Well we all have used glue or gum often but never realised that how it actually works so lets find out how does that glue really work.

All glues use two forces to attach the things to be joined together.

These forces are adhesion, which is the relationship between the glue and the item to be glued, and cohesion, the structural

relationship between the glue molecules themselves.

Good adhesion requires glue at the point of application to be as liquid as possible, and to develop chemical bonds with the material to be glued.

Good cohesion which means bonding in simple terms which requires the glue to become as solid as possible after curing and to develop into a few, but very long-chain, molecules.

The most popular glues are solvent adhesives, in which the molecules of the adhesive (the actual glue) are dissolved in organic solvents or in water.

  While the solvent evaporates within the air, the adhesive molecules can develop chemical bonds with one another .

Hot-melt adhesives work best at temperatures of about 120-180°C when it is at its most adhesive. Cohesion improves because the glue gradually cools down.

 adhesives  or glue stay soft in liquid form and sticky at almost all temperatures - they are used on labels and sticky tape and only need gentle pressure to adhere.

Two-component adhesives can cure because their two components -a binder and a hardener - react chemically with each other once they are mixedtogether.

Finally, the so-called superglues - usually cyanoacrylates- need moisture in order to cure.

Simply glue comes in contact with air and dries cum sticks.

Why does not the glue adhere or stick inside tube?

Solvent glues consist of about 30­% adhesive and 70% solvent, the latter component being organic molecules or water, Only when the solvent is able to escape can the remaining molecules stick together.

if there is a large enough hole However, tubes are usually made of aluminium or a synthetic materials so as a result there will be less sticking inside of the container.

Superglue during a tube consists of the adhesive only, but this, too, requires contact with air from which it captures the water that starts a sequence reaction among its molecules, causing it to harden.

This will result as the enemy moisture is penetrated in.

Why does sticky tape stick more firmly to paper than Post-it Notes do?

Well Notes and sticky tape both make use of pressure-sensitive adhesives that stay soft all the time and work through the force of adhesion only.

However, while Post-it Notes can be peeled off and reused, sticky tape can only be peeled from very smooth surfaces.

The difference lies in the form of the adhesive molecules.

In the case of sticky tape, the molecules lie randomly on a carrier layer and their attraction to the molecules of the other surface is effective throughout its length.

The attraction is so strong that when

the tape is pulled off it can take paper fibres with it.

On uneven, microscopically fissured surfaces there is an additional effect which reinforces the adhesive strength.

Tiny air bubbles are trapped during

adhesion and expand when the tape is pulled off.

Low pressure is created within these bubbles, and this needs to be overcome.

On Notes, the adhesive forms tiny balls with a diameter of 30-50 micrometers.

A bed of another adhesive holds them onto the note, while still allowing them to move.

It's all due to the spherical shape

of the balls, the adhesive forces work only at the point of contact.

when pressed more firmly they spring back, and only a small area of adhesive touches the paper. 

The many small adhesive points provide barely any adhesive force to prevent the notes irom being peeled off Since they are able to rotate in their bed ot adhesive, the bonding area remains 'fresh for longer.

Hope you all enjoyed the article stay curious see you in next article.