What is the Cohesion - What is cohesion??

Also called cohesive attraction or cohesive force cohesion refers to a property of materials that describes the tendency of similar particles within that substance to hold together due to intermolecular forces The cohesive strength of a substance is determined by the shape and structure of its molecules when molecules within cohesive materials get close together the electrons orbiting the molecules are distributed irregularly which creates an electrical attraction that causes the molecules to be attracted towards each other In labelling cohesion is important in the construction of a label from a number of layers and its application onto a substrate while it is important that labels have good adhesion to ensure that the layers within the construction remain firmly bonded together and the labels adhere successfully to a substrate they also need good cohesion to ensure that each layer has the internal strength to remain in its original form even when labels are stressed or put under pressure by the manufacturing and printing processes and during application onto and removal from a substrate Good cohesive strength can also help to avoid common label problems such as adhesive residue and creep also known as cold flow

Glossary

Adhesion - What is adhesion?

Definition of ADHESION:

The tendency of dissimilar particles or surfaces to hold together; a state in which two different substances are held together by interfacial forces.

These forces may include chemical bonds (the surface atoms of the two materials bond together), covalent bonds (the surface atoms share electrons), electrostatic forces (positively and negatively charged surfaces are attracted to each other), mechanical interlocking (surface particles physically interlock), polymeric diffusion (molecules from one polymer penetrate into another polymer, while remaining bound to their original source), van der Waals forces (interaction between surface molecules based on regions of slight positive and negative charge within each molecule that are attracted to an oppositely charged region of a neighbouring molecule), or any combination of these.

In labelling, the primary interfacial forces that create adhesion (and cohesion) are van der Waals forces. Adhesion is important in the application of a label to a substrate and in the construction of a label from a number of layers; the adhesive and the substrate must have good adhesion to ensure the label remains on the substrate and the layers within the construction must have good adhesion to ensure the label doesn't delaminate.

A person sticks a label onto a parcel; adhesion ensures that the label sticks to the parcel (and that all the layers in the label stick to each other).

Here is the Harvard-style citation to use if you would like to reference this definition of the word adhesion:
Label Planet (2020) What is adhesion? | Adhesion Definition. Available at: https://www.labelplanet.co.uk/glossary/adhesion/ (Accessed: January 1, 2024).

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