The most effective method for remove the adhesive labels from glass or plastic jars is the use of heat to make the glue softer. Or, substances easily available at home such as alcohol or white vinegar they can temporarily weaken the interactions between adhesive molecules and the contact surface. This is because many labels are designed to ensure durability and reliability. Modern ones are fixed with adhesive systems designed to work simply but extremely effectively, such as Pressure-Sensitive Adhesive (PSA), which adhere stably even with just a slight pressure. Depending on your needs, these adhesives can be based on glues hot meltapplied hot, or on other substances such as acrylic polymers.
Heat is the most effective method for removing labels from jars: tricks
Among the simplest methods to facilitate its removal are the use of hot water or of hot air (for example with a phon). Heat makes the adhesive softer and less cohesive, making it easier for the label to peel off. In fact, many glues use polymers thermoplasticsthat is, they soften with heat and solidify again when cooled, sticking to the jar. Applying heat makes them “soft” again and easy to peel off.
In this regard we must pay attention to thermal shock: Glass can break or even explode if subjected to sudden changes in temperature. It is therefore important to heat gradually or in any case not to use too high temperatures.
There are also other home tricks. It should be noted that There appear to be no scientific studies that systematically analyze the effectiveness of these methods on labels. However, they are also often used isopropyl alcohol, denatured ethyl alcohol ol’white vinegar. These substances can interfere with the interaction between adhesives and material: alcohol can penetrate the adhesive film, softening the glue and reducing cohesion. THE’acetic acid (CH3COOH, contained in vinegar) is less effective on modern glues, such as PSA, but can act as a solvent, affecting the stability of the adhesive. These methods work in some cases, but they are not universal: it all depends on the type of glue used and the adhesion time.
How labels are glued
Among the most used labels are the Pressure-Sensitive Adhesive (PSA), a category of adhesives that adhere to surfaces simply thanks to pressure. In practice, the adhesive is already “ready”: just remove the protective support and press the label against the jar so that it remains firmly glued. This type of adhesive is very widespread in the manufacturing sector packagingespecially when it comes to packaging such as jars and bottles, because it works well on smooth surfaces such as glass, allows for quick application and guarantees good stability over time.
When we talk about PSA we are not referring to a single glue, but to an adhesion method. The glues used can in fact be different, depending on the manufacturer’s needs. Among the most common we find acrylic adhesives or so-called glues hot melt. The latter must be applied hot: the heat makes them fluid, allowing them to be spread on the surface, then once cooled they solidify ensuring adhesion. There are solutions hybrid which combine the practicality of PSA adhesives with the chemical characteristics of hot glues: the combination of pressure and hot application guarantees adhesion even stronger of the label.
What is jar glue and how is it made?
A glue, or adhesive, is a substance capable of joining two different surfaces through physical and chemical phenomena that lead to the formation of a stable bond. The hills hot melt are mainly made up of polymersthat is, long chains made up of two or more repetitive units linked together, called monomers. These units have two or more reactive centersoften double bonds: metaphorically, we can imagine them as the two arms that they use to bind to neighboring units and form the polymer. Among the most widespread monomers we have theisoprene, The butadiene and it styrene. The resulting polymers are thermoplasticsa feature that allows both easy adhesion and detachment of the label, as already mentioned.
In the food label sector, labels are also very widespread water-based acrylic adhesivesas they guarantee good transparency, stability over time and compatibility with the requirements of food safety. From a chemical point of view they are polymers made up of the repetition of aacrylic unit (acrylic acid or its derivatives) which are dissolved in water in the form of tiny particles. Once the label is applied, the water evaporates and the polymer forms a solid adhesive film.
