With these 15 tips & tricks we enable you to better understand the world of adhesives. The files support you in gaining initial knowledge about our products & products features and how they can improve your production & productions processes.
T&T 01 – Ice water resistant labelling adhesive:Ice water resistance usually indicates the adhesion of labels to bottles that spend up to 72 hours in ice water. However, the specifications are always different. Reproducible tests can be carried out on a laboratory scale, which can give more precise information about ice water resistance.
T&T 02 -Bonding:Adhesion is based on several factors such as internal forces (physical, chemical or mechanical bonds), the effects of interfaces (paper, glass, metals,…) and any interfering bodies such as dust, water or grease. Only the interaction of all three factors will result in the highest possible adhesion.
T&T 03 – Formation of Condensate:Most labelling adhesives are water-soluble, which poses a problem in areas with high humidity. Here, the warm air condenses on the cold bottle and can carry away any adhesive that has not yet dried, resulting in less-than-ideal adhesion and can also cause the labels to slip. There is no universal solution, but some remedies can reduce this problem.
T&T 04 – Preservation of water-based Adhesives: Water-based adhesives are not naturally protected against biological attack. By adding preservatives, the adhesive can be prevented from decomposing. However, cph tries to avoid the use of questionable preservatives.
T&T 05 – Wetting:Wetting of surfaces is an important issue in labelling, as not every label composition is the same. As we know from everyday life, water beads up on greasy or waxed surfaces and forms a film on clean surfaces. It is the same with glue on labels. But the liquid itself also influences wettability, as this is based on the natural law of surface tension.
T&T 06 – Surface Energy and the Young Equation:Optimal wetting is achieved when the surface energy (of the surface to be treated) is at least as high as the surface tension of the wetting liquid. The energy can be calculated with the help of Young’s equation.
T&T 07 – Temperature and its Influence on Labelling:Temperature has many effects on labelling adhesives. Viscosity increases with decreasing temperature, decomposes more easily at higher temperatures and running properties vary from adhesive to adhesive, which is why all adhesives have a recommended processing temperature.
T&T 08 – Bonding Price Labels to Bottles&Peel-off Labelling:In order to make labels easy to remove again, as in the case of promotional labels, a special release lacquer is incorporated between the layers during the production of these labels, which makes it possible to remove them after a certain time without much effort. However, it is important to note that the factors influencing the substrate to be wetted and the adhesive itself have a major impact on the overall result.
T&T 09 – Water Absorption from Label Stock:Since wettability plays a major role in labelling, attention must also be paid to the different sizing (water absorption of the paper) of the labels. This can be determined by means of the Cobb test, in which the labels are in contact with water for a defined period of time and the absolute water absorption can be determined gravimetrically.
T&T 10 – Viscosity:Viscosity indicates the rotational force of a cylinder or disc in the liquid. The thicker the adhesive, the higher its viscosity. It should also be noted that a comparison of viscosities can only be made in relation to the measuring device, the geometry of the measuring rod and the measuring conditions, as different conditions also produce different data which are still “correct”.
T&T 11 – Hotmelt safety advice:Caution is advised when handling hot-melt adhesives, as the name implies, they are molten adhesives that usually reach temperatures of over 100 °C. The correct measures must be taken in case of burns and inhalation of vapours.
T&T 12 – Processing of Hotmelts for Packaging Applications: This compact guide to packaging hotmelts should not be missing from any plant.
T&T 13 – Cleaning Nozzles:Proper maintenance of spray nozzles is an important part of hot melt adhesive application. Nozzles that are not properly cleaned will result in suboptimal application or may clog the machinery altogether, posing a high safety risk to both man and machine.
T&T 14 – Chemical Oxygen Demand:The decomposition of bioorganic substrates has long posed problems for the environment. One way to simulate and evaluate this decay is through COD and BOD determination, where the oxidation of organic components provides information about biodegradability.
T&T 15 – Troubleshooting Cold Glue for Labelling:A comprehensive list of problems that occur during cold glue labelling and how they can be prevented or remedied.