Will weather changes affect flexible packaging production?

January 21, 2023

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The materials used in flexible packaging are all kinds of films. Regardless of the final formation and application of film materials, temperature is basically inseparable from the element. Today I will talk about the impact of climate change temperature differences on flexible packaging.Everyone knows the principle of thermal expansion and contraction. This principle exists around us but is relatively easy to ignore. It also exists in our flexible packaging all the time. The most obvious change in the process is the rubber roller: the soft rubber roller in summer is particularly hard in winter. Then when the rubber roller is soft, the elasticity is better, and our pressure can be slightly reduced during production, and the transfer rate of glue and ink will increase at the same time; when the rubber roller is particularly hard in winter, our pressure should be increased appropriately A little bit, in severe cases, it is necessary to consider whether the rubber roller will slip, and at the same time, the transfer rate of glue and ink will decrease. We need to deal with and solve these microscopic changes in advance in process design and actual production.The material films, glues, inks, and solvents we use are basically chemical substances. Generally speaking, the surface activity of materials is positively correlated with temperature: the higher the temperature, the better the material activity, and the better the material activity, the better the surface affinity. The higher the affinity, the better the surface activity of the material. The higher the temperature, the better the wettability of the material to the glue and ink, and at the same time, the affinity of the material to the glue and ink also increases. Therefore, the performance is particularly obvious in the compounding process. With the same material and machine speed, the probability of foaming is extremely low in summer, but it is easy to foam in winter. The temperature is low, the surface activity of the material is low, that is, the inertness of the material is high, and the compatibility with each other will naturally decrease.Changes in weather and temperature will cause changes in the temperature of the glue and ink itself, that is, the workability of the same glue and ink will change due to changes in temperature. In actual production, many manufacturers are now paying more and more attention to viscosity control. , but if the influence of temperature is ignored, it is only a one-sided pursuit. Different resins may have different temperature sensitive regions, but it is an indisputable fact that temperature is inversely proportional to viscosity. I have done a viscosity change test of a certain resin at different temperatures.25°The test viscosity under the condition is2300(painted4Cup date25s) resin, the15°reached3000(painted4Cup date32seconds), that is, reducing the10degrees of temperature, the viscosity has almost increased7second! ! Of course, in our actual production, because the resins are different and have been diluted with solvents, the difference in viscosity change may not be that big, but the viscosity will change due to different room temperature. It is true that sometimes production has been used With a viscosity controller, the change of viscosity is also according toSOPsStrictly controlled, but the quality still has a large deviation, because the viscosity has not changed, in fact, the solid content of our glue ink has actually changed.Furthermore, as the temperature changes, the temperature of the glue and ink itself will also change, and the low temperature of the glue and ink itself will cause the solvent to need more heat to volatilize; at high temperatures, the solvent is very volatile. Some friends have done experiments. exist35One glue tank under high temperature can be volatilized3kg/hours ethyl acetate. Therefore, our temperature has a great influence on the volatilization efficiency of the solvent. In summer, dry plate is produced, and in winter, non-dry plate is produced. In addition to the change of material activity, it is also closely related to the heat required for solvent volatilization.Flexible packaging materials, inks, and glues are basically polymer materials, which are petroleum derivatives. The basic processing path of films (except aluminum foil and paper) is to use heating and melting to change the pellets from solid to fluid, which has processability. After that, we will cool and shape according to the requirements, and then process to form the film we need (as for various types of film processing methods or material functional requirements, the scope is too large to explain here). After processing, the surface of the film is inert, and we still need to perform surface treatment such as corona, but the film material is generally modified by blending for subsequent processability and market demand, and some additives such as: slippery agent, Anti-blocking agents, antistatic agents, etc., these are generally small molecular weight things that will exist inside the film, and the film contains them like a container, that is, low molecular weight things are stored in the polymer film (can be imagined as There are a lot of things in a glass bottle), these small things will become active once the temperature rises, and they will lie latent when the temperature drops. If there are defects in the control and design of the formula during processing, it will directly affect the performance of our membrane materials. Performance: Precipitation or deficiency directly lead to increase or decrease of friction coefficient. Therefore, the anti-blocking agent and slip agent in the film material are generally different. Most anti-blocking agents on the market are added with inorganic micropowder particles to ensure that the surface roughness of the material and the impact on the ambient temperature are reduced.To sum up, the actual temperature still has a great impact on our flexible packaging. Only when we do every step carefully, can we make stable and qualified products.

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