The materials used in flexible packaging are all kinds of thin films. Regardless of the final formation and application of thin film materials, the temperature is basically inseparable from this element. Today, we will talk about the impact of temperature difference on flexible packaging caused by climate change.
The principle of heat bilges cold shrink, as you know, this is real our side but also the principle of easy to ignore, is always exists in our soft packing, we to equipment, blown film (salivate) printing, composite, bag, etc all processes of the feeling of the most obvious change is the rubber roller: in summer is soft plastic roller in winter is especially hard. Then the rubber roller is soft when the elasticity is better, the production of our pressure can also be slightly reduced, at the same time, the glue, ink transfer rate will increase; When the cots are especially hard in winter, our pressure will increase a little bit, serious need to consider whether the cots will slip, at the same time, the transfer rate of glue and ink will be reduced, these microscopic changes we need to deal with and solve in advance in process design and actual production.
The materials we use, such as film, glue, ink and solvent, 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, the better the material activity, the higher the affinity of the surface, the higher the affinity of the material surface activity, the higher the temperature is higher than the glue, ink on the material infiltration is better, and at the same time, the affinity of the material for glue, ink also increases. Therefore, the performance in the composite process is particularly obvious, the same material, machine speed, in summer, the probability of fast foaming is very low, and in winter, it is easy to bubble. Temperature IS LOW, THE SURFACE ACTIVITY OF THE MATERIAL IS LOW, NAMELY THE inerTNESS OF THE MATERIAL IS TALL, EACH OTHER COMPATIBILITY DECREASES NATURALLY.
Temperature changes in the weather will be caused by glue, the temperature of the ink itself also produced change, also is the same glue, ink construction can arise because of the change of the temperature change, now many manufacturers pay more and more attention to the viscosity of the actual production control, but if you ignore the influence that also is just a one-sided pursuit. Different resins may have different sensitive areas to temperature, but it is an indisputable fact that temperature and viscosity are inversely proportional. I have done a viscosity change test of a resin at different temperatures. Under the condition of 25°, the viscosity of the resin is 2300 (coating 4 cups about 25 seconds), and reaches 3000 (coating 4 cups about 32 seconds) at 15°, which means that the temperature is reduced by 10 degrees, and the viscosity is fully increased by 7 seconds!! Of course, in our actual production, passing through different resin and solvent on thin, the difference of viscosity change may not be so big, but the viscosity will be because of different room temperature change is real, this is sometimes production has been in use for viscosity control instrument, also according to the SOP strictly control the change of viscosity, but still have large deviation, quality because viscosity didn't change, In fact, the solid content of our glue ink has actually changed.
Moreover, the temperature change, then the glue and ink itself temperature will change, then the low temperature of the glue ink itself will lead to the solvent needs more heat to volatilize; Under the condition of high temperature solvent is extremely volatile, a friend had done the experiment, in 35 degrees under the condition of a glue tank can volatilize 3KG/hour ethyl acetate. Therefore, the effect of our temperature on the solvent volatilization efficiency is great, produced in summer dry version, in winter not to produce dry, in addition to the activity of the material changes, and the heat needed for solvent volatilization is also closely related.
Soft packaging materials, ink, glue basically belong to polymer materials, belong to petroleum derivatives, film (except aluminum foil, paper) processing of the basic path is the use of heating melting, the grain from solid to fluid, with processing, we then according to the demand, After cooling and shaping, the film is processed to form the film we need (as for various types of film processing methods or material functional requirements, the range is too large to be explained here). After processing the surface of the film is inert, we also need to carry out surface treatment such as corona, but the film material for the subsequent processing and market demand, generally will be blended modified, inevitably add some additives such as: Smooth agent, opening agent, antistatic agent, etc., these are typically small molecular weight will exist within the film and film like a container put them inside, which is within the low molecular weight in the polymer film (as you can imagine is put inside a bottle a lot), once the temperature rise to these things they will be active, temperature reducing latency, If there are defects in the control and design of the formula during processing, it will directly affect the performance of our membrane material: precipitation or lack of friction coefficient directly leads to increase or decrease. So the membrane material of the opening agent and the general degree of the smooth agent is different, most of the opening agent on the market to add inorganic powder particles, is to ensure that the surface roughness of the material and the impact on the environmental temperature is reduced.
To sum up, the actual temperature for our flexible packaging is still a great impact, as long as we carefully do a good job in each link, to make stable qualified products.
