Dry compounding is the process of using a dry compounding device to bond two or more films together using an adhesive. The amount of adhesive used in dry compounding is small, accounting for about 10% of the material cost, but it has a very important influence on the quality performance of the composite film. It determines the peel strength of the composite film, and affects the transparency of the composite film, heat seal strength, heat resistance, resistance to media, etc., so the choice of adhesives for composite flexible packaging companies should be very cautious.
The selection of adhesives for composite flexible packaging should mainly consider the following aspects:
one. According to the requirements of packaging products to choose adhesive products should consider the following aspects.
1, after the packaging product after the processing temperature is different, the choice of adhesive will be different. If the common temperature classification has a cooking temperature of 135°C for 30 minutes, you must choose the adhesive that can meet this temperature requirement, such as the YH502/YH10 of Gaomeng; if your product only requires 121°C for 30min cooking, you do not need to use 135 °C adhesive, as long as the adhesive to reach 121 °C for 30min is like YG502S/YH10 from Gaomeng, otherwise it is wasteful to use the adhesive that resists 135°C, which causes your production cost to increase.
2, according to the nature of the packaged product to choose adhesive helium gas (inflatable packaging)
Packaged product category │ liquid: water-soluble, solvent-based, pH, wet solid └ solid: different from the packaging of volatile, non-volatile products, the choice of adhesive is also different. Such as mustard packaging must consider when the adhesive acid, spicy, salty and other patience; such as washing two. According to the structure of the composite packaging, the materials used for the adhesive composite packaging are varied. The commonly used materials include BOPP (light film, pearl film, matting film, etc.), PET, BOPA, AL, and yttrium aluminum film (VMPET, VMCPP, VMPE, etc.) ) CPP, PE, etc. The single PE film is very different. If the thickness of the PE is different and the resin used is different in the characteristics of the PE film, the selected adhesive is also different. For example, during the rolling process, aluminum foil needs to be supplied with a release agent (oil). Although it has been cleaned after rolling, there is still the problem of oil contamination. Therefore, in the selection of adhesives for compounding, it must be considered that there is a certain degree of resistance to oil contamination, especially in the selection of high solid content adhesives.
In the composite aluminized film, the use of ordinary adhesives, the general peel strength is only 0.3-0.615N/mm aluminum transfer serious. If such a packaging bag is used to package some irregular solids (such as tea leaves) and then vacuumed, after a period of time, large white foam will appear on the outer surface of the packaging bag, that is, the outer layer of the aluminum-plated composite film will come off. Floor. Therefore, it is necessary to find ways to improve the peeling strength of the aluminized composite film (the adhesion strength of the aluminized layer before the uncoating of the aluminized film is 2N/15mm), and the problem of transferring the aluminized film is resolved. The method is to use a special adhesive for aluminizing films, such as 10YH501S/YH10S or YH501SL/VM10 from Beijing Gaomeng Chemical Industry Co., Ltd.
In the aspect of composite PE film, if more PE additives are used for thicker additives, the precipitation of PE additives must be considered. If you do not pay attention to this problem, use an ordinary adhesive. After the composite film is compounded, the peel strength will become lower and lower as the curing and time passes. It will be separated, due to lead in the compound high-adhesive content of PE film, you must be very careful to precipitate the problem of additives, use the adhesive can adapt to the additives. Such as Beijing Gao Meng Chemical's high-auxiliary film composite special adhesive series.
three. According to the use of dry composite equipment selection of adhesives many composite flexible packaging companies will find such a phenomenon, the same kind of adhesive in different manufacturers with different effects. There are many reasons for this, and one of them is that the equipment used is different. There is a big gap in the grade of dry laminating machines used today. When selecting adhesives, adhesives should be selected according to the conditions of their own equipment.
Select the adhesive according to the tension system of the device's equipment. If the tension control system of the equipment is poor, the precision of the tension control is not high, and the tracking feedback is poor, then when selecting the adhesive, the initial adhesion should be good, so that the formation of the tunnel can be reduced and the yield can be improved. On the contrary, the tension control system is very good, so that the initial adhesive force of the adhesive is not bad, it does not matter, there will be no tunnel, and there will be no effect on the yield.
The adhesive is selected according to the working speed of the device. If the working speed of the device is high, then the viscosity should be selected when the adhesive is selected. If the viscosity is too high, the adhesive will generate a large amount of bubbles in the adhesive tank. Seriously affect the adhesive coating state, and then affect the quality of the product. On the contrary, the working speed is lower, and when the adhesive is selected, the viscosity can be higher.
four. According to the technical indicators of the adhesive to select the adhesive If the technical indicators of the adhesive change range is smaller, indicating that the performance of the adhesive is more stable, the more conducive to the soft package plant to control the quality of composite products. If an adhesive plant proposes a solids content of 75%, the adhesive plant proposes a solids content of 75% and an adhesive viscosity of 4000 to 8000 mpas. This is an ordinary adhesive, generally having an adhesive viscosity of 8000 mpas. The best working concentration is 30%. If the working concentration is 35%, the coating state of the adhesive will be deteriorated, affecting the product quality; the adhesive with the viscosity of 4000mpas, the best working concentration is 35%, if it will work If the concentration drops to 30%, the cost will increase, affecting the residual solvent and production efficiency.
In addition, if the solid content changes greatly, the amount of adhesive applied will be affected.
Fives. The adhesive is selected according to the working concentration of the adhesive.
At the same speed and other process conditions, the greater the working concentration of the adhesive, the more economical it is, and the better the transparency and other quality factors. The higher the solids content, the higher the working concentration of the binder. A 50% solids binder has a working concentration of 20% to 30%; and a 75% solids binder has a working concentration of 30% to 40%.
An example is given below (in the case of adhesive dry base: 3.0 g/m2):
Option A: Use 50% solids binder, working concentration 25%, wet glue volume 12g/m2
Option B: Use 75% solids binder, working concentration 40%, wet glue volume 7.5g/m2
Scheme A consumes 4.5 g/m2 of ethyl acetate, which is approximately 0.0315 yuan/m2, more than scheme B. If this 4.5 g/m2 ethyl ester is completely volatilized, it must consume a certain amount of heat and affect the production efficiency.
Therefore, when the adhesive is selected as high solid content as possible, the use of the highest possible working concentration, only with very good economy, can improve efficiency. At the same time, the transparency of the composite film will be better.
six. The adhesive is selected according to the manufacturer of the adhesive.
Nowadays, there are many manufacturers of adhesives. The era of oversupply is long past. When selecting adhesives, we should also see how much service the company can provide and how much technical support it can provide. The current social division of labor is more meticulous, and related industries can provide certain support services in the vertical direction, which will play a significant role in the development of the company.
Now that the market is in shape, it is no longer just a mere commodity exchange. It also attaches support, services, and brand image. Behind the tangible transaction, how many intangible supports and services are there?
Seven. Depending on the food hygiene performance of the adhesive, if the adhesive is selected as a food package, the food hygiene performance of the adhesive must be taken into consideration when selecting the adhesive, and whether there is an odor. Otherwise, some unhygienic factors in the adhesive, such as odors, will penetrate into the food, and the resulting losses and effects are incalculable.
In summary, the flexible package plant should consider the packaged product, the structure of the composite material, the condition of the dry laminating machine, the technical indicators of the adhesive, the working concentration, the manufacturer, the food hygiene, etc. Many factors. (Text / Sun Changhe) ("Printing Weekly")
The selection of adhesives for composite flexible packaging should mainly consider the following aspects:
one. According to the requirements of packaging products to choose adhesive products should consider the following aspects.
1, after the packaging product after the processing temperature is different, the choice of adhesive will be different. If the common temperature classification has a cooking temperature of 135°C for 30 minutes, you must choose the adhesive that can meet this temperature requirement, such as the YH502/YH10 of Gaomeng; if your product only requires 121°C for 30min cooking, you do not need to use 135 °C adhesive, as long as the adhesive to reach 121 °C for 30min is like YG502S/YH10 from Gaomeng, otherwise it is wasteful to use the adhesive that resists 135°C, which causes your production cost to increase.
2, according to the nature of the packaged product to choose adhesive helium gas (inflatable packaging)
Packaged product category │ liquid: water-soluble, solvent-based, pH, wet solid └ solid: different from the packaging of volatile, non-volatile products, the choice of adhesive is also different. Such as mustard packaging must consider when the adhesive acid, spicy, salty and other patience; such as washing two. According to the structure of the composite packaging, the materials used for the adhesive composite packaging are varied. The commonly used materials include BOPP (light film, pearl film, matting film, etc.), PET, BOPA, AL, and yttrium aluminum film (VMPET, VMCPP, VMPE, etc.) ) CPP, PE, etc. The single PE film is very different. If the thickness of the PE is different and the resin used is different in the characteristics of the PE film, the selected adhesive is also different. For example, during the rolling process, aluminum foil needs to be supplied with a release agent (oil). Although it has been cleaned after rolling, there is still the problem of oil contamination. Therefore, in the selection of adhesives for compounding, it must be considered that there is a certain degree of resistance to oil contamination, especially in the selection of high solid content adhesives.
In the composite aluminized film, the use of ordinary adhesives, the general peel strength is only 0.3-0.615N/mm aluminum transfer serious. If such a packaging bag is used to package some irregular solids (such as tea leaves) and then vacuumed, after a period of time, large white foam will appear on the outer surface of the packaging bag, that is, the outer layer of the aluminum-plated composite film will come off. Floor. Therefore, it is necessary to find ways to improve the peeling strength of the aluminized composite film (the adhesion strength of the aluminized layer before the uncoating of the aluminized film is 2N/15mm), and the problem of transferring the aluminized film is resolved. The method is to use a special adhesive for aluminizing films, such as 10YH501S/YH10S or YH501SL/VM10 from Beijing Gaomeng Chemical Industry Co., Ltd.
In the aspect of composite PE film, if more PE additives are used for thicker additives, the precipitation of PE additives must be considered. If you do not pay attention to this problem, use an ordinary adhesive. After the composite film is compounded, the peel strength will become lower and lower as the curing and time passes. It will be separated, due to lead in the compound high-adhesive content of PE film, you must be very careful to precipitate the problem of additives, use the adhesive can adapt to the additives. Such as Beijing Gao Meng Chemical's high-auxiliary film composite special adhesive series.
three. According to the use of dry composite equipment selection of adhesives many composite flexible packaging companies will find such a phenomenon, the same kind of adhesive in different manufacturers with different effects. There are many reasons for this, and one of them is that the equipment used is different. There is a big gap in the grade of dry laminating machines used today. When selecting adhesives, adhesives should be selected according to the conditions of their own equipment.
Select the adhesive according to the tension system of the device's equipment. If the tension control system of the equipment is poor, the precision of the tension control is not high, and the tracking feedback is poor, then when selecting the adhesive, the initial adhesion should be good, so that the formation of the tunnel can be reduced and the yield can be improved. On the contrary, the tension control system is very good, so that the initial adhesive force of the adhesive is not bad, it does not matter, there will be no tunnel, and there will be no effect on the yield.
The adhesive is selected according to the working speed of the device. If the working speed of the device is high, then the viscosity should be selected when the adhesive is selected. If the viscosity is too high, the adhesive will generate a large amount of bubbles in the adhesive tank. Seriously affect the adhesive coating state, and then affect the quality of the product. On the contrary, the working speed is lower, and when the adhesive is selected, the viscosity can be higher.
four. According to the technical indicators of the adhesive to select the adhesive If the technical indicators of the adhesive change range is smaller, indicating that the performance of the adhesive is more stable, the more conducive to the soft package plant to control the quality of composite products. If an adhesive plant proposes a solids content of 75%, the adhesive plant proposes a solids content of 75% and an adhesive viscosity of 4000 to 8000 mpas. This is an ordinary adhesive, generally having an adhesive viscosity of 8000 mpas. The best working concentration is 30%. If the working concentration is 35%, the coating state of the adhesive will be deteriorated, affecting the product quality; the adhesive with the viscosity of 4000mpas, the best working concentration is 35%, if it will work If the concentration drops to 30%, the cost will increase, affecting the residual solvent and production efficiency.
In addition, if the solid content changes greatly, the amount of adhesive applied will be affected.
Fives. The adhesive is selected according to the working concentration of the adhesive.
At the same speed and other process conditions, the greater the working concentration of the adhesive, the more economical it is, and the better the transparency and other quality factors. The higher the solids content, the higher the working concentration of the binder. A 50% solids binder has a working concentration of 20% to 30%; and a 75% solids binder has a working concentration of 30% to 40%.
An example is given below (in the case of adhesive dry base: 3.0 g/m2):
Option A: Use 50% solids binder, working concentration 25%, wet glue volume 12g/m2
Option B: Use 75% solids binder, working concentration 40%, wet glue volume 7.5g/m2
Scheme A consumes 4.5 g/m2 of ethyl acetate, which is approximately 0.0315 yuan/m2, more than scheme B. If this 4.5 g/m2 ethyl ester is completely volatilized, it must consume a certain amount of heat and affect the production efficiency.
Therefore, when the adhesive is selected as high solid content as possible, the use of the highest possible working concentration, only with very good economy, can improve efficiency. At the same time, the transparency of the composite film will be better.
six. The adhesive is selected according to the manufacturer of the adhesive.
Nowadays, there are many manufacturers of adhesives. The era of oversupply is long past. When selecting adhesives, we should also see how much service the company can provide and how much technical support it can provide. The current social division of labor is more meticulous, and related industries can provide certain support services in the vertical direction, which will play a significant role in the development of the company.
Now that the market is in shape, it is no longer just a mere commodity exchange. It also attaches support, services, and brand image. Behind the tangible transaction, how many intangible supports and services are there?
Seven. Depending on the food hygiene performance of the adhesive, if the adhesive is selected as a food package, the food hygiene performance of the adhesive must be taken into consideration when selecting the adhesive, and whether there is an odor. Otherwise, some unhygienic factors in the adhesive, such as odors, will penetrate into the food, and the resulting losses and effects are incalculable.
In summary, the flexible package plant should consider the packaged product, the structure of the composite material, the condition of the dry laminating machine, the technical indicators of the adhesive, the working concentration, the manufacturer, the food hygiene, etc. Many factors. (Text / Sun Changhe) ("Printing Weekly")
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