Application technology of the hottest alcohol solu

2022-08-21
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The application technology of alcohol soluble adhesives in composite packaging

the rapid development of society makes people pay more and more attention to their own living environment and improve their own quality of life, which requires social production enterprises to produce products that meet environmental protection requirements while creating a toxic working environment for their employees. At present, many raw materials used by plastic flexible packaging enterprises are toxic substances, including solvents, inks, adhesives and so on. The produced packaging composite film may penetrate into the contents through the film because it contains a certain amount of toxic substances, which is potentially harmful to consumers. In recent years, many non-toxic or low toxic raw materials have been developed in the plastic flexible packaging industry, such as alcohol soluble inks and adhesives, water-soluble inks and adhesives, solvent-free adhesives and so on. Among them, alcohol soluble adhesives have attracted increasing attention in the industry because of their excellent performance, ease of operation and excellent performance price ratio, and are recognized by more and more customers. Here is my opinion on its application technology, for the reference of insiders, welcome criticism and correction

I. characteristics of alcohol soluble adhesives

1. Compared with the current general ester soluble adhesives, alcohol soluble adhesives do not contain - NCO groups and highly toxic free TDI, MDI and other aromatic isocyanate molecules in the main agent and curing agent, so there is no possibility of hydrolysis to produce carcinogenic aromatic amines. Therefore, they are non-toxic and harmless in the production of composite membranes and the future use of products, It will not pollute the contents of the package

2. Alcohol soluble adhesives use industrial ethanol as solvent, which has low pollution to the working environment of the workshop and low production cost. The solvent used for ester soluble adhesives is ethyl acetate, which is a toxic solvent, which has strong irritation to human eyes and liver and is harmful to human health

3. For plastic flexible packaging enterprises, the application of alcohol soluble adhesives does not require equipment transformation, does not increase the application cost, and does not affect the work efficiency

4. Alcohol soluble adhesive uses industrial grade ethanol as solvent, which is insensitive to moisture content, and can be produced safely in humid climate without quality accidents

5. Alcohol soluble adhesive has good initial adhesion, strong operation adaptability, and the composite film has good transparency; It has good leveling property, and can also avoid the generation of white spots and bubbles under the condition of low glue amount

6. The combination of alcohol soluble adhesive and alcohol soluble ink can achieve excellent composite strength. In order to meet the packaging requirements of benzene free in China, the alcohol soluble industrial ecology is undergoing in-depth changes. Ink is used by more and more manufacturers. The residue of solvent of alcohol soluble ink after printing will react with the curing agent of ester soluble adhesive, which will affect the curing of ester soluble adhesive and reduce the composite fastness

7. Alcohol soluble adhesives require low curing temperature and short curing time, which can save energy and shorten the delivery time of products

II. Suitable for composite substrates

alcohol soluble adhesives can be widely used on pretreated PE, PP, PA, pet, Pt, Al, aluminized film, paper and other substrates

III. reference to composite process

the application process and performance of eco series alcohol soluble adhesives produced by OMAX industry (Shenzhen) Co., Ltd., a wholly American owned enterprise, are introduced as an example

1. Membrane structure BOPP/CPE

adhesive model: eco501a/B, the ratio of main agent to curing agent is 13:1

application process: working concentration 25%, line model 150, line 40 μ, The drying temperature is 60 ℃, 70 ℃, 80 ℃, the composite roller temperature is 65 ℃, the machine speed is 120m/min, the composite pressure is 4kg, the curing temperature is 40 ℃, and the viscosity of the glue is 14s (No. 3 chaen cup)

test results and properties: glue dry basis: 1 45g/m2

2. Composite membrane structure BOPP/VMPET (full version white ink)

adhesive model: eco702a/B, the ratio of main agent to curing agent is 12:1

application process: working concentration 30%, line model 120, line 55 μ, The drying temperature is 60 ℃, 70 ℃, 80 ℃, the composite roller temperature is 60 ℃, the machine speed is 100M/min, the composite pressure is 4kg, the curing temperature is 40 ℃, and the glue viscosity is 17 S (No. 3 chaen cup). Test results the power supply is the horizontal spring tension testing machine, which mainly changes the spring and performance: glue dry basis weight 1 97G/m2, good appearance, no white spots

IV. precautions for operation

1 If the equipment used ester soluble adhesive before, the scraper frame, glue groove, corrugated roller and circulating pump should be cleaned with ethyl acetate before using alcohol soluble adhesive, and then cleaned with ethanol to avoid polluting the glue and blocking the line roller

2. The working concentration of alcohol soluble adhesive is generally 20% - 35%

3. Preparation sequence: first add the main agent, then add the solvent, stir evenly, then add the curing agent, and finally stir evenly

4. The curing speed of the composite film can be accelerated by curing in the curing room, but the curing temperature should not be too high, generally controlled within 45 ℃, and it can also be naturally cured

5. It is best to use up the prepared glue on the same day. If there is too much residual liquid left, it can be diluted several times with diluent and stored (2) resolution. When it is produced the next day, it can be used as diluent, and a small amount of it can be added to the new glue several times each time. If the glue has begun to solidify or thicken, it cannot be used

6. Other precautions: alcohol soluble adhesives are not suitable for cooking packaging, and cannot be used for media resistant packaging. For example, they neglect the overall improvement of the functional characteristics of local products, such as packaging with liquid pesticides, Baijiu, pepper sauce, etc

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