Determination and measurement of the hottest glue

The determination and measurement of gluing amount

the determination of gluing amount is one of the important factors to be considered in the production of composite flexible packaging. The gluing amount is directly related to many properties of the product, such as the violence strength, medium resistance, appearance, soft and hard of the composite film

if the glue amount exceeds 6g/m2, it will lose its significance. The performance has been saturated, and it will also cause many side effects, such as slip and high cost. The gluing amount also involves the product cost. According to years of experience, refer to table 1 for dry composite film

requirements for gluing amount classified by use

classification of film characteristics and use

dry basis coating amount (g/m2)

general purpose

transparent and smooth film

1 5

light packaging of printing film, aluminized film and coated film water containing packaging

2 5

contents containing chemical media

3 0

boiling sterilization

100 boiling

3 5

cooking and sterilization

transparent

3 0

including aluminum foil layer

4 0

method 1:

theoretical estimation method

w= (1/4 ~ 1/6) μ Nd

w - glue amount on dry basis g/m2

μ— The dot depth of the gravure top roller is mainly determined by the selection technology. The volatile content of the material in the vacuum state

n - the concentration of the glue%

d - the density of the glue%

the empirical coefficient is related to the dot shape, usage, pressure and elasticity of the top roller. Generally, the corrosion top roller is taken as 1/4, the carving top roller is taken as 1/6, and in practice, it is often taken as 1/5

method 2:

total amount method

w= (amount of adhesive used × one thousand × Solid content%)/processing area =g × N/l × d × 1000 (g/m2)

w - glue amount on dry basis g/m2

n - glue concentration%

l - length of composite film produced m

d - glue width, i.e. width of rubber roller for glue application m

for one or more rolls of composite film produced, weigh the amount of adhesive in the rubber bucket before and after compounding, that is, the total glue application amount, and then obtain the composite length from the meter, and then 1 can be calculated The first is the amount of glue applied to the force sensor of the tension machine. This method is simple and easy, but it also has obvious defects: first, it cannot control and monitor the production process, which is a kind of post statistics; Second, the distribution of adhesive coating cannot be understood; Third, due to the exertion of ethyl acetate, the coating amount has errors. The total amount method can also be calculated in another way, that is, take the length and width as 50mm*220mm

w= (W main × N main + W solid × N solid)/ld × 1000 (g/m2)

w main - main agent usage kg

n main - main machine solid content%

w solid - curing agent usage kg

n solid - curing agent content%

method 3:

weight difference method

first cut the two layers of film to be compounded into 10cm respectively × 10cm in size, weigh the two pieces and add them together. The weight is W1, and then cut the composite film into 10cm × 10cm in size, the measured weight is W2, then the glue amount is (w2-w1) × 100. This method is simple, but due to the thickness uniformity of the film substrate and the uneven amount of ink, the error is large

method 4:

direct coating method

first cut three films with a width of 10cm and a length of less than the circumference of the upper cot, weigh their weight, and turn on the oil pump to W1, and then stick them on the pilot film at the left, middle, and right points. After the actual coating, weigh the sum of their weights to W2, and then calculate the glue amount. This method has high accuracy and can measure the average at the same time

method 5:

solvent removal method

combine the untreated surface of the film with the untreated surface. Cut this composite film 10 × 10cm, weighing W1. After stripping the composite film, wipe the adhesive on the film with ethyl acetate, and weigh the sum of the weight of the two films as W2, then the coating amount = (w2-w1) × 100

in this method, the adhesive must be wiped clean and the weight can be measured after the solvent is fully used. This method has the highest accuracy and can measure the uniformity of glue distribution

source: Huashi chemical