Judgment of thermoforming effect of paper card:
- When the blister-sealing packaging is torn open, the damaged interface occurs in the blister oil layer (the surface is a peeled plastic film without ink), indicating that the surface coating of the paper is tightly closed, and the blister oil is difficult to penetrate into the paper layer.
- When the blister packaging is torn open, the damaged interface occurs in the ink layer (it appears as the peeled plastic film with ink, but the peeled paper hair is less), indicating that the strength of the paper coating is lower than that of the paper layer, which may be the latex of the coating If the dosage is not enough, the combination of the primer and the topcoat is not good, and the migration of the adhesive causes the uneven strength of the coating.
- When the blister packaging is torn open, the damaged interface occurs on the surface of the paper coating, indicating that the coating strength of the paper surface is low and the coating is tightly closed, and it is difficult for the blister oil to penetrate into the paper layer.
- When the blister packaging is torn open, the damaged interface occurs at 1/2 and 1/3 of the thickness of the paper, indicating that the blister has a good effect.
Influencing factors of blister effect:
One part is the four major packaging materials, including paper, blister oil, ink and plastic sheets; the second part is the welding production process of packaging machines.
The specific performance is as follows:
- For vacuum blister packaging, paper is the most critical factor affecting welding. If the selected paper itself cannot be blistered, then even if the ordinary blister oil is replaced with a strong blister oil, or the thickness of the blister oil is increased, the blister oil is passed twice, and other operating parameters (such as increasing the blister) are adjusted. temperature and pressure), etc. are also useless. Therefore, in order to produce qualified paper blister packaging, we must first choose suitable paper. The correct choice of paper is 80% successful. There are many performance indicators of paper, and the affected factors are extremely complex. For special products for blister, the surface strength, absorption performance, interlayer bonding strength and moisture content of paper are mainly concerned.
The degree of crosslinking of different inks is inconsistent, resulting in different hardness and permeability of the resin after curing. The ink should ensure a certain adhesion to ensure its smooth penetration on the surface of the paper. The ink formulation should not contain any additives such as paraffin, grease, lubricating oil or mold release agent that reduce adhesion. After the ink is dried, in order to make the blister oil wet well on the ink surface and firmly adhere to the ink surface, the degree of conjunctiva on the ink surface should not be too dense, which will affect the penetration of the blister oil during the coating process.
- For the performance of blister oil, it is required to have good leveling, good permeability and adhesion to ink and paper, fast drying speed, and the surface of the printed part after oiling should be smooth, with a certain gloss and wear resistance. sex. The blister oil must be used within the shelf life. If the quality of the blister oil itself changes, it will affect the blister effect.
- The detailed process of blister heat sealing is that the blister and the paper card coated with blister oil are pressed together by the pressure device equipped with the machine, and at the same time, the blister and the paper card are heated by electric heating or high-frequency method, so that the The softened blister is bonded with the melted blister oil, and after cooling, the blister, the blister oil and the paper card are firmly integrated to complete the blister packaging process. No matter what type of blister packaging machine, the blister heat sealing device is the most important mechanism, which can directly affect the quality of blister packaging. According to the heating mechanism of the blister heat sealing package, the welding machine can be divided into two types. One is a high-temperature welding machine, which uses a resistance wire heating rod to heat to achieve the purpose of bonding the blister and paper card; the other is a high-frequency (or high-frequency welding machine), which uses high-frequency waves to make the internal molecules of the material collide violently. The high temperature achieves the purpose of bonding the blister and the paper card, and the welding temperature is uniform inside and outside.