Six factors restricting the heat sealing strength of pharmaceutical aluminum foil packaging products

2016/10/31 14:51:55

On the aluminum foil pharmaceutical packaging is concerned, the quality of the merits of a large extent reflected in the product of heat sealing strength. Therefore, the impact of pharmaceutical aluminum foil bag sealing strength of several factors, as the key to improving the quality of the product packaging.

1, raw and auxiliary materials

The original aluminum foil is the carrier of the adhesive layer, its quality has a great impact on the heat sealing strength of the product.

On the one hand, the surface of the original aluminum foil oil, will weaken the bond between the adhesive and the original aluminum foil. If the original aluminum foil surface oil and surface tension less than 31 × 10-3μm, it is difficult to achieve the desired heat sealing strength. On the other hand, the original aluminum foil metal composition and surface brightness are not enough to affect the strength of the heat seal, we must strictly control the quality of the original aluminum foil.

2, the adhesive side

Adhesive is a special material containing solvent, it is in a certain process conditions, the original coating of aluminum foil in the dark side (or smooth), drying through the drying tunnel to form adhesive layer, the product sealing strength plays a decisive role.

At present, most of the domestic manufacturers to use imported raw materials to formulate the adhesive, the product can achieve a higher heat sealing strength. However, the price of imported raw materials is too expensive, in order to be able to get high-profit products, some strong research and development of domestic manufacturers will proceed with similar raw materials.

3, the production process

In a certain process parameters under the control of the adhesive in the original aluminum foil coated film, the quality of composite film products will directly affect the heat sealing strength. Among the more important parameters include the speed of coating, the drying section of the tunnel temperature, the A roll pattern roller, depth, line number and the location of the blade, angle.

The speed of application determines the time the coating dries in the drying tunnel. If the coating speed is too fast, the baking temperature is too high, will make the coating surface solvent evaporation too fast, resulting in residual solvent film, film drying is not enough, it is difficult to form a strong dry and strong adhesive layer, it will Affect the product sealing strength, so that the product layer and the adhesion between layers.

Coated roller reticulate shape, depth, line number and the location of scraper, angle determines the coating thickness and evenness. If the selection or adjustment is not appropriate, the adhesive can not be evenly coated on the surface of the original aluminum foil lead to uneven film, the product sealing effect will not be good, the strength will be affected.

4, heat sealing temperature

Heat sealing temperature is an important factor affecting the heat sealing strength. The temperature is too low can not make good adhesive layer with PVC film heat sealing, adhesive layer and PVC film between the bonding is not strong. If the temperature is too high, will make the drug affected. Therefore, a more reasonable heat sealing temperature is usually between 150 ℃ ~ 160 ℃.

5, heat sealing pressure

To achieve the desired heat sealing strength, it is necessary to set a certain heat sealing pressure. If the pressure is insufficient, not only can not make the product of the adhesive layer and PVC film fully fit heat sealing, and even left the bubble between the two, fail to achieve good sealing effect. So the national standard provides the heat sealing pressure of 0.2mPa.

6, heat sealing time

The heat-sealing time also affects the heat seal strength of the product. Under normal circumstances, in the same heat sealing temperature and pressure, a little longer heat sealing time can make the sealing part of the seal is more solid and perfect, to better achieve the desired heat sealing strength. However, modern high-speed pharmaceutical packaging machine process conditions can not provide a long time, the heat sealing, if the sealing time is too short, then the adhesive layer and PVC film will be between the heat sealing is not sufficient. To this end, the national standard provides a scientific sealing time of 1s.