Factors pharmaceutical packaging aluminum foil sealing strength of the following main aspects:

1. raw and auxiliary materials aspects

Primary aluminum is the carrier of the adhesive layer, its quality has a great influence on the heat seal strength of the product. In particular, the original aluminum foil surface oil will weaken the adhesive force between the adhesive and the original aluminum foil. If the original surface of the aluminum foil oil and surface tension of less than 31 × 10-3μm time, it is difficult to achieve the desired heat seal strength and must therefore be strictly to good quality primary aluminum.

In addition, in the production process of discovery, all technical indicators are in line with some of the original batch of aluminum foil required, applying the adhesive in the case of all the conditions have not changed, but the heat seal strength of the final product are lower than requirements, and because of the original metal component and the surface finish of the aluminum foil relevant enough. The results showed that the conversion of a special session, so that the original aluminum foil to get full use of the product will reach the desired heat seal strength.

2. The adhesive aspects

Special adhesive is solvent-containing substance, which under certain conditions, the coated aluminum foil in the original dark side (or glossy), after drying drying tunnel forming an adhesive layer, heat seal strength of the product plays a decisive effect. Adhesive color can be divided into colorless, transparent, and golden color series, can be selected according to the needs of users. Different components of the adhesive, heat seal strength of the final product is different. Most domestic manufacturers using imported raw materials formulated adhesive, the product can achieve a high seal strength. But the import of raw material prices are too expensive, in order to obtain high-margin products, some of the research is strong in research and development of domestic manufacturers will begin the same raw materials. This research direction is very tempting, if successful, will bring enormous benefits. It is understood that the process is limited domestic production of raw materials manufacturers, and domestic raw materials to a large extent can replace imported raw materials. If used improperly, it will seriously affect the heat seal strength of the product.

3. The production processes

Under certain process parameters, the adhesive applied to the surface of aluminum foil in the original filming, filming will directly affect the quality of heat seal strength of the product. The more important parameters include coating speed, position bake temperature segment, A pattern coating roll shape, depth, number of lines and the blade angle.

Coating speed determines the coating drying tunnel drying time. If the speed is too fast coating, drying temperature is too high, the solvent evaporation coating surface too quickly, resulting in residual film of the solvent, the film dries inadequate, difficult to form a strong and solid dried adhesive layer, which will It will affect the product's sealing strong, degrees, so that adhesion occurs between the product layers.

Anilox coating roll shape, depth, location, number of lines and the blade angle determines the thickness and uniformity of the coating film. If you select or adjust too inappropriate, adhesives can not be uniformly coated the surface of the aluminum foil in the original cause uneven deposition, sealing effect of the product will not be good, the intensity will be affected. In accordance with the national standard adhesive layer coating, the difference should be less than ± 12.5%. Therefore, we must strictly in accordance with the parameters prescribed in the process to complete the process of forming a film coated adhesive layer, in order to ensure uniform solid film formation.

4. The sealing temperature

Sealing temperature is an important factor affecting heat seal strength. Temperature is too low, the adhesive layer is not well with the PVC film heat sealing, gluing and PVC adhesive layer between the film will not solid. If the temperature is too high, it will make the drugs affected. Therefore, it is reasonable sealing temperature is generally between 150 ℃ ~ 160 ℃.

5. The sealing pressure

To achieve the desired heat seal strength, it is necessary to set a certain sealing pressure. If the pressure is insufficient, not only can not make the product an adhesive layer bonded with PVC film full sealing even make bubbles remain between the two, reach a good sealing effect. Therefore, the national standard sealing pressure of 0.2 × 10Pa.

6. sealing time

Sealing time will also affect the heat seal strength of the product. Under normal circumstances, at the same heat seal temperature and pressure, a little longer sealing time allows heat-seal sealing more solid perfect, better able to achieve the desired heat seal strength. But conditions of modern high-speed pharmaceutical packaging machine is unlikely to provide a very long time, heat-sealed, if the sealing time is too short, the adhesion between the PVC layer and the film will be inadequate sealing. To this end, the national standard scientific sealing time of 1s.