The molding method of blister packing machine

The molding method of blister packing machine

Blister forming (negative pressure forming). The blister is formed by drawing the film softened by heating into the blister and forming the geometric shape. Blister molding generally adopts roller mold, forming bubble cover size is small, simple shape, bubble cover stretch is not uniform, thin top.

Blow molding (positive pressure molding). Using compressed air, the heated softened film is blown into the bubble of the forming mold to form the bubble of the desired geometry. The wall thickness of the formed bubble cover is more uniform, the shape is quite wide, the bubble cover with large size can be formed, blow molding is used for plate mold.

Punch assisted blow molding. With the help of punch, the heated and softened film is pressed into the mold cavity. When the punch is completely pressed into the mold cavity, compressed air is injected to make the film close to the inner wall of the mold cavity to complete the molding process. Punch size is about 60 % - 90 % of the mold cavity: reasonable design punch shape size, punch press speed and press distance, can get the wall thickness uniform, edges and corners of the broad, large size, complex shape bubble shell. Punch auxiliary molding is widely used in flat plate type blister packaging machine.

Punch and die cold stamping forming. When the packaging material is rigid, the hot forming method is obviously not applicable. Instead, the cold stamping forming method of convex and concave die is adopted, that is, the convex and concave die is closed, and the film is formed and processed, in which the air is discharged by the exhaust hole inside the forming die.

A variety of fillers can be used to fill the molded plastic hollows and a row of grooves can be filled simultaneously. Through strict mechanical control, the clearance of a single grain of material in the plastic groove, can also be a certain speed uniform spread of the type of material, at the same time to a number of rows of grooves feeding. Between the hopper and the rotating baffle, only a single drug falls into the cavity or hole of the rotating baffle restricted by the scraper or the fixed baffle. The rotating speed of the rotating baffle should match the moving speed of the plastic film with bubble, that is, to ensure that each row of grooves on the film falls into a single drug. If there are several rows of foams on the plastic film, sufficient length or number of rotating baffles shall be provided accordingly. For the horizontal shaft separator on the left, sometimes there is no soft skin, but for the plastic film width on both sides must be set cofferdams and baffles, in order to prevent drugs fall out of the film.