Blister packaging is a widely used form of packaging. Different blister packaging, blister, cavity, box body are different, the shape is also different, according to the different products packaged. In addition, blister packaging has a variety of substrates, materials and heat sealing methods.
The working principle of blister packaging will be discussed below. Shows the general workflow of a blister package:
- 1. Unfold
- 2. Film formation (roller type / flat plate type)
- 3. Filling products
- 4. Heat sealing (roller type / flat plate type)
The plastic film such as PCV on the uncoiler is transported forward, heated to a suitable temperature, and then smooth blisters are formed on the softened plastic film. Then, the PVC blister is filled with the material while pressing the PVC blister into the mold to check the formed blister and the filling material. After that, the aluminum foil and PVC are heat sealed together. If necessary, the batch number, date, etc. can be printed on the back of the aluminum foil. Finally, the blister is cut as required, and the waste is removed according to the signal stored in the storage device.
In the above process, the biggest difference between the machines is based on the blister forming device and the heat sealing device. Blister molding is divided into drum type and flat plate type. The performance of flat-plate blister forming devices is generally better than that of drum-type devices. Heat sealing is divided into roller type and flat plate type. As far as the heat sealing effect is concerned, the flat plate type is better than the drum type, and the drum type has advantages in terms of speed and reliability.
The above process can be completed by manual operation, semi-automatic operation or automatic operation. For the large production volume of blister packaging, the relatively fixed variety, and the requirements for safety and health, automatic packaging lines should be used for production. In addition, the automatic blister packaging machine can be connected with automatic printing machines, manual inserting machines, cartoning machines, etc. to form a fully automatic blister packaging line, saving labor and time.
Unfold
PVC plastic and aluminum foil need to be placed on the aluminum foil coiler, and they will be different in operation and filming methods. Generally, under the drive of a motor, the bearing rotates, and the clamped film is brought to the forming station through the guide roller and the positioning roller.
Film formation
Due to the thermoplasticity of the plastic film, PVC can be molded as required when transferred to the molding die. The heating temperature is adjusted according to the difference of PVC, and the heating temperature of rigid PVC needs to be 110-130 degrees Celsius. The temperature of the heating element is much higher than this.
Heating methods are divided into radiant heating and conduction heating. The conversion rate of radiant heating is higher. Most thermoplastic packaging can absorb infrared energy with a wavelength of 3.0-3.5μm, so it is best to use radiant heating to heat the PVC. For conduction heating, also known as contact heating, PVC will directly contact the heating source, heating roller or heating plate.
Filling products
After the PVC is formed, it is transported to the filling station by the drive device. The filling is controlled by the machine, with constant speed and high precision. Pills are generally distributed. The feed speed should be consistent with the forming speed. The accuracy of different machines varies greatly. After filling the product, check it manually or through the sensor, and adjust it manually if necessary. However, a more common method is to use a rotating soft brush to sweep when the PVC is stepped on,-the excess pills will be pushed to the bottom, and then the soft brush will push the pills to fill the voids.
Heat seal
After the product is filled, it needs to be sealed with a substrate immediately. In the case of packaging pills, aluminum foil is generally used as the material, and there are generally two heat sealing methods:
Rolling type: PVC tape and aluminum foil are heat sealed by parallel heat sealing rollers and anilox rollers under certain temperature and pressure. The time for the material to pass through the two rollers is extremely short, so in order to obtain a qualified heat sealing effect, the speed of the rollers must be very slow, and it needs to be preheated sufficiently.
Press plate type: Use the heated sealing plate and the lower template to press the blister and the base material to seal. In this way, the blister pack is flatter, and the pressure required for sealing is greater.
Trimming, printing, scrap removal
After the above steps, the product packaging has been roughly completed, and then the work of trimming, printing, and scrapping will be carried out. At this time, the blister is still integrated, and it is conveyed to the trimming station for trimming, and the corners are generally round. In some cases, a fragile intermittent short mark is placed on the blister for manual splitting.
After that, the necessary information such as the production date and batch number is printed on the blister through the printer, and finally the unqualified blister is taken out. In addition, some machines can also directly pack the blister.
Through the above steps, the blister packaging can be completed.
