Heat sealing is the process of joining two or more thermoplastic films or sheets by heating areas in contact with each other to the temperature at which fusion occurs, usually aided by pressure. When the heat is applied by dies or rotating wheels maintained at a constant temperature, the process is called thermal sealing.
Heat seal card-to-card blister packaging is the combination of a fold-over, or separate front and back blister card and a transparent blister, bonded under heat and pressure. Together, blister and card form a beautiful, highly visible shelf presentation of your product.
Heat sealing of plastic-to-plastic (clamshell, printed blister, separate front and back blister) is done by bonding two parts of plastic together under the influence of heat, either radiant or impulse, and pressure. For successful heat sealing of plastic-to-plastic it is of the utmost importance that the right type of plastic is used for making the blisters. Not all types of plastic are suitable for heat sealing, and depending on the design of the blisters, the tooling design is always a critical factor in getting the packaging process to run smoothly. Another factor to control in producing a high-quality finished product is that the blisters need to be cooled down under pressure in a separate cooling press to keep the flanges perfectly straight.
Heat seal card-to-plastic – this heat seal blister technology consists simply of a single piece of board and a blister, and is therefore very economical to produce. The board is coated with a layer of our proven, environmentally friendly, water-based seal coating. After adding a product, the blister can be bonded directly to one side of the card using heat and pressure. Depending on the market in which they are used, the blisters are typically made of PET or PVC.