Paper-plastic composite bag is a packaging bag formed by combining paper and plastic film, referred to as paper-plastic composite bag. Paper-plastic composite bag manufacturers use PVA film to provide excellent oxygen isolation, degradation speed can be adjusted fast and slow, good tensile properties, aging resistance, in the face of moisture, biodegradability and other advantages; and kraft paper, white cardboard and other suitable for compound The packaging paper is easy to print, and the surface of the paper is treated with moisture and water.
1. Common types of paper-plastic composite bags
According to the different types of window opening and window opening on the paper-plastic composite bag, there are three common types of paper-plastic composite bag: no window bag, strip window bag and special-shaped window bag.
1) A windowless bag is a bag without any window on the composite paper. This bag is opaque, and the contents of the bag cannot be seen from the outside of the bag.
2) Strip window bag is also called strip window bag, that is, a bag with a horizontally transparent window opened on the composite paper. The strip window of this bag is actually composed of two paper tapes and one plastic film spliced together with another wide plastic film. This bag is partially transparent, and the contents of the bag can be partially seen from the outside of the bag.
3) The special-shaped window bag is a bag with irregular windows on the composite paper. This irregular window is pre-molded on the paper tape and then composited. This bag is partially transparent, and the contents of the bag can be partially seen from the outside of the bag.
2. Common types of paper-plastic composite bags
Corresponding to the above three different paper bags, there are roughly three different types of paper-plastic laminating machines:
Ordinary paper-plastic laminating machine can complete the compound without window bag.
This type of laminating machine is generally close to the ordinary flexible packaging laminating machine. The paper roll is usually placed on the second release, using a floating roller or micro-displacement tension control method. The laminating unit is equipped with a cooling roller and a single-component glue supply machine is required.
Spread paper-plastic laminating machine, mainly to complete the strip window bag laminating.
Most of the functional units of this type of laminating machine and ordinary flexible packaging laminating machine are the same as or similar to those of ordinary flexible packaging laminating machines. Similarly, the compound unit is equipped with a cooling roller, and a single-component glue supply machine is required. However, in the second put, it is necessary to adopt a suitable way to arrange the layout. The splicing method should realize the seamless splicing of "paper tape-film tape-paper tape". The specific method differs depending on the model, and the structure is also different.
Special compound machine for special-shaped window, mainly used for compounding special-shaped window bag.
Paper-plastic composite bags manufacturers use special laminating machines for coating under the protection of lining film. According to the number and size of different shaped windows, select a liner film of a certain size, and put a piece of paper (pre-molded special-shaped holes) into the coating unit. After coating, the liner film is rewinded immediately, and the glued paper tape enters. The compound unit is compounded with another film with the same width from the second amplifier.