The process technology of Micro Perforated Plastic Bags on Wickets (hanging plastic bags with micro-perforations) involves multiple manufacturing links, with the goal of achieving comprehensive performance such as breathability, automatic packaging efficiency, and product preservation. The following is a detailed introduction to the process technology:
1. Material Selection
Common materials include:
BOPP (biaxially oriented polypropylene)
CPP (cast polypropylene)
LDPE (low-density polyethylene)
HDPE (high-density polyethylene)
These materials have good flexibility and transparency, and are suitable for micro-perforation processing and food-grade use.
2. Micro Perforation Technology
2.1 Mechanical micro-perforation
Use a roller or needle plate to penetrate the material in a hot or cold state.
The pore size is generally 0.5mm ~ 2mm, which can be customized according to product requirements.
2.2 Laser Micro-Perforation
Using laser perforation technology, the holes are uniform and smaller in size (usually <1mm).
High control accuracy, can be fixed-point perforation or full-surface arrangement.
3. Perforation density control
Common ones are: single-line holes, matrix holes, random holes.
The perforation density affects the air permeability and fresh-keeping ability of the bag.
4. Bag Making Process
4.1 Roll Film Printing
Flexographic printing or gravure printing is performed according to customer needs.
Customized LOGO and multi-color printing can be achieved.
4.2 Heat Sealing Bag Making
The front and rear membranes are heat-sealed to form, and various structures such as bottom sealing, edge sealing, and three-edge sealing can be performed.
High-temperature heat sealing requires control of edge sealing strength to avoid damage to the air holes.
4.3 Wicketing
The bag mouth is perforated and a metal/plastic wicket bar is inserted to facilitate the use of high-speed automatic bagging machines.
Each bundle of bags usually contains 100~250 bags, and is perforated with positioning holes for easy feeding by the machine.
4.4 Slitting and Stacking
After bag making, precise slitting is performed to keep the bag shape consistent.
Automatically or manually stacked into batches, packaged with PE ropes, plastic clips or cardboard.
5. Optional Features
Anti-fog coating: used for food packaging to prevent condensation of water vapor.
Tear notch design: convenient for consumers to use.
Punch position customization: only holes are opened in specific areas of the bag body, such as the fruit area or breathing window.
6. Quality Control
Aperture consistency test: detected by optical or gas permeation instrument.
Seal strength test
Packaging sealing test
Automatic hanger adaptability test
