Cutting and Forming of Packaging Bags
The cutting and forming of plastic bags are crucial steps in the production process, ensuring that the final products have the desired dimensions, shapes, and functionalities. Below are the main steps involved in cutting and forming plastic bags:
1. Material Preparation
Material Selection: Choose appropriate plastic materials such as polyethylene (PE), polypropylene (PP), polyester (PET), etc.
Roll Preparation: Prepare the large rolls of printed and laminated plastic film for cutting and forming.
2. Slitting Process
Slitting Machine: Use a slitting machine to cut the large roll of plastic film into smaller rolls of the required width, suitable for subsequent processing steps.
Set Parameters: Set the cutting width and speed of the slitting machine according to the required bag dimensions.
Slitting Operation: Start the slitting machine to precisely cut the large roll into multiple smaller rolls.
3. Forming Process
Heat Sealing and Cutting Machine: Use a heat sealing and cutting machine to form the plastic film into bags.
Set Molds: Configure the machine’s molds according to the bag design, including the length, width, and shape of the bags.
Heat Sealing Operation: Use heat and pressure to seal the edges of the plastic film together, forming the structure of the bag.
Cutting Operation: After heat sealing, the cutting machine cuts out individual bags.
4. Quality Control
Appearance Inspection: Inspect the appearance of the bags, including print quality, sealing edges, and any damages.
Dimension Measurement: Measure the length, width, and thickness of the bags to ensure they meet design specifications.
Functionality Testing: Conduct functionality tests such as tensile strength and burst resistance to ensure the bags meet usage requirements.
5. Final Packaging and Storage
Packaging: Sort, count, and pack the qualified bags, usually done using automatic packaging machines.
Storage: Store the packed bags in the finished goods warehouse, ready for shipment.
Equipment Used
Slitting Machine: Used to cut large rolls of film into smaller rolls of the desired width.
Heat Sealing and Cutting Machine: Used to process the smaller rolls into bags, consisting of heat sealing units and cutting units.
Quality Testing Equipment: Used to inspect the appearance, dimensions, and performance of the bags, including tensile testers and seal integrity testers.
Types of Bags
Flat Bags: Common plastic bag types suitable for various daily packaging needs.
Resealable Bags: Bags with resealable strips, suitable for packaging that requires repeated opening.
Carry Bags: Bags with handles, suitable for shopping and carrying items.
Custom-Shaped Bags: Custom-designed bags according to client requirements, suitable for specific purposes.
Through precise cutting and forming processes, high-quality plastic bags that meet customer needs can be produced, widely used in food packaging, daily goods packaging, industrial packaging, and other fields.
Summary
If roll film is required, the finished product, after curing, is slit according to customer specifications. This roll film is then used for automatic packaging machines to package products.
If bags are needed, the cured product proceeds to the bag-making workshop. We operate 15 production lines with a monthly capacity of over 200 million bags.
During the bag-making process, our QC and production managers will confirm the first sample based on the design draft or the customer's pre-production sample (PPS). Only after this confirmation can mass production begin. During mass production, our patrol QC will conduct regular inspections and maintain records to ensure the production of qualified packaging bags.
Related:
The process and procedures of custom printed packaging bags