PP Woven Bag is a bag made from polypropylene (PP), which is a type of thermoplastic resin material produced through the polymerization of propylene that has high elasticity and strength. This bag is made by weaving using a machine. The fabric that has been woven is then sewn on one side as the bottom and the other side is left open.
PP Woven Bag is a bag that has many uses and advantages. It has a smooth surface, can withstand chemicals, has high flexibility and durability, and can reduce electricity. Apart from that, the price is relatively cheaper compared to other raw materials. This bag is also one of the most popular bags and is widely used in various ways, both in industry and for everyday purposes such as agricultural product packaging, food packaging, geotechnical engineering such as in highway and irrigation construction, tourism and transportation, and daily necessities.
To produce high quality PP Woven Bags with guaranteed durability, several stages of the production process must be carried out. These stages include:
- Preparation of raw materials
The main raw materials needed are PP (Poly Propylene), PE (Poly Ethylene). Additional raw materials include: Master Batch (dye) if you want to produce colored sacks, Ultra Violet (UV) which protects the sacks from sunlight so they are not easily broken or damaged, and CaCO3 (Calcium Carbonate) which is useful as sack bleach. All the raw material mixture is placed in a tub which will later be used to make plastic tape.
- Making Plastic Tape
Plastic tape is produced using an extruder machine. The raw materials that have been provided in the tub will be sucked in by a pump from the extruder machine to be put into the hopper. From the hopper, the raw materials will fall into the screw conveyor, where on the cylinder wall of the screw conveyor there are heaters to melt the PP ore and the mixture until it is liquid. After leaving the screw conveyor, the liquid is pushed towards the T-die. The T-die is where the PP mixture is placed which will be molded in the form of a T-shaped plastic sheet. The resulting plastic sheet will be cut into ribbons using a razor blade called a clipper.
- Plastic Ribbon Spinning Process
The ribbons produced by the extruder will continue with the ribbon knitting process carried out by a circular loom machine. The ribbon knitting process begins by placing the bobbins from the extruder winder on the shelves located at the edge of the circular loom machine. The knitted product will move upwards with the help of the roll located above the circular loom machine so that the knitted product will be rolled up
- Cutting, Sewing and Printing Process
The results of the circular loom in the form of sack rolls will be cut at the cutting section. The ABM I & ABM II machines are printing cutting machines for woven bags, while for sewing the manual method is used, namely sewing using a sewing machine. The MPJ I-IV machine is a sewing cutting machine for woven bags, while printing can be done on a Tsutsumi machine for woven bags.
- Packing Process
After the production process is complete, the next process is: packing process, where the finished sacks will be packed inside a certain amount using a hydraulic press machine.
- Testing Process
Tests carried out in producing plastic tape include elongation, strength (tensile strength), and denier (weight of the sack). Testing is carried out with taking a sample of 5 bobbins randomly from one harvest.
By carrying out a series of production processes and testing processes for elongation, strength and denier above, high quality PP Woven Bags are ready to be used for your daily and industrial needs.