First, mesh bags raw material selection
Main material: polypropylene (PP) particles, with high strength, acid and alkali resistance, anti-aging properties.
Auxiliary materials: antioxidants, color masterbatch (add as needed), to enhance weather resistance and visual effect.
Standard: Raw materials need to meet the food contact grade safety certification (such as FDA), to ensure that agricultural products are not contaminated.
Second, mesh bag drawing process
Melt extrusion:
Pellets are heated to 180-230°C and melted, then injected into the wire drawing die through the screw extruder.
The aperture of the mold controls the diameter of the monofilament (usually 0.15-0.3mm), forming a continuous plastic wire.
Cooling:
The bundle is rapidly cooled by a water bath or air cooling to enhance tensile strength.
Tensile Strengthening:
Stretching through multiple sets of haul-off rollers, so that the molecules are oriented and arranged to enhance the toughness of the monofilament.
Third, weaving molding
Circular loom weaving:
The drawn wire is wound into cylindrical spindles and installed in the circular loom.
The warp and weft threads are crossed to form a mesh structure (aperture diameter 5-15mm is adjustable).
Density control:
Different grammage (20-50g/㎡) can be realized by adjusting the rotational speed and the number of spindles.
Bag customization:
Synchronize the knitting of bag body, handle or bottom closure, support open/closed bag type.
Mesh bags cutting and printing
Ultrasonic welding:
Cut the excess mesh and use ultrasonic fusion to fuse the edges to avoid stripping.
Printing Logo:
Screen printing or heat transfer printing process, add brand logo, specifications, ventilation holes and other logos.
V. Quality Inspection
Appearance inspection:
Mesh uniformity, the presence or absence of broken wire, printing clarity.
Physical properties:
Load bearing test (≥20kg), tear strength (≥80N), temperature resistance (-20℃ to 50℃).
Environmental certification:
Recyclability test to ensure compliance with EU EN13432 or China GB/T 18006.3 standards.
Packing and storage of mesh bags
Packing: 50-100pcs/bundle, covered with moisture-proof film.
Storage: ventilated and dry environment, avoid direct sunlight, stacking height ≤ 3 meters.
Process Advantage:
The whole process is automated, the daily production capacity of a single machine reaches 30,000 – 50,000 pcs.
Low cost of raw materials (about 0.1-0.3 RMB/pc), and the proportion of biodegradable materials is gradually increasing.
Good air permeability, reduce the risk of mold and mildew of agricultural products, and extend the freshness period.
Applicable scenes: garlic, onions, potatoes, corn, watermelon, ginger, olive groceries and other fruits and vegetables packaging. If there are questions about mesh bags for agricultural products, you can also contact me by email and I will surely answer them for you.
Email: chinameshbags@gmail.com
