I. Agriculture: A Protective Barrier for Crop Planting and Agricultural Product Storage

Agriculture is one of the earliest and most widespread applications of woven film. From field planting to post-harvest storage, woven film addresses three core issues: environmental control, crop protection, and agricultural product preservation, becoming an important auxiliary material in modern agricultural production. Different agricultural scenarios have significantly different performance requirements for woven film, necessitating precise adaptation through material selection and process optimization.

(I) Field Planting: Environmental Control for Crop Growth

In field planting, woven film is mainly used for greenhouse covering, mulching, and bird and insect netting. Through physical isolation and environmental control, it creates suitable growing conditions for crops, reducing the impact of natural factors.

1. Woven Film for Greenhouse Covering: Balancing Light Transmission and Weather Resistance

Traditional agricultural greenhouses mostly use pure plastic films (such as PE Films), but these films have poor weather resistance, a lifespan of only 1-2 years, and weak wind resistance, making them easily torn by strong winds. PP woven film (or PP/PE composite woven film), with the addition of UV stabilizers and toughening agents, has become a preferred material for greenhouse coverings. Its tensile strength can reach 250-300 N/5cm, its wind resistance is more than 50% higher than pure PE film, and it has excellent UV aging resistance, maintaining more than 70% of its strength even after 3 years of outdoor exposure, extending its service life to 3-5 years and reducing greenhouse maintenance costs.

To adapt to the light requirements of different crops, the light transmittance of greenhouse woven film can also be adjusted: High light transmittance (above 85%) is required for growing vegetables (such as cucumbers and tomatoes) to ensure normal photosynthesis; low light transmittance (below 30%) is required for growing edible fungi (such as shiitake and oyster mushrooms) in black or gray woven film to create a shaded environment. In addition, some high-end greenhouse woven films use a composite structure of "PP woven layer + PE film + anti-fog coating". The anti-fog coating reduces fog condensation inside the film (fog can cause crop diseases), stabilizing the relative humidity inside the greenhouse at 60%-70%, and reducing the incidence of diseases by more than 30%. For example, at a vegetable planting base in Shouguang, Shandong, cucumber yields increased by 15% compared to traditional PE film greenhouses after using transparent composite woven film to cover the greenhouses. Furthermore, due to the extended lifespan of the film, annual replacement costs were reduced by 2000 yuan per mu.

2. Woven Film for Mulching: Insulation, Moisture Retention, and Weed Suppression

The core function of mulch film is to increase soil temperature, maintain soil moisture, and suppress weed growth. Traditional mulch films are mostly thin PE films, but they are prone to damage and difficult to recycle (leaving soil residue that pollutes the environment). PP/LLDPE composite woven film (15-20μm thick) has become a new type of mulch film material due to its excellent puncture resistance (puncture strength ≥30N) and biodegradability (some with added biodegradable coatings). Its puncture resistance can withstand punctures from soil stones and crop roots, reducing the breakage rate by more than 60% compared to traditional PE mulch film. Its service life can reach 6-8 months, covering the entire crop growth period (such as the 3-5 month growth period for cotton and corn).

Different crops have different mulch film requirements: cotton planting requires black woven film, utilizing its shading properties (shading rate ≥90%) to suppress weed growth and reduce herbicide use; rice seedling raising requires transparent woven film, which raises soil temperature by 2-3℃ through light transmission, promoting early and rapid seedling growth; while tobacco planting requires silver-gray woven film, which provides both heat and moisture retention, reflects sunlight, and repels pests such as aphids, reducing pest incidence. For example, in a cotton-growing area in Henan Province, after adopting black PP woven mulch film, the weed coverage rate dropped from 30% with traditional PE mulch film to below 5%, reducing herbicide usage by 1.5 kg per mu (approximately 0.067 hectares), while cotton yield increased by 8%.

3. Woven Film for Bird and Insect Netting: Physical Isolation, Reducing Pests and Diseases

Bird pecking and insect infestation are common problems in agricultural planting. Traditional protection methods often use nylon netting, but nylon netting has low strength, is prone to aging, and has a lifespan of only 1-2 years. LLDPE woven film (80-100 g/m²) is an ideal material for bird and insect netting due to its high tear strength (right-angle tear strength ≥80 kN/m) and good weather resistance. Its mesh size can be adjusted according to the type of pest (e.g., 40 mesh for aphid control, 20 mesh for bird control), providing significant physical isolation, and its lifespan can reach 3-4 years, more than twice that of nylon netting.

In orchard cultivation, the application of bird-proof and insect-proof woven film is particularly widespread. For example, in the apple-producing areas of Shaanxi, losses due to bird pecking during the apple ripening season can reach 10%-15% annually. After covering the orchard with 20-mesh LLDPE woven netting, bird pecking losses are reduced to below 2%, and the netting can be reused for 3 years. The annual cost per mu (approximately 0.16 acres) is only 80 yuan, far lower than the 120 yuan/year cost of traditional nylon netting. Furthermore, some insect-proof woven films contain added insect repellents (such as menthol and pyrethroids), which enhance the insect-proof effect by slowly releasing their odors. The repellency rate against pests such as aphids and whiteflies can reach over 70%, reducing pesticide use.

(II) Agricultural Product Storage: Moisture and Insect Prevention, Extending Shelf Life

After harvesting agricultural products, the main problems during storage are "moisture and mold," "insect infestation," and "scattering losses." Woven film, with its sealing, barrier, and protective functions, has become an important material for ensuring the storage of agricultural products, commonly used in the storage packaging of grains, fruits and vegetables, and feed. 1. Woven Film for Grain Storage: Moisture-proof and Sealing to Prevent Mold

The core requirements for grain (such as wheat, corn, and rice) storage are moisture protection and sealing. Traditional storage often uses burlap sacks or ordinary Woven Bags, but burlap sacks have poor moisture protection, and ordinary woven bags are not airtight enough, making grain prone to mold after storage for more than 3 months. PP/PE composite woven film (20-25μm thick) solves this problem through the moisture-proof layer of the PE film (moisture permeability ≤10g/(m²・24h)) and a heat-sealing design. After the grain is placed in the composite woven bag, the bag opening is sealed with a heat sealer, which can stabilize the relative humidity inside the bag at 50%-60%, reducing the mold rate from 8% with ordinary woven bags to below 1%, and extending the storage period to 6-12 months.

To adapt to the storage needs of different grains, composite woven films can also be coated with insecticides (such as deltamethrin), achieving a kill rate of over 90% against common grain storage pests such as corn weevils and rice weevils, thus avoiding grain losses caused by pests. For example, a grain reserve in Heilongjiang Province used PP/PE composite woven films containing insecticides to store corn. During a 6-month storage period, pest losses decreased from 5% to below 0.5%, saving approximately 10 yuan per ton of corn. Based on a storage capacity of 100,000 tons of corn, this translates to annual cost savings of 1 million yuan.

2. Woven Films for Fruit and Vegetable Preservation: Breathable and Moisture-Retaining, Reducing Water Loss

The core requirements for storing fruits and vegetables (such as potatoes, onions, and citrus fruits) are breathability and moisture retention. Excessive sealing leads to the accumulation of carbon dioxide produced by respiration, causing rot; excessive ventilation leads to moisture loss, affecting taste. PE/PP breathable woven film (with added air pores or a microporous structure) achieves a balance between breathability and moisture retention by precisely controlling the air permeability (100-200 cm³/(m²・24h・0.1 MPa)). Its moisture retention performance reduces the water loss rate of fruits and vegetables from 15% with ordinary woven bags to below 5%, while its breathability prevents the carbon dioxide concentration inside the bag from exceeding 5% (high carbon dioxide concentration inhibits the respiration of fruits and vegetables), thus extending the shelf life.

For example, in potato storage, using PE breathable woven film extends the shelf life from 2 months with ordinary woven bags to 4 months, and the potato skin remains smooth without wrinkling. In citrus storage, breathable woven film reduces the mold rate of citrus fruits (from 8% to 2%) while maintaining the sweetness and moisture of the fruits. Furthermore, some fruit and vegetable woven films use colored designs (such as orange and green) to reflect sunlight, preventing excessively high storage temperatures and further enhancing the preservation effect.

3. Woven Film for Feed Packaging: Preventing Contamination and Ensuring Feed Quality

The core requirements for feed storage (such as pig feed and chicken feed) are prevention of contamination and oxidation. If feed comes into contact with dust, moisture, or oxygen, it is prone to mold or oxidation, producing harmful substances (such as aflatoxin) and affecting livestock health. PP/LLDPE composite woven film (with added antioxidants and a moisture barrier) has become the mainstream material for feed packaging due to its excellent sealing properties (oxygen permeability ≤15cm³/(m²・24h・0.1MPa)) and anti-contamination performance. Its smooth surface does not easily attract dust, and the moisture barrier prevents moisture intrusion, ensuring that the mold rate of feed remains below 0.5% and the oxidation value (acid value) remains within a safe range (≤5mg KOH/g) within 3 months of storage.

To meet the needs of automated feed packaging, this type of woven film also has good heat-sealing performance (heat-sealing strength ≥15N/15mm), making it compatible with automated packaging production lines and increasing packaging efficiency by more than 3 times compared to manual packaging. For example, a feed production company in Guangdong Province increased its packaging efficiency from 50 bags/hour to 150 bags/hour by using PP/LLDPE composite woven film to package pig feed. At the same time, the customer complaint rate decreased by 40% due to the reduced feed mold rate.