Plastic films are a crucial component of modern agriculture, providing versatile solutions to increase productivity, improve crop quality, and optimize resource use. Their applications span the entire production cycle, from soil preparation to crop preservation.
Main applications of plastic films in agriculture
- Greenhouse and tunnel covers: This is one of the most established applications. Films, typically made from polyethylene (PE) or copolymers such as EVA, are used to cover greenhouse and tunnel structures. The main functions are:
- Extension of the cultivation cycle, allowing for early or delayed harvests.
- Protection of crops from adverse weather conditions such as rain, wind, and frost.
- Creation of a controlled microclimate, facilitating temperature and humidity management to optimize plant development.
- Mulching: This technique involves covering the soil with plastic films, bringing numerous benefits:
- Weed control, reducing the need for herbicides.
- Preservation of soil moisture, lowering water consumption for irrigation.
- Soil heating, useful for accelerating the development of early crops.
- Protection of crops from direct contact with the soil, keeping them cleaner and reducing the risk of rot.
3. Silage: Plastic films are essential for forage preservation (e.g., grass, corn), creating an anaerobic environment that triggers controlled fermentation. This process, known as silage, helps retain the nutritional properties of animal feed.
4. Soil sterilization: Before planting, the soil can be treated with plastic films to eliminate pathogens, fungi, and weeds, through two main methods:
- Solarization: Uses solar heat trapped under a transparent film to “disinfect” the soil’s surface layers.
- Fumigation: Employs barrier films to contain fumigant gases, ensuring a targeted disinfectant action.
5.Water resource management: Plastic films are also used to improve water efficiency, such as through drip irrigation tubes or as liners for small water collection basins.
6. Protection and storage: In addition to crop protection, robust tarps made from materials like PVC are used to shield agricultural equipment, hay, and harvests from weather conditions. They are also used to cover barns, stables, and to create windbreak barriers.
Technological advancements have introduced advanced plastic films, such as biodegradable mulching films, which naturally degrade at the end of their cycle, or films with special optical properties to modulate sunlight for specific crops.
The importance of printing on agricultural plastic films
Contrary to what one might think, printing on agricultural films is not just an aesthetic enhancement but a strategic functional component. It helps make the product more efficient, safer, and identifiable, adding value for both the farmer and the producer.
The main functions of printing can be divided into four categories:
- Technical information and usage guidance: Printing provides essential instructions for the proper use of the film:
- Technical specifications: Thickness (in microns), dimensions, and UV protection duration (e.g., “36 months”, “Long Duration”) help the farmer plan investments and replacements.
- Installation instructions: Many films have specific properties on only one side (e.g., anti-drip or anti-fog treatment). Printing indications such as “THIS SIDE INWARD” is essential to ensure proper installation and functionality.
- Material identification: Information on the type of polymer used (e.g., PE-LD, EVA) can help choose the most suitable product for a specific crop or climatic condition.
- Optimization of field activities: Printed markings are practical tools that simplify and speed up agricultural operations:
- Alignment lines: Center or lateral lines printed on greenhouse covers help operators correctly position and stretch the film symmetrically on the structure, saving time and ensuring better stability.
- Placement grids: In mulching films, printing a grid or reference points indicates the exact spacing to position plants. This ensures uniform crop spacing, optimizes land use, and facilitates subsequent harvesting.
- Cutting markings: Pre-printed lines indicate where to cut the film to create plant openings without compromising its integrity.
- Identification, traceability, and marketing: Printing is a vital tool for the film producer, quality management, and market recognition:
- Producer branding: Reinforces customer trust and promotes brand recognition.
- Traceability: Printing the batch number and production date is crucial. In case of a manufacturing defect, it allows the producer to trace the specific batch, manage warranty claims, and withdraw only the affected products from the market.
- Product differentiation: Printing, including color codes, helps distinguish different product lines (e.g., a film for solarization from one for mulching, or a standard tarp from a premium version).
- Compliance and sustainability
Printing also conveys environmental and regulatory information:- Recycling Symbols: Guide proper disposal or recycling of used films, supporting environmental sustainability and regulatory compliance.
Flexographic printing on agricultural films
Flexographic printing on agricultural films, used for applications such as greenhouse covers, is particularly suited for non-absorbent materials like polyethylene and large-scale production typical in the agricultural sector. Printing is carried out inline with the extrusion process, i.e., during the same production cycle of the film. After polymer extrusion and film formation, the still-processing material passes directly through a printing unit.
This approach offers significant advantages:
- Production efficiency: Eliminates the need for separate processes, reducing time and costs.
- High productivity: Suited to the high speeds of modern extrusion lines.
- Immediate quality control: Allows real-time verification during production.
Although off-line printing solutions are available for complex processing or small batches, inline flexographic printing is the most common solution in the agricultural sector, thanks to its cost-effectiveness and capacity to handle large volumes. This technology turns plastic films into “smart” products by adding technical information, operational functionalities, and identification and compliance tools.
Written by Fabrizio V. | Team Giugni®
