Plastic packaging bags, food packaging films, express delivery plastic films and other plastic products are widely used in daily life. While bringing great convenience to people’s lives, they also impose a severe burden on the environment. Most plastics are for single use. Improper disposal and inadequate waste recycling have led to increasingly serious white pollution. Traditional plastic products take more than 200 years to degrade naturally, failing to decompose easily and causing long-term contamination to soil and the ecological environment.
Industry statistics show that the global total output of plastic products has reached 8.3 billion tons since the 1950s. The vast majority has turned into plastic waste, among which only 9% gets recycled. Over 70% ends up in landfills or directly enters the natural environment. Based on current plastic consumption and waste disposal patterns, the volume of global plastic waste is expected to exceed 12 billion tons by 2050. Against this backdrop, developing high-performance fully biodegradable polymer composites to replace conventional non-degradable plastics has become a core solution to curb white pollution and drive green upgrading of the packaging industry.
Material Properties & Modification Advantages of Biodegradable EVA Composites
Ethylene-Vinyl Acetate Copolymer (EVA) is a high-performance thermoplastic resin copolymerized from ethylene and vinyl acetate. Its molecular structure contains both polar and non-polar segments, and its properties can be flexibly adjusted according to VA content. Virgin EVA features good flexibility, excellent low-temperature resistance, non-toxicity, odorlessness and superior processability, and is widely used for producing various film products. However, neat EVA has no biodegradability and cannot meet the requirements of eco-friendly industrial development.
Biodegradable EVA composites are fabricated by blending EVA matrix with eco-friendly components such as PLA, PBAT, starch-based materials and biodegradable masterbatches via physical blending, modification doping and bio-additive filling. The resulting materials retain EVA’s original flexibility, processability and weather resistance while gaining excellent biodegradability. After disposal, they can be completely decomposed by microorganisms into carbon dioxide and water in soil, compost, anaerobic and other natural environments, leaving no solid residues or secondary pollution. They are ideal green alternatives to traditional single-use plastic films.
Key Forming Characteristics of Precision Processing for Biodegradable EVA Films
EVA-based biodegradable composites are multi-phase blending systems, which present multiple processing challenges including uneven filler dispersion, unstable melt rheological properties, film thickness deviation and surface defects. For multi-layer functional composite films, stringent requirements are set on interlayer adhesion and forming uniformity, which cannot be satisfied by ordinary simple equipment for R&D and process verification.
There are three major technical difficulties in producing biodegradable EVA films. First, fillers must be uniformly dispersed in multi-component blends to avoid agglomeration that impairs biodegradability and mechanical properties. Second, modified melt features fluctuating strength, which demands high precision in forming tension and cooling setting. Third, multi-layer composite forming requires tight lamination without delamination to guarantee both mechanical performance and appearance quality. Therefore, professional forming technologies and dedicated laboratory equipment are essential for formula iteration and industrialization of new biodegradable materials.
Multi-layer Co-extrusion Cast Film Line: Custom R&D Solution for Biodegradable EVALeveraging years of experience in developing polymer processing equipment, Guangzhou Putong has launched a three-layer co-extrusion cast film pilot line tailored for biodegradable EVA composites. Designed for formula development, process optimization and pilot production of biodegradable polymer films, it fully replicates industrial production processes, enabling seamless conversion of laboratory data to mass production and helping cut costs and accelerate industrialization of green biodegradable materials.
Adopting an integrated design, the equipment covers the whole process including independent multi-layer plasticization, precision melt conveying, co-extrusion lamination, cast film setting and automatic winding. It supports one-stop forming tests for both single-layer and multi-layer composite biodegradable EVA films. Compatible with blends of EVA with PLA, PBAT, starch and other biodegradable systems, it matches the rheological characteristics of modified materials well and solves common defects of biodegradable films such as brittleness, uneven thickness, interlayer delamination and surface flaws.
Core Process Advantages
●Uniform and stable plasticization for modified systems
Equipped with precise flexible plasticization design and smooth speed regulation, the equipment adjusts shear intensity according to properties of biodegradable fillers. It ensures homogeneous plasticization of multi-component materials and even distribution of additives, preventing filler agglomeration and melt degradation, and securing consistent film performance across batches.
●Accurate multi-layer composite forming with zero defects
Optimized co-extrusion die head features smooth flow channels with no dead zones or material retention. Multi-layer melts converge evenly and bond tightly, effectively eliminating interlayer delamination and poor adhesion, and maintaining stable overall structure of composite films.
●Wide process adaptability and flexible commissioning
All drive systems adopt independent synchronous control. Extrusion, traction and cooling parameters can be flexibly adjusted to adapt to varying melt strength of biodegradable EVA with different formulas. The cast film unit allows adjustable forming height and tension to suit diverse modified formulations, offering wide adjustable range and high fault tolerance.
●Premium finished quality & traceable accurate data
Fitted with high-precision mirror casting rolls, it produces films with smooth surfaces free of crystal points and wrinkles. The intelligent measurement and control system records full-process forming data in real time. Visualized, repeatable and traceable data fully meet high standards for new material R&D, process calibration and performance testing.
●Compact design for efficient laboratory R&D
The benchtop structure features low material consumption and easy maintenance & cleaning, facilitating rapid iteration of multiple formulas and batches. It tackles potential production problems in advance and greatly shortens the cycle from formula development to mass production of biodegradable EVA films. An optional on-line defect detection system is available to further improve R&D accuracy.
Main Application Scenarios
●R&D of new biodegradable materials
Suitable for formula screening, modification tests and performance verification of EVA-based biodegradable composite films and multi-component biodegradable blends, supporting iterative upgrading of eco-friendly new materials.
●Process optimization and finalization
Used for parameter debugging of multi-layer co-extrusion cast film processes, production simulation and defect prediction & resolution, providing reliable process parameters for industrial production lines.
●Evaluation of functionality and dispersion performance
Capable of assessing dispersion effect of biodegradable masterbatches and functional additives, as well as testing mechanical properties, appearance, barrier performance and other comprehensive indicators of films, providing data support for material performance improvement.
●Academic research & teaching
Ideal for research projects and practical training in universities and research institutes focusing on forming technology and modification of biodegradable polymers, fostering scientific innovation and talent cultivation in the field of green environmental materials.
