Green and Low-Carbon Process: Standardized Production Technology Flow for Eco-Friendly Paper Discs Made from Sugarcane Residue
With the implementation of the "dual carbon" policy and the shift toward more environmentally conscious consumption, the issue of white pollution caused by disposable plastic tableware has garnered increasing attention. Biodegradable plant fiber tableware is gradually replacing traditional plastic and conventional paper tableware. Sugarcane bagasse paper plates are fully biodegradable tableware manufactured from waste sugarcane residue generated in the sugar industry, through physical pulping, molding, and precision processing. They offer advantages such as being non-toxic, harmless, water-and oil-resistant, heat-resistant, and compostable. These plates not only enable the resourceful utilization of industrial waste but also meet low-carbon environmental standards; they are now widely used in various settings including food delivery services, supermarket retail, banquets, and airline catering. This article provides a detailed overview of the complete production process, key technical aspects, and quality control standards for standardized sugarcane bagasse eco-friendly paper plates.
I. Raw Material Selection and Pre-treatment Process
Sugarcane bagasse is the residual fibrous material obtained after sugarcane juice extraction, rich in high-quality plant cellulose and serving as an ideal raw material for producing food-grade paper plates. Raw material pretreatment constitutes a fundamental step essential for ensuring the strength, flatness, and food safety of paper plates, directly determining the final quality of the product.
The process begins with raw material screening and impurity removal: Fresh sugarcane bagasse purchased initially contains various impurities such as cane skin, pulp, sand, and crushed leaves, with an initial moisture content as high as approximately 50%. During production, screening equipment is first used to remove large impurities and ineffective pulp; excessive pulp content reduces the toughness of the paper sheets and increases their brittleness. After screening, high-quality fiber segments measuring 10–50 mm in length are retained to ensure uniform fiber length, laying a solid foundation for subsequent forming processes. Subsequently, dehydration and conditioning treatment is performed using drying equipment to reduce the moisture content of the bagasse to 40–45%, which prevents mold growth in high-moisture materials while softening the fiber structure and enhancing production efficiency in the subsequent pulping stage.
After completing the tempering process, cleaning and high-temperature sterilization are performed: High-pressure clean water spray is used to remove residual sugars, dust, and fine impurities from the raw material surface; sugar residues can lead to mold growth and bacterial proliferation in the final product. The treated bagasse is then sent to a high-temperature sterilization unit where it undergoes steam treatment at 120°C, completely eliminating microorganisms and insect eggs while further softening fibers and breaking down any remaining colloidal substances. The entire process employs purely physical methods without adding any harmful chemical agents, ensuring full compliance with food safety production standards. Finally, the processed bagasse is compressed into standardized slurry sheets for uniform storage, guaranteeing consistent fiber quality across different batches.
II. Environmental-friendly Pulping and Pulpa Preparation Processes
Pulp preparation is the critical process determining the toughness, density, and performance of paper discs. The industry currently employs a chlorine-free, environmentally friendly mechanical pulping method, fundamentally addressing the pollution issues associated with traditional chemical pulping processes and achieving truly clean production.
First, the pre-treated sugarcane bagasse slurry is fed into a hydraulic pulper. Sterile water is added for soaking and disintegration, followed by high-speed agitation to ensure thorough dispersion of solid fibers and formation of a uniformly textured fiber slurry. During the soaking and disintegration process, water temperature and stirring speed must be strictly controlled to preserve fiber integrity and minimize disruption, thereby maximizing retention of the fibers' inherent toughness. After initial dispersion, the slurry proceeds to the grinding stage, where a fine grinder refines the fiber structure, sorts fiber bundles, enhances fiber interweaving, and produces a fine, uniform slurry texture that ensures a smooth surface free from particles or protrusions.
To meet the requirements for food-grade tableware to be waterproof, oil-resistant, and heat-resistant, food-grade additives must be formulated. The entire formulation process involves only the addition of chlorine-free, non-toxic food-grade waterproof and oil-resistant additives as well as reinforcing agents; the product exhibits no fluorescence and contains no heavy metal residues, fully complying with national safety standards for food contact materials. After thorough mixing with the slurry, these additives are uniformly distributed across the fiber surface, enabling the finished product to withstand immersion in hot water or hot oil at temperatures exceeding 100°C without leakage or deformation. The slurry concentration must be precisely controlled to maintain its solid content within an optimal range: excessively high concentrations may result in uneven thickness, while too low concentrations can lead to a loose structure and insufficient strength. The formulated slurry is then filtered through multiple sieves to remove fine impurities and undispersed fiber clumps before being stored in a holding tank for stabilization, ensuring consistent performance.
III. Core Process of Molding by Pressing
Mold pressing is the critical process in manufacturing bagasse paper plates, directly determining the product's dimensional specifications, structural strength, and surface smoothness. The industry employs fully automated wet pressing combined with high-temperature, high-pressure shaping technology.
The qualified pulp in the storage tank is evenly conveyed via pipelines to the fully automated pulp molding machine. Utilizing vacuum adsorption technology, the equipment ensures uniform pulp adhesion onto the surface of custom metal molds. By precisely controlling adsorption time and pressure according to paper disc specifications and shapes, it guarantees consistent pulp thickness throughout, preventing issues such as thin edges, material shortages, or thickness variations. The resulting wet blank exhibits a preliminary shape, high moisture content, and soft texture.
This is followed by the high-temperature, high-pressure hot pressing stage, which serves as the critical step for enhancing the strength and stability of the finished product. The wet blank is fed into a precision hot press mold and pressed under conditions of 160–180°C temperature and constant high pressure. The elevated temperature rapidly evaporates free moisture within the blank, while the high pressure promotes tight fiber interweaving and solidification, significantly improving the density, compressive resistance, and toughness of the paper tray. Additionally, this process provides secondary sterilization, further ensuring product hygiene and safety. The pressing duration is precisely controlled according to the tray thickness to guarantee complete shaping without deformation or springback.
IV. Drying, Finishing, and Polishing Processes
Paper discs produced by hot pressing still contain trace amounts of moisture, with rough edges and burrs at the periphery. These defects require drying, trimming, and finishing treatments to enhance both product appearance and user experience.
First, continuous drying is performed by feeding the shaped paper discs into a constant-temperature drying line, where they undergo stepwise gradient temperature control to gradually remove residual moisture from the product and precisely maintain the final moisture content within the standard range of 8%–12%. Excessively high moisture content can lead to dampness, mold growth, softening, or deformation; conversely, insufficient moisture may cause disc brittleness and reduced toughness. The gradient drying process effectively prevents cracking and deformation caused by rapid high-temperature drying, ensuring structural stability of the paper discs.
Upon completion of drying, the process proceeds to edge trimming and shaping. Automated cutting equipment precisely removes excess waste material and burrs from the paper tray edges while correcting dimensional deviations, ensuring uniform product specifications with smooth, flat surfaces free from burrs or notches. All trimmings generated during cutting are fully recycled for pulp regeneration, achieving 100% raw material recycling without production waste – aligning with sustainable manufacturing principles. Finally, surface finishing is performed using flexible grinding equipment to refine the surface by eliminating fine protrusions and particles, resulting in a smooth, refined surface that enhances both texture and user comfort.
V. Sterilization Quality Control and Aseptic Packaging Process
Food-grade sugarcane residue paper plates must come into direct contact with food ingredients; therefore, hygiene safety and quality testing constitute the final critical safeguard before product release, requiring strict adherence to comprehensive inspection standards.
The finished products are first transported to a sterile sterilization facility, where a combined "ultraviolet + low-temperature pasteurization" process is employed. This method ensures no chemical residues remain throughout the treatment, completely eliminating bacteria, mold, and other microorganisms on the product surface, thereby guaranteeing that the total bacterial count meets food contact safety standards. After sterilization, the products undergo comprehensive quality inspection: visual inspection identifies defective items with issues such as deformation, cracks, color discrepancies, stains, or rough edges; performance testing evaluates water resistance, oil resistance, heat resistance, compressive strength, and degradation resistance; safety testing detects hazardous substances like heavy metals, fluorescent agents, and harmful residues. Non-compliant products are uniformly recalled for reprocessing. Qualified finished products then proceed to a closed sterile packaging facility, where automated counting, bagging, and sealing are performed in a dust-free environment. Food-grade eco-friendly packaging film is used, offering strong sealing properties and protection against moisture and dust to prevent contamination during transportation and storage. The packaging additionally displays essential information including product specifications, production batch number, shelf life, degradation criteria, and food contact certification, ensuring full traceability throughout the entire supply chain.
VI. Core Process Advantages and Environmental Benefits
The entire production process for sugarcane bagasse paper plates adheres to the principles of clean, resource-efficient, and low-carbon manufacturing, offering significant advantages over traditional plastic tableware and conventional paper plates. In terms of raw materials, this process utilizes industrial waste sugarcane bagasse as its base material, transforming waste into valuable resources; it reduces pollution from agricultural and forestry waste incineration while minimizing timber consumption, making it a viable alternative to traditional wood pulp papermaking processes with notable ecological benefits. Regarding production methods, the process employs a fully physical processing workflow without adding harmful chemicals and is supported by a closed-loop water recycling system that achieves a water reuse rate exceeding 90%, substantially lowering energy consumption and wastewater discharge-a hallmark of a low-carbon, environmentally friendly production model.
In terms of product performance, sugarcane bagasse paper plates formed through high-temperature and high-pressure molding exhibit excellent toughness, superior load-bearing capacity, heat resistance, as well as water and oil resistance. They are suitable for various applications such as serving hot and cold foods and short-term microwave heating, offering far greater practicality than conventional disposable tableware. Regarding end-of-life disposal, the finished products degrade rapidly under natural conditions or industrial composting processes; their degradation products can be converted into organic fertilizer without causing white pollution, fully aligning with the trends of green consumption and environmental protection.
VII. Process Summary and Development Prospects
The production process for sugarcane bagasse paper plates involves five standardized steps: raw material pretreatment, environmentally friendly pulping, precision molding, drying and finishing, and sterile quality inspection and packaging. This approach enables efficient resource utilization of agricultural and forestry waste, establishing a mature, clean, and highly efficient green production system. The entire process balances product quality, production safety, and ecological sustainability, addressing the key challenges associated with traditional disposable tableware-severe environmental pollution, high energy consumption, and inadequate safety standards.
Against the backdrop of global plastic bans and dual carbon reduction goals, the technology for producing biodegradable paper plates from sugarcane bagasse has undergone continuous iteration and improvement. Automation, intelligence, and precision in production have steadily advanced, product performance has been continuously optimized, and costs have gradually decreased. In the future, this process will be widely adopted across various sectors-including catering, food processing, supermarkets, aviation, and hospitality-as a core solution for replacing disposable plastic tableware. It will facilitate the green and low-carbon transformation of the catering industry, fostering a win-win relationship between environmental protection and industrial development.
