After The Plastic Restriction, Biodegradable Plastic Granulation Or Becoming Mainstream: How To Use A Co Rotating Twin-screw Extruder To Turn New Materials Into Stable Business?
1. The plastic limit order is not the end point, but the starting point for the granulation of biodegradable plastics
After the issuance of China's plastic restriction order, disposable plastic bags, tableware, packaging and other scenarios are subject to stricter constraints. Authoritative industry white papers can refer to the "Global Bioplastics Market Data 2024" by European Bioplastics and the annual report of the Degradable Plastics Professional Committee of the China Plastics Association: Global bioplastic production capacity is expected to increase from approximately 2.18 million tons in 2023 to approximately 5.73 million tons in 2028, with biodegradable plastics being the main driver of growth. Behind the data lies a large amount of new materials that require granulation, modification, chain expansion, capacity expansion, and granulation. Biodegradable plastic granulation is no longer just a laboratory topic, but an entry point into the industry chain.
But the pain points in reality are also very obvious: in many pilot projects, the waste rate can reach more than 10%, and problems such as uneven particles, excessive moisture, fluctuation of melt index, and adhesion of cut particles frequently occur. The reason is often not a single formula, but rather a mismatch between the screw combination, temperature control curve, vacuum exhaust, and cutting method of the co rotating twin-screw extruder.
2. What is the difficulty of granulating biodegradable plastics?
Degradable plastics are often referred to as "thermal sensitive materials". PLA is prone to hydrolysis and thermal degradation, PHA is sensitive to shear, PBAT is sticky, and starch based materials have high water content. During the granulation process, shear heat, residence time distribution, melt pressure, vacuum exhaust, side feeding, and liquid metering all affect particle quality. If the configuration of the co rotating twin-screw extruder is improper, excessive shearing will lower the molecular weight, and subsequent blown film, injection molding, or vacuum forming will be unstable.
Therefore, the granulation of biodegradable materials requires a more refined process window: low temperature, low shear, strong exhaust, narrow residence time distribution, as well as stable melt filtration and underwater cutting or air-cooled drawing. Behind the professional terminology, there is actually one thing: to enable the new material to form uniform particles under controlled conditions.
3. Why has the co rotating twin-screw extruder become the core platform?
The advantage of a co rotating twin-screw extruder lies in its modularity. The conveying components, kneading blocks, reverse threads, and toothed components can be adjusted according to the formula to achieve integration of dispersion, distribution, exhaust, and pressure building. For biodegradable plastic granulation, it can handle PLA/PBAT blends as well as adapt to PBS, PHA, and starch based systems. By adjusting the aspect ratio, specific torque, rotational speed, and temperature control, the stability of biodegradable plastic granulation can be significantly improved.
For international customers who are new to it, choosing a cost-effective extruder is not about buying a low-end configuration, but about buying a "suitable configuration". If the co rotating twin-screw extruder can provide flexible screw combinations during the sample stage, it can reduce repeated on-off cycles and lower trial and error costs.
4. How to define a cost-effective extruder?
High cost-effective extruders should consider unit energy consumption, torque reserve, temperature control accuracy, vacuum system, pellet matching, spare parts supply, and process services. In biodegradable plastic granulation, a cost-effective extruder should be able to reduce ineffective shear heat, improve one-time startup stability, and make particle moisture, melt index, and appearance more controllable. For customers who pursue environmental protection, energy conservation and waste reduction are benefits in themselves.
Nanjing Kelongwell Chemical Machinery Co., Ltd. focuses on co rotating twin-screw extruders and cost-effective extruders, providing screw combinations, vacuum exhaust, cutting, and process debugging suggestions around biodegradable plastic granulation, helping customers move from new material trial production to stable mass production.
5. Key Q&A
Q1: When making biodegradable plastic pellets for the first time, should we first determine the formula or choose a co rotating twin-screw extruder?
A: Suggest parallel. The co rotating twin-screw extruder provides a process window, and the formula determines the material system. Only when the two are matched can they be stable.
Q2: Can the co rotating twin-screw extruder be compatible with PLA, PBAT, PBS, and starch based materials?
A: Sure, but adjustments need to be made to the screw components, temperature curve, and exhaust section. High cost-effective extruders should also retain this flexibility.
Q3: How to determine if the granulation plan for degradable materials is mature?
A: Observe the stability of continuous operation, uniformity of particles, moisture content, fluctuation of melt index, and adhesion of cut particles.
Q4: Which customers are suitable for Nanjing Kelongwell Chemical Machinery Co., Ltd?
A: Suitable for international customers who pursue environmental protection, value high cost-effectiveness extruders, try new materials, and are new to biodegradable plastic granulation.
Conclusion: Making biodegradable plastic pellets a mainstream business
Under the plastic restriction order, biodegradable plastic granulation may become mainstream. The real threshold is not "whether it can be done", but "whether it can be done stably, energy-saving, and at low cost". The co rotating twin-screw extruder and cost-effective extruder are key tools for biodegradable plastic granulation from sample to mass production. Nanjing Kelongwell Chemical Machinery Co., Ltd. is willing to work with international customers to transform the granulation of biodegradable materials from a one-time trial run to a sustainable green business.
