The bioplastics industry is growing steadily, driven by a widespread research for sustainable solutions in material choices, production methods and technologies. However, bioplastics processing presents complex challenges, particularly in terms of ensuring a proper drying of plastic granules.
Here we will focus on the area of bioplastic drying, describing its needs and challenges. Finally, we will present the advanced solutions proposed by Vismec for this sector, with an innovative line of bio dryers.
Bioplastic drying challenges
The drying of bioplastics is a critical phase in plant-based or biodegradable plastic processing. Unlike traditional plastics, bioplastics have characteristics that make them more sensitive to moisture. The presence of residual moisture in plastic granules, as we have already explained in previous pieces, can negatively impact the final quality of the product.
Let’s see some of the main challenges that the industry have to face in bioplastic dehumidification:
- High hygroscopicity – Bioplastics, such as PLA (polylactic acid), bio-based polyethylene, or Mater-Bi, are highly hygroscopic: they tend to absorb moisture from the surrounding environment. This characteristic can lead to various problems during manufacturing, such as thermal degradation, reduced viscosity, and the formation of bubbles or imperfections in the finished product. Moisture removal is, therefore, essential to maintain the mechanical and visual properties of the product. For more information, we have explored the concept of “hygroscopic material” in our article on dew point.
- Thermal degradation – Bioplastics are particularly sensitive to high temperatures. Inadequate or excessive drying can lead to a sensitive heating during extrusion or moulding, causing material degradation. This phenomenon can compromise the strength and integrity of the product, needing an extremely precise temperature management during the dehumidification process.
- Sensitivity to environmental conditions – Bioplastics are organic materials derived from corn, rice and wheat, which make them more sensitive to environmental changes compared to traditional plastics. Relative humidity, temperature, and even air quality can influence the moisture content of plastic granules. This sensitivity requires a constant and precise control of the drying process to avoid defects during the production.
- Need for consistent processes – One of the most delicate challenges in bioplastic drying is maintaining process uniformity. Even small variations in moisture content among different granules can lead to significant differences in the final product quality. This makes it essential to adopt technologies that ensure uniform dehumidification on a large scale.
- Environmental impact – Sustainability is at the heart of the bioplastics industry. Therefore, drying processes must be designed to minimise the environmental impact. This means, for example, minimizing energy consumption and managing resources efficiently, reducing waste while maintaining effectiveness.
Facing these challenges requires both a deep understanding of the materials involved and the adoption of cutting-edge technologies to precisely manage the characteristics and critical issues of bioplastics. As we are going to see in the next paragraph, Vismec Bio Dryers are designed and built keeping in mind these needs.
Vismec’s advanced solutions for the sector
Starting from our standard machinery, our company has developed a line of driers specifically designed to meet the needs of the companies that process bioplastics.
The innovative design approach we have chosen eliminates the need for compressed air or cooling water, thanks to the presence of a post-cooler with a thermostat integrated directly on the dryer. This approach not only reduces system complexity but also lowers the operating costs and environmental impact.
Moreover, Vismec’s bio dryers are designed to operate at low temperatures, keeping the bioplastics intact and ready for use. Their technical features include:
- wide range of drying temperatures – These dryers can operate effectively between 35°C and 50°C, ideal for low-melting-point biopolymers. The minimum adjustable temperature that can be set is 30°C, with a maximum differential of 7°C compared to ambient temperature.
- Air-to-air heating system – An innovative heating chamber with ventilation ensures that the heated air maintains the optimal temperature for the process, avoiding thermal fluctuations that could compromise the quality of the treated bioplastics.
- Model variety – Vismec dryer range includes several models, from DW14 with a capacity of 14 m³/h up to DP1200 with a capacity of 1200 m³/h. This versatility allows us to offer flexible solutions for both small-scale and large-scale manufacturing.
- Optional HEPA filter – To ensure the highest purity of the air used in the drying process, the bio dryers can be equipped with our HEPA filter, ideal for applications that require particularly rigorous hygienic conditions.
So, Vismec bio dryers offer several advantages to companies working with bioplastics. The ability to operate at low temperatures ensures that materials are not damaged, preserving the quality and integrity of the final product. Additionally, the eco-friendly technical design helps to reduce the overall environmental impact.
Would you like to examine in depth the topic and discover how our dryers for bioplastics combine operational efficiency with attention to the environment? Contact our team: we are at your disposal.