Advances in Multimaterial Injection Molding Technology: Driving Sustainability with Recycled and Virgin Plastics

The plastic processing industry is undergoing significant evolution, driven by the increasing demand for innovative products and the need to incorporate more sustainable production practices. In this scenario, multimaterial injection molding machines are emerging as key players, offering the ability to combine different types of plastics in the same part. This technology not only expands the possibilities for design and functionality but also plays a crucial role in integrating recycled and virgin materials, promoting the circular economy. 

The Multimaterial Injection Molding Process

Multimaterial injection molding is a process that stands out for its versatility. Unlike conventional injection molding machines, multimaterial models can inject two or more different types of plastics into the same part. This capability allows for the creation of products with complex and optimized characteristics, such as a core of recycled material coated with an outer layer of virgin material to ensure a superior aesthetic finish, or the combination of materials with distinct properties to meet specific functional requirements.  

The multimaterial injection molding process is carried out by machines that have more complex systems compared to traditional injectors. The main differences include:

• Multiple injection units: Multimaterial machines have two or more injection units, each responsible for injecting a specific type of plastic.  

• Specialized molds: The molds are designed with channels and cavities that direct the different materials to precise areas of the part.  

• Advanced control systems: Precise synchronization of the injection units is essential to ensure the correct distribution of materials and the quality of the final product.  

  
  

There are different methods of multimaterial injection molding, such as sequential injection, where the materials are injected in stages; co-injection, in which the materials are injected simultaneously or almost simultaneously; and sandwich injection, which consists of "sandwiching" one material between two layers of another.  

Manufacturers of Multimaterial Injection Molding Machines

The global market for multimaterial injection molding machines comprises several renowned manufacturers that offer technological solutions for a wide variety of applications. Among the main players, the following stand out:  

• Arburg (Germany): Recognized for its high-precision injection molding machines and advanced technologies for processing various materials.  

• Haitian International (China): Considered one of the largest manufacturers of injection molding machines in the world, offering a variety of machines, including models for multimaterial injection.  

• Sumitomo Demag (Germany): Stands out for its innovation and efficient machines, including solutions for multiple component injection.  

• Husky Injection Molding Systems (Canada): Specializes in injection molding systems, including machines capable of processing different types of resin in the same part.  

• FCS (Fornaciari Stampi) (Italy): Focuses on machines for multimaterial and multicolor injection molding, offering solutions for various applications.  

• Tederic (China): A manufacturer that also offers machines with the capacity for multiple component injection.  

• KraussMaffei (Germany): Provides a wide range of injection molding machines, with significant experience in multimaterial applications.  

• Milacron (USA): A global company that offers equipment for the plastics industry, including multimaterial injection molding machines.  

• Wittmann Battenfeld (Austria): Specializes in injection molding technology, with solutions for multi-component processes.  

  
  

Engel: Leadership in Innovation and Sustainability

Engel, an Austrian manufacturer of injection molding machines, stands out in the global arena for its innovative solutions in multimaterial molding and its commitment to sustainability. The company has invested in developing technologies that enable the efficient integration of recycled materials into the molding process, seeking to combine productive performance with environmental responsibility.  

Engel offers technologies such as the skinmelt process, where a layer of virgin material forms the visible surface of the part, while the interior is filled with recycled material. The company has also demonstrated its capacity for innovation with the development of a new co-injection process in collaboration with Top Grade Molds, which allows for the production of buckets with a high content of fully encapsulated recycled material.  

To overcome the challenges of processing recycled plastics, which can present variations in quality and compatibility issues, Engel develops solutions such as:  

• Advanced control technology: Engel's machines are equipped with control systems that monitor and adjust process parameters in real-time, ensuring production stability even with the variability of recycled materials.  

• Optimized mold design: The company designs specialized molds that optimize material flow and ensure adhesion between recycled and virgin plastics.  

• Versatile injection units and feeding systems: Engel's machines can be configured with injection units and feeding systems that allow processing a wide range of materials, including recycled ones, with precision and efficiency.  

  
  

Engel's machines find applications in various sectors, such as packaging, automotive components, and consumer goods, enabling the production of more sustainable and innovative products.  

Trends and Future Perspectives

The multimaterial injection molding machine market presents promising growth potential, driven by the demand for complex products, the pursuit of efficiency and productivity, material innovation, and the increasing importance of sustainability. The integration of automation, artificial intelligence, and advanced control systems, along with a focus on bio-based materials and recycling, will shape the future of this sector.  

The Role of CRW Slovakia

CRW Slovakia plays a fundamental role in supporting companies seeking to adopt multimaterial molding with recycled materials. The company offers specialized consulting, assists in the selection and integration of machines, and provides technical support and training, acting as a strategic partner for the success of its customers. The partnership with leading machine manufacturers, such as Engel, allows CRW Slovakia to offer high-tech and high-performance solutions.  

In conclusion, multimaterial injection molding represents a significant advancement in the plastics industry, offering the ability to produce innovative and sustainable products. With the continuous evolution of machine technologies and the support of companies like CRW Slovakia, the future of plastics production looks promising, with the potential to combine efficiency, design, and environmental responsibility.