3. Conclusion

Multi-material injection processes represent an undeniable technological advance over conventional injection molding, enabling materials of different natures, colors and structures to be combined in a controlled way in a single operation, adding new functionalities to plastic parts in line with industrial needs and market trends.

Single-material injection molding is now a well-established technology, and the production of technical appearance parts has become commonplace in all areas of activity, with increasingly demanding aesthetic and functional requirements justifying the extra investment costs involved.

The additional cost of equipment, and above all the difficulty of mastering the process, partly explain the difficulty sandwich injection molding has had in taking off, even though it was introduced industrially more than 30 years ago....