New generation of plastic recycling technology is not simple

EREMA, known for its innovation in the Ansfelden region of Austria, is a world leader in the field of plastics recycling equipment manufacturing. With its newly developed and successfully launched “TDD” technology, it further consolidates and enhances international plastics recycling technologies and processes. On the leadership position.

This current state-of-the-art technology (ie, EREMA's fourth-generation equipment) realizes the dream of uninterrupted continuous mass transfer during the plastic regeneration process. As a result, with the same size of equipment, the output can be greatly increased to 15% of the conventional technology, and the energy required for production (energy consumed per 1 kg of pellets produced) can save up to 20%.

Material pretreatment and bifurcation of the extruder feed

With the technical improvements in the Erema cutting and compacting machine, the “material pretreatment” work (ie: crushing, drying, preheating, compaction, mixing of materials) is separated from the work of “feeding the extruder screw”. This changed the traditional principle of combining two steps into one. The successful separation of these two tasks will affect the quality or the factors that may affect the screw conveying and thus affect the output, such as: high humidity or non-uniform humidity materials, different density materials, larger bulk materials, uneven temperature Materials, etc., are effectively blocked at the front end of the extrusion screw and its feed zone.
The ultimate advantages it brings are: without the influence of the above-mentioned unfavorable factors, an extremely constant and uniform screw feeding is always achieved, which guarantees the uniform operation of the extruder and thus guarantees an optimal and constant production of the equipment.

This TDD system can also be retrofitted and updated to some extent for conventional equipment. This improvement update is firstly suitable for this application, ie the equipment yield is limited due to the poor feeding factors of the upper finger. According to customer feedback, after modifying the TDD technology on the traditional Erema regenerative equipment, the output can be increased by up to 15% and it is worth considering.

The advantages of TDD technology at the same time: Although the output can be increased, the average temperature of the melt in the extruder can be reduced. The reason why this effect can be achieved is that the materials fed into the screw of the technology machine have been uniformly preheated, allowing the screw to have a deep groove design, thereby minimizing the local temperature spike due to friction. The ultimate advantage is that the regeneration process has minimal damage to the material and greatly improves its reuse rate.

Amazing regeneration advantage

For specific applications such as scrap recycling of BOPET film, this new technology can bring surprising advantages: the incoming material can be controlled with reliable and high-quality pre-drying before entering the extruder, and this effect and new development The extruder screw design matches, ultimately eliminating the need for a vacuum exhaust area in a conventional screw.

At the same time, TDD technology can ensure the high quality of products. Because it is known that the traditional PET regeneration technology, especially in the vicinity of the vacuum exhaust area can not properly control the residence time of the material, which easily leads to local accumulation of the melt, and re-mixed into the melt flow after a certain time. These “unclean” melts, which have long residence times, high temperatures, and changes in vacuum thermal properties and chemical characteristics (such as viscosity), appear as “fish eyes” after the BOPET main line film is mixed with a large proportion of recycled pellets. And the main reason for the rupture of the film. According to feedback from customers, using TDD technology can greatly increase the proportion of recycled pellets mixed into the main line (up to twice the original) compared to the use of conventional technology, without any “fish eyes” or a significant increase in the number of film ruptures. In addition, due to the removal of the vacuum pump, production costs and maintenance work are greatly simplified, and sewage problems are also solved.

In addition, the length-to-diameter ratio of TDD equipment is greatly reduced (nearly half) compared to conventional equipment, so that users can save energy up to 20 to 30%. According to the universal energy costs in Europe and Asia, a medium-sized plant (production of approximately 700 kg/h and 5000 tons/year) can save energy costs to 40,000 euros per year. This greatly improves the economics of the equipment.

“What about impurities like monomers and PET oligomers that should have been sucked out of the exhaust zone, and how will it change?” many customers interested in TDD technology will ask similar questions. The answer is that the amount of such "impurities" that can actually be extracted is extremely limited even in the vacuum exhaust zone. Even if it is removed, a very small amount of water will immediately form in the screw part behind the exhaust zone. Impurities, but for PET, a highly hygroscopic material, can not avoid with a small amount of water.
in conclusion

Compared with the traditional BOPET regeneration technology, there is no increase in monomers and PET oligomers in the recycled pellets using TDD technology, and the gel content is significantly reduced, and the removal of gels is the key to regeneration. It was also a blind spot in the past.