Moretto X Technology for PET
Moretto, one of the world’s leading manufacturers of automation equipment for the processing of plastics, introduces X Technology, highly energy-efficient comprehensive drying, dosing and other relevant systems for the manufacture of bottles and containers for liquids in the beverage, food, cosmetic and other industries and using PET.
Conscious of the need for energy efficiency and an increasingly vital need to safeguard the environment, Moretto, based in Massanzago, near Padua in Italy, has for many years been focused on the development, design and manufacture of equipment and machines used in the processing of plastics, such as hopper loaders, hot air dryers, dehumidifying dryers, grinders, micro-dosing, gravimetric and volumetric dosing units, storage bins, temperature controllers, chillers, cooling systems, moisture measuring equipment as well as feeding and conveying equipment, satisfying the most demanding technical standards whilst, at the same time, provide users with added value.
PET, a thermoplastic polymer resin of the polyester family, is frequently used in the production of bottles and containers in extremely high quantities, i.e. millions of tons of the material are used every year. Efficient production requires particularly precise drying criteria with low final residual moisture content not higher than 30 ppm. This can only be achieved by employing highly sophisticated equipment guaranteeing consistently high performance and a reliably high quality end product.
Among the energy-efficient and environmentally friendly dehumidifying solutions developed by Moretto in the X Technology range are the:
PET-PRO Drying System – XD Dryer 600, combined with the CTX Crossed Thermal Exchanger (CTX), stainless steel hopper and the Flowmatik Uni System (optional). The PET-PRO combination, particularly the use of the CTX, specifically designed for spent energy recovery in conjunction with the use of PET, brings maximum benefits with regard to the reduction in energy costs.
The X Technology XD 600 Dryer has been designed as an innovative exclusive dehumidifying solution in the use of technical polymers, such as PET, particularly with high throughput in mind. Control of the system is entirely based on two parameters: material to be treated and hourly throughput. This means that control of the system no longer relies on the traditional material/temperature ratio. Variable airflow, touch-screen control, high efficiency (-75°C dew point), equipped with a series of sensors controlling the polymer treated, ensure that the XD 600 adjusts the process to minimum variations in the working parameters, thus avoiding thermal stress and possible variations in viscosity. In addition, the need for the use of compressed air is eliminated.
The X PET-PRO CTX Crossed Thermal Exchanger, providing vitally important energy recovery, is located on top of the hopper so that the transfer of exhaust air heat to the processing air before entry into the heating unit can take place. This sequence results in a reduction of energy use as well as in a decrease in return air temperature. The special battery of the exchanger, combined with the exclusive characteristics of the XD 600 series dryers, results in significant energy recovery. This, in conjunction with the high performance of the XD 600 dryer(s), provides the essential platform for all polymers that require high treatment temperatures, such as for instance PET. The hopper can be opened by pneumatic control; this enables the trouble-free cleaning of the interior. Total operating safety is provided by parapets to protect the gallery. The CTX is protected by a series of easily accessible stainless steel filters.
As the second highest expense – apart from the purchase of raw materials – energy consumption forces producers to look for low energy consumption production solutions, particularly when it comes to dehumidifying, material transport, dosing, recovery and crystallisation. These Moretto X Technology solutions are designed to recover up to 30 kWh of pure energy. The graph below gives an example of annual savings possible, comparing the XD 600 PET-PRO and XD 600 drying systems with conventional dryers. The figures are based on the climate in Europe at an average temperature of 20°C, with a humidity of 80 percent. Calculations are based on a throughput of 8000 h/pa, the drying temperature is 180°C. Figures are based on a reference dryer with an airflow capacity of 2500 m³/h, a throughput of 700kg in a treatment time of six hours. The material is PET. The currency used is Euro.
Another chart demonstrates savings using the XD 612 PET-PRO system versus a standard dryer. Prior to activation, the relevant currency (US$, YEN, € etc) can be chosen to establish energy costs per kW. This results in the exact calculation of energy consumption/saving at a given location at any given time in percentage terms and the given currency. The example shows a saving of just over € 36,000.
Moretto X Technology can be configured in a variety of applications and set-ups, thus providing total flexibility and optimisation of a variety of local conditions:
SX Standard Drying system:
- PET-PRO Drying system on a mezzanine platform – a space saving solution, also allowing the material to be delivered into the machine by gravity.
- Split PET-PRO Drying system – lack of height provides a split level solution.
- The Flowmax PET System is the latest innovation developed by MORETTO for large scale flexible processing, i.e. of up to 6,000 kg/h of PET and drying stations up to 20,000 m3/h. The Flowmax PET system is a combination of a series of hoppers – up to 30 – and a series of dryers – up to 10.
The core of the system comprises a specifically designed computerised management system controlling the battery of dryers and the single hoppers. Process air is withdrawn via the Flowmatik control, individually calibrating and managing the correct airflow required by each hopper during any given processing cycle. The system identifies the single airflow required and directs the exact quantity of process air to the X-MAX battery of dryers. X-MAX CONTROL manages the battery of dryers employing the single machines proportionally in order not to waste energy. In addition, when the airflow is calibrated, regeneration will be carried out according to the yield; this ensures a great reduction in energy consumption. It is possible to install this device at the point of use under the hopper. The Moisture Meter device is capable of measuring the final moisture in real time inside the PET material before transformation. Flowmatik receives the input from the MM and calibrates all parameters according to the final humidity required. This is the first time that a dynamic closed loop system is employed in the drying process of PET)
The chart below shows the annual savings, comparing the performance of the Moretto Flowmatik PET System and the Moretto XD 612 system with a conventional dryer. Again, the material is PET, with a treatment time 6 hours at an operating temperature of 175°C, and a reference throughput of 3,500 kg/h. Hours p/a = 8,000, the sample cost of energy is 0.11 €/kWh.
X-MAX represents the most attractive and flexible drying solution for big processing up to 6.000 kg/h of PET. In this X Technology single tower machine, up to 10 units can be integrated. X-MAX Control with FLOWMATIK interface enables operating management at the hopper end, with X-MAX looking after the drying technology, resulting in a fully synchronized system.
The X Technology Moisture Meter (MM) is extremely relevant in the PET production process. Online readings can be taken at any point, giving the final moisture value of the granulate, right up to 10 ppm. Therefore, trouble-free closed-loop control dryer management to that point is easily achieved.
The X Technology Volumetric Dosing Unit DVM H with X DRY AIR applications is a volumetric screw dosing unit for additives or master-batch in granular form, including PET. It is specifically designed to accommodate production at high temperatures, also taking into consideration the different humidity levels of a variety of other polymers. This unit can be combined with DRY AIR dryers to treat humidified master-batches up to 180°C. The dosing body is installed on a vertical support, just like a conventional doser. The unit is thermally insulated to avoid heat dispersion.
The recycling of materials plays a major part in the operation of any plastics processing operation, not only to ensure efficient and economic production, but also to contribute to the responsible participation in the long-term protection of the environment. Moretto is at the forefront of the development in this field, offering automated crystalliser systems up to 1,500 kg/h, such as for amorphous granules, for flakes from preforms, and also for scales from bottles.
The solutions mentioned above are cutting-edge technology in drying systems that take foreseeable developments into consideration. However, present costs are a considerable factor, offset by significant long-term business and environmental benefits.
