Since November 2014 the Spanish recycling company Reciclajes Plásticos, S.L. (Reciplast), based in San Ginés, Murcia, is producing recycled LDPE resin on a Starlinger Rectostar basic recycling line equipped with a C-VAC degassing module. This high-capacity degassing module allows them to turn heavily printed and laminated film scrap from industrial and post-consumer applications into high-quality regranulate. “Almost 100 % of this regranulate is used for the manufacturing of plastic products for agriculture such as irrigation pipes”, says Ginés Martínez, General Manager at Reciplast. “
Thanks to the extensive degassing capacity of the C-VAC module during the extrusion process the recycled resin has no gas or moisture inclusions, and the customers no longer need to filter the melt and add anti-moisture additives in the following extrusion process”, he adds. Moreover, the pipe producers were able to reduce the wall thickness and increase production output to 180 m/minute. All these factors resulted in a significant reduction of production costs for the manufacturers.
Reciplast is processing mixed grade LDPE film from the washing line in their Starlinger recycling line. “We process input material from industrial applications such as highly printed production scrap from packaging film production, or contaminated post-consumer film waste used for agriculture or in greenhouses”, explains Martínez. “This kind of input material develops a lot of gas during the extrusion process. This is due to the ink from the printing on the film, possible humidity, as well as foreign substances and contaminants such as paper, metal, sand, wood or other organic matter which cannot be removed entirely even by thorough sorting and washing”. Existing solid substances are caught in the filter which is cleaned by means of hydraulic power backflushing to avoid that they burn in the process. In the high-capacity C-VAC module all the gases that have formed during the extrusion process are suctioned off. The rheologically optimised melt channels in the module increase the degassing surface of the melt by 300 % compared to conventional degassing systems, thus vastly enhancing the degassing efficiency.
Reciplast bought the first Starlinger recycling line – a Recostar universal VAC for hard-to-grind materials with different bulk densities featuring a vacuum degassing unit and a single-shaft cutter directly attached to the extruder – in 2006. The new recoSTAR basic 125 C-VAC is used for recycling LDPE – and occasionally PP – film and features a Dynamic Automation Package (DAP) with speed-controlled SMART feeder drive, electrically driven slider and automatic regulation of the extruder load. The DAP increases productivity and machine uptime, reduces energy consumption, and ensures constant production and high output due to perfect preparation of the material in the SMART feeder before the extruder. Air flushing in the SMART feeder helps to achieve better material drying so that input materials with very high moisture levels can be processed.
The multi-piston power backflush filter efficiently cleans clogged filter screens with a pressure of up to 300 bar which increases the lifetime of the filter screens significantly. The special construction of the C-VAC degassing module increases the melt surface so that the trapped gas escapes and is suctioned off, ensuring the production of high-grade, gas and moisture free pellets suitable for direct further processing. In-line measurement of the line output and continuous energy measurement indicate the current throughput and power consumption of the recycling line on the touch screen. “We are very satisfied with the performance of the recycling line regarding the product quality and aim to achieve even better results in the future”, adds Ginés Martínez.