Fabrication of Extrudate Filaments from Waste Polyethylene Terephthalate Plastics for 3D Printers

The use of 3D printers for manufacturing processes comes with the challenge of filament replacement for subsequent processes. This aforementioned including the environmental problems posed by plastics wastes formed the basis for the current work which is focused on design and construction of a simple single extruder for the production of filaments from waste polyethylene terephthalate (PET) plastics for rapid prototyping machines and 3D printers. Three Band heaters were used to melt the PET plastics and a screw was used to move the melted PET plastics longitudinally along the barrel. The screw is consisted of three zones namely feed zone, compression zone and metering zone. The temperature of the band heaters is controlled by a Digital temperature controller. This paper describes the design, fabrication and testing of a filament extruder. A 2mm die was used to extrude the filament to1.75 mm. The performance of the system was quantified through relevant tests and the findings reported. When the barrel and die assembly are at 200°C, melting begins to occur and at 230°C, the extrudate begins to appear at the metering zone. The energy efficiency of the system was found out to be 75.2%. Keywords— 3D printer, Design, Extruder, Filament, Polyethylene terephthalate.

Enhanced Processing of Regrind as Recycling Material in Single-Screw Extruders

Regrind processing poses challenges for single-screw extruders due to the irregularly shaped particles. For grooved feed zones, the output is lessened by the reduction of bulk density in comparison to virgin material. Simultaneously, the melt temperature increases, reducing the extruder’s process window. Through experimental investigations on a test stand, a novel feed zone geometry (nominal diameter 35 mm) is developed. It aligns the regrind’s specific throughput with that of virgin material. The regrind processing window is essentially increased. As the solids conveying in the novel feed zone cannot be simulated with existing methods, numerical simulations using the discrete element method are performed. Since plastic deformation occurs in the novel feed zone geometry, a new hysteresis contact model is developed. In addition to spheres, the regrind and virgin particles are modeled as superquadrics to better approximate the irregular shape. The new contact model’s simulation results show excellent agreement with experimental compression tests. The throughput of the extruder simulations is considerably underestimated when using spheres to represent the real particles than when using irregularly shaped superquadrics. Corresponding advantages can be seen especially for virgin material.

TECHNOLOGICAL SOLUTION OF A MEAT FARM WITH EQUAL VEAL SUPPLY DURING A YEAR

The technological solution of a meat farm for 1000 cows of a broodstock with a three-round hotel of cows is presented. The first round is planned in january – march, the second round – in may – july and the third-from september to november. The goal of the development is to ensure regular production of beef during the year, obtained from the slaughter of 6–7-month-old steers and 8–9-month-old chicks, grown on suckling under mother cows to a live weight of 170–216 kg. The average daily growth of bulls – 800, heifers-700 g. the daily supply of meat will reach 62.4 c, an average of 2 c per day. The average level of profitability is 30.6%. New design and planning solutions for industrial buildings are proposed. The parameters of the feed zone of the farm and the need for in-farm equipment were determined. When developing the master plan of the farm, the following main zones were identified: production purposes, storage and preparation of feed, auxiliary production. For the use of loose keeping of animals, the structural scheme of buildings was chosen without internal supports. Keeping cows with calves in winter is loose on a deep non-replaceable litter. Unlike young animals, the delivery of adult animals for meat takes place in September – October. For the mechanization of production processes, there are two mixers, a mini-feed mill, auto-watering machines, ball drinkers with electric heating, a water dispenser, a straw roll shredder, and a machine for treating animals with a disinfectant solution.

Realitization and Testing of Mini Extruder for Biomaterial Filament in Biomedical Application

The use of biomaterials in tissue engineering technique requires an engineered scaffold that allow the cells to be growth. Therefore, a specific biomaterial is required to provide a supportive environment for the seeding cell. This study focused on the design and realization of mini-extruder to produce a biocompatible filament material. Later, the filament is applied in a fused deposition modelling to realize biocompatible scaffold. The extruder uses a single screw extruder of 25mm diameter with compression ratio of 2. Moreover, the extruder has an effective length of 305mm with a screw length ratio of the feed zone and metering zone by 20% and 40%. A forming die used has a diameter of 1.7mm. At the end of the realization step, the device was tested to produce the filament with various parameters which are screw rotational speed, winding speed, temperature and torque. Characterization of the produced filaments were done by measuring the diameter of filaments using the material of polycaprolactone (PCL). The filament results have a range of 0.05-1.48mm in diameter during the testing process.

Karakterisasi Feed Zone dan Potensi Produksi Sumur Panas Bumi ML-XX Muara Laboh, Solok Selatan

Penelitian mengenai uji komplesi guna untuk mengetahui karakterisasi sumur dan reservoir panas bumi, antara lain lokasi feed zones dan kontribusinya, injectivity index (II), profil tekanan dan temperatur, jenis fluida, serta potensi produksi sumur telah dilakukan di sumur panas bumi ML-XX Muara Laboh, Solok Selatan. Uji komplesi dilakukan melalui beberapa tahap, dimulai dari PTS injection, multi-rate injectivity test, PT heating-up survey hingga pemodelan sumur. Data dari hasil uji komplesi akan digunakan untuk menghitung estimasi potensi produksi dari sumur tersebut dengan melakukan pemodelan sumur. Hasil dari uji komplesi pada sumur ML-XX menunjukkan adanya 4 lokasi feed zone dengan feed zone utama terletak pada kedalaman 1536 m, lokasi lain terletak pada kedalaman 1617 m, 1797 m, dan >1878 m. Feed zone mayor memiliki laju alir massa sebesar 49 kg/s, kontribusi aliran 60% dan injectivity index (II) sebesar 9 kg/s.bara. Untuk estimasi potensi produksi, didapatkan sebesar 8,2 MWe pada tekanan kepala sumur (WHP) 9,2 bara dengan tekanan separasi sebesar 7 bara menggunakan metode Hagedorn-Brown. Sumur ML-XX merupakan sumur satu fasa dengan sistem dominasi air.Kata kunci: uji komplesi, feed zones, injectivity index, pemodelan sumur