In a thermoplastic extrusion, the material is first softened by heating so that it can be shaped. This process is performed by the extruder, or extrusion machine. This heat softening is referred to by different names, such as ‘thermal softening’, ‘plasticization’, or ‘plastication’.
Most extruders are single screw machines. The screw is what forces the material towards, and then through, the die. Shape is imparted by the die, and/or by post-extrusion forming, and the product is then set to shape by cooling while maintaining its shape. The equipment used to perform this process is known as the post extrusion equipment, while the entire system is known as an extrusion line. In addition, there are food extruder machine and feed extruder machine.
Extruders may be categorized by three figures, for instance, 1-60-24. The first number specifies the amount of screws the machine has, the second number indicates the screw diameter in millimeters (mm), and the third number indicates the effective screw length as a multiple of the screw diameter. Therefore, in the given example, a single screw machine is being described that has a screw diameter of 60 mm and a length of 24 (i.e., a L/D ratio of 24/1).
Figure 1 shows a cut-away diagram of a simple single screw machine. This diagram shows the arrangement the different parts of the machine. The two units - screw and barrel - interact together to convey the plastic material, melt the material, and then push it through the die.
The screw is rotated at a predetermined speed with the electric motor drive unit and gearbox. Temperature controllers are connected to heating/cooling elements on the barrel to maintain the temperature at the set-point temperatures.
The capability of the screw and barrel assembly to extrude a given material is based on the characteristics or construction of the barrel and screw, the characteristics of the plastics material, and the circumstances under which the system is operated.
When the extrudate leaves the die, it can either be set to the desired shape or its shape can be altered and then set to shape. The equipment that performs this process is known as the ‘post extrusion equipment’ or the ‘haul off’, and in terms of size, it is generally much larger than that of the extruder. This is because plastics take a considerable amount of time to cool, and this cooling process determines the speed the line will operate.
The growing demands of today’s pet food market require increasingly specialized knowledge combined with advanced processing technologies. As a longtime partner to hundreds of premium pet food producers worldwide, we provides comprehensive processing solutions and aftermarket services to keep your operations ahead of the curve. All to guarantee easy, safe, and efficient operations that can quickly adapt to the next market trend.
We offers a full range of pet feed machinery – from raw material intake to finished feed bagging – as single unit or complete plant solution. The individual process machines offered are selected from the standardized and proven range of product families.
A wide variety of food products is produced worldwide on our complete twin screw extrusion processing lines to answer increasing consumers demands : cereals, snacks, crispy breads and crackers, baby food, textured proteins and food ingredients.
At the same time, we also offer pasta machinery and couscous turn-key processing lines integrating our specific design Rotante hot air drying technology.
To enable our partners in the Food industry to gain market shares and leveradge their brands, our expert teams are continuously innovating to develop and produce high-quality food products with new flavors and taste combinations.
Over 50 years, pasta production line has offered complete production solutions for a wide range of typical short-cut pasta shapes. Over the years, Clextral experts have continuously refined every component in the production process, building high-performance lines to customer specifications, including its exclusive VHT (Very High Temperature) drying system. Clextral short pasta extruders are particularly adapted to the modern requirements of production in terms of cost-effectiveness, flexibility, ease of use, hygiene and maintenance.
The raw materials are mixed with a precise dosing mechanism to maintain constant flow and obtain homogenous dough in the pasta extruder. The pressing phase is carried out with a single screw system specially designed to ensure optimal semolina hydration, mixing, compression and extrusion. Once the dough is kneaded to the required consistency it is put through fitted dies to produce the required shapes and cut to length. Drying is achieved in two phases : first, the pre-drying Trabatto is used to crust the dough surface in order to avoid sticking. The second phase is done on Rotante drying units which include a VHT (Very High Temperature) drying system, which offers several advantages, including faster pasta producton, heightened quality of the final product (especially for pasta made with soft wheat), reduced product loss, short changeover times and very hygienic processing. After drying, the pasta is cooled and stabilized in the industrial pasta machine and then transported to storage or packaged directly.
Clextral pasta extruders are designed and manufactured to strict production standards ensuring:
Quality construction and superior hygienic standards – stainless steel parts, easy cleaning, low loss of raw materials, etc.
Quick and easy on-site assembly – modular pre-mounted parts
End-to-end process control – full automation to guarantee product consistency
Flexibility – quick changeover, easy shape changes and adjustment of production parameters, capacity varies from 1,500kg to 6,000kg/h
Efficient maintenance – standardized extrusion and drying parts, easy access for servicing
Follow-up services –training, support, new product design expertise
Sustainability – intensified processing to generate energy and water savings, as well as cost-effectiveness
Microtec Engineering Group is an eminent name in the modified starch industry. With a vision to be one of the world-leading Provider of premium modified starch technology, our focus is to increase our penetration in global markets by helping clients to manufacture quality modified starch products using the latest technology and strictly adhering to the Industrial Standards. Using our advanced equipment and processing technology ,you’ll obtain starch pr