Thermoplastic extrusion technology

Thermoplastic extrusion technology has been used to texturize many defatted vegetable protein ingredients, and produce many fibrous structures and meat-like textures. Such processes have been used extensively to prepare meat analogs (1, which have found their widest application in formulation of foods for institutional markets (3). A primary disclosure of extrusion texturization of vegetable proteins was made by Atkinson ( ). General descriptions of various extrusion processes have also been reported (1, 5-14). ... 

A bioadhesive hot-melt extruded film for intraoral drug delivery and the processing thereof has been patented.f Applications of these films may be utilized in transmucosal drug delivery or even transder-mal systems. The films may be produced separately and layered after extrusion, or in some cases, a multilayered system may be extruded in one continuous process. Currently on the market is an extruded film device that is utilized as a denture adhesive. This system includes thermoplastic polymers that have a bioadhesive quality when the film is wetted. Before application and wetting, however, this thin film may be held in one s hand and shaped or cut. This device is again produced by a one-step, continuous process using hot-melt extrusion technology. 

Biodegradable thermoplastics, like PHB and PLA, can be processed by conventional thermoplastic processing technologies, such as extrusion, injection molding, melt spinning, blowing film, and melt blown, for a wide range of application as enviromnentally friendly materials and for medical applications. 

Heiber J, Clemens F, Graule T, Hulsenberg D (2004) Fabrication of Si02 glass Fibers by Thermoplastic Extrusion. J Glass Science and Technology vol 77 No 5 pp 211-216... 

Starch can be destructurized using extrusion technologies in specific conditions. Sufficient work, heat and time have to be applied to a cereal-based starch product in the presence of plasticizers to destructurize it. The best plasticizer for starch is water in quantities lower than 45%. Other plasticizers are glycols such as glycerol and sorbitol. Whereas thermoplastic starch can contain a certain amount of granular residue and a few Maltese crosses can be detected in polarized light microscopy, destructurized starch is substantially free from those features. 

Starch-based polymers have been intensively studied for their extrusion characteristics, since extrusion processing plays a primary role in establishing the polymer s properties. Starch can be made thermoplastic using technology very similar to extrusion cooking [13]. Granular beads of starch are approximately 15-100 pm in diameter and can be blended as a filler with other polymeric materials [91]. Under special heat and shear conditions during extrusion, starch can be transformed into an amorphous thermoplastic material by a process known as destructurisation. 

What is thermoplastic extrusion Give at least two examples of breakfast cereals produced by direct and pellet-forming technologies ... 

Whereas all conventional thermoplastic fabrication techniques have been successfully employed to convert pellets of HIPS into useful articles, extrusion (film, sheet, profile and multi-layer) and injection molding (solid, structural foam and gas-assist) are the predominant processing technologies. Innovative hardware technologies, in both extrusion and injection molding, have provided means to combine less expensive materials, such as polystyrene, with polymers or structures offering key performance characteristics. 

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