Molding shear controlled orientation

SCO RIM stands for Shear Controlled Orientation in Injection Molding, a technology offered by British Technology Group. 

Shear controlled orientation injection molding (SCORIM) is a novel technique for establishing the alignment of polymer molecules and fiber reinforcements in molded p arts. S olid-state properties, which are highly dependent on molecnlar and additive alignment, can be improved through the use of controlled orientation. 

FIGURE 14-52 Schematic diagram of shear controlled orientation injection molding. 

Shear controlled orientation technology was developed to optimize plastic properties by orientation of filler particles. In this patented technology, the single feed is split into a plurality of feeds which can supply pressure to the mold cavity independent of the feed channel. Figure 7.3 shows feed arrangements. The shear is applied by a controlled movement of pistons which imposes microscopic shear. A perfect alignment of fibers can be obtained. 

Modified processing techniques have been useful for thermoplastic starch polymers. Recent work [45, 46] has examined the use of coextruded sheet processing to produce polyester / thermoplastic wheat starch / polyester multilayer films. They found that adhesion strength between the layers and stability of the interface were crucial properties in controlling the final performance properties of the films. Work by Sousa [47] has examined use of the novel shear controlled orientation injection molding (SCORIM) process to control morpholoiges and provide tensile property increases of thermoplastic starch/synthetic blends. 

Application of shear-controlled orientation in injection molding of isotactic polypropylene... 

The conventional injection molding of polypropylene is introduced in the related chapter. This chapter extends the subject of injection molding of polypropylene with the addition of shear-controlled orientation in injection molding (SCORIM), which has proved to be an excellent way of managing the morphology and hence the physical properties of polypropylene [1, 2]. 

Keywords injection molding, SCORIM, structure-propjerty relationships, shear-controlled orientation, molecular orientation, SCORIM pistons, impact strength. Young s modulus, shish-kebab morphology, y-phase, a-phase, p-phase. X-ray diffraction. 

When the PP is subjected to shear-controlled orientation injection molding (SCORIM), the molecular orientation may be enhanced, resulting in a self-reinforced molding. For example, by the SCORIM method, moldings of improved stiffness (by 75%) can be obtained [3] - see the related chapter in this book. 

Single Polymer Composites via Shear Controlled Orientation Injection Molding (SCORIM) or Oscillating Packing Injection Molding (OPIM) Techniques... 

Ogbonna C I, Kakay G, Allan P S and Bevis M J (1995) The self-reinforcement of polyolefins produced by shear controlled orientation in injection molding, J Appl Polym Sci 58 2131-2135. Mano J F, Sousa R A, Reis R L, Cunha A M and Bevis M J (2001) Viscoelastic behaviour and time-temperature correspondence of HDPE with varying levels of process-induced orientation. Polymer 42 6187-6198. 

Shear Controlled Orientation in Injection Molding of PLLA... 

A technique based on injection molding, as it is a versatile, efficient and highly reproducible process, and capable of fast production of complex geometric shapes with tight dimensional tolerances has been studied. The mechanical property of PLLA can be optimized up to a certain level through manipulation of thermomechanical environment of conventional injection molding. Non-conventional injection molding processes like shear controlled orientation in... 

Kalay G and Bevis M J (1999) Application of shear-controlled orientation in injection molding of isotactic polypropylene, in Polypropylene An A-Z Reference (Ed. Karger-Kocsis J) Kluwer, Dordrecht, pp. 38-46. 

The counter-rotating die of Figure 11.5 can be used for film, tubing, and blow-molded containers, as well as multilayer coextruded products. The machinery, processing, and applications are described in subsequent sections of this chapter. Specifically, section 3 will describe the importance of stretching, combined with shear, to control orientation. 

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