Shear-controlled orientation injection moulding

Medina, E.M.G. (1996) Alignment and management of talc platelets in polypropylene matrix by the application of shear controlled orientation injection moulding (SCORIM) technology. PhD thesis, Brunei University, UK... 

Figure 6 (a) Shear controlled orientation injection moulding (SCORIM). (b) Klockner puch-puir injection moulding... 

In injection-moulded polypropylene products, densely packed row stmctures are typically found near the surface of the object. At least one process has been developed which is able to deliver this morphology throughout the moulded object, namely shear-controlled orientation injection moulding (SCORIM) (Kalay and Bevis 1997). 

Modified processing techniques have also been useful for thermoplastic starch polymers. Recent work by Martin et al. (2001) and Martin and Avemous (2002) has examined the use of coextruded sheet processing to produce polyester/thermoplastic wheat starch/polyester multilayer films. It was 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 et al. (2000) has also examined use of the novel shear controlled orientation injection moulding (SCORIM) process to control morphologies and provide tensile property increases of thermoplastic starch/synthetic blends. 

Shear Controlled Orientation in Injection Moulding (SCORIM)... 

Shear controlled orientation in injection moulding (SCORIM) is based on the progressive application of macroscopic shears at the melt-solid interface during solidification in the moulding of a polymer matrix. 

PE/hydroxyapatite (hydroxyapatite is the main inorganic component of human hone) composites are produced by extrusion compounding and subsequent injection moulding. Shear-controlled orientation in injection moulding induces a strong anisotropic character. 

UHMWPE and HDPE processed by shear-controlled orientation in injection moulding (SCORIM) exhibit a reduction in the formation of microvoids and microcracks and an enhancement in wear... 

SCORIM Shear-controlled orientation in injection moulding... 

Kalay G and Bevis M J (1997), The effect of shear controlled orientation in injection moulding on the mechanical properties of an aliphatic polyketone ,/PoZym Sci Polym Phys, 35,365-291. 

Altpeter H, Bevis MJ, Gomes ME, Cunha AM, Reis RL, (2003) Shear controlled orientation in injection moulding of starch based blends intended for medical apphcations , Plastics Rubber and Composites, v32 n4 173-181. 

Control of fibre orientation with short fibres, such as those sometimes used in injection moulding or reaction injection moulding (RIM) is also important. The flow in the mould may be constrained in two directions such as width and thickness, giving linear flow only in one direction. Or, the flow can instead be radial, that is, constrained in just one direction, for example the thickness, in which case the usual shear forces due to the mould walls will operate, but there will be an additional extensional force, caused by the expanding flow front. This results in fibre orientation being normal to the flow direction. The orientation angle is usually very small at the surface, but it can be almost 90° at the mid-plane [7]. 

Recent research has included studies of short glass fibre reinforced polypropylene samples made either by conventional injection moulding or shear controlled injection moulding (SCORIM) [17,18], using image analysis to determine fibre orientation. The aggregate model was combined with Wilczynski [1], Tandon and Weng [10] or a finite element... 

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