Composite characteristics testing speed

De Man (1983) has reviewed this property of fats. Consistency is defined as (1) an ill-defined and subjectively assessable characteristic of a material that depends on the complex stress-flow relation or as (2) the property by which a material resists change of shape. Spreadabil-ity, a term used in relation to consistency, is the force required to spread the fat with a knife. The definition is similar to that for hardness the resistance of the surface of a body to deformation. The most widely used simple compression test in North America is the cone penetrometer method (AOCS Method Cc 16-60, 1960). More sophisticated rheological procedures are also available. Efforts have been made to calibrate instrumental tests with sensory response. With the cone penetrometer method, penetration depth is used as a measure of firmness. Hayakawa and De Man (1982) studied the hardness of fractions obtained by crystallization of milk fat. Hardness values obtained with a constant speed penetrometer reflected trends in their TG composition and solid fat content. 

The polymers, whose characteristics are summarized in Table 1, were melt mixed in a Brabender-like apparatus at 200 C and at two residence times 6 min, at 2 r.p.m. and further 10 min. at 32 r.p.m. The blend compositions are listed in Table 2. After premixing, cylindrical specimens were obtained directly by extrusion using a melting-elastic miniextruder (CSI max mixing extruder mod. CS-194), Thermal and tensile mechanical tests were performed on these specimens by an Instron Machine (mod. 1122) at room temperature and at cross-head speed of 10 mm/min. Also made were morphological studies by optical microscopy of sections microtomed from tensile samples and scanning electron microscopy of fractured surfaces of samples broken at liquid nitrogen temperature. Further details on the experimental procedures and on the techniques used are reported elsewhere . 

It is necessary to note, that shock tests differ that in conditions of high-speed deformation the relative contribution to durability and plasticity of effective intermolecular interaction sharply grows. Here it is necessary to take into account that impact strength Ast - the integrated power characteristic of durability of polymer or a composition, showing power expenses for destruction, Ob and E - power. 

The preliminary reduction (reconsolidation) of the samples before recovery of its natural density, was made by recovery phase composition method. Vertical load was put with earlier reached pressure in a chamber and blocked drainage under kinematic mode of loading, with a speed of 0.5% in a minute. Defended deformation characteristics were modulus of deformation and Poisson s ratio. The durability of samples was estimated by the meaning of the resistance of undrainaged shear. For their definition the soil samples were tested by putting vertical load under the set comprehensive pressure... 

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