Bulk factor

The bulk factor (i.e. ratio of the density of the moulding to the apparent powder density) of powder is usually about 2-3 but the high-shock grades may have bulk factors of 10-14 when loo.se, and still as high as 4-6 when packed in the mould. Powder grades are quite easy to pellet, but this is difficult with the fabric-filled grades. 

Bulk factor Ratio of the volume of loose molding compound to the... 

SchUtt-volumen, n. iPlaatica) pourability, also bulk factor. - Hnkel, m. angle of repose. Schtitz, m. relay shuttle sluice. 

The ratio of the apparent volume of a material in powder form to the volume of the material in solid form, i.e., after removal of the air entrapped between the particles. In moulding (plastics or rubber) using powdered material, the bulk factor is thus the ratio of the volume of the powder to the volume of the moulding made from it. Bumping... 

Galliani G, Nali M, Rindone B, et al. The rate of N-demethylation of N, N-dimethylanilines and N-methylanilines by rat-liver microsomes is related to their first ionization potential, their lipophilicity and to a steric bulk factor. Xenobiotica 1986 16(6) 511—517. 

Bulk factor Ratio of the volume of loose molding compound to the volume of the same amount in molded solid form ratio of density of solid plastic component to apparent density of loose molding compound. 

Have a lower bulking factor, reducing handling and disposal costs. 

Although debulking is routinely conducted at room temperature using vacuum pressure, hot debulking in an autoclave is sometimes required to sufficiently reduce the bulk factor when close tolerance matched die tools are used (i.e., the tool will not fit together unless the bulk factor is reduced to near final dimensions). It is unfortunately a nuisance to debulk every part every several plies and it can dramatically increase the collation costs. A trade-off between part quality and production cost must once again be made in a logical manner. 

Preheating is usually carried out at 150 to 300F (66 to 149C) followed by quick transfer to a mold cavity. The actual heat depends on the material, the heater capability, and the speed of transfer. Circular preforms are normally used with dielectric heaters so they can be rotated to obtain uniform heating. Pills of compressed compound are used to produce preforms to facilitate handling, reduce the bulk factor in the cavity, and control the uniformity of charges for mold loading. Preforms can also be the shape of the mold cavity. 

ASTM D 1895 Standard Test Methods for Apparent Density, Bulk Factor, and Pourability of Plastic Materials ... 

Even if it is not possible to attain the desired ideal conditions of operation, and less desirable conditions (nonlinear adsorption isotherm, fluctuating numbers of adsorbing centers, induction time, or delay not related to adsorption) occur, the time At is in every case characteristic of the particular catalyst and is sensitive to the smallest alteration in its condition. Thus, one may learn much about differences in particle size, porosity, and bulk factor, as well as about the surface area of a catalyst. The method also is... 

The bulk factor of a molding is defined as the ratio of the volume of a given mass of molding material to its volume in molded form -the ratio of the density of the molding to its apparent density before molding. ISO 171 [24], BS 2782, Method 621 C [25], and the procedure in ASTM D 1895 all require determination of apparent powder density and molded density by the appropriate methods discussed above. 

ASTM DI895. Apparent density, bulk factor and pourability of plastics materials, 1989. 

BS 2782, Method 621 C. Determination of bulk factor of moulding materials. 1983. 

Bulk Factor—the ratio of the volume of any given quantity of the loose plastic material to the volume of the same quantity of the material after molding or forming Pourability—a measure of the time required for a standard quantity of material to flow through a funnel of specified dimensions... 

Butters. G.. Plastics Pneumatic Conveying and Bulk Storage. Applied Science Publishers. 1981. ASTM D1895-89( reapproved 1990) Apparent density, bulk factor, and pourability of plastics materials, 1990. 

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