Basis weight

Polyesters are also used in continuous filament spunbonded nonwovens (see Nonwoven fabrics). Reemay spunbonded fabric is composed of continuous filament PET with a polyester copolymer binder. These spunbonded fabrics are available in a wide range of thicknesses and basis weights and can be used for electrical insulation, coated fabric substrates, disposable apparel for clean rooms, hospitals, and geotextiles (qv). 

Product Basis weight, g/m Thickness, mm a b Tensile strength, N a b Tear strength, N Mullen burst, kPa Bonding method... 

MultiwaU. shipping sacks are suitable for transport in aU kinds of carriers from tmcks to seafaring vessels. Particular care must be taken to prevent the storage of objects with sharp projections adjacent to the bags in case of doubt, it is advisable to line the enclosure with kraft paper of a basis weight >23 kg. Additional rules for the transportation of multiwaU sacks are contained in appHcable tariff specifications and should be consulted for rail, tmck, and ocean-going shipments. 

The type of varnish used in the process depends on the kraft paper manufacturer and basis weight of the papers the machine, temperature, and control (scraper bars, squeeze roUs) used the method of cutting the paper to size the laminate being produced (post-forming or regular) and the press-cure cycle (see Laminated materials, plastic). 

Humidf denotes the amount of condensable vapor present in a gas, expressed as weight of vapor per unit weight of dry gas ie, dry basis weight. 

Fig. 1. Relationship between dry and wet weight bases where dry basis = weight moisture per weight of dry material wet basis = weight moisture per weight of moisture + dry material.

Multiwall kraft-paper basis-weight equivalents ... 

Paper, kraft, wrapping quality, 50-lh/ream basis-weight yield = 3000 fr/ream 0.50... 

For kraft paper, conversion will eventually be a hard conversion to two basis weights of 75 and 90 g/m", which will replace the 40-, 50-, and 60-lb basis weight currently used. 

Tinplate can be purchased in a wide range of tempers and thicknesses. Currently 17 different basis weights are available commercially, from 55 /BB (pounds per base box or 217.78 ft2) to 135 /BB. These weights range in nominal thickness from 6.1 to 14.9 mils. 

When specifying a composition as a percentage it is important to state clearly the basis weight, molar or volume. 

Trace quantities are often expressed as parts per million (ppm). The basis, weight or volume, needs to be stated. 

Nonwovens are widely utilized as separators for several types of batteries. Lightweight, wet laid nonwovens made from cellulose, poly (vinyl alcohol), and other fibers have achieved considerable success as separators for popular primary alkaline cells of various sizes. The key nonwoven attributes include consistently uniform basis weight, thickness, porosity and resistance to degradation by electrolytes. Nonwovens are also successfully employed as separators in NiCd s. 

Porosity of a separator is defined as the ratio of void volume to apparent geometric volume. It is usually calculated (eq 6) from the skeletal density, basis weight, and dimensions of the material and so may not reflect the accessible porosity of the material. 

Warning Don t try to fold a resume that s printed on a heavy paper stock (over 28-pound basis weight) in order to insert it into a business-size envelope. If you re using a heavier paper stock for a resume package, send it in a large (9 by 12-inch) envelope. 

Do select paper with at least 50% cotton content and a basis weight of between 24 and 28 pounds. 

However, melt-blown nonwoven fabrics with a microscopic variation of basis weight in different parts are a further drawback. The variation changes little even after the melt-blown nonwoven fabrics are pressed or embossed with metal rolls or press plates. Accordingly, the fabrics or pressed products, when used as separators, cause a microscopic nonuniform passage of electrolytes or ions in different parts of the membrane. 

Preferably, the lithium ion battery separators range in average fiber diameter from 1-3 p, and in basis weight from 10-20 g m-2 The average fiber diameter and basis weight are substantially the same before and after the pressing. The lithium ion battery separator desirably has a porosity of 40 to 50%, and a thickness of 20-45 p. A lithium ion battery separator with this porosity value provides a low internal resistance and does not pass electrode substances to prevent short circuits. The thickness in the above range is suitable for the separator to be applied to small sized lithium ion batteries (21). 

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