Quiz 1

a manufactured sheet, web or batt of directionally or randomly orientated fibers, bonded by friction, and/or cohesion and/or adhesion, excluding paper

can be natural or man-made or staple or filament

nonwoven production rate

nonwoven production cost

nonwoven uses

cheaper, faster, integrated processes, engineered to meet end use requirements, can be molded to desired shape

machine direction

cross machine direction

angle between the reference direction and the fiber direction; used to specify the direction of a fiber (or a segment of fiber) in a fiberweb

describes the fiber orientation distribution in a fiberweb or nonwoven fabrics; determined by counting the number of fibers in angle intervals

a fiberweb (or nonwoven fabric) in which most of the fibers are oriented in MD

a fiberweb (or nonwoven fabric) in which most of the fibers are oriented in CD

a fiberweb in which the fibers are oriented randomly

fiber type, fiber linear density, fiber orientation, areal density, bonding parameters

its performance properties (strength, elongation, stiffness, pore size that determine permeability and filtration behavior, etc)

polyester fiber property

nylon fiber property

wool fober property

glass fiber property

cotton fiber property

acryllic fiber property

polypropylene fiber property

nonwoven process steps

fiberweb formation options

fiberweb bonding options

a process by which clumps of staple fibers are separated into individual fibers that are oriented and laid in the machine direction, and then collected into a coherent web

the fed fiber tufts are cleaned (natural fibers), separated, mixed, leveled, and drafted to form a uniform web

card types

used for short staple

used for long staple

purpose of carding

feeds the fiber matt to the licker-in

opens the fibers to much smaller tufts and feeds them to the cylinder

opens the fibers to even smaller tufts and feeds them (after passing several carding groups) to the doffer in a form of uniform, coherent fiberweb with individualized fibers

worker picks certain percentage of fibers from the cylinder, stripper strips all the fibers from the worker and returns them back to the cylinder which will lead to fiber orientation in the MD, fiber separation (individualization), mixing and leveling to provide uniform fiberweb

collects the fiberweb from the cylinder and feeds it to the delivery apron

feeds the fiberweb to the next stage (bonding) or to take-up to wind up the fiberweb on a roller

cleaning is required, high speed processing, fibers are 2-12.5 cm, fiber denier >.5, lightweight fiberwebs, weight/areal density is controlled by doffer speed and feed of fiberweb and card webs, fiber orientation mostly in MD, low strength in CD

weight controlled by speed of delivery apron and feed of fiberweb, width controlled by stroke of traverse mechanism, orientation mostly in CD and then stretched in MD, equal properties in MD and CD (not other directions)

feeds fibers (which was already opened into extremely small tufts) to the licker-in

individualizes the fibers and feeds them to the stream of air

transports the fibers and lays them on the surface of the condenser

forms the fiberweb and transports it to the delivery apron

feeds the fiberweb to the next stage (bonding) or to take-up to wind up the fiberweb on a roller

cleaning, opening, and blending is required, high speed processes, lightweight-heavyweight, weight controlled by speed of delivery apron and fiber feed, random orientation, equal properties in all directions

isotrpic

anisotropic

continuously mixes fibers and water in the tank to provide homogenous fiber/water mix, which in turn provide uniform fiberweb

Allows drainage of water and forming of fiberweb on its surface and conveys the fiberweb to the delivery apron

Several water vacuum slots are mounted under the top layer of the woven apron to reduce the amount of water content in the fiberweb to reduce drying time and cost

feeds the fiberweb to the next stage (drying and bonding) or to take-up to wind up the fiberweb on a roller

high speed, short fibers, weight is controlled by speed of delivery apron and fiber/water mix, random orientation, equal properties in all directions

mechanical bonding technology in which the fabric is formed by means of fiber entanglement achieved by the repeated penetration of barbed needles through a preformed dry fiberweb