Page 66 - February-March-2017

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4DG TM

Fibre

definition have the same cross-sectional area
A modified cross-section can provide added Characteristics when the polymer type and denier per filament are
functionality, such as unique lustre or moisture 1. Move Fluids Spontaneously the same.
transport. Type 4DG ™ is a uniquely designed Fluid movement is shown below in a nonwoven fabric
product with deep grooves or channels along the of 4DG fibre vs. round fibre using 6 denier per Note: 1) the relative size and number of micro-denier
longitudinal axis of the fibre. These fibres can be filament, both being bonded with binder fibre and round fibres and 2) the size of a single round fibre
produced for a range of commonly used polymers. with the same hydrophilic lubricant. The fluid is needed to match the perimeter or surface area of the
These grooves provide unique features to the fibre Milliken Syl-Tint® blue and has spread for 20 4DG fibre. The specific capillary volume (SCV)
that can serve as ducts to move fluid spontaneously, seconds. In addition to this visual test, fluid relates to the dark-coloured open area of the grooves
store or trap substances, provide large surface areas movement is measured by a maximum potential flux as opposed to the light-coloured area of fibre
for a given denier per filament, and many other test (MPF) developed by Eastman and recorded as mass shown.
features. Choices of finish applied to the fibres cubic centimetres of fluid per gram of fibre per hour.
include hydrophilic or hydrophobic, based on the
needs being served by the fibre.
4. More Bulk and Cover Than Round Fibre
Fibre bulk is achieved by the same factors that
produce higher surface area. The space occupied by
the 4DG fibre in structures is much greater than
round fibre from the same polymer. 4DG has a
preferred bending modulus to provide unusual
softness rather than stiff resilience. Excellent cover is
4DG™
a result of these features, also.
The diverse characteristics of 4DG fibre lend it to a
The graph below shows specific surface area as a wide area of end-use applications. Functionality may
function of denier per filament for a round fibre even be enhanced by the interaction of more than
(shape factor = 1) and a 4DG fibre (shape factor = one characteristic at a time, for example, cover and
2.5). The shape factor is a ratio of the perimeter of a fluid movement or bulk and surface area. It also has
fibre to that of a round fibre of the same denier per high thermal and acoustic insulation. The idea of
filament. Shape factors for 4DG fibre range from 2.5 filling the grooves with materials for subsequent
Round to 3.0 producing surface areas of 250 to 300 percent release either immediately or over a period of time, or
of round fibre. for controlling surrounding conditions.
2. Store and Trap Substances
The physical properties are given in the table below The size of the grooves are large enough as
indicated below to contain many types of
substances, whether they accumulate in use or are
intentionally placed there for release while being
used. Below are examples of dust particles collected
in the grooves on the left and carbon particles placed
in the grooves for odour absorbency on the right.

3. Provides Large Surface Area
The cross-sectional views above show the 4DG fibre
compared to round cross-section fibre. Both fibres by