HECOL170 Study Guide - Fall 2018, Comprehensive Midterm Notes - Bres, Nylon, Cotton
12 Oct 2018
School
Department
Course
Professor
HECOL170
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Knit Fabrics
Knit Fabrics
the formation of a fabric by the interloping of one or more sets of yarns
the looped yarn shape imparts bulk and more yarn is require to produce a knit than a woven
looped structure is porous with holes or spaces and provide less cover than woven
can be made so that each side has a different composition, texture, or function
high performance knits provide freedom of movement and support
yarns do not move in both directions as in woven fabrics, there are not separate sets of warp
and weft yarns
knit characteristics are dependant on the type of knit and the stitches and yarns that form the
fabric
fabric density - defined by counting the number of stitches, not yarns, in a specific direction
-designated as wales by courses
quality and performance of knitted fabrics will vary widely depending on:
type of knitting used - warp or weft
fibre content
fineness, evenness and twist level of the yarns
closeness of the knitting, gauge, how many needles
extensibility of the finished fabric - stretchy or non stretchy
does not require the yarns to be as twisted,just enough to keep as a yarn
Two Categories of Knits:
1. weft (filling) knits:
one yarn or yarn set is carried back and forth (or around) and under needles to form a fabric
fabric formation is horizontally across the fabric - similar to the weft direction in woven fabric
packages of yarn - similar to weft in weaving - are used to hold the knitting yarn
create the fabric across the length of the fabric
basic structure consists of a single element interloped to form a fabric
what we typically think of as knitted fabrics is usually weft-knit construction
•sweaters, t - shirts, socks, yoga pants, fleeces, hosiery
things that will stretch, don’t tend to wrinkle as much, have more movement
more form fitting, close fitting garments
2. warp knits:
a warp beam is set into a machine and yarn sets are interloped to form a fabric
yarns work vertically through the fabric - similar to the warp direction in woven fabric
knitting yarns are held parallel to each other on a warp beam are fed through guides to the
needle bed
basic structure consists of one set of elements interloped to form a fabric
warp knits are unlike weft knits and are not what we typically think of as a knit fabric
warp knits usually have a stretch similar to woven fabric
-lower than weft knits - unless spandex is used in the construction - e.g. swimsuit fabric
often form fine open structures - netting and lace like fabrics
both weft-knit and warp-knit fabrics are composed of wales and courses
-unlike worn fabrics which have weft and warp
can count wales and courses for a knitted fabric count
find more resources at oneclass.com
find more resources at oneclass.com
but it is more common to use the knitting gauge of the fabric - needles/cm on knitting machine -
to indicate fineness/ courseness of the knit structure
-the more needles/cm - the finer the fabric
Needles
done by spring-beard, latch, double-latch, or compound needles
differ from hand knitting needles
commercial knitting uses knitting machines with needles engineered to fit in the needle bar and
be controlled by the machine
most weft knits are made with latch needles
most warp knits are made from compound needles
Stitches
the loops in knits
can be opened or closed
-open stitches most common in weft knitting
-open and closed found in warp knitting
help identify the product but have little affect on the fabric performance
Wales and Courses
wales form verticals in weft knit fabric:
one needle is required on the knitting machine for each wale formed in
the fabric
weft knitted fabrics can created on circular weft- knitting machines or on
a flat needle machine
courses form horizontally in weft knit fabric:
yarns forming the fabric follow the direction of the courses horizontally
across the fabric
in machine knitting, additional courses can be started before the
preceding one is completed
wales form vertically in warp knit fabric
courses form horizontally in warp knit fabric
one needle is required on the knitting machine for each wale formed
yarns forming the fabric follow the direction of the wales vertically
through the fabric
wales interloping with wales parallel to them
Other Fabric Characteristics
gauge or cut:
the number of needles in a specific distance on the needle bar
often expressed as needles per inch (npi)
indicates fineness of the stitch - higher the gauge, the finer the fabric
finished fabrics might not have same gauge because of shrinkage or stretching during finishing
technical face:
outer side of the fabric as knitted
may not be the side used as the fashion side in a product
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Designated as wales by courses quality and performance of knitted fabrics will vary widely depending on: type of knitting used - warp or weft. Lower than weft knits - unless spandex is used in the construction - e. g. swimsuit fabric often form ne open structures - netting and lace like fabrics both weft-knit and warp-knit fabrics are composed of wales and courses. The more needles/cm - the ner the fabric. Stitches the loops in knits can be opened or closed. Open stitches most common in weft knitting. Open and closed found in warp knitting help identify the product but have little affect on the fabric performance. Other fabric characteristics gauge or cut: the number of needles in a speci c distance on the needle bar often expressed as needles per inch (npi) indicates neness of the stitch - higher the gauge, the ner the fabric.
