oral exam

Question 1

Burn test

Answer 1

• Melting or burning

- Characteristics, oddor of fumes, appearance of residue after burning

Question 2

Acetone testing

Answer 2

• Acetate will dissolve

Question 3

Chlorine bleach testing

Answer 3

• Silk or wool will disintegrate

Question 4

alternative to wool

Answer 4

acrylic

Question 5

sun yarns

Answer 5

• Can be untwisted
• Longer fibres
• Provide warmth and softness

Question 6

Filament yarns

Answer 6

• Made of manufactured fibres or silk
• Made and marketed by chemical fibre producer
• Good for when you need smoothness and luster since yarns are finer

Question 7

Compassion of sun and filament yarn properties

Answer 7

Yarn uniformity:
SPUN- Less uniform
FILAMENT- More uniform

Yarn smoothness & luster:
SPUN- Less smooth and dull with slight surface fuzz
FILAMENT- Smother and more luster, Yarns have no fuzziness due to short fibres

Yarn strength:
SPUN- SOme fibres break and others slide away from each other
FILAMENT- Stronger than spun yarns of the same diameter because it requiers more force to break all the fibres

Comments:
SPUN- More twist will increase strength of spun yarn
FILAMENT- Smooth surface can cause yarns to slip and slid in a fabric

Question 8

Mono filament yarns

Answer 8

Single filament

- used in nylon hosiery, fabric webbing for patio chairs

Question 9

Multi

Answer 9

• Many filaments

- Makes fabrics that are softer and more flexible

Question 10

Yarn twist

Answer 10

• Spun and filament yarns are made by twisting together fibres
• The amount of twist is designated as turns- per- intch or TPI of the yarn

Question 11

Knitting

Answer 11

Is the process of making cloth by the interlooping of yarns

• A single yarn is looped through itself to make a chain of stitches
• A knitted loop is referred to as a stitch when it is pulled through another.

Question 12

Weft Knits

Answer 12

Yarns run horizontally, from side to side, across the width of the fabric.

Question 13

Warp knits

Answer 13

• Yarns run vertically in the length of the fabric.
• Warp knit fabrics can be identified by the clearly defined knit stitches running vertically, but slightly angled from side to side.

Question 14

Wales

Answer 14

• the vertical rows of stitches that run in columns along the lengthwise direction of the knitted fabric. (similar to warp in a woven fabric).

Question 15

Courses

Answer 15

the horizontal rows of stitches in a knitted fabric. They run from side to side in the knitted fabric (similar to the filling in a woven fabric).

Question 16

Wales and Courses per inch

Answer 16

Fabric weight, hand, insulation, shape retention, drapability and cost.
Wales per inch depend on the number of needles used per inch
Courses per inch depend on the height of the stitch loop.

Question 17

Cut

Answer 17

refers to the number of needle slots in a knitting machine.

Higher the cut = more closely knit fabric

Lower the cut = coarser knit fabric.

Question 18

Gauge

Answer 18

refers to the closeness of knit stitches. It also refers to the needles per inch in the knitting machine

Question 19

Types of Knitting Stitches

Answer 19

• There are 4 principal stitches in knit fabrics:

- KNIT, PURL, MISS, TUCK

Question 20

Knit Stitch

Answer 20

the basic knitting stitch. Also called plain stitch

Question 21

Purl Stitch

Answer 21

The reverse of the knit stitch

Question 22

Miss Stitch or Float Stitch

Answer 22

A miss stitch (see fig.6.12 ) is a floating unknit yarn on the back of the fabric. It’s used to create color and patterns in knitted fabric. It’s prone to snagging

Question 23

Tuck Stitch

Answer 23

The stitch is elongated and appears as an inverted V on the back of a fabric

Question 24

Basic Weft Knit Fabrics

Answer 24

Jersey knit, Rib knit, and Purl knit

Jersey knit: Smooth face with vertical ribs (wales) on right side of fabric and horizontal ribs (courses) on the back.

Characteristics of Jersey knit:

Fabrics made with jersey knit: sheer, light weight hosiery, men’s underwear, t-shirts, knit terry, knit velour.