Threads & seams -1.3

Question 1

what are sewing machine threads made from?

Answer 1

Polyester fibres, but sometimes cotton and silk

Question 2

why are polyester fibres used in sewing machine thread production?

Answer 2

because polyester fibres are:
-strong
-they have a degree of give so they are good to use with stretch fabrics
-they do not shrink
-they are resistant to rot

Question 3

what form are the polyester fibres in?

Answer 3

filament form- however the fibres are either covered with a sheath of cotton fibres or cut to staple length and spun into a sewing thread because on their own the friction caused by the sewing machine needle during high-speed machining causes them to soften, break or melt completely

Question 4

what are the 6 different specialist threads?

Answer 4

-quiliting thread
-buttonhole thread
-elastic thread
-invisible thread
-overlocking thread
-fusible thread

Question 5

what are the two different types of embroidery thread?

Answer 5

-machine embroidery thread
-stranded embroidery cotton thread

Question 6

what happens to the cotton fibres in stranded embroidery cotton thread?

Answer 6

they are mercerised to help improve dye uptake, strength, lustre and reduce shrinkage.

Question 7

what twist is stranded embroidery thread made from?

Answer 7

S twist- the twist is much looser and you can easily separate stranded embroidery thread into 6 separate strands.

Question 8

what twist is used in machine sewing thread?

Answer 8

Z twist- the twists are much tighter and the threads are hard to separate

Question 9

what are the 4 different special effect threads?

Answer 9

-metallic threads
-glow in the dark threads
-metallic-effect threads
-multi-coloured / variegated threads

Question 10

how are metallic threads made?

Answer 10

By core spinning:
1. you can loosely wrap fine yarn around a core metal laminate
2. by wrapping coloured metallic foil around a polyester, viscose or nylon core thread

Question 11

what are metallic effect threads made from?

Answer 11

synthetic fibres such as a polyester or polyamide (nylon) blend, or even Rayon which can give a lustrous 3D effect and look like metal

Question 12

what is the advantage of metallic-effect threads over metallic threads?

Answer 12

metallic-effect threads are easier to work with

Question 13

what are glow in the dark threads made from?

Answer 13

from coated polyester which has a phosphoescent pigment- the thread is ‘charged’ by exposure to light.

Question 14

what do multi-coloured/ verietgated threads have?

Answer 14

repeating multi-coloured dye patterns running throughout.

Question 15

what are seams used for?

Answer 15

Permanently joining two pieces of fabric together/ two garment pieces together when constructing a final product. There are different types of seams and each is appropriate for different products

Question 16

what will the choice of seam depend on? (3 things)

Answer 16

1. the type of fabric being used- is it thick, thin, opaque or see-through. For example, fabrics such as chiffon and organza which are sheer will make the inner construction of the garment entirely visible and therefore a neater seam such as a french seam will need to be used
2. the type of product being made- will it be subject to hard wear or be laundered regularly?
3. should the seam not be seen easily or is it a decorative feature- such as french seams on opaque fabrics

Question 17

what two groups can seams be divided into?

Answer 17

• those that need to have an edge finish- e.g open seams and knitted fabrics which need their seams overlocked
• seams that are self finishing such as french seams, fell seams or double machined seams.

Question 18

which seam is the simplest?

Answer 18

plain (open) seam is the simplest

Question 19

which seam is the least visible?

Answer 19

plain (open seam)

Question 20

what are the negatives of fraying?

Answer 20

fraying looks untidy and may eventually cause the seam to fall apart- if a knitted fabric is used and the seam edges are not overlocked, the unfinished edges can unravel or curl up.

Question 21

on thick fabrics, how may seam edges be neated?

Answer 21

using a zig-zag stitch on the raw edges without turning them under

Question 22

what are the four ways of preventing fraying?

Answer 22

1. edge stitching
2. overlocking
3. pinking
4. binding

Question 23

what is edge stitching and what fabrics is this an exception?

Answer 23

the edges of the seam can be turned inwards by 5mm and stitched in place using a straight stitch or zig zag stitch to prevent fraying. On thicker fabrics there is no need to turn over the edges inwards , and a zig zag stitch can be used directly on the edges

Question 24

what is overlocking?

Answer 24

a quick way to neaten seams, and gives a strong and neat finish. The majority of seams for garments that are made industrially are overlocked.

Question 25

what happens when an overlocker is used with two needles and what is the benefit of this?

Answer 25

when overlocking is done with two needles, one can stitch the seam at the same time as trimming and neatening the edges. This saves time and is an ideal seam to use on knitted and stretch fabrics because it has more give than other types of seams

Question 26

what types of fabrics is overlocking the most suitable for?

Answer 26

Stretch and Knitted fabrics, as it has more give than other types of seam

Question 27

what types of fabrics is pinking most suitable for?

Answer 27

Fabrics that do not unravel or fray easily and are firmly woven

Question 28

for a stronger finish, what can happen before pinking?

Answer 28

seam turnings can be stitched around 6 mm from the edge before pinking.

Question 29

what products is pinking not suitable for?

Answer 29

products that will be washed frequently or subject to hard wear.

Question 30

how can seam edges be neated with binding and what is bias binding?

Answer 30

seam edges can be neated with bias binding- bias binding is a strip of fabric cut on the bias (diagonal to the grain) which gives stretch and flexibility. First, a plain seam is sewn and opened using an iron. The folded bias binding encloses the raw edge of the seam, and can then be either pinned or basted in place. The bias binding is then sewn into place using a straight stitch very closely to the folded edge of the binding (the stitching should go through three layers- the front of the bias binding, the raw edge of the fabric and the back of the bias binding) A seam ripper can then be used to remove the basting on the bias binding. This is then repeated on the other raw edge of the seam

Question 31

what are the benefits of bias binding seam edges?

Answer 31

can be both functional and decorative: - it is a good finish for heavy weight fabrics or ones that fray easily -gives a neatened appearance on garments where the seams may be visible such as in unlined jackets -adds strength to the seam -creates a decorative contrast

Question 32

what is a curved seam?

Answer 32

essentially the same as a plain seam, but it may curve slightly inwards (concave) or outwards (convex). It is important to remember however, that the two sides of the seam should match up

Question 33

what needs to happen on a curved seam?

Answer 33

the turnings on the curved seam will need to be snipped at regular intervals so that they can lie flat when the seam is pressed open. This will also allow for flexibility in the seam. the raw edges, including the clips will also need to be protected from fraying

Question 34

to achieve a smooth finish when stitching a curved seam, what needs to happen?

Answer 34

a guide must be used on the sewing machine and stitched at an even speed. using a slightly shorter stitch length will also be helpful

Question 35

what is the benefit of french seams?

Answer 35

- gives a neat and strong finish on fine and sheer fabrics because all of the edges are closed - the seam is not seen on the outside of the product , but it can be bulky if used on heavy weight fabrics -the seam is particularly useful and beneficial when used on opaque and sheer fabrics where the inner construction is entirely visible, as French seams are neat and are self finishing

Question 36

what are the benefits of bias binding being stretchy?

Answer 36

it can be easily stretched /folded over the curved edges neatly without giving a creased/ crinkled appearance

Question 37

can thick is bias binding usually?

Answer 37

15-25 mm wide with its edges folded inwards

Question 38

what else can bias binding be used for?

Answer 38

covering boning in cosetry

Question 39

what are the negatives of french seams?

Answer 39

can be time consuming and challenging to construct and will also appear bulky if used on heavy weight fabrics- therefore they are only typically used on sheer and lightweight fabrics

Question 40

what is a clean seam?

Answer 40

a plain seam that is pressed open with the raw edges folded inwards and secured using a zig zag stitch

Question 41

what is a fell seam?

Answer 41

a strong, flat seam which two rows of stitching and all the raw edges are enclosed. it is visible on the outside of the garment and therefore can often be used as a decorative finish on some garments- it is most commonly seen on jeans

Question 42

what are the typically uses of a fell seam?

Answer 42

products that need to withstand heavy wear and frequent washing e.g shirts, jeans and anything denim

Question 43

what are the advantages of a fell seam?

Answer 43

-very strong and durable as the seam is stitched twice -can be used as a decorative feature as the parallel lines of stitching are visible on the outside of the garment and can even be sewn in contrasting colours for decorative effect

Question 44

what are the negatives of fell seams?

Answer 44

-challenging and time consuming to construct

Question 45

what are the issues with cheap sewing threads?

Answer 45

- they rarely give satisfactory results -they can cause problems with the sewing machine as they form lint- a dusty residue around the moving parts, which can clog up the machine, therefore making it noisy and slow

Question 46

what are the negatives of using polyester thread?

Answer 46

due to the thermoplastic properties of Polyester, it can melt when a hot iron is used to press fabrics- but this can be counteracted by corespinning

Question 47

why and how is a polyester core sewing thread made?

Answer 47

Polyester, due to its thermoplastic properties, can easily melt when a garment is ironed or during high-speed machining. However, polyester can have benefits such as being strong and adding strength to the sewn edges and seams. To counteract Polyester's ability to melt, it is corespun. The polyester core is covered in a sheath of Cotton fibres through core-spinning, which prevents the machine needle from overheating during high-speed machining and the core from softening.

Question 48

what is invisible thread made from and what can it be used for?

Answer 48

Nylon, and is entirely colourless and can be used for garments made of sheer materials such as chiffon and organza, ensuring the stitching is not visible.

Question 49

what is the negative of nylon invisible thread?

Answer 49

Just like polyester thread, it also has thermoplastic properties and can melt under a hot iron or high-speed machining

Question 50

how many strands does cotton embroidery thread usually have?

Answer 50

6 which can be easily separated as they are made using a s-twist form of yarn making- S-twist is anti-clockwise and produces a softer, weaker, bulkier yarn that can be easily separated such as embroidery thread