Lesson 6

FUNCTIONAL TEXTILE

Protection pilot jacket

Description of the style

3-in-1 function work jacket with detachable, padded quilt inside waistcoat and detachable sleeves. According to the producer it is water reflecting due to high quality Tex-Protector®-coating, which also enables cleaning and machine washing at high temperatures. It is easily printable, so it is possible to put a company logo etc. on it. The jacket has ribbed knitted cuffs and hemline. There are a lot of pockets for different things needed at work.

2 breast pockets with zip

2 hip pockets with flap

1 sleeve pocket with combination

1 mobile phone pocket at the inside of the waistcoat

1 breast pocket at the inside of the waistcoat

Composition

Outer material: 60% cotton / 40% polyester

Inside waistcoat: 100% polyester

Padding: 100% polyester

Lining: 100% polyester

Polyester 

Properties

Polyester (together with nylon) has the highest tensile strength and abrasion resistance of all apparel fibres. The strength is the same dry as wet. The braking extension is between 15% and 50%. It is a wrinkle resistant. Polyester is thermoplastic and can therefore be textured. The material has the best heat resistance of all synthetic fibres used for appeal fabrics. 

Clothing comfort

Flat filament yarns enclose little air whereas textured yarns are better insulators. It almost doesn't absorbs water. The transport of the liquid water in the yarn capillaries is good. 

Applications

Polyester is the one of the man-made fibres which can be used for most things. About 60% of polyester production is in the form of stable fibres. Stables fibres are used primarily in blends. Typically it is blend with wool, cotton, viscose and modal. Some of the most important blends are in suits, costumes, dresses and workwear. Flat filament yarns are used in rain wear and linings. 

Cloth construction

Vest 

Plain weave. It's the simplest and tightest method of interlacing wrap and weft.  

Inside pocket

This is a plain weave as well. 

Lining

Plain weave. 

Outer layer

It is a warp faced twill which shows the predominance of warp yarns on the face.The lines on the fabric run in Z-direction. The interlacing makes diagonal lines. On the back side of the fabric the twill lines run in the opposite direction. Face of the fabric shows polyester yarns while the back side shows cotton yarns.

The repeat size is three warp and three weft threads. This is the smallest repeat size for a twill weave.

Weight of the fabric

Lining                                                                           

50 g m2/1.45 Oz

Inside vest

240 g m2/7.05 Oz 

Outside shell fabric

236 g m2/6.95 Oz

Workwear standards 

There are different standards for workwear. Even though our jacket doesn't have any specific protective function we decided to look at EN standards for protective clothing which are used outdoors. 

- Wetness 

ENV 343 - this prestandard specifies the requirements for protective clothing against the effects of foul weather (precipitation, wind, low temperatures > -5°C). It specifies requirement for thermal insulation, imperability to water, water vapour permeability, tensile strength, seam strength, tear strenght, colur fastness, dimensional stability.

- Cold

ENV 342 - this prestandard specifies the requirements for protective clothing against temperatures lower than -5°C. It specifies requirements for resultant thermal insulation, air permability and water vapour permeability)

- Poor visibility

EN 471 - this standard specifies requirements for protective clothing aiming to signal the presence of the wearer visually in daylight as well as under illumination by headlights of cars. These requirements cover the area of materials used, the colour and retroreflection.

TESTING

Inspired by the requirements for outdoor workwear we decided to perform the following tests

Tearing test (ISO 13937-1/AC:2007)

To make a tear strength test we cut two pieces out of the outer fabric of the jacket. We were able to get the piece with weft direction torn into two pieces, the even though we tried to get the piece with wrap direction to brake three times, it was torn apart differently. The weft direction pieces was torn at 21.63 N with a 32.4%. Warp direction is stronger than 29.41 N as we cannot break it further than that. 

Zip strength

We decided to check the strength of the main zip. In order to do that we used the same machine as for testing the snap fastener in the baby bodysuit. We placed the zip in the machine and turned it on, so the pulling strength will make the zip open. However, even after 5 tries the zip did not open, but instead the seams holding the zip to the fabric broke, making the zip to come out. That is why we started to question the strength of the thread. We performed the burning test to check the fibres that the thread is made from. It turned out to be a polyester thread, which usually should be a rather strong type of thread. However, this particular thread seems unsuitable for the type of jacket is used for. Work-wear clothes are prone to many mechanical damages, that is why the thread holding the garment together should fit the purpose as well.

Water vapour permeability test (ISO 2528)

To find out if the fabric could transfer water from the inside of the body to the outside, we used the upright cup method. We cut the fabric out, put water in the box and taped the box. Then we weighed it, to be able to compare the start weight to the end weight to see if the water had disappeared. 

The start weight of the sleeve

21470.59 g/m2

The end weight of the sleeve

17771.91 g/m2
Sleeve breathability rate
3698.68 g/m2/24h

The start weight of the jacket (outer fabric and the lining)

21495.74 g/m2

The end weight of the jacket (outer fabric and the lining)

20310.53 g/m2
Jacket breathability rate
1185.21g/m2/24h

There is no universally accepted standard for fabric breathability as five different test methods can be used to get breathability figures and most of them don't correlate to one another. However, according to the upright cup test results comparison we found on Wikipedia, fabrics with performance result under 4.000 g/m2/24h are placed in the low breathability range.

Hydrostatic head testing (ISO 811:1981)

We filled the machine up with water and then put the fabric in. The first drop of water appeared at 172 mmwc (millimetres of water column). The final result of the test was 181 mmwc. The test shows that the jacket is not waterproof, as typical result for waterproof garments is more than 6,000 mmwc.* Our jacket can probably withstand light rain and dry snow.

*http://www.evo.com/waterproof-ratings-and-breathability-guide.aspx

Spray test (ISO 4920:2012)

We used 250 ml of soft water in 20 degrees. Then we fastened the fabric in the ring and put it in the machine. We let the water run down on the fabric. Both of the tests we made we graded 90 ISO 4 because it has a slight random sticking or wetting of upper surface.

Lesson 5

CLOTHING AFTER OWN CHOICE

T-shirt

T-shirts are most popular garments in the world worn as outerwear or underwear. Since their creation in 1920 T-shirts are available in a variety of colours, patterns, and styles, such as the standard crew neck and V-neck, as well as tank tops and scoop necks. T-shirt sleeves may be short or long, capped, yoked, or raglan. Additional features include pockets and decorative trim. T-shirts are also often customised with different prints featuring political slogans, humour, art, sports, as well as famous people and places. T-shirts can be worn by anyone in any size, from infants to seniors.

Raw materials

The majority of T-shirts are made of 100% cotton, polyester, or a cotton/polyester blend. Environmentally conscious manufacturers may use organically grown cotton and natural dyes. Stretchable T-shirts are made of knit fabrics, especially jerseys, rib knits, and interlock rib knits, which consist of two ribbed fabrics that are joined together. Jerseys are most frequently used since they are versatile, comfortable, and relatively inexpensive. They also are a popular material for applying screen prints and heat transfers. Some jerseys come in tubular form, simplifying the production process by reducing the number of seams. Rib knit fabrics are often used when a snugger fit is desired. Many higher quality T-shirts are made of durable interlock rib knit fabrics.

Neckbands add support to the garment and give the neckline of the T-shirt a more finished look. Neckbands are generally 1x1 rib knits, although heavier fabrics or higher quality T-shirts may require 2x2 rib knits. Neckband fabrics may be tubed rib knits of specific widths, or flat fabric that must be seamed. Additional T-shirt materials include tape or seam binding, made of a twill or another stiff fabric. Binding reinforces the neckline and shoulder seams and by covering the seams, it protects them from ripping apart under tension. Alternatively, elastic may be used at the shoulder seams so they remain flexible.

Thread is of course an essential element in sewing any garment. Several types and colours of thread may be used to make a single T-shirt. Some manufacturers use white thread for seams on all their shirts, regardless of colour, thus eliminating the extra labour involved in changing the thread. Visible top-stitching is done with a colour of thread that blends with the fabric. Colourless, or mono-filament  thread could be used for hems of any colour fabric, again eliminating the need to change thread often, though mono-filament thread may irritate the skin somewhat. Finally, optional decorative features may include trim, such as braiding, contrasting cuffs, appliqués, and heat transfer or screen print designs.

The manufacturing process of a T-shirt

Making T-shirts is a fairly simple and largely automated process. Specially designed machines integrate cutting, assembling, and stitching for the most efficient operations.

1.    Styling

The T-shirt style is designed and the dimensions are transferred to patterns. Adjustments are made for size differences and stylistic preferences.

2.    Cutting

The T-shirt sections are cut to the dimensions of the patterns. The pieces consist of a tubed body, or separate front and back sections, and sleeves.

3.    Assembling the front and back

For fabric that is not tubed, the separate pieces for the front and back sections must be stitched together at the sides. They are joined at the seam lines to form a simple, narrow, superimposed seam and stitched together using an overedge stitch. Care must be taken to avoid a needle cutting the yarn of the fabric, which can lead to tears in the garment.

4.    Assembling the sleeves

a)  The hems of sleeves are generally finished before they are fitted into the garment, since it is easier to hem the fabric while it is flat. An automated system moves the sleeves to the sewing head by conveyor. The edge may be finished by folding it over, forming the hem and stitching, or by applying a band. The band may be attached as a superimposed seam or folded over the edge as binding.

b)  If the T-shirt body is tubular, the sleeve material is first sewn together, and then set into the garment. Alternatively, if the T-shirt is "cut and sewn," the unseamed sleeve is set into place. Later during the final stage of sewing the shirt, the sleeve and side seams are sewn in one action.

5.    Stitching the hem

The garment hem is commonly sewn with an over-edge stitch, resulting in a flexible hem. The tension of the stitch should be loose enough to allow stretching the garment without tearing the fabric.

6.    Stitching the shoulder seams

Generally, shoulder seams require a simple superimposed seam. Higher quality T-shirt manufacturers may reinforce seams with tape or elastic. Depending on the style of the T-shirt, the seams at the shoulder may be completed before or after the neckband is attached. For instance, if a tubular neckband is to be applied, the shoulder seams must first be closed.

7.    Attaching the neckband

For crew neck shirts, the neck edge should be slightly shorter in circumference than the outer edge where it is attached to the garment. Thus, the neckband must be stretched just the right amount to prevent bulging. Tubular neckbands are applied manually. The bands are folded, wrong sides together, stretched slightly, and aligned with the neckline. The superimposed seam is stitched with an over-edge stitch.
Bound seams are finished with a cover stitch and are easy to achieve. Bound seams may be used on a variety of neckline styles. The process entails feeding ribbed fabric through machines which fold the fabric and apply tension to it.

Some neckbands on lower-priced shirts are attached separately to the front and back necklines of the garment. Thus when the shoulder seams are stitched, seams are visible on the neckband.

V-necks require the extra step of either lapping or mitering the neckband. In the former process, one side is folded over the other. A mitered seam is more complex, requiring an operator to overlap the band accurately and stitch the band at centre front. An easier method for a V-neck look is to attach the band to the neckline and then sew a tuck to form a V.

8.    Finishing the neckline

Necklines with superimposed seams may be taped, so that the shirt is stronger and more comfortable. Tape may be extended across the back and over the shoulder seams to reinforce this area as well and to flatten the seam. The seam is then cover stitched or top stitched.

9.    Label setting

One or more labels are usually attached at the back of the neckline. Labels provide information about the manufacturer, size, fabric content, and washing instructions.

10.  Optional features

Some T-shirts will have trim or screen prints added for decorative purposes.

11.  Finishing operations

a)  T-shirts are inspected for flaws in the fabric, stitching, and thread.

b)  High-quality T-shirts may be pressed through steam tunnels before they are packaged. Packaging depends on the type of T-shirt and the intended distribution outlet. For underwear, the shirts are folded and packaged in pre-printed bags, usually of clear plastic, that list information about the product. Shirts may be boarded, or folded around a piece of cardboard, so that they maintain their shape during shipping and on the shelf. Finally, they are placed into boxes by the dozen or half-dozen.

Source: http://www.enotes.com/t-shirt-reference/t-shirt

MEN'S T-SHIRT

Description of the style

Men's blue T-shirt with a print at the front.

Composition

100% cotton

Cloth construction

The T-shirt material is weft knitted. It is a plain, single jersey. It's a structure made with only a single set of needles. The two sides of the fabric have a different appearance. One side shows only face loops, the other side only back loops. It has relatively small extensibility in the width and tends to curl at the edges.

Plain jersey is used in different weights for shirts, blouses, T-shirts and underwear.

T-shirt fabric is knitted on Circular knitting machine. This is what makes it possible to have tubular T-shirts or without side seams. Tubular T-shirts are not very popular, since they could lose shape after wash, unless knitted in the right gauge & weight, using good quality yarn. Maintaining the exact measurements also is an issue of T-shirts with seamless sides.

Cotton

Properties of the cotton fibres are available for the reference in our previous posts.

Printing method 

There are several printing techniques, and each of them is suitable for a certain business strategy.

- screen printing

- direct to garment printing

- heat-press transfer printing

- heat transfer vinyl printing

- dye sublimation printing

The printing method used for this particular T-shirt was screen printing. It is the most common printing technique on the high street. This is because the production costs for high volumes of screen printed T-shirts is very low. Designs are printed on to the T-shirt with plasticol inks (which give a slightly coarse and rubbery texture) and are sealed by a process called heat tunnel curing. The problem with screen printing is that each of the colours needs to be printed on to the T-shirt separately, using its own unique screen.

Weight of the fabric

150g/m2 or 4.40 oz

From a customers point of view
We decided to look at the T-shirt from the perspective of a customer.
Peter is an 17 years old student, who just moved out from home. He is an active young men, who plays football and likes meeting with friends. His mother used to do his laundry, so he doesn't really know the rules. He simply puts all his dirty clothes in the washing machine without looking at care labels.
That is why we wanted to see what will happen to the T-shirt while being used by Peter.

TESTING

Colour fastness to washing DS/EN ISO 105-C06:2010

We decided to run the test on the T-shirt to check it's colour fastness to washing. As we agreed that the person wearing this T-shirt would be a young men who just moved out from home, he probably doesn't know the rules for washing and doesn't check care label instructions. He might just put the T-shirt with his bedclothes . That is why we washed the sample in 60° for 30 minutes and with a bleaching agent. After that we used the ISO 105-A03 light grey scale to asses the sample.

Luckily for him, nothing has changed. The fabric didn't influence any of the materials on the sample.

Shrinkage test DS/EN ISO 6330:2012

When washing in the machine we used the 2A washing procedure with 2+/- 0,1. With a load of 5 kg. 

We washed and tumble dried the top, to find out if there was a dimensional change. After washing and drying we assessed the top again using DS/EN ISO 5077:2008.

Colour fastness to perspiration test DS/EN ISO 105-E04:2009

In order to check how Peter's perspiration could influence the colour of his T-shirt we performed colour fastness to perspiration test where we soaked two pieces of fabric in acid solution and alkaline solution. After that we put them in the oven for 4 hours at 37°. As seen on the results none of the fabrics were influenced by the test. The T-shirt has a very good colour fastness to perspiration.

Bursting strength test DS/EN ISO 13938-1:1999

We did a bursting test to see how must it would take until the t-shirt burst. The pressure was 191.8 kPa, the distension was 37.7 mm and the time was 19.1 seconds. 

Appliqué test by using the bursting strength machine with the extension and recovery program

To find out if the print on the front of the t-shirt would stay we used the bursting strength machine. We put the t-shirt in the machine and added air and took the air out again before it burst. The extension and the recovery test was done 5 times. When looking at the print afterwards we found out that nothing really happened with it, except the t-shirt had extended. These were the results from the test. 

Lesson 4

CHILDREN'S WEAR

Description of the style

The long sleeve bodysuit with an envelope neck which will slip easily over baby's head without stretching out of shape. There is also a popper opening (snap fastener) on the gusset for quick and easy nappy changes.


Composition
100% cotton

Cotton 
Please find information about the cotton fiber properties in the previous posts. 

Cloth construction

The bodysuit is weft knitted. It is a 1x1 rib fabric. 

The thread used to sew the garment is made of polyester. Polyester are one of the best fibres to use for threads because it is very strong and almost always colour-fast.  It recovers quickly after extension and absorb very little moisture. Polyester is heat resistant and therefore it can be ironed with medium strength.  There are four types of polyester thread: Spun polyester, multi-filament polyester, trilobal polyester and texturized polyester. The thread used for the bodysuit is a multi-filament polyester. Multi-filament polyester thread is a continuous fibre thread. This is the largest category of polyester and is also the strongest type of polyester. Multi-filament strands are twisted together to form a smooth, lint-free thread. 

Source: http://www.superiorthreads.com/polyester-thread/

Weight of the fabric 
194 g/m2 or 5.70 oz


TESTING

Shrinkage test DS/EN ISO 6330:2012

When washing in the machine we used the 5A procedure with a 2+/-0,1 with a load of 5 kg. We also tumble dried the garment. The difference between the measurements before and after washing were not that big. It is typical what you can expect when a garment is made of cotton. 

Colour fastness to washing DS/EN ISO 105-C06:2010 test no. A2S

We have washed the pieces at 40° and used the ISO 105-A03  light grey scale to asses the sample. We only noticed a little colouring on the cotton material.


Snap fastener durability 

A snap fastener (also called snap, popper, and press stud) is a pair of interlocking discs commonly used in place of buttons to fasten clothing. A circular lip under one disc fits into a groove on the top of the other, holding them fast until a certain amount of force is applied. Snap fasteners are often used in children's clothing, as they are relatively easy for children use.

Snaps can be attached to fabric by hammering (using a specific punch and die set), plying, or sewing. For plying snap fasteners, there are special snap pliers.

During testing we noticed that every time we put the sample in the machine and perform the test, the snap fasteners opened more easily. Based on this observation we concluded that probably after long usage and many openings and closing, the fastener will loose it's strength and might be opening by itself.

Appliqué test by using the piling box machine

We used the piling machine to test whether the print on the bodysuit would stay on without looking used or if the print would brake. The machine was on for 5 hours and spun around 18.000 times. After having taken the piece out, we found that nothing really happened to the print. To see how much it would take until the print would brake, we tried tearing it slowly apart by hand. Only little strength had to be put in until the print started braking and falling apart. 

Bursting strength test DS/EN ISO 13938-1:1999

We only did the bursting strength test once because it was a small garment and we therefore didn't have enough material to test it more times.