SB Tutorial

TEXTILES #1

Exam Tutorial Quarter 1.

Study Buddy Program_Gabriela Ananieva

Date: 28-10-2021

Index

02. Toolbox

03. Examples

01. Justification

05. Thank you!

04. Extra Cases

01. JUSTIFICATION

Time management

Unability to provide solutions to all cases due to badly distributed time

"A database of knowledge, easily accessessible in critical situations, through established pathways"

02. TOOLBOX.

PROCESS

End Application

2. Fiber/yarn

3. Fabric

1. Raw Material

3. Assembly

PROCESS

End Application

2. Fiber/yarn

1. Raw Material

3. Fabric

3. Assembly

• Production process parameters (chemistry, cost, sustainability)
• Product properties

(moisture regain, handle, degradability, tensile strength, dyeability, etc.)

• Cellulose

(Regenerated)

• Protein

(Regenerated)

• Synthetics

What is required by the end application?

PROCESS

End Application

2. Fiber/yarn

1. Raw Material

3. Fabric

3. Assembly

• Yarn spinning

(ring, rotor, etc.)

• Yarn properties

(strength, roughness, compactness, softness, etc.)

• Staple fiber

• Filament

FineTextured

What is required by the end application?

PROCESS

End Application

2. Fiber/yarn

1. Raw Material

3. Fabric

3. Assembly

• Fabric production

(knit, weave, nonwoven)> strength, drape, coverage, etc.

• Finishing

(chemical) > dyeability, flame retardancy, waterproofness, biodegradability, etc. (mechanical)> surface properties (roughness)

• Construction
• Finish

Wet/chemicalDry/mechanical

What is required by the end application?

PROCESS

End Application

2. Fiber/yarn

1. Raw Material

3. Fabric

3. Assembly

Source: NCSU readers on dyes

PROCESS

End Application

2. Fiber/yarn

1. Raw Material

3. Fabric

3. Assembly

• Seam joining

Seam typesWelding

What is required by the end application?

03. EXAMPLE CASE 1

Woolen blanket

You are a manufacturer of woven 100% woolen blankets. The blankets are woven from dyed yarns. One of your customers would like you to develop a soil repellent blanket for use on their café terrace.

• What category of dyestuff would you choose for this application?• What type of dyeing isotherm would apply to the dyeing process with this dye? Please explain why. • The dyeing process is executed at high temperatures, 90 °C, in a yarn dyeing machine, according the dyeing schedule below. To save energy, your energy consultant proposes to lower the dyeing temperature from 90 °C to 60 °C. Please explain what will be the results of this action for your dyeing process? • The blanket should be soil repellent. Which fabric property determines whether the fabric is soil-repellent? How would you define the required product specification for soil repellence in this application? • Which type of chemistry would you choose to fulfil this requirement? Explain why?

I would use a acid dye for this blanket. Anionic dyes can be applied from an acidic dyebath. The dye will form an ionic bond with the wool Acid dyes have an average cost and are rather average compared to other dyes to apply. They have an overall good fastness properties. A dyeing process can be devided into; 1. The transport of the dye, 2 absorption of the dye, 3 diffusion of the dye. For an acid dye, the Langmuir isotherm would be the best. Acid dyes are anionic and need a cationic spot on the fibre molecule, this means that when all the cationic spots are covered, there is no more absorption. If temperatures are lower than recommended. The dye is not as soluble which causes the absorption of the dye to be really difficult. This will be visible because the dye uptake will be lower. The fabric should be soil-repellent. The surface energy of both the soil and the fabric are important to create a soil-repellent product. The surface energy of the soil must be larger than the surface energy if the fabric to be able to say that they are soil repellent. It can also be said that the contact angle between the soil and the fabric needs to be >90° (~Vague). As this product will be used on the teras of a café, we have to make sure that the product is soil-repellent for beer, coffee and wine. The lowest surface energy of these products is 40mN/m. This means that for the fabric to be soil repellent, PP, Si-O-CH3, -CH3, - CF2 and -CF3 dan be used. However, the fluorocarbons are not good for the environment, so I would not pick those. However, I would choose the silicone because it has a good wash fastness and in these COVID-19 times. It might be necessary to wash the product frequently.

Flo van Tongel, Q1, 2020

03. EXAMPLE CASE 2

Odor stopping fabric for sport bags

Your company is a producer of woven and knitted fabrics. Additionally, your company has all modern technologies to apply finishes. You are asked to develop a fabric used for sports bags that reduces the odor of used sportswear in the bag and prevents the odor to come out of the bag.

• Which raw material would you use for your fabrics?• What kind of fabric construction would you advise?• What dyeing and finishing techniques would you use and how do these influence the properties of the fabrics?• Give advantages and disadvantages of your fabric during use.• What else do you need to consider in the design of your bag?

The raw material I would choose is PET. PET is hydrophobic and has a very low moisture regain, so fabrics made of polyester are moisture wicking and quick-drying and less susceptible to bacterial growth, which would prevent odor. The fabric construction would be a twill or plain weave. The weaving method would allow for a stronger fabric to be created with high abrasion resistance. Plain weave has the most interlacing points and creates very stiff fabric. It has good resistance to skewing, picking and snagging. A denser woven fabric would ensure higher tensile strength, due to the more material bearing the force. The tear strength of the plain weave is lower than that of other weaves, as it propagates one yarn at a time, but synthetic yarns possess inherently high resistance to mechanical strain, as they have uniform cross sections. Additionally, finishing the fabric edges with tape or welding them, together with the higher amount of yarns per square inch, would reduce the chance of tear rupture. The dye is going to be a disperse dye, as it is suitable for PET due to similarities between the two (hydrophobicity). The method of application begins from aqueous media. The process has to be done at 130 degrees and high pressure for the dye to penetrate the fiber. The bonds formed are hydrogen and Van der Waals. The wash fastness and light fastness should be quite sufficent, especially regarding that the bag would be antimicrobial and therefore, not require to be washed often. An antistatic agent could be added such as quaternary ammonium compounds, which would also give antimicrobial properties. However, that would influence the hydrophilicity of the fiber, and is not permanent to repeated laundry. Other ways to make the bag anitmicrobial is to add zink oxide, TiO2 or another compound to the polymer matrix before extrusion. The main benefits of the bag are that it would be durable, and easy to clean. ~Vague The seams of the bag could be welded for maximum durability.

Gabbi Ananieva, Q1, 2020

04. EXTRA CASES

Case 1: A sustainable colorful clothing collection

As part of a project with the goal to develop a colorful sustainable clothing collection for a fashion house you are assigned to evaluate different dyeing options for cellulosic fibers.

• Discuss at least three different potential dye classes (including a natural sourced dyestuff) in terms of their sustainability during the dye production, the dyeing process itself and the garment use period.• Based on your theoretical research you have to select one option, explain your choice.• In order to ensure the high-quality standards of the brand you have to monitor the dyeing process and ensure that the desired colors can be obtained. Which techniques are you using to test the colors and which parameters are important to measure?

Case 2: A new type of fiber for recycling applications

In the circular economy, materials should be kept in a constant loop several times before they are disposed. For used textiles that cannot be refurbished, this means that they need to be mechanically or chemically recycled. The most environmentally friendly option at the moment, is still mechanical recycling. However, mechanically recycled fibers are often very short and cannot be used for 100% in a yarn. For this reason, they are often blended with virgin cotton and polyester, which has negative environmental effects due to the water usage of virgin cotton and fossil-based character / microplastic shedding of polyester. You are asked to (theoretically) develop the perfect fiber to be blended with mechanically recycled short cotton fibers in a 50/50 yarn to improve the strength of the yarn.

• Describe the (polymer)chemistry that your new type of fiber is based on• Describe the advantages that your new fiber has compared to cotton and polyester in blending with mechanically recycled fibers. • What kind of yarn spinning technique would you use to make yarns out of your fiber blends? Discuss two techniques and their advantages and disadvantages. • What kind of fabrics (weave, knit, or nonwoven) could be produced from your yarns? • Considering the chemistry that you choose what kind of dyestuffs could be used to dye your fibers.

Case 3: A new product for a test market

You are a product developer at the company ‘Good sporting’. They want to develop a new fabric for sportsmen (active moving, but no top sport). The company plans to produce garments out of this fabric for the higher market segment. Before market introduction Good sporting wants to evaluate the quality and comfort of the new fabric and produces garments for a test market that are send to test consumers.To develop a new garment many choices are made before the product is available for the customers.

• The selection of the raw material. Make a choice from the following raw materials: wool, cotton, PET, Acrylics, viscose or a blend with two or more of the above-mentioned raw materials. Also shape and length of the fibers/filaments can be important.• Describe the production steps to make the fabric. Discuss at least the following issues: spinning – weaving or knitting -finishing (incl. dyeing or printing). What equipment would you choose for the various process steps? • After the garments have been used they will be collected for evaluation from the test consumers. On which aspects will you evaluate the fabric?

Case 4: A novel cellulose based sewing thread

Case 4: A novel cellulose based sewing thread

A well-recognized problem in recycling is the fact that most textiles are blends of several materials. Even a 100% cotton shirt most likely contains polyester sewing threads. To overcome this problem, you are asked to develop a cellulose based sewing thread for high speed/volume industrial sewing of garments. Please, describe the production of your novel cellulose based sewing threads from raw material to yarn and also give advantages and disadvantages of your thread during usage.

• Which raw material would you use for your thread?• What kind of production techniques would you use to make a thread out of your material? • What is important in terms of dyeing and finishing of these threads? • Describe the expected properties of the thread that you produce. Take tenacity, friction etc. into account. • Can you tell something about production costs in comparison to common sewing threads?

Case 5: Future proof printing

Congratulations to your new function as the head of the printing and dyeing division in a globally operating textile company. As a variety of mergers and reorganizations have taken place, you are instructed to set-up the division in a stable and future-proof way.

• You have to invest a new textile printing line. For which printing technology would you chose and what are the reasons to go for that technology? Discuss why you chose this technology over the alternative(s), i.e. in terms of costs, quality, variability etc.? • The reorganization has released a budget for the development of a new more sustainable reactive dye for cellulosic fibers. Describe which requirements are essential for a dye molecule and which concept could result in a more sustainable dyeing process.

Case 6: A sustainable terry towel

You are a producer of terry towels and your costumer wants you to develop a more sustainable version of your 100% standard grade cotton terry towel for industrial laundries. Costs are not important for the customer only sustainability counts. You only need to consider the first use phase and life cycle of the product.

• Which factors are important for the sustainability of a terry towel in the first life cycle? • What raw material would you use: natural or synthetic fiber or a blend? • What yarn constructions would you use for the yarns? • Describe the production steps to make the towel. Discuss at least the following issues: spinning – weaving or knitting -finishing (incl. dyeing or printing). What equipment would you choose for the various process steps? • Describe what evaluation/quality test you advice to get insight in the quality and sustainability of the towel.

Case 7: A novel biodegradable agro-fabric

Case 7: A novel biodegradable agro-fabric

Farmers tend to use biocides and other chemicals to protect their crops from weed. Some farmers already use foils to cover the ground from sunlight and by this prevent unwanted grows of weed. Most of these foils are made from oil-based polymers like polypropylene or polyethylene. These foils need to be removed each time the farmer wants to work on the land, which makes this process costly.Farmers tend to use biocides and other chemicals to protect their crops from weed. Some farmers already use foils to cover the ground from sunlight and by this prevent unwanted grows of weed. Most of these foils are made from oil-based polymers like polypropylene or polyethylene. These foils need to be removed each time the farmer wants to work on the land, which makes this process costly. To overcome this problem, you are asked to develop a biodegradable textile-based solution for the farmer. There are two main functions this product has to fulfill. The ground needs to be sufficiently covered to prevent weed grows and the material has to degrade in the ground or at the field after the season.

• Would you go for a pure textile like product or a combination with a foil? • Which raw material (s) would you use for your product? • How would the production process from raw material to product (not in detail) look like? • Describe the expected properties of the product that you produce. Take properties like tenacity, UV resistance etc. into account. • How does the biodegradability take place, which factors are important? Does your product need a trigger to degrade?

Thank you for the attention

Any question?