Textile Finishes Midterm

Give 5 properties of polymeric starch?

-Be easily removed -Have low viscosity that allows time to be absorbed by fibrous surface -Flexibility -Abrasion resistance -Tensile strength -Adhesion

What are the three main objectives of pretreatment or routine finishing?

-To convert fabric from hydrophobic to hydrophilic state -To remove dust, dirt, etc. from fabric -To achieve the degree of desired whiteness, color or finish

What is a textile finish?

A physical or chemical treatment or process to a fiber, yarn, fabric, either before or after the fabrication to change the appearance, hand, or the performance of the textile.

Why is it crucial for the finish to be uniformly applied to the textiles?

Because when it is in production we cannot afford to have glitches, mistakes in calculation. All that is pre done and tested before the production is started. Uniformity of the finish application will result in uniform appearance, hand, and strength. If this does not happen, the product does not comply with the specs or specification, it will be rejected in QC, and the company will lose money.

The excess liquor on the engraved roller surface is removed by an oscillating _________________

Doctor blade

What is dry-add-on and why is it important to note it?

Dry add on is the difference in dry weight of the treated and untreated fabric expressed in %. It is important to know the dry add on weight because we do not want too much add on to the treated fabric as it will interfere with the hand, drape and strength of the fabric.

Wrinkle resistance finish is often referred to as __________ finish as it may last for the life of the product, but its effect diminishes with use or age?

Durable

Engraved roller is a poor choice in large finishing plants where same type of fabric is continually and continuously processed

False

Finishes do not add properties to textile fabric they do not possess naturally?

False

Finishes do not give textile products any properties they do not possess naturally

False

Finishing does not add to the cost of textile products and does not increase production time?

False

Finishing does not enhance performance of fabric, increase comfort, and reduces care?

False

Finishing does not improve appearance or durability?

False

It is not mandatory for all greige fabrics to undergo cleaning even though they contain size and other impurities due to handling, often soiled during fabrication and storage?

False

Most cotton and synthetic staple fiber yarns are not sized prior to weaving with various types of natural or synthetic polymers?

False

Pad-dry-cure application method is used only in academic lab settings?

False

Pile fabrics are finished such that the pile is flattened.

False

The critical add-on value does not vary according to fiber type, fabric construction, and level of chemical pretreatment

False

All finishes are beneficial?

False In the long run and considering sustainability, they are not beneficial

In chemical finishing, fabrics are treated with mechanical devices to impart aesthetic look and properties.

False In chemical finishing, not for aesthetic look but for functional properties.

_________ is a physical or chemical treatments (other than preparation and coloring) or processes imparted to a fiber, yarn or fabric?

Finishing

_____________is the final processing of the cloth and its purpose is to make the fabric suitable for its intended end use?

Finishing

____________is usually categorized as aesthetic and functional finishes?

Finishing

_________can be applied either before or after the fabrication to change the appearance, hand or the performance?

Finishing

Keeping sustainability, water pollution, environmental concerns, and energy costs in mind, ______________________ has been used as an alternate mode of application

Foam Technology

_______________ uses a foam which is usually a mixture of air and liquid and there is low wet pickup and decreased amounts of chemicals needed.

Foam technology

Why is it important to note the wet pick up while applying chemical finish onto the textile material?

High pick up can lead to uneven finish distribution due to migration of the chemical formulation on the fabric surface. Therefore, higher the wet pick-up = higher migration. Low wet pick up finishing can lead to saving chemicals applied to fabric. You do not want too low or too high pick up. We want to ensure that the % wet pick up specified by the chemical company matches the range specified by them. If the pickup is less or more, it is a problem. That is why we have CAV.

Textiles needs finishing to :

Improve durability and improve the cost value of fabric

In the ___________application process, the pick-up depend on the degree of wetting of the roller surface and absorbency of the fabric

Kiss Roll

The application technique used in the application of stiffening agent on the back side of corduroy.

Kiss Roll

_____________is also known as slop padder is one of the simplest methods of liquor application consisting a single roller rotating in the liquor?

Kiss Roll application

______________used either for removal of water after washing, or excess dye liquor or for chemical finishing operations?

Pad-dry-cure

Examples of Permanent finish

Parchmentization, mercerization

Mercerization, is a _________________ finish?

Permanent

What are 3 different categories of finishes?

Permanent, durable, and temporary finishes

Examples of temporary finish

Simple Calendaring, Softening

What is Singeing? Describe 3 singeing techniques?

Singeing is the removal of protruding fiber by burning them off. This finish is often given to cotton or polyester/cotton fabric which makes the fabric smooth, improves luster, and reduces piling. -Direct controlled singeing -Singeing on water-cooled roller -Tangential or open singeing

Examples of renewable finish

Sizing, sprayable water repellent

What is water-bath-finishing?

The chemical is mixed with water to form a solution and padded onto the fabric by immersing in the solution and squeezing out excess liquid by passing through a pad-cure machine.

Define Critical Add-on Value?

The lowest amount of finish liquor that can be applied to a cotton fabric without producing a non-uniform distribution of crossing linking after drying and curing.

What are the factors influencing variation in finishes?

The type of fiber and its arrangement in the yarn or fabric. The physical properties of fibers. The capacity of fibers to absorb chemicals. The susceptibility of the materials to undergo chemical treatment. The desirable properties for the material's end use.

Why should the initial dry weight of the untreated fabric be different from the dry weight of the treated fabric?

There should be a difference in the initial weight of the untreated fabric and the final weight of the treated fabric in dry weight because that is an indication that a chemical reaction took place between the fiber polymer and the chemical finish.

Why do textiles need finishing?

They help improve appearance, comfort, and durability They make the fabric more suitable for its end use, improves the performance for a specific end use such as antibacterial, flame retardant, water absorbency, and soil release. They help reduce care.

What are the three stages in pad-cure application method? Describe them in detail.

Three stages are padding, drying and curing. In the padding stage the fabric is dipped in the finish formulation trough or bath, and then passed through the mangles or bowls to attain a uniform nip. In the drying stage the fabric is made free of solvent, which is water in most cases. During the curing stage, the chemical from the finish bind or crosslinks with the polymer of the fiber.

A simple example of permanent finish is parchmentization which is used to produce organdy.

True

All gray (greige) fabrics undergo cleaning because they contain size and other impurities due to handling, often soiled during fabrication and storage.

True

Almost all apparel and furnishing textiles are subjected to some type of finishing process and frequently have more than one finish?

True

Finished goods are also called converted goods?

True

Finishing can be categories as mechanical and chemical finishes?

True

Finishing can be categories as wet finishing or dry finishing?

True

Finishing can be categorized as permanent, durable, semi-durable and temporary?

True

High pick up can lead to uneven finish distribution due to migration on the fabric surface?

True

In spraying method, the amount of chemical deposited depends upon the concentration of the liquor, diameter of the nozzles, and pressure inside the manifold.

True

It is less expensive to process in a continuous process where large quantity of fabric is processed through the machine.

True

It is the woven and the knit fabrics which have the most likelihood of being finished

True

Low wet pick-up leads to more efficient and homogeneous distribution as compared to high wet pick-up:

True

Most cotton and synthetic staple fiber yarns are sized prior to weaving with various types of natural or synthetic polymers.

True

Most fabrics go through some kind of preparation process prior to dyeing or after dyeing but prior to finishing.

True

Sizing is also known as slashing

True

Spraying application method is a good choice when a low wet pick-up is desired?

True

Synthetic fibers contain spin finishes, oils, and grease.

True

The dyers or printers also does finishing. Finishing add to the cost of textile products and increase production time.

True

We use Triton-X 100 as the surfactant in our lab?

True

Variations in finishing depend on following factors?

Type of fiber and its arrangement in yarn or fabric The physical properties of fibers The capacity of fibers to absorb chemicals

What is wet pick up in terms of textile chemical finishes?

Wet pick-up is the amount of liquid absorbed by a fabric after it has been dipped and padded as a percentage of the weight of the dry fabric. It is influenced by the fabric material, weave, weight and pad pressure.

Examples of durable finish

Wrinkle Resistance, antimicrobial, water repellent

1. Low wet pick-up is also known as ______

low add-on

Advantages of pad-cure application are uniformity of ______ and ________

nip and efficient water removal

Two advantages of low wet-pick up are _____ and ______

saving chemicals and homogenous distribution

Routine Finishing often follows the following pattern:

· Desizing, scouring, mercerization, bleaching

In the ____________application method, the roller rotates in a liquid bath, in which the cavities engraved on the roller surface become filled with the liquor.

· Engraved Roller

The production sequence for fabric for apparel and interiors are :

· Fiber processing >yarn processing >preparation >fabrication >preparation with cleaning agent >whitening >coloration >Finishing >Inspection and reworking

Variations in Finishing Depend on Following Factors

· Physical properties · Capacity · Susceptibility

A durable finish last for :

· The life time of fabric but the effect goes down