Scope of Seam Engineering to Increase the Seam Strength by Controlling Different Parameters (Part-1)

Scope of Seam Engineering to Increase the Seam Strength by Controlling Different Parameters (Part-1)
Authors: MD. Momenur Rahman,
Kazi Mustafijur Rahman
Rabeya Siddiqua

Atish Dipankar University of Science and Technology
Dhaka, Bangladesh 



Abstract
  1. Stitches and seams are two important elements of apparel construction.
  2. Stitches are used to join the materials and hold the apparel together, and seams give the shape/contour and detail of the apparel.
  3. These two elements together with the material properties contribute to the quality of the apparel.
  4. Change in parameters in terms of Sewing Thread Size/Ticket Number, GSM, Stitch Per Inch (SPI) & Stitch Per Minute (SPM) are necessary parameters to calculate different types of variation and variable on which the whole fabric construction depends.
  5. The purpose of this study is to investigate the performance of seam quality in terms of seam appearance and strength constructed with different sewing parameters.
Research Aims and Objectives

A. Investigating the performance of seams constructed with different sewing parameters.
  • The seam quality is defined by appearance and strength.
  • Seams are constructed with different sewing parameters which include the types and sizes of threads, needle sizes and stitch densities for five fabric weight categories.
B. To validate the predictive equation using new fabrics for each category of fabric weight.
  • Comparison between experimental and predictive evaluation of seam quality is done in order to measure the effectiveness and limitations of the equations.
Literature Review

Seam - joining of pieces of fabric together with stitching
Fig: Seam
Properties of Seam
  • Seam Performance (Functional Properties)
  • Seam Appearances (Aesthetic Properties)
Functional Properties of Seam
  • Seam Strength
  • Seam Elasticity
  • Seam Durability
  • Seam Comfort
  • Seam Security
Seam Engineering
The mechanism through which the strength or seam is controlled by improving its different aspects.

Factors that Effect Seam Strength
  • Fabric type and weight.
  • Thread fiber type, construction, and size.
  • Stitch type.
  • Stitches density (SPI).
  • Stitch balance.
According to Eberle, Hermeling et al. 1996 following table summarizes different types of thread with the description and applications for each thread:

Typical properties of thread
(Ukponmwan, Mukhopadhyay et al. 2000)

The size of sewing thread is usually denoted using the ticket number
  • A few different systems are available for producing the ticket number but the systems are mostly based on the weight and thickness of the sewing thread.
  • The two most common systems are Tex and Metric.
  • Thicker and heavier sewing threads have a higher value of Tex and smaller value of Metric number.
The selection of thread size depends on a few factors which include fabric weight and thickness, stitch and seam types, and needle size (Ukponmwan, Mukhopadhyay et al. 2000).

Examples of end product with suggestions of suitable ticket number of thread to be used during production (Carr and Latham 2000)

Needles:
The way the needle penetrates the fabric during sewing will give different effects in respect of seam strength (Stjepanovic and Strah 1998)

Needle size for different thread size

Next part will publish soon....
 

Incoterms of Apparel Merchandising Business

InCoTerms of Apparel Merchandising Business

Muhammad Rahat
Dept. of Knitwear Manufacturing Technology
BGMEA University of Fashion & Technology (BUFT)
Email: smrahatsaif@gmail.com



INCOTERMS is the combination of (IN – International, Co – Commercial, Terms – Terminology). INCOTERMS is very important those who doing garment merchandising business. It is also important for international business. Incoterms were first developed by ICC (International Chamber of Commerce) in Paris France. Incoterms was first developed in 1939. It defines the trade contract, responsibilities and liabilities between buyer and seller. It is invaluable and cost saving tool. The importer and exporter need not go under lengthy negotiation about a condition of each transaction after that revised version published in 2000 and 2002.
InCoTerms of Apparel Merchandising Business

Terms of Apparel Export Business:
  1. FOB – Free on Board
  2. CFR – Cost and Freight
  3. C&F – Clearing and Forwarding
  4. CIF – Cost Insurance and Freight
  5. CM – Cost of Manufacturing
  6. CMT – Cost of Manufacturing and Trim
  7. FCL – Full Container Load.
  8. L/C – Letter of Credit
  9. LCL – Less Container Load.
  10. DAT – Delivery and Terminal.
  11. DAP – Delivery and Port.
  12. CFS – Container Freight Station.
  13. FOA – Free on Air
  14. DDU – Delivery Duty Unpaid.
  15. POD – Port of Discharge.
  16. POD – Proof of Delivery.
  17. POL – Port of Landing.
  18. POL – Port of Loading.
  19. ETA – Estimate Time of Arrival.
  20. ETD – Estimate Time of Departure.
  21. GSP – Generalized System of Preferences.
  22. MAWB – Master Air Way Bill.
  23. HAWB – House Air Way Bill.
  24. FFU – Forty Fit Equivalent
  25. TFU – Twenty Fit Equivalent
  26. PC – Pont Cash.
  27. CO – Country of Origin
  28. GOH – Garments on Hanger.
  29. FPC – Flat Pack Container.
  30. CPT – Carriage Paid to.
  31. CY – Container Yard.
  32. CBM – Cubic Metter.
  33. NVOCC – Non Vassal Operating Common Carrier.
  34. DDP – Delivery Duty Paid.

Swelling of Textile Fibers

Swelling of Textile Fibers

Muhammad Ibrahim Khalilullah
Department of Textile Engineering
Daffodil International University
Facebook: https://www.facebook.com/ibrahim.khalil.002
Email: ibrahim23-3123@diu.edu.bd



Swelling:

When the fibers absorb water, they change dimensionally (length, diameter, area). Swelling occurs in transverse direction (width wise) and axial direction (length wise). It can be expressed in terms of increase in diameter, length, area and volumes. That means the dimensionally changes due to absorbing water or moisture by any fiber is termed as swelling property.
Significance of Swelling:
  • The predominant width-wise (transverse) swelling results in a shrinkage of twisted or interlaced structure.
  • The closely woven fabrics will be completely blocked when the fabrics are swollen, and they may be impermeable to water. Thus this property of fiber is used to make water proof fabric.
  • It is also an important factor in crepeing due to increased twist angle in swollen yarn, and in drying and dyeing.
Types of Swelling:
  1. Transverse dial swelling
  2. Transverse area swelling
  3. Axial swelling
  4. Volume swelling
1. Transverse dial swelling: Fractional increase in diameter of a fiber after swelling is called transverse dia swelling.

Mathematically,
Transverse dia swelling, SD = ∆D / D
Where, D = original diameter of fiber, ∆D =increased diameter of swollen fiber.

2. Transverse area swelling : Fractional increase in area of a fiber after swelling is called transverse area swelling.

Mathematically,
Transverse area swelling, SA = ∆A / A
Where, A = original area of fiber, ∆A =increased area of swollen fiber.

3. Axial swelling: Fractional increase in length of a fiber after swelling is called axial swelling.
 
Mathematically, Axial swelling, SL = ∆L / L
Where, A = original length of fiber, ∆L = increased length of swollen fiber.

4. Volume swelling: Fractional increase in volume of a fiber after swelling is called volume swelling.
 
Mathematically,
Volume swelling, SV = ∆V / V
Where, V = original Volume of fiber, ∆V = increased volume of swollen fiber.

Importance of Swelling:
  • Improve the absorption capability of dyes and chemicals.
  • It has technical consequences in the dimensional stability of the fabric, the predominant transverse swelling measurement.
  • Due to swelling the pores of interlaced structure will be blocked, this idea is used to produced shower proof fabric.
  • Improve fastness of dyed materials.
  • Elastic properties changed.
  • Static Electricity is reduced.
Rates of Swelling Depends on
  • Size and form of the sample, such as - fiber, yarn, fabric etc.
  • Composition of the material, such as - cotton, polyester, acrylic, nylon etc.
  • External condition, i.e. Temperature.
  • Chemical content, i.e. oil, wax and other impurities.
What is the reason?
  • We know, a fibre is consisted of polymer chains. This chains are arranged differently in different regions. The region having parallel arrangement of chains are called Crystalline region and disoriented region is called amorphous region.
  • This polymer chains have empty spaces among them, known as the ‘molecular space’. When a fibre is immersed into water, water molecules enter into these spaces and pushes the fiber chains. As a result, Swelling occures.
More orientation means less Swelling, and vice-Versa!
  • In a highly oriented fiber, the moleculear chains are lying parallel to the fiber axis. Which results in low molecular space, so swelling will be lower
  • For the same reason, less oriented fibre has high swelling, because they have high molecular space for water molecules to enter!
  • That’s why Viscose swelling is greater than Nylon swelling, cause Nylon is much more oriented than Viscose.
Typical values of Swelling of some well known fibres:

L/C (Letter of Credit) Operation Chart

L/C (Letter of Credit) Operation Chart

Muhammad Rahat
Dept. of Knitwear Manufacturing Technology
BGMEA University of Fashion & Technology (BUFT)
Email: smrahatsaif@gmail.com


L/C means Letter of Credit. It is one of the most used words in garment merchandising sector. L/C plays an important role both buyer and seller. Generally L/C is used for international sales transactions. L/C deals only in documents but not goods. An apparel merchandiser should have clear concept on LC. If you see the following picture carefully then you can learn how to operate L/C in apparel exporting business.
Operation chart of L/C
Fig: Operation chart of L/C
Explain of the the above image:
  1. Exporter ↔ Importer: Negotiation.
  2. Importer → Importer Bank: Import license, L/C
  3. Exporter: Commodity
  4. Importer Bank → Exporter Bank: L/C
  5. Exporter Bank → Exporter: L/C
  6. Exporter ↔ Trade department, inspection, custom, insurance. Shipper: License, Documents.
  7. Exporter: Shipping
  8. Exporter → Exporter Bank: Documents
  9. Exporter Bank → Exporter: Payment
  10. Exporter Bank → Importer Bank: Documents
  11. Importer Bank → Exporter Bank: Payment
  12. Importer Bank → Importer: Notification
  13. Importer → Importer Bank: Payment
  14. Importer Bank → Importer: Documents
  15. Importer → Customs: Claiming.