Team Apparel Resources presents a series of five technical articles based on the premium sewing thread range offered by A&E and Gütermann – a leading high-end thread provider – and its importance in garment factories. The series talks about the five different challenges faced by SMO (Sewing Machine Operators) in garment factories. In this present article, A&E and Gütermann talks about Down Garment manufacturing, its challenges and solutions.
Down Jackets / Coats
When it comes to down jackets, the perfect seam is critically important. Only the right sewing thread can prevent feathers and down from migrating out through the seam.
During a fishing trip in the winter of 1936, the American adventurer Eddie Bauer almost died from hypothermia. Following this episode, he went on to design the down jacket. The principle developed by Bauer is still valid today – pockets of down separated by quilted seams, which should be warm yet as light as possible. Nothing feels so airy and warm at the same time as a high-quality down jacket. However, this is only possible by using the best materials and processing methods. Premium jackets are usually made with a pure down fill, which makes them very wearable and comfortable. More affordable jackets on the other hand are usually filled with a mix of down and feathers. This is cheaper and is less efficient at insulating heat because of the feathers. The hard quills can also penetrate and migrate out of the fabric or the seam holes. The best way to prevent this is therefore a down-proof seam so that the filling stays where it should. A&E and Gütermann has developed very fine sewing threads for this specific purpose.
Pay attention to the mix
Down jackets with a high down content have a better quality. The percentage of feathers should not exceed 10 per cent. When purchasing a high-quality down jacket, the consumers often receive a small sachet with a sample of the filling so that they can see what it is made of.
WHAT TO WATCH OUT FOR
From the Michelin man look to a refined and feather-light style, while current fashion trends determine the appearance of high-value down jackets, their quality also depends on the way in which they are processed. The position and shape of the individual pockets of down or of a mix of down and feathers can vary according to the design. Since this determines the quality of the insulation, it is important to prevent the filling from migrating. The most vulnerable parts in this regard are the seams and the holes of stitching. For this reason, it is very important to select the correct sewing threads and needles during production.
Down Migration is a common issue with the manufacturing of down or feather-filled garments.
- Made of fibrous protein, keratin
- Spherical-shaped arrangement with very soft feather barbs
- One single downy feather has over one million down barbules, allowing down to enclose a large quantity of air
- More lightweight than feathers to provide a much larger volume with the same weight
- Only waterfowl possess down in addition to feathers
- Feathers have a long shaft, which in waterfowl is curved, providing a two-dimensional arrangement of the feather barbs
- A feather’s shaft is responsible for a spring effect
- Feather barbs interlock with neighbouring feather branches, producing the required stiffness of the feather-flags
- The quill from younger birds tends to be sharp on the end, while older birds are more rounded
Insulation Type – Down Versus Synthetic Insulation
|Excellent heat retention||Reduces insulation ability when wet|
|Improved comfort range for warm and cold temperatures||Does not dry quickly|
|No special cleaning required||Requires special cleaning|
|Compresses easily||Migration/leakage often occurs|
Down Migration – Common Areas
- Migration takes place when the shaft of a feather bores through the garment.
- This generally occurs in 3 main garment areas:
- Punching through the fabric
- Escaping through the needle hole
- Pushing through the seam
Why does Migration happen?
Below are the top 10 reasons why this problem occurs:
- Insulation / Filling
- Filling Pressure
- Factory Conditions
- Machine Type
- Sewing Thread
- Needle Size / Type
- Sewing Speed
- Thread Tension
- Stitch Density
Interestingly, A&E and Gütermann provides thread solutions to effectively manage and reduce migration by catching the feather shafts or simply causing them to slide away from the seam.
A&E and Gütermann accomplishes this through developed proprietary, innovative production technology and employing technical know-how gained from its 130+ years of doing business.
Migration Industrial Thread Solutions
A&E and Gütermann provides thread solutions to effectively manage and reduce migration by catching the feather shafts or by simply causing them to slide away from the seam.
Technical Parameters for the Sewing of Down Garments
Goal: To determine a standard best practice for sewing of down garments. Let’s take a look at the areas included:
- Examining appropriate top and bottom sewing thread for the type of fabric used
- Determining the correct sewing needle system through collaboration with needle manufacturers
- Testing the alignment of the correct foot and throat plate size for the needle size
- Optimising the sewing speed of the machine with operator performance
- Differentiating fabrics according to unique characteristics
- Thread Type
- Thread Size
- Needle Size
- Needle Point
- Needle Coating
- Pressure Foot
- Throat Plate
- Machine Speed
- Sewing Tension
- Proper Handling
Solutions – Thread type and size offered by A&E and Gütermann
It is very essential that the correct sewing thread is chosen to fill the needle holes perfectly and adequate seam strength and size to use in needles are ensured that create the smallest holes during stitching.
Needle threads used for this are SUPRA SEAM Tex 16, 18, 24; Mara 150, 120; Ultimate 150 ,120
and PERMA CORE Tex 18, 24 that permit smaller needle sizes and provide:
- Smooth thread surface
- Zero shrinkage
- High initial modulus
- High tenacity
Bobbin Threads used are ANESOFT Tex 18; Piuma 140; E151 Series 160; and WILDCAT Tex 18 that provide:
- Textured polyester
- Minimum friction
- Coverage on needle holes
- Large amount of micro-denier filaments
- Shape flexibility that allows for flat or circular
More processing tips
When producing down jackets, the length of the stitch should ideally be equal to 4 ½ stitches per cm at a machine speed of 3,500 to 3,800 rpm (revolutions). Smaller stitches mean more stitch holes, and because of the even thread tension, feathers are less likely to migrate.
The machine tension should be as low as necessary to prevent a high thread tension. The threads must also interlace between the layers so that holes in the material are sealed by interlacing.
The size of the needle should be as fine as possible to avoid damage to the material as well as to keep the stitch holes as small as possible. This prevents the feathers from penetrating through the seam hole. In general, it is advisable to check each fabric before processing for sewability and the correct needle insertion.
Solution – Needle Plate Selection
Long-head automatic sewing machines have been used for seaming quilt lines.With maintenance team assistance, select the smallest size of needle plate from the available variations for the correct fabric.
Solution – Pressure Foot
The used machines are adjusted with the standard cup pressure foot. The cup dimension changes with the pattern of quilting. Available pressure foot types used for down garments are as below:
The factories need to take care of all the solutions and the standards/best practices explained above. The down migration / loosing / seepage cannot be eliminated but minimised to a tolerance limit.
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