SEWING MACHINE PARTS AND FUNCTIONS:

There are different types of machine and equipments are used to manufacture garments. Among them sewing machine plays an important role in apparel manufacturing industry. There are a lot of sewing machines used in garment industry. So it is essential to know about sewing machine. If you know the basic parts of sewing machine and how they work is an essential part of sewing. It enables you to properly use your machine and makes troubleshooting easier when problems do arise. In this article I will give explanation of different parts of a sewing machine and their functions with images.

Parts of a Sewing Machine and Their Functions: The basic sewing machine components are shown in Figure-1 and their functions with pictures are described below. 

Figure-1: Basic sewing machine components

1. Foot pedal: It controls the speed of the machine which depends on the force exerted on it. But it is not an essential part of high-speed sewing machines as the machine speed can be set by one single adjustment and start and stop of the sewing machine is then controlled with the push of a button. 

Figure-2: Foot pedal2. Power cord and switch: The electricity for the machine is supplied by the power cord which has to be connected tightly to the machine for constant supply of power. The power switch is used for switching ON and OFF of the sewing machines electrically. 

Figure-3: Power socket3. Hand wheel: It is used for slowly raising and lowering the sewing needle manually to provide better control to position fabric under the needle. The clutch knob positioned inside the wheel acts as a safety feature, that is, when the knob is pulled out, it avoids the needle from jabbing up and down while winding a bobbin. 

Figure-4: Hand wheel4. Reverse lever: It is situated on the front side of the machine. This is used for making reverse stitching while sewing at the end of every seam to secure it. 

Figure-5: Reverse lever5. Spool pin and holder: It holds the sewing thread besides controls the sewing thread direction as it goes through the machine. 

Figure-6: Spool pin6. Bobbin winder: It is used to wind the bobbin thread on the empty bobbin. Bobbin winders can be located at the top or right side of the machine. 

Figure-7: Bobbin winder7. Pattern selector: It is used to decide the kind of stitch to be sewn on the fabric, such as straight stitches or zigzag or an embroidery stitch. Based on the machine type, a variety of stitches can be selected beside straight stitches. 

Figure-8: Pattern selector8. Stitch length adjustment: 

Stitch length determines the length of the stitch The range on the machine is from 0 to 4. 0 is the shortest stitch, 4 is the longest. The stitch length adjustment adjusts the length of stitches the sewing machine makes. The adjustment takes place at the feed dog not the machine needle. Shortening the stitch length shortens the amount of fabric that is fed under the presser foot before the needle comes down and vice versa.

Figure-9: Stitch length adjuster9. Tension disks: Thread tension determines the looseness or firmness of the stitch. Tensions disks control the pressure applied to the thread for uniform feed to the machine needle. The main functions of tension device is to 

Position the thread to needle Regulate the flow of the thread Maintain the smoothness in stitching Control the thread passage precisely

There are two kinds of tension device, such as direct tension device and indirect tension device. Both types have parts like (a) pressure disk, (b) tension spring, (c) thumb nut, (d) tension mounting bar and (e) pressure releasing unit. 

On high speed and modern machines, the tension dial with numbers graduated on it is used for

varying the tension. The higher the number, the greater the tension and vice versa. When the tension is adjusted correctly, the stitch line will be straight and even on either side of the fabric. 

Figure-10: Tension disks10. Needle and needle clamp: The needle fits into the needle bar, which holds it in place with a small screw. The needle clamp is used to fix the needle in place.

Figure-11: Needle of sewing machine

Figure-12: Needle clamp11. Take-up lever: The take-up lever moves up and down during the stitch formation to provide the extra thread while forming the loop and takes back the needle thread after each stitching to set the stitch. It is used to regulate the needle thread tension at an optimum level. 

Figure-13: Take-up lever12. Presser foot: It is used to grip the fabric from the top counter to the feed dog; therefore, the feed dog can move the fabric through the machine. It applies downward pressure on the material as it is fed under the needle.

Figure-14: Presser foot13. Presser dial: The presser dial determines the quantity of pressure to be exerted on the fabric through the presser foot. Lighter weight fabrics necessitate higher pressure for better control of fabric during stitching and vice versa. 

Figure-15: Presser dial14. Feed dog: Feed dogs are a ‘teeth-like’ component that combines with the presser foot to transport the fabric by one stitch. It also regulates the stitch length by adjusting the fabric movement per stitch. 

Figure-16: Feed dog15. Face plate: It is a cover that conceals all the internal working elements of the machine. 

Figure-17: Face plate16. Throat plate: It has a hole for the needle to go through to the bobbin casing, a pair of slots for the feed dog to move and stitching guide lines. It is a removable part, which covers the bobbin and bottom of the sewing machine. 

Figure-18: Throat plate17. Sewing light: It aids in threading the needle and allows you to see the stitching in both day and night. 

Figure-19: Sewing light

18. Presser foot lever: It is used to engage and disengage the presser foot on the fabric against the feed dogs gently. When it is in the upward position, the tension disks are disengaged and vice versa. 

Figure-20: Presser foot lever19. Thread cutter: Sewing machine thread cutters are usually located behind the needle of the sewing machine, so that it is convenient while the fabric is moved to the back of the machine, the sewing thread can be cut using the thread cutter. 

Figure-21: Thread cutter20. Slide plate: It is a plastic cover that protects the bobbin case from the dirt and dust. It also gives the open space for accessing the bobbin zone under the sewing machine for changing the bobbins and other maintenance work to be carried out in this area. 

Figure-22: Slide plate

21. Bobbin case: It is the case where the bobbin has to be fixed. This can be found under the needle plate and usually has a piece of plastic that flips up to cover the bobbin case when not sewing. Bobbin cases are not exchangeable in different sewing machines. 

Figure-23: Bobbin case22. Bobbin: A bobbin is a small package that carries the bottom sewing thread and is fitted onto the bobbin case. Bobbins are filled on the bobbin winder and the thread should be evenly distributed on the bobbin. 

Figure-24: Bobbin

Types of Sewing Thread Used in Apparel Manufacturing:Various types of sewing thread which are vastly used in garments manufacturing has mentioned in the below:

1. Linen thread,2. Silk thread,3. Soft cotton thread,4. Mercerized cotton thread,5. Glaced cotton thread,6. Viscose thread,7. Polyester thread,8. Nylon thread,9. Aramide thread,10. PEFE thread.

1. Linen thread:Oldest sewing thread and was used at a wide range for sewing threads during making of garments. This type of sewing thread has high strength and slightly can make more strength of seam. Linen sewing thread was used at a large rate to sew canvas, course fabric and so on. But now it is mostly replaced by synthetic threads.

2. Mercerized cotton thread:

This type of thread is finished by caustic soda solution with tension. As a result, the entire fibres in the threads become round in shape and gain higher strength and brightness.

3. Glaced cotton thread:Glaced cotton sewing thread is made by using surface coating on the soft cotton threads. As a result, the threads become stiff, smooth and increase the frictional resistance.

4. Viscose thread:It may be made from continuous filament or staple fibres. The strength and stability are comparatively less but more brighten. It has a limited use as a sewing thread but widely used in embroidery work.

5. Aramide thread:Aramide threads are not used as a large rate because of more expensive. Aramide threads are used in special cases i.e. fire fighting garments. It is costly. Its commercial name is Nomex.

6. PEFE thread:The using of PEFE sewing thread is limited due to the higher cost. It is used for protecting against flame, melt and chemical garments.

7. Cotton thread

Cotton threads are suitable for sewing projects involving cotton, linen and rayon. It is the thread of choice of many seamstresses due to its softness, flexibility, durability and wide range of color

choices. It works best for delicate fabrics like lingerie. This type of thread is also known for heat resistance, so it is great to use with pieces that would later need to be pressed with clothes iron.

There are many types of cotton thread in the market – some have relatively rough texture, and some have a smoother finish. One type to avoid for use in machine sewing is the glazed cotton thread, which is waxed and treated for a lustrous appearance. The glaze from it can rub off and clog up machines and sewing needles.

8. Polyester thread

Known as a multi-purpose thread, polyester is a great choice for most sewing projects, both machine and hand-sewn. Polyester is a little more elastic than cotton threads, making it perfect for sewing synthetic fabrics, knitted fabrics, and fabrics that are a bit stretchable. This material is also chosen for its strength, durability, low stretchability and low shrinkage.

Regular or all-purpose thread is typically used for general sewing. Extra-fine is for machine embroidery and lightweight fabrics. For other embroidery projects, also consider using high-sheen polyester thread to give it a rich appeal. A cotton-covered polyester is a good if you want the appearance of cotton and the strength of polyester. Meanwhile, extra-strong is used for heavyweight fabrics, carpets and buttons.

9. Nylon thread

Nylon is picked as a thread because of its light weight, flexibility, strength and durability, making it perfect for sewing heavy fabrics. This thread is usually used for sewing activewear,

leather goods, handbags, shoes and upholstery. It also suits sewing projects that use vinyl, canvas, fleece, suede and tricot.

Nylon thread comes in different types. If you need to sew a bathing suit, a dance costume and other garments using spandex and Lycra, it’s best to use a woolly nylon thread. But if you’re working on draperies, wallets, luggage, tarpaulins and plastics, consider using a high-quality bonded nylon thread.

10. Silk thread

Silk threads are made of natural silk fibers. A silk thread is very fine, so it won’t leave holes on fabric, making it an excellent choice for sewing very delicate fabrics like silk or wool. It’s also good for basting thread.

Although this is a very fine thread, it is also durable. People usually don’t use this thread regularly because it is expensive.

11. Wool thread

You won’t be using wool thread a lot when sewing garments. This type is often used for embroidery projects, but it is also perfect for sewing heavier fabrics like canvas, linen, lightweight denim and wool, of course.Wool thread is also a good option for topstitching. You only need to use a larger needle and adjust the sewing machine’s tension properly.

12. Metallic thread

Metallic thread is usually made of polyester with a metallic sheen. This thread comes in wide range of colors, typically in silver, gold and copper varieties. It’s a great choice if you’re looking for a thread with a little shimmering effect for topstitching.

This type of thread is often used in machine embroidery and in decorative sewing, usually seen in handbags and other fashionable items.

Care and Maintenance Of Sewing Machine

Dust is the enemy of machinery. To keep your machine as clean as possible, store it under a dust cover or in a hard case.

To prevent interior lint buildup, Martha Stewart recommends using only new and high quality thread when you sew. She also recommends unplugging the machine regularly, and dusting inside the bobbin case with a cosmetic brush.Change Needles Regularly

It’s easy to forget how much work your needle does. Over time, needles become dull, which can lead to looped threads, skipped stitches, pulls in the fabric and potential damage to the machine.

Experts recommend changing your needle every eight hours, or every time you complete a project.

You may also need to change your needle to match the weight and weave of the fabric you’re using. Use Compressed Air to Remove Lint

Whenever you complete a project, give your machine a thorough cleaning. Using high-quality, new thread will help minimize lint build-up, but it won’t eliminate it entirely.

Compressed air can help remove lint and thread from feed dogs, tension discs and the bobbin area.

When using compressed air, make sure the nozzle is at least four inches away from the machine. Keeping the nozzle a fair distance away will help ensure you don’t introduce any moisture into the machine.

Annual Servicing

To keep the machine in tip top shape, make it a point to have it professionally serviced each year. No matter if the machine is cheap or an expensive model, annual servicing is a good idea.A knowledgeable and experienced service person will adjust the timing and tension, and clean the areas of the machine that we can’t get to without taking the entire machine apart. Sewing machine’s life will be greatly extended if the machine serviced by a professional from time to time.

Oiling the Machine

Like most other machines, sewing machines benefit from regular oiling. Sewing machines have a lot of internal moving parts. Oiling the machine will help these parts run smoother and for longer.

Sewing machine oil can be purchased online or in most craft stores, and is designed specifically for use with sewing machines.

Never use anything but sewing machine oil for the machine.

Quality sewing oil is clear and should not stain the garments. A couple of drops only need to keep the machine well-oiled. Just be sure to clean out the machine, particularly the bobbin case, before apply the oil.

Follow the instructions in the user’s manual on how to oil the sewing machine. Once applied the oil, run stitches across a few pieces of scrap fabric to remove any extra oil.

Note: Some machines are self-lubricating and don’t need to be oiled.

Clean One Part of the Machine at a Time

Every sewing machine comes with a user’s manual, and that manual often includes directions on how to clean various parts of the machine. Once start opening up the machine, it can quickly get confusing if the screws and parts strewn across the table.

To avoid this confusion, work on one part of the machine at a time. Once you’ve finished cleaning and working on one part, return that part back to how you found it.

By working a little at a time, you can ensure that you put your machine back together properly.

Wipe Down the Machine After Each Use

To keep a machine clean, wipe it down with a rag after each use. Be sure to unplug the machine before wipe it down.

A quick once-over with a rag and a quick cleaning of the bobbin case can help remove dust, lint build-up and thread pieces that may damage the machine.

Common Sewing Problem with Causes and Remedies:Various types of sewing problem which are arise during sewing the garments are-

1. Skipped stitches,2. Unbalance stitch,3. Staggered stitch,4. Variable stitch density,5. Seam puckering,6. Bobbin or looper thread breakage,7. Needle thread breakage,8. Thread fusing when sewing machine stops.

1. Thread breakCauses: Sudden jerk while sewing

A manufacturing defect in the needle with ‘eye’ being rough Use of poor quality thread Thread getting wrap around the spool holder Improper selection of thread

Remedies: 

Uniform smooth start of the machine Use of good quality needle and replace in proper interval Use of good quality thread Do proper threading in the machine Use of recommended thread

2. Missed or irregular stitchCauses: 

Needle put in the wrong way round Insufficient pressure on the pressure foot Blunt or bent needle

Remedies: 

Check the manual for proper needle insertion Increase the pressure Change needle upon damage

3. Fabric not moving forwardCauses: 

Stitching has bunched forming a lump Feed teeth not raised Negligible pressure on the pressure foot Stitch length set at Improper selection of thread

Remedies: 

Increase stitch length Raised feed teeth Increase pressure in pressure foot Increase stitch length

4. Needle breakCauses: 

A needle inserted in the wrong way

Fabric pushed or pull through machine Incorrect foot attachment Incorrect needle plate attached

Remedies: 

Insert needle as directed in manual Allow fabric to feed at its normal pace Attach foot as required Check needle plate

5. Machines fail to turn onCauses: 

Switch of the machine not turned on or insufficient power available

Remedies: 

Check for the switch and power supply

6. PuckeringCauses: 

Zig-zag too wide for the thickness of the fabric Stitch length too long for thickness in fabric High thread tension High SPI (stitch density)

Remedies: 

Change to a narrower stitch width Change to a shorter stitch length Check the thread tension Set SPI based as per the material 

7. Birds nesting Birds nesting means looping on the back of the fabric and down the bobbin area

Causes: 

Incorrect threading of the machine Insufficient pressure on the pressure foot Balance wheel turned clockwise Needle thread not passed through the take-up lever Thread not passing properly due to dirt in the tension disk

Remedies: 

Rethread machine properly again Check and control pressure Balance wheel should always be turned anti-clockwise Rethread the machine properly Check for thread insertion between tension disk and clean it in process

8. Fabric gets pushed down through the needle plate into the bobbin areaCauses: 

Fabric is fine Needle is blunt

Remedies: 

Do adjustment with the pressure foot, like for straight stitch use straight stitch foot and needle plate

Change the needle

9. Thread not locking in the centre of the fabricCauses: 

Weight(thickness) of the two thread(needle &bobbin thread) not balanced Top and bottom tensions are not correctly balanced

Remedies: 

Use same thread or threads of same properties Change tension of both needle as well as bobbin thread

10. Stitches bunch at the start of sewingCauses: 

Starting to sew too quickly without letting down the pressure foot Not allowing the fabric to feed freely under the foot

Remedies: 

Start smoothly by properly placing the pressure foot. Do hold back the threads pulled tight at the back of the foot while starting to sew

Do not hold on to the fabric

11. Machine jamming and knottingCauses: 

Thread or a broken needle caught in the raceway

Remedies: 

Clean the bobbin area

Classification of stitches: Stitch and seam are related to each other. Because seam cannot be made without stitch and vice versa. Stitch is the unit of seam made by three principles interlooping, intralooping, interlacing to join two ply of fabric. Stitches are very important in apparel making. It is not possible to make a single garment without stitch.

Fig: Different types of sewing stitches

1. Stitch class-100 (Single thread chain stitch):

In this stitch, one loop passing through the another loop of same thread. It can produce easily and high speed using one needle. Only one needle thread is used for making this stitch. Uses temporary purposes which can easily pick up. It one unit is break then whole stitch is open. It is also used blind stitch purpose.

Fig: Stitch class-100/101

2. Stitch class-200 (Hand stitch):

Stitch under this class are also produced with single thread by the use of special type of sewing machine. This stitch cannot be produced for longer length sewing. Uses for stitch costly garments.

Fig: Stitch class-200/209

3. Stitch class-300 (Lock stitch):

It required two types of sewing thread. Both sides are same. It is difficult to pick up. Less extensibility. Yarn consumption are comparatively less. It is widely used in garments factory.

Fig: Stitch class-300/301

4. Stitch class-400 (Multi-thread chain stitch):

One or more thread is used. One group is called upper thread and another group is called looper thread. Security of this stitch is higher than lock stitch about 30%. This type of stitch are used to prevent the traying of yarn of fabric. It is widely use for making knitted garments.

Fig: Stitch class-400/401

5. Stitch class-500 (Overlock or over edge neatening):

It is required for more than two threads. One group is called upper thread and another group is called looper thread. It has good preventing power and edge protection. It is used for making knitted garments. It is also used decorative purpose. It is only use din the edge of the fabric.

Fig: Stitch class-500/505

6. Stitch class-600 (Covering chain stitch):

Three or more sewing thread are used to make this stitch. Three group of sewing thread are used. Such as needle, looper and covering thread. Sewing thread consumption is very high. These types of stitch are used to join side by side of fabric without increasing thickness. This stitch is used for sewing under wear for attaching lace, braid, elastic etc.

Fig: Stitch class-600