2.While stitching what is the maximum temp.which the needle achieves?

With Coolers

Maxm – 176c (at 4000 stitches per min)

Without Coolers

Maxm – 273c(at 4000 stitches per minute)

3.How many times the thread passes through the needle thread before it get stitched?

Twice.

5. WHAT ARE THE CONVENTIONAL NEEDLE POINTS MANUFACTURED BY THE NEEDLE MANUFACTURING COMPANIES? GIVE THE LIST OF THE NEEDLE TYPES MANUFACTURED BY GROZ & BECKERT.

Needle Points

Needles are manufactured with a wide variety of needle points appropriate for the different

properties of materials which have to be sewn. The needle point can be located wither centrally

or eccentrically. There are two basic classes of points:

Round points

Cutting points

Slim Set Point Needles – can be penetrate the yarns of the material being sewn through its sharp

point and is ideal for all woven fabrics because it helps to produce an even stitch and causes a

minimum of fabric puckering. They are used for Blind stitches and for fine, densely woven

fabrics. These points are not suitable for knitted fabrics.

Set Cloth Point – needles are slightly rounded to displace yarns of the material being sewn

without damaging them. This is most commonly used point.

Heavy Set Point – needles are strongly blunted. These are used for button sewing machines.

Ball Points – Light Ball Point is used for sensitive fabrics such as knits, to prevent damage to the

loops. This is crucial for maintaining the fabric’s elasticity. Medium ball point and heavy ball

point are used for fabrics containing stretchable yarns. While sewing the threads are displaced

not pierced. The needle pushes between the fabric yarns rather than “cutting rough” the yards.

Cutting Points – are used for sewing leather, coated or laminated fabrics. These are classified

and named according to the position of the cutting edge and its shape. The shapes are named

with regard to the form of the cutting edge for example spear point, triangular point, diamond

point etc. The shape of this needle will create a slit (rather than a large hole) through which the

thread will pass.

Needles manufactured by Groz Beckert as per the needle point types

The GB - Point Styles / Tipo De Puntas GBDescription / Descripción Application/ Aplicación Designation /

denominaciónSymbol / Simbolo

Regular round pointPunta redonda normal

Universal application for LOCKSTITCH (FST 301) and woven clothAplicación universal para puntada de dos hilos y ropa tejida

R

Sharp round pointPunta

redonda aguda

Standard for BLINDSTITCH. Also for very straight stitchlines (susceptible to damage)Tipo normal para ciega. También para lineas de puntadas muy rectas

R S

Round point with

slightly rounded tipPunta ligeramente redonda

Recommended application for CHAINSTITCH (FST 401) knitted fabrics and button sewingAplicación recomendada para punto de cadeneta Tejidos de punta y para coser botones

R G

Light ball pointPunta

de bola fina

For all kind of knitted and synthetic fabricsPara toda clase de tejidos y fabricados sintéticos

F F G

Medium ball pointPunta de bola fina

For highly elasticated material with rubber or elastomeric contentPara materiales muy elásticos con goma o contenido de elastómeros F G

Heavy ball pointPunta de bola pesada

For coarser materials of high elasticity. Also for open-structured fabricsPara materiales bastos y alta elasticidad. También para fabricados de estructura abierta

G

Special ball pointPunta de bola

especial para LYCRA

Knitted and woven fabrics with high content of elastomerics (Licra, Dorlastan, etc.)Fabricados de punto y tejidos con alto contenido de elastómeros (Lycra, Dorlastan, etc.)

S K L

Round point with a small

triangular cutting edge at tipPunta de bola pesada

For plastic foils, laminates and leather clothing cutting edge at the tipPara hojas de plastico, laminados y vestidos de piel/td>

S D

Narrow Wedge (NW) pointPunta de cuña estrecha

For dense stitch formation in leather. Edge and cup seams on uppersPara secuencias de puntadas densas en piel. Borde y costuras en la parte superior

P

Narrow Cross (NCR) pointPunta de cruz estrecha

For long stitches deeply set and very straight stitchlines in leatherPara puntadas largas y profundas. Lineas de puntadas muy rectas en piel

S

Diamond (DIA) pointPunta de diamante

For straight stitchlines in hard and dense leathers and for bag seamsPara lineas de puntadas muy rectas en piel dura y densa. También para costura de bolsos

D I

Narrow reverse twist (NRTW/RTW) pointPunta estrecha torcida al reves (NRTW/RTW) (45°)

For slanted stitch appearance in leathers and ornamental seamsPara puntadas de apariencia oblicua en piel. Costuras ornamentales

L R

Narrow reverse twist (NRTWSP/RTWSP)Punta estrecha torcida al reves por encima de 45° (NRTWSP/RTWSP)

Application similar to LR, but slightly stronger cutting effectAplicación similar a LR, pero con el efecto cortante ligeramente más fuerte

V R

Narrow twist (NTW/TW)Punta estrecha torcida (NTW/TW) (225°)

Stitch appearance almost straight. For regular joining seams in leatherPuntada de apariencia casi recta. Para costuras de unión regular en piel

L L

Triangular (TRI) pointPunta triangular (TRI)

Stitch appearance almost straight. For hard and dense leathersPuntada de apariencia casi recta. Para pieles duras y densas

D

Reverse triangular (RTRI) pointPunta triangular inversa (RTRI)

For twin needle machines (left needle) to match the seam of the right needle (D)Para máquinas de dos agujas (aguja izquierda) para aparejar la costura de la aguja derecha

D U

Square (RSQ) pointPunta cuadrada inversa (RSQ)

For heavy, hard and homogeneous materials. Bag seamsPara materiales pesados, duros y homogeneos. Costura de bolsos

Q

Reverse square (RSQ) pointPPunta cuadrada inversa (RSQ)

Application similar to QAplicación similar a Q Q R

Flattened round (STAY) pointPunta redonda aplanada (STAY)

Application similar to Q. Also for buttonholes in leather clothinAplicación similar a Q. También para ojales en vestidos de piel

S T A Y

6.How does the needle face on the puckering and what prevention measure one should take.How to improve it?

The puckering caused by the needle is called Displacement puckering.

Reason

Displacement of individual warp and/or weft threads by needle penetration and sewing thread.

The extent of the displacement depends on the density of the fabric and the way it is woven, as well as on the needle thickness and thread thickness. Very fine and specially treated(easy care) fabrics permit only very limited lateral displacement of the fabric.

The risk of displacement puker arises particularly at high sewing speeds. This problem is very typical because of todays finely woven microfiber fabrics. The structure of plain woven fabrics means that these are more likely to be affected by displacement pucker than satin woven or twill woven fabrics.

Prevention

Maintain the correct tension of the thread.

Maintain the correct tension of the bobbin case thread.

Use the correct thread type

Use the correct feed dog according to stitch and fabric

How to Improve.

Use the finest possible needle for a given thread size.

Wherever possible two-thread chainstitch (stitch type 401) should be used. This is because this type of stitching, with a loop of thread on the underside of the fabric causes less displacement of the warp and weft threads .

7.Where do we use reinforce needle blade?

These needle are designed for use in high speed sewing machines. The shoulder is often extended into the upper part of the blade to give a thicker cross section which just enters the material when the needle is at its lowest point on each stich. This reinforced blade strengthens the needle and also enlarges the hole in the material when the needle is at its lowest point , thus reducing friction between it and the material during withdrawl after each stich .

The needle with reinforced blade and pronounced needle scarf are special designed to skip stitching result from wrong loop formation, needle shaking and thread breakage..

8. Why we do coating?

The final feature of a sewing machine needle which can vary is the surface finish which is given it. needles are made from steel and in the final stages of manufacture they are polished , especially in the area of the eye. In many cases they are electroplated to given corrosion resistance, resistance to mechanical were reduction of friction during sewing and a good overall appearance. The materials used for plating are chromium or nickel. One requirement of the surface finish of the needles is that they

should not easily pick up any particles of synthetic fabric or synthetic sewing thred which they may have caused to melt as a result of excessive friction-generated hear.it has been found that chromium-plated needles resist the adherence of melted synthetic residues rather better then nickel-plated needles do, despite the fact that chromium-plated needles actually develop higher temperatures during sewing than do non-plated or nickel-plated needles.

9.Short Note on needel, parts, functions, variation………

Part 1

Part 2

Part 3

Part 4

Part t 5

10.Where do we use tapered needle?

On tapered blade needles, top of blade at shoulder is larger in thickness than at eye.blade tapers gradually to eye position, which is the diameter indicated by the needle size number. A tapered blade serves to strenghthen the needle blade, although in doing so, nearly the entire blade length is subjected to friction when penetrating the material.

It is only made in small sizes(5 – 11).The taper permits a smaller initial perforation in fine materials yet maintains blade strength in the curved portion of the blade.

Question:11 How do we identify the size of the needle ?

Answer: The needle size can be as small as 60(.6mm) or as large as 250(2.5mm). needle size is related to the diameter at a point at the middle of the blade above the scarf or short groove but below any reinforced part. The metric system size (Nm) describes the diameter of the needle blade in hundredths of mm.

Example of diameter-

In mm Nm

.65*100=65

.90*100=90

1.10*100=110

1.30*100=130

2.50*100=250

Question- 12. What care you will take while placing the order of the needle?

Answer-

Sewing machine needles should be chosen according to the weight and texture of the fabric to be sewn.

While placing the order, I will take care of these points.

1) The most readily available machine needles are sized from 9 to 18 - the smaller the number, the smaller the needle. This remains true, even if the needles we purchase use a different numbering system.

2) We should Use standard sharp sewing machine needles in sizes 11 to 14 for most sewing projects. A smaller-sized needle is best for sheer or lightweight fabrics. Sizes 16 to 18 are used for heavyweight fabrics like denim.

3) We should Use ball-point machine needles to sew knits or other stretchy fabrics. Their blunt edges allow the thread to pass between the fabric's fibers rather than through them. This is crucial for maintaining the fabric's elasticity.

4) We should Use wedge-point machine needles to sew leathers, suedes and vinyls. The shape of this needle will create a slit (rather than a large hole) through which the thread

will pass.

5) if I am unsure which is appropriate for our fabric. I will Purchase a package of assorted needle sizes.

6) I will Test the various sizes on some scrap fabric until I determine the correct size to use.

7) I will Check the label on the needle package before I make a purchase. For most brands, there will be a sizing guide that will tell us which fabrics can be sewn with the enclosed needles.

8) I will Refer to my sewing machine manual to determine which needles are compatible with my machine model.

9) I will Write down the make and model of my sewing machine and take this information with me when I purchase needles. That way I'll be able to check for needle compatibility.

10) Both ball-point and wedge-point needles are sized in the same manner as the standard variety - the higher the size number, the larger the needle.

11) We should Use sewing machine needles for most sergers and Check our serger manual, however, to make sure that a special needle is not required.

14.Write down the needle type of the following m/c

NEEDLE TYPE USED FOR FOLLOWING M/C-

1)single needle lockstitch-DB*1,DP*5

2)five thread needle flat lock m/c-4*128

3)button holing m/c- 501/180 7D

4)button attaching m/c- DPX5 11-14#

5)Batek m/c- DPX5 11#-14#

6)eyelet m/c-

7)blindstitch m/c-LW*6T

8)four thread overlock m/c-DC*1,DC*27

9)five thread overlock m/c-

10)feed of the arm m/c-TV*1,TV*5

11)single needle chain stitch m/c-

12)edge cutter chain stitch m/c-

13)double needle lockstitch m/c-DB*1,DP*5

14)kansai special belt attaching m/c-

15) kansai special placket attaching m/c-44113G5

16) kansai special elastic attaching m/c-

17)pocket facing attaching m/c-

18)belt loop attaching m/c-

15. why do we use spiral groove needles?

ans. Lockstitch needles are usually made without a short groove. the function where such a groove is provided is much the same as that of long groove, that is to provide protection for the needle-thread as it passes through the fabric.

But in case of dense or resistant materials being stitched it is sometimes advisable to use a needle in which the grooveis longer than usual and is extended spirally downward to the point so that the needle-thread will not be chafed as it is drawn through the eye whilst the is still passing through the material on the upward stroke of needle.These needles are called as Spiral Groove Needles.

16. DEVELPMENTS IN NEEDLES

1. SELF-THREADING NEEDLESHandicap or Self-Threading Needles are needles that have an ever-so-slight slit in the side of the needle at the eye of the needle. Sliding the thread against the side of the needle, allows the thread to slide into the eye of the needle.Self-threading needles are not available in all types of points and are only available in sizes 80/12 and 90/14

2. TWIN AND TRIPLE NEEDLES

Twin and triple needles are attached to a single shank by way of a crossbar. These needles are perfect for evenly spaced rows of stitching.To use these needles your machine should have zigzag capability and a throat plate that has a hole wide enough for the needle. You can NOT zigzag with the multiple needle in the machine. More than one thread spool holder is required so that each needle has its own thread source. The threads usually follow the original threading pattern, as one thread and then are threaded into each needle. Your sewing machine manual is the best resource for operating your sewing machine with multiple sewing machine needles.

The numbers on the packages for these needles is slightly different than regular sewing machine needles. The first number is the space or distance between the needles. The second number is the needle size.

Triple needles are labeled Drilling Needles

3. STRETCH NEEDLES

A stretch needle is the last-resort needle when ballpoint needles still leave skipped stitches. Many people will not attempt sewing Lycra and swimwear without a stretch needle.

Sizes Available: 11/75 and 90/14

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