SCHMETZ needles of special geometry
Challenging sewing processes require the use of special needles. Conventional needles often do not correspond to the requirements, for instance in the processing of especially fine or elastic materials, when using thicker sewing threads or in multidirectional sewing.
- Processing of particularly fine or (extremely) elastic materials
- Use of thicker sewing threads even with sensitive materials
- Multidirectional sewing
- Processing of high and solid material layers with different number of layers
- Combination of materials
- Cross seams
- Use of elastic sewing threads
- Processing of very fine and extremely fine knitted and warp-knitted fabrics
For special uses, SCHMETZ offers a range of needles of special geometry: SERV 7 (increased needle stability and reliable seams), KN (slim needle against knitwear damage), SF (extra slim point and eye area for finest knitwear) and GO (large eye area for heavy sewing threads).
SCHMETZ SERV 7
Increased needle stability and reliable seams
Besides fabric damage, skip stitches are a problem that frequently arises when sewing elastic material. To prevent them, SCHMETZ developed the SERV 7 needle. This specially shaped needle is made for almost all needle systems, with all the main point shapes and in all current needle sizes.
The SERV 7 needle in comparison to standard needles:
The main distinguishing features of the SERV 7 design are the hump scarf that makes a particularly large loop of thread which can be more easily caught by the point of the hook and the blade reinforcement, that ensures the extraordinarily high stability of the needle. To produce the smallest possible stitch holes and optimise fabric displacement, the SERV 7 design thus often allows the use of a needle one size smaller without any reduction in the stability of the needle.
The illustration shows how the design of the SERV 7 forms a large loop of thread. The hump scarf extends the loop so that the hook or looper can catch it easily; this greatly reduces skip stitches.
In a standard needle, the loop is considerably smaller and is therefore not caught by the point of the hook or looper. A skip stitch occurs.
SERV 7 needles have a 15 % reinforcement, and as much as 20 % in some needle sizes. Therefore, the needle is especially stable and far less likely to “bend”. Neither the hook or looper nor other machine parts, e.g. the throat plate, are damaged.
Both needle designs were deflected with a force of one Newton (N). The SERV 7 needle was bent far less by this lateral force than the standard needle.
The special stability of the SERV 7 needle is particularly valuable for use with thick materials and multiple layers of fabric, such as in sewing cross seams in jeans manufacture. Other classic instances of deployment of SERV 7 needles are in production of interior upholstery for the car industry , but also for the processing of particularly fine materials. Due to their greater stability, thinner needles can be used for finer materials without difficulty and yet still have the requisite stability.
SCHMETZ KN
Slim needle against knitwear damage
SCHMETZ KN needles have a slim, continuous cylindrical blade without any reinforcement. Compared to a standard needle, the cross-section of the eye area is reduced and the shape from the eye area to the ball point is slim.
Advantages:
- Smaller stitch holes than with standard needles
- Minimises knitwear damage due to the slim shape
- Reduced penetration force in comparison to standard needles
Application:
- Very fine knitwear
- Reduction of seam puckering
SCHMETZ SF
Extra slim point and eye area for finest knitwear
Similar to the KN geometry, the blade of needles with SF geometry is slim and continuously cylindrical without any reinforcement. Apart from that, the SF geometry shows an extra slim shape from the eye area to the ball point.
Advantages:
- Smaller stitch holes than with standard needles
- Minimises knitwear damage due to the very slim shape
- Reduced penetration force in comparison to standard needles
Application:
Extremely fine knitwear, e.g. 40 to 42 gauge
SCHMETZ GO
Large eye area for heavy sewing threads
Usually, the needle size to be used is determined according to the sewing thread. However, sometimes it is necessary to sew with heavy sewing threads and it is not possible to match them to the corresponding needle size. For those cases, needles with GO design can help to avoid thread breakage and skip stitches and to achieve proper seams. The eye of GO needles is enlarged by 2 sizes in relation to the needle size, e.g. in a needle of size 70/10 the eye is of a needle size 90/14. Also the groove is enlarged.
Advantages:
- Thread guidance optimized by lowered friction, smooth passage of the sewing thread
- Minimization of damage to the sewing thread
- Reduced machine downtime
- Allows the use of thinner needles without changing the thread size
- Allows the use of a thicker sewing thread without changing the needle size
Application:
- Use of heavy threads or effect threads
- Decorative seams
- For achieving smaller stitch holes by using thinner needles, without getting thread problems
