Description
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.
