My guess is ‘not often enough’, says ETC Supplies’ managing director, Jas Purba. Find out just how often you should be changing your hardworking embroidery needles.
The embroidery needle is probably the single hardest working part of your embroidery machine. It is responsible for creating the perfect stitch, but can also be the single most troublesome item on your machine.
Before we get into the subject of how often you change your needle, let’s consider what your needle does.
Job of the needle
The needle is responsible for transporting your top embroidery thread through the fabric, creating a loop and returning back to the top.
To carry out this task, the needle should be able to feed the embroidery thread at perfect tension. The last point at which the top thread is released to the needle is by the take up lever, where the thread tension is controlled by the last tension spring discs.
The job of the take up lever is to feed the needle with the thread tension that has already been set, so when the lever is at the top position the thread is under a controlled tension and when the lever is at the bottom, enough top thread is released to form a loop for the under thread to catch it.
The take up lever has three jobs:
- Draws the needle thread from spool.
- Releases the required thread length for the stitch formation.
- Tightens the stitch.
The next step is to learn how the needle works
The embroidery thread is fed through the needle along the groove. The thread then goes through the eye of the needle ready to be inserted into the fabric.
But just wait a minute
In my opinion we have just missed out the other hard working parts of the needle that most people over look, and that is the following.
The shape and size of the loop is influenced by the type of embroidery thread used and by the rise of the needle from LDC to the point where the hook is picking up the loop from the needle.
The scarf is a trough‑shaped recess in the needle blade, which permits the unobstructed movement of the looper and the reliable uptake of the loop even in case of poor loop formation. Of course a perfect machine setting is the prerequisite for a safe loop pick up. The hook tip should be set approx. 0.1mm from bottom of the scarf.
From my experience you can change the thread and using the same needle without problems, as long as the thread size fits to the eye size of the needle. The thread should run freely through the needle eye. In case the thread does not fit to the needle eye, the loop formation will be affected and thread fraying and thread breakages might occur. The eye surface should be smooth as thread runs through the needle eye.
High quality needles such as Schmetz and Groz-Beckert have highly engineered needle scarfs. During the manufacturing process these scarfs are chemically polished to provide the smoothest running service for the thread.
Often people think it is the point of the embroidery needle that causes problems and is subjected to maximum wear and tear. But, just remember, all that the point of the needle is doing is to separate the yarn to allow the needle smooth passage through the fabric. Yes, the point will wear out over time and a damaged or worn out point can damage the fabric to be embroidered.
Normally point damage happens when the needle hits machine parts like the throat plate. This can happen for example when stitching caps with a hard surface or the middle seam. The needle can be deflected during stitching by the hard seam in the middle of the cap and hitting machine parts. A wear out of the point only by the textile fabric is happening very rarely. Only in cases where very hard materials are being embroidered.
The shape and length of the scarf is almost similar, regardless of brand. The scarf of the needle normally does not wear out, except when the machine is not correctly adjusted and the hook point is touching the bottom of the scarf. In this case the scarf does show wear marks, caused by the hook point itself. Of course this contact can also damage the tip of the hook and this is more critical as a damaged hook point can create stitching problems like skip stitching or thread fraying.
So it is critical that the thread tension is set to a perfect level that the needle is not being pulled back by over high tension.
During sewing it might happen that the needle is slightly deflected and bend. But the hardening process of the needle allows a certain flexibility of the needle, so that the needle always goes back to its original position.
The type of thread you use will also have an impact on how your needle wears out. Polyester threads are stronger and these will insert more pressure on the eye before breaking. Rayon/ viscose threads are softer and these will break due to any problems with your embroidery needle.
So the above information will provide you with some guidance as to what to look out for and help you decide when to change a needle.
I understand that not everyone can do this and that it takes time for your staff to learn the above principles of thread tensions and needle wear issues. So now let’s look at this subject from a different angle. Probably, the cheapest and easiest part to change on your embroidery machine is your needle.
You can decide on the following options for needle change:
- A set number of machine hours.
- A set number of stitch counts.
- Changes for different fabrics.
- Changes for different shifts.
- Just wait for problems to occur with your embroidery before changing the needle.
I think most people work on the last option, which is crazy considering the cost of the damaged garment to the cost of an embroidery needle.
So in my opinion, Please change your embroidery needles more often for better trouble free embroidery.
*With thanks to Fred Schneider of Groz-Beckert KG for his technical support