Flat seam (cover stitch): description, purpose. What is the difference between a stitcher and a carpet?

2024 Author: Sierra Becker | [email protected]. Last modified: 2024-02-26 03:46

One of the main seams used to grind and process knitted items is considered a flat, or, as it is also called, a cover stitch. It is characterized by an atypical weave of threads, due to which the line is elastic. It is able to withstand heavy tensile loads without tearing or deformation of the fabric. What are the other benefits of a flat stitch, what does it look like, and what kind of sewing machine is capable of making such stitches? You will learn about all this from the article.

Appearance

It is possible that even people who are very far from professional sewing have seen stitches laid right on top of the fabric. Outwardly, they are very similar to decorative finishes, but they have a more serious value and purpose. Most often they are found on sports and children's clothing. For those who don't know howsuch a finish of the fabric is called, we hasten to tell you that this is the notorious flat seam.

Visually, it resembles a zigzag stitch, but much more difficult to perform due to its edging with short straight stitches on both sides and a connecting middle seam. In machines that lay such a line, there is no familiar shuttle, it is replaced by lower loopers. When threads are fed during sewing, they form loops that are intertwined with each other like an elastic pigtail. In fact, a flat seam is a complicated version of overlock stitching. It can be laid not only along the edge of the product, but anywhere.

Special cover stitch sewing machines are equipped with two or three needles, they have the function of adjusting the width and length of the stitch, due to which there are several modifications of the flat seam.

Features

The most characteristic distinguishing feature of the described type of seam is precisely in its elasticity. A flat seam can be produced by different types of machines - cover stitches, coverlocks and overlocks. Each of them has its own advantages and disadvantages, which will be discussed later.

The cover stitch is also interesting because of how it lays on the fabric. To achieve optimal elasticity, the machine can tighten or stretch (depending on the settings) the feed material during each stitch after each needle step. In addition, these sewing machines also have a specific thread tension: unlike shuttle mechanisms, a cover stitch sewing machine makes stitches"relaxed". Yielding to tension in the finished product, the loops are stretched, but not torn, which ensures the integrity of the knitted fabric. The seams of two pieces to be sewn are edge to edge rather than overlapping flush.

Where use

The main purpose of machines with the function of issuing a flat seam is the processing and sewing of knitwear, primarily sportswear. Such products are made from special types of fabric, which are characterized by increased elasticity, contain stretch fibers, in addition, they are subjected to increased loads during use. Handling knitwear is never an easy task, but using a sewing machine makes it a lot easier.

Another important advantage of such a seam is the absence of an edge protruding above the surface of the fabric. This is an additional plus for sportswear and children's clothing, because the absence of reliefs minimizes injury and skin irritation.

Which fabrics can be sewn with a sewing machine?

As it became clear from the previous section, the main material on which you can make a flat seam on a coverlock or a sewing machine is knitwear. However, this definition includes a huge number of types of fabrics. Among them are not only the usual thin T-shirt knitwear, but also two-thread, interlock, cooler, velsoft, viscose, stretch satin, machine knitted fabrics and many others.

For stretch fabricsa flat seam is the main way to process products from them. It is suitable for overcasting (neck, pockets, sleeves and cuts) or seaming individual parts, sewing on elements, including decorative ones, such as elastic bands, appliqués and labels.

Finishing with this type of seam of other types of fabrics comes as a surprise to many. When purchasing a carpet, what it is, many do not always understand right away. However, its use is not limited to sewing knitwear. These sewing machines are programmed with a large number of stitches that can be excellent finishing stitches, useful for making quilting or patchwork. They are also useful for sewing on lace or elastic bands. Nevertheless, experienced seamstresses do not recommend stitching excessively dense and thick fabrics together - the seam will look rough on them.

Threads for cover stitch machines

The number of bobbins that can be installed is one of the most important distinguishing characteristics of sewing machines with loopers. The most common option is four or five thread machines, they are suitable for processing not only knitwear, but also any other types of fabrics.

Selection of threads for cover stitch machines is an extremely important aspect. This sewing material must be bought of proper quality, moreover, the simultaneous use of threads of different thicknesses or compositions is unacceptable. Otherwise, the seam will be defective. Most often, a flat seam on a coverlock or coverlet will have skipped stitches, but the settings in the machine may also fail, fix whichalmost impossible on its own. It is better not to experiment with the choice of threads and take all the bobbins from one batch - this will be an additional guarantee of the safety of the technique.

Equipment

The flat knitted seam can only be made using special sewing techniques. Initially, these were only industrial machines, but their simplified household counterparts have appeared relatively recently. It is noteworthy that on an industrial scale, flat stitch machines mainly perform only one function, namely, the issuance of a flat seam, as well as their smaller counterparts - household stitchers.

Similar in function, but more maneuverable overlocks and coverlocks are much more functional. It is worth noting that the more types of stitches a sewing machine can do, the higher its cost. A household stitcher and an inexpensive overlock can cost about 20-30 thousand rubles, while carpet locks are usually 8-10 thousand rubles more expensive. Next, we will talk about each type of sewing machine with a flat seam function in more detail.

Spreader

Under this name it is customary to mean typical cover stitch machines that do not perform any lines other than flat or chain stitch. It becomes clear that this is a technique of rather narrow specialization and it is used for stitching canvases together. It is not capable of overcasting edges or sewing like a conventional machine. Since, in principle, she does not have a shuttle, the lower looper performs its function, and it captures the thread from the bobbin. This type of machine is different from each other.the number of threads and needles. So, for models in which two needles are provided, three threads are used, and the width of the gap between the needles is 5.5 mm, in three-needle models - four threads and the distance between the outer needles is a maximum of 6.5 mm.

Distinguishing a sewing machine from other specialized equipment is quite simple - it has a fairly large sleeve overhang (as in ordinary household sewing machines). Due to the fact that this technique has few possibilities - 4 lines, few manufacturers make them. The most popular models are "Janome", "Minerva" and "Family" covers.

Overlock

This is a type of machine that is usually used for overcasting the cuts of products, however, there are models that include the function of flatness. Initially, overlocks go on sale with a special knife that cuts the fabric after overcasting it. When switching the equipment to the stitching mode, the knife must be removed. The working presser foot also changes, the pressure level of which can be adjusted depending on the thickness of the material being fed.

Before sewing, it is necessary to adjust the operation of the machine and adjust the thread tension manually. This is not an easy task and it is best to practice on a draft of the fabric first. A flat seam with an overlock is made along the fold of the material. After the stitch is completed, it must be unfolded, as a result of which the loose loops are pulled out, forming the required wide seam. A characteristic feature of the overlock is the absence of a sleeve overhang. It is believed that the overlock is a machine for overcasting inelastic fabrics, but this is not entirely correct. In modern models, a special differential rail is provided, which allows you to successfully work with knitwear.

Coverlock

One of the most expensive, but optionally diverse types of machines is the carpet. What it is, not everyone knows. These machines are equipped with a medium-sized overhang, and a trimming knife is also required. Additional accessories are completely dependent on the cost of the carpet, which can reach several tens of thousands of rubles. The most expensive machines are equipped with an electronic display and pre-configured factory programs that allow you to easily switch stitch modes.

Most of the models suggest the possibility of changing the number of working needles and threads, which greatly expands the capabilities of the coverlock. So, it can perform the function of an overlock, raspochivalka, make a chain stitch and many other decorative and finishing seams.

Household machines

The technique described above is from the category of household sewing machines. They are compact in size, light in weight and easy to use. The main advantage of most of them is the ease of adjustment, so that the seamstress can independently adjust the thread tension, the width and length of the stitches. Manual tuning allows you to fully use the machine and maximize its capabilities. However, standard seams are already adjusted at the factory.

Morecolor indicators of threads, automatic threading mode, convenient fabric feed conveyor.

Manual threading is not out of the question as the seamstress can use one, two or three needles as she pleases. Some models of machines on their surface contain a schematic memo instructing beginners in sewing. Such machines can be used at home. Among them there are models at budget prices, there are also options with stronger motors designed for professional activities (fashion houses or studios).

Industry

Unlike domestic machines, the industrial cover stitch machine is very difficult to maintain. It is overall and even more narrowly focused than household. The installation of such a stitcher requires a special table-stand, its setting involves debugging on numerous tuning units. In such machines, it is possible to install more needles (up to 8 pieces) and thread bobbins. Another difference is the presence of an upper expander. This device allows you to make the seam on the product the same from the wrong side and from the front side, which is especially useful for sewing underwear. In production, each individual unit is usually oriented to a specific batch of products.