One of the main seams used to grind and process parts of knitwear is considered to be a flat, or, as it is also called, a stitch seam. It is characterized by atypical weaving of threads, due to which the line is elastic. It is able to withstand large tensile loads without tearing and deformation of the fabric. What other advantages are distinguished by a flat seam, what is its appearance and what sewing machine is capable of doing 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 saw stitches laid directly on top of the fabric. Outwardly, they are very reminiscent of decorative finishes, but have a more serious value and purpose. Most often they are found on sportswear and children's clothing. For those who don’t know the name of this fabric finish, we are in a hurry to tell you that this is the notorious flat seam.
Visually, it resembles a zigzag stitch, but much more complicated in execution due to its framing into the hem from short straight stitches on both sides and connecting the middle seam. In cars, laying such a line, there is no familiar shuttle, it is replaced by lower loopers. When feeding threads during sewing, they form loops that are intertwined like an elastic pigtail. In fact, a flat seam is a complicated version of overlock overlocking. It can be laid not only along the edge of the product, but anywhere.
Special ploskoshovny 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. Different types of seams can be produced by flat seams - binder, carpet and overlocks. Each of them has its advantages and disadvantages, which will be discussed later.
The stitch seam is also interesting in how it rests on the fabric. In order to achieve optimum elasticity, the machine can tighten or stretch (depending on the settings) the feed material after each next needle step during the stitch process. In addition, the specific tension of these sewing machines is also the thread tension: unlike shuttle mechanisms, a flat-seam sewing machine makes stitches “relaxed”. Succumbing to tension in the finished product, the loops are stretched, but not torn, which ensures the integrity of the knitted fabric. The joints of the two parts being machined are positioned edge to edge, and are not flush with each other.
Where to use
The main purpose of machines with the function of issuing a flat seam is the processing and sewing of knitted products, especially sportswear. Such products are made from special types of fabric, which are characterized by increased elasticity, contain stretch fibers in the composition, in addition, it is subjected to increased loads during use. Processing knitwear is always a difficult task, but the use of openers at times makes it 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 models of sports and children's clothes, because the lack of relief minimizes injury and skin irritation.
What fabrics can be sewn with a stitching?
As it became clear from the previous section, the main material on which to make a flat seam on the carpet or sewing machine is knitwear. However, a huge number of types of tissues fall under this definition. Among them - not only the usual thin football jersey, but also two-thread, interlock, cooler, velsoft, viscose, stretch satin, machine knitted fabrics and many others.
For elastic fabrics, a flat seam is the main way of processing products from them. It is suitable for trimming edges (neck, pockets, sleeves and sections) or sewing together individual parts, sewing on elements, including decorative ones, such as elastic, appliqués and labels.
Finishing with this type of seam of the remaining types of fabrics for many comes as a surprise. When purchasing a carpet, what is it, many do not always understand right away. However, its use is not at all limited to sewing knitted clothes. In these sewing machines, a large number of stitches are programmed, which can be excellent finishing seams, and will be useful for making quilting or patchwork products. They are also useful for sewing on lace or elastic tape. Nevertheless, experienced seamstresses are not advised to grind excessively dense and thick fabrics together - the seam will look rough on them.
Threads for flat-seam machines
The number of installed bobbins is one of the most important distinguishing characteristics of sewing machines with loopers. The most common option is a machine for four or five threads, they are suitable for processing not only knitwear, but also any other types of fabrics.
The selection of threads for flat-seam machines is an extremely important aspect. This sewing material must be purchased of the proper quality, besides, the simultaneous use of threads of different thickness or composition is unacceptable. Otherwise, the seam will be defective. Most often, the flat seam on the carpet or the opener will be with skipped stitches, but there may also be a malfunction of the settings in the machine, which is almost impossible to fix on your 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 equipment.
Equipment
A flat knit stitch can only be made using special sewing equipment. Initially, these were only industrial machines, but their simplified household counterparts also appeared relatively recently. It is noteworthy that on an industrial scale, ploskoshovny machines primarily perform only one function, namely, the issuance of a flat seam, as well as their smaller counterparts - household binder.
Similar in function, but more maneuverable overlocks and carpetlocks are much more functional. It is worth noting that the more types of lines a sewing machine can do, the higher its cost. A household locker and an inexpensive overlock can cost about 20-30 thousand rubles, while carpet covers are usually more expensive by 8-10 thousand rubles. Next, we will talk about each type of sewing machine with a flat seam function in more detail.
Binder
Under this name, it is customary to mean typical ploskoshovny machines that do not sew any stitches except for flat or chain stitch. It becomes clear that this is a rather narrow specialization technique and it is used to grind paintings among themselves. It is not capable of sewing over edges or sewing like an ordinary machine. Since she basically does not have a shuttle, its function is performed by the lower looper, and it grabs the thread from the bobbin. Between themselves, this type of machine differs in the number of threads and needles. So, for models that have two needles, three threads are used, and the gap between the needles is 5.5 mm, in three-needle ones there are four threads and the distance between the outer needles is a maximum of 6.5 mm.
It’s quite simple to distinguish the flare lock from other specialized equipment - it has a sufficiently large reach of the sleeve (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 the “Janome”, “Minerva” and “Family” folders.
Overlock
This is the type of machine that is usually used to trim sections of products, but there are models that provide for the flatness function. Initially, orelooks go on sale with a special knife that cuts the fabric after trimming it. When switching equipment to the opener 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 feed material.
Before sewing, it is necessary to adjust the operation of the machine and adjust the thread tension in manual mode. This is not an easy task and it is better to first practice on a draft version of the fabric. A flat seam with an overlock is done by bending the material. After completing the stitching, it needs to be unrolled, as a result of which the free loops are stretched, forming the required wide seaming seam. A characteristic feature of an overlock is the absence of a sleeve overhang. It is believed that overlock is a machine for trimming 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.
Carpetlock
One of the most expensive, but optionally diverse types of machines is the carpet. What is this, not everyone knows. These machines are equipped with medium-sized shoulders, and a trimmer is also a must. Additional accessories are completely dependent on the cost of the carpet, which can reach several tens of thousands of rubles. The most expensive cars are equipped with an electronic display and pre-configured factory programs that allow you to easily switch the stitch modes.
Most models suggest the possibility of changing the number of working needles and threads, which greatly expands the capabilities of the carpet. So, it can perform the function of an overlock, openwork, make a chain stitch and many other decorative 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 simplicity of settings, due to which the seamstress can independently adjust the thread tension, width and length of stitches. Manual tuning allows you to fully use the machine and maximize its capabilities. In this case, standard seams are already adjusted at the factory.
The color indicators of threads, the automatic mode of dressing, and the convenient conveyor for feeding fabric simplify working with overlock, carpet and opener.
Manual threading is not excluded due to the fact that the seamstress can use one, two or three needles at her discretion. Some models of cars 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 options with more powerful motors designed for professional activities (fashion houses or ateliers).
Industry
Unlike household units, an industrial surface machine is very difficult to maintain. It is dimensional and even more narrowly focused than household. Installation of such a flashing requires a special stand table, its adjustment involves debugging on numerous tuning nodes. In such machines it is possible to install more needles (up to 8 pieces) and thread bobbins. Another of its differences is the presence of the upper expander. This device allows you to make the seam on the product the same with the wrong side and the front side, which is especially useful for sewing underwear. In production, usually each individual unit is oriented to a specific batch of products.