Carpets are everywhere. In your home, office, some of the restaurant and cafes… Even when you walk down a busy street, your chance is high to see a shop that sells carpet. It takes that much bigger place in our lives, but the question that how carpet is made does not comes most of the people’s mind. Maybe you ask this question to yourself when your mind is confusing and you are questioning your life’s meaning while staring the carpet. Your answer is probably something like that: “They put the one side the cotton, polyester, acrylic or something like that and in a factory, machines do something and bum! The carpet is ready.”
I will make a quick start with the little information about the carpet’s history, then I will move to the most basic materials carpet is made. After I give you detailed information about the industrial process of carpet manufacturing, this subject will be more and more interesting with the titles of handmade carpets and knot techniques much more detailed information.
If you really do not believe the magic of machines in carpet factories, then let me explain in detail how carpet is made so far.
Starting from the Beginning!
Carpet covers the whole ground between the walls in a room and it is fixed to the room floor. These featuring make carpet different from the term that is more general than the carpet, rug. In the past, people used animal skins, woven reed mats, grass and later as materials for covering the floor. After people learn to use and process cotton and wool, woven mats take the place of other materials that used as coverings. It is also known that around 3000 B.C., the Egyptians sewed the pieces of woolen cloth which they tinge brightly onto flax and use them on the floors like carpet.
It can be said that nomads weaved the first carpets. They put the thick carpets they were woven over the sand floor of the tent dwellings. Also, it was easy to carry these carpets.
In time, in addition to an increasing number of material types that can be used and improving woven technique, weaving carpet itself becomes an art in a lot of countries in the world. The process was really hard and time-consuming, for the higher quality carpets knots per square cm is nearly 372.
In 1791, William Sprague built the first carpet factory that produces one carpet per day in the beginning. With improvements in technology until the day, the carpet factories produce a lot of carpets now.
After some trip on carpet history, let’s return to today and continue: How carpet is made?
The Most Basic Component: Fiber
When you start with something, it is good to start its base to understand it with its all detail and, you know, the base affects the all. For carpet, the base is fiber, the material carpet made of. More than ninety percent of the carpets made from the synthetic fiber, not natural but are produced in laboratories, the others are natural and mostly wool.
Most of the synthetic fibers made up one of these materials: nylon, polypropylene or polyester. They are produced from similar gases and chemicals. Let’s take a look in details to most commonly used synthetic fibers:
Nylon: It is the most preferred fiber from carpeting factories, 65% of all carpet is made from the nylon today. It shows the best performance amongst all fibers with a tighter molecular construction, that is why it preferred that mush. Even its cost is a little bit high, its resistance in the fade, heat, soil, crush, stain make its appearance remain unchanged and make it more useful in daily life, especially in high traffic areas.
Polypropylene: One of the most common synthetic fiber is polypropylene in carpet manufacturing, among all fibers used in the carpet industry, the percentage of the polypropylene is more than 20%. It is not as resistant as nylon, so its usage area is limited, mostly used in loop pile carpets and commercial installations (like offices) but it is fade and stain resistant.
Polyester: It ranks third in commonly used materials in carpet manufacturing. Its bulkiness, color clarity, and good stain and fade resistance are low compared to nylon, but it is thought that with new technologies it can show better performance.
Olefin: The next most commonly used fiber after nylon. It is strong, resistant against wear and permanent stains, and cleaning it easily. The color added during the process of fiber production, so it is colorfast. It resists also moisture and mildew, so it is used both indoors and outdoors.
Shag: It gives grass-like appearance but does not fit usage in stairs. Two features of shag carpets make different them from the other types of carpet and rug, the length and configuration of the carpet yarns used in the design. The yarn has longer sections, also, the fiber is twisted in a loose design, not in the design as short loop carpeting.
Acrylic: Its appearance and the feeling it gives us is similar to wool and its cost is low compared to low. It is resistant to moisture and mildew, so it is preferred to use for bath and scatter rugs.
The Natural Fibers
Wool: The majority of carpet manufacturing used synthetic fibers, but the other type, natural fibers are still used, and the most preferred natural fiber is wool. Because of its resistance to foot fall, it looks good for years. Carpets made from the wool are also resistant to combustion and, under normal conditions, it is anti-static. What is more is because wool is renewable and environment-friendly, maybe it is not as resistant as synthetic fibers, but people start to prefer wool carpets more.
Silk: Because it is so delicate, it is not too much used in carpets, but some of the finest hand-made rugs from the Middle East regions contain it.
Jute: Mostly used in traditional carpets to make their backings. Nowadays, because its depth of texture is perfect for rugs, it has gained popularity.
Coir: Its fibers are made from coconut husks, so it is a really strong and resistant natural fiber.
Sisal: It is one type of toughest fiber amongst the all natural fibers. If sisal used with wool, it can be softer and used for natural and colorful floors.
Seagrass: It is easy to find its raw material. When the fields flooded with seawater, the fiber is harvested, and it is transformed into waterproof yarn. It can be hard to dye this yarn, but it is easy to care for.
Industrial Three Steps Carpet Manufacturing Process
In the past, carpets weaved by the mothers of the houses or people which expert in weaving carpets. Today, of course, still there are people continuing this job, but compared to the past, the number of people expert in this field drastically decreases because of industrializing of carpet manufacturing. Producing carpet in the factory is faster, cheaper, time-saving and easier. Before how hand-made carpet is made, I will write about how the carpet manufacturing process in factories.
The First Step: Tufting
This step starts with weaving the fiber, synthetic or natural, into a primary backing material. This backing material, mostly made of woven polypropylene and the purpose of weaving fiber into backing material is to provide the base hold a cloth to prevent yarns from displacement during tufting.
The tufting machine is similar to a sewing machine, but its larger version. To push and pull yarn through the primary backing material, it contains from 800 to 2000 needles everywhere. The standard tufting machine is approximately 12 feet wide.
For Some Carpet Styles… There Can Be Extra Step!
The carpets we called a cut pile carpet, the looper then rocks back against a knife, where the small loops of yarn are cut. This happens after the first step, but as I mentioned, just some types of carpets. The distance between the primary backing and looper is equal to the length of cut pieces with a knife, these pieces also called pile height.
These cutting processes are controlled by a computer. When a computer is programmed not all the carpet, but only some of the loops to cut, this is called selectively cutting, this composes pattern on the carpet.
Second Stage: Dyeing the Carpet
Coloring the carpet can look the most unimportant stage for you, but for its attraction, as a decoration, its harmony with your furniture, it is really essential. There are several methods of course to dye carpets, but now I will explain the most commonly used 3 methods.
The yarn can dye both before and after tufting, but dyeing carpet after dyeing provides better control, options, and efficiency.
Boiling: To dye solid color carpeting, this is the most effective method. The end of the tufted carpets is stitched together and placed in a vat filled with heated water in which dye and chemicals are mixed for several hours.
Silkscreening: Another method for coloring the tufted carpet using different types of dye heads with spraying or printing. The process is similar to the way in T-shirts, but you can think its bigger version. This method is used for making multicolor, up to 8 different color, or patterned effects on the carpet.
After the carpet is dyed, to set colors, carpet is steamed, an extra dye is rinsed and dried.
New Technique: Solution Dyeing!
It is possible that you hear this term frequently when you look for a carpet, but what does it mean actually?
It is a method to dye synthetic carpet fiber, but a little different from traditional methods. In other methods, firstly the fiber is produced and then the color are added to these fibers, but in solution dyeing method, the color is added to fiber when it is in the beginning producing process and in the liquid state and it gives us colored fiber. Because it is added in the producing state of fibers, it is not applicable for the natural fibers because they already exist as a fiber.
Because it is added in initial processing, it becomes a part of fibers and fiber cells, it is more effective, resistant to fade and stain dyeing technique compared to other ways. It is useful for both indoor and outdoor carpets.
When it comes to its disadvantages, there is a limited color range compared to other fibers dyed with other techniques. Another disadvantage, carpet manufacturers do not have always all models of the solution dyed carpets. Because, in their perspective, it is easier and more convenient to dye carpet according to the customer’s desire, so they prefer to dye carpet not every time but when and how the customer wants.
The Third and Final Step: Finishing
The last step of the manufacturing carpet is just a single production line. In the finishing, latex coating is applied both primary and secondary backing (secondary backing mostly made from polypropylene material) of tufted and dyed carpets. These two parts put under the larger heated press and squeeze together to supply the backings stability.
Then, before carpets leaving from the factory, carpets are brushed, vacuumed, steamed and to remove all unsuitable tufts and make its surface smooth and uniform, run through a machine. And at last, before the carpet rolled, shipped, wrapped, it is strictly controlled if the all colors are separated consistently or is there other defects that can be created during manufacturing.
Manufacturing Carpet… Three Main Factors That Affects Carpet Durability
The weight of the fiber: The fiber gets heavier, it will be harder wearing the carpet.
The density of the Pile: It depends on the tightness of the yarn twist, so the higher density is better.
Stitches of the Yarn Per inch: More stitches improve the carpet’s crush resistance so the more, the better.
After the manufacturing process, before the carpet reaches shops and your homes or offices, the last thing is controlling its quality. Firstly, its tufts are controlled, people who work on the quality control department look if there are any missing tufts by shooting pile yarn everywhere holes are found with a single needle tufting gun. And then each part of the carpet is inspected. Besides shock potential, the height of the tufts and the pieces’ dimensions are also checked if they are proper or not.
One of the quality tests measure the flammability level of carpet. On a steel plate which has a 20-centimeter hole in its middle, an 8-centimeter square specimen is placed. In the center, a methenamine tablet is burned. If in seven out of eight trials, the charred part does not reach the circle of the hole, this means the carpet passes the test.
Another important test is applied to measure the carpet’s wear resistant. A sample of the carpet is put in a drum and hit for 20.000 to 50.000 revolutions with a steel ball which has rubber studs on it. The expectation from carpet is after all these hitting processes, it should look quite new. When you put yourself to carpet’s place, it sounds like crazy…
To test the carpet’s resistance to sunlight, there is another test. A sample of the carpet is taken and put under the light source that simulates sunlight. Then the needed exposure units are measured to produce visible color fading.
One of the significant tests is the mass per unit area of pile yarn because the density of pile shapes the feeling that carpet gives. Firstly, synthetic yarn is removed from the carpet. Then the yarn is put in the solvent to dissolve it, after this process, to take away this solvent, it is dried in an oven. When the drying process finishes, the carpet is weighed to check if its weight is specified for this type of carpet. For every type of the carpet, this process details change, that means, the solvent, chemicals, drying minutes or drying temperature can be different for each type of carpet.
The carpet weave on a specific counter that called carpet weaving loom. Its lower part is fixed to the ground and the upper part can move. It is made of thick poles. On the carpet weaving loom, the wool yarn stretched often because the carpet weaves on these stretched yarns which are also called as warp. These warps stretched to form two surfaces, one is in front and the other is back. Between these sides, there is a wand to release a gap between the yarns in the front and the back by pulling it up and down and it makes knotting easier.
Among all yarns in the weaving loom, the yarn that is placed parallelly at between yarns one warp wire the front and the other is back is called the weft. To provide passage of this yarn there is a scheme called weaving reed. This scheme helps to separate warp wires to the front or back when they are woven. Every time the knotting sequence is completed and the time when the weft is applied, the weaving reed is pushed back to push back the yarns. After knotting, the knotted line is compressed by pushing down.
The carpet weave either solid or with a flowered pattern. If the flowered pattern is woven, there should be an example divided into frames, paper on which the pattern weaved. As the carpet getting larger, because it is hard to weave, a lot of women lined up in front of the carpet weaving loom. Every woman assigns their areas and look the example, then take the suitable color yarns to their assigned areas and calculate how much and where they knot. When everyone finishes a line to knot, they push down to compress that line.
In the past, people used the natural colors to dye their carpets, but now, even in handmade carpets, synthetic colors are preferred. One of the features of good quality carpets is that it does not discard its color.
When the weaving carpet finishes, the experts in this field make readjustments on the surface of the carpet and they align the feathers of the carpet.
The expertise of weaving carpet depends on:
- The stitches have the same tightness
- The compression process should set according to the flexibility of the used wool yarn
- After the weaving finishes, the number of knots in the per centimeter square should be equal and this number depends on the thickness of the yarn used and the tightness of knots.
The carpet’s degree of quality depends on if its weaving frequent or loose and this is about the number of knotting each square centimeter. The more the number of knots, the higher quality carpet. Also, the size of the stature and the quality of the weft yarns have effects on the quality of the carpet.
There are 4 commonly known knot types used in carpet weaving. These knots not only different in terms of their names, but also, there are differences in patterns. Tying knots with hands is a really hard task to do. In eight hours working day, an average carpet weaver can exceed 8.000 knots easily. When the difficulty of the motif increases, only can be woven by a skillful weaver.
The carpet weavers have some tools to ease their work and they process the weft and knots together. These are a knife with a hook, a pair of scissors and a heavy comb, made of wood and metal.
Even the conditions can change, the knot density has a big influence on the carpet’s durability. In a thick nomad carpet handspun yarn is not close much, but in Isfahan or Nain carpets, it has to be close because of the features of the carpet and meets the expectations. After the weaving is finished, the carpet is removed from carpet weaving loom and then the pile is trimmed with scissors, fringes and the sides are made stable. When the all process is finished, the carpet is washed, polished, dried and if there is any fault, it is repaired.
Let’s take a look at how different they are from each other
Symmetrical knot: This type of knot also known as Gordian knot or Turkish knot because actually its origin is located in Turkey. In symmetrical knot, the loop is tied around the two warp wires and cut through them, so the knot tied both wires. It supplies strong consistency and mostly prefers to use on thick carpets. It is commonly used in Turkey, Caucasian area and western parts of Iran and also some European carpets.
Asymmetrical knot: It is also known as the Persian, Iranian knot or Senneh knot, it can be also called “farsibaff”. In asymmetrical knot, In the asymmetrical knot technique, the loop moves around only one warp wire and the other end of the loop is released. This technique is mostly used in Iran, India, Turkey, Egypt, and China.
If we compare these two knotting techniques:
- If the carpet woven with symmetrical knot began to fray, the weft and the warp of the carpet do not start to appear, so the carpet maintains its beauty and color for many years. But when it comes in a carpet woven with the asymmetrical knot, the warp threads of the carpet begin to appear because of the asymmetrical bond, since there is no loop in the knot when the carpet begin to wear and fall. It is possible that after some time, the node of the carpet will not be held and the color and the pattern in the old parts of the carpet will disappear permanently.
- When you pull the one end of the carpet woven with symmetric knots, the nodes cannot be removed but become tighter. But in the carpet woven asymmetric knots has a possibility to dissolve when it is pulled one side.
- Because tying Symmetrical knot is more difficult and time-consuming, if there is a two carpet one is woven with asymmetrical knots and the other woven with symmetrical knots, the one with symmetrical knots is more valuable and preferable than the other.
- Using an asymmetric knot, it is easier to weave carpets with higher knot density and more details compare to the symmetrical knot technique.
Jufti knot: In this type of knot, the knot is placed over not two warps but four. The weft can be put in one or more than one rows. Using this type is a faster way, the work finishes quickly compared to other types of knot techniques, but the carpet will lack the knot density. The carpets woven with this knot also tend to be less resistant and sometimes even they look shaggy and loose. It is easier, cheaper, but at the same time less resistant. It can be seen in Khorasan carpets from Iran.
Tibetan knot: It has a completely different structure compared to other knot types. The temporary rod which has the same length with the width of the carpet is put in front of the warp. The long yarn is first tied around two wraps, and then around the rod. When the weavers do rightly all knots in a row, to form the knots, the rod is removed.
Knot density is one of the most common ways to understand the quality of hand-made carpets. It is the number of the knots per inch, centimeter or meter. If we calculate density per inch,
1. Ithe number of knots < 80: poor quality carpet
2. If the number of knots between 120 to 330: medium quality carpet
3. If the number of knots > 330: very good quality carpet.
Let’s think you want to buy a carpet for your guest room because it is for the guest room, you want to buy a really good carpet. After you look a lot of shops, internet sites, magazines so everywhere, you find your carpet. What you see is there is two different prices for the same carpet. The origin, design, size, everything except costs the same for the two carpets. Why?
If all other features are the same, then that is because of the number of knot size. The carpets knot numbers for per centimeter is different, the carpet with more knots is more valuable so that means more expensive. But you know, the number of knots is directly associated with the quality of the carpet so that is normal.
Knot density is also related and have an effect on the width of the warp, the degree of thickness of the length of the pile and designs, motifs and patterns used. It is easy to weave detailed motifs if a weaver makes a low-density carpet, but in high-density carpets, it is hard. That is why simpler and rectilinear motifs preferred in high-density carpets.
After the Weaving Process: Polishing
Polishing the carpet requires stable work so it can be very hard to deal with for us. This process becomes pretty much easier with machines.
In the process of manufacturing, weaver cuts the yarn longer than it should be in the final for the polishing process. The carpet looks fuzzy and puffy right after it is woven so to give the carpet nice and clearer appearance and pattern, polishing is needed.
To do this process, there is a machine works in the same way as a beard trimmer. Before this machine is invented, the pile was cut with scissors and a comb and because even the little mistake can cause irreparable damage and ruin the weavers’ whole work, this process needs extreme attention in the past.
After polishing the carpet, the next step is to wash the carpet. The reason why the carpet is should wash is to take away the all dust remaining from previous steps and excess of the color of the carpet beside fixing colors of the carpet.
Firstly, the carpets layout abreast of each other and are rinsed with a huge amount of cold water. Because hot water can cause colors to run, the cold one is more convenient for this process.
After the cold water soaks all of the carpets, the water is removed from the carpets, sometimes with a rubber rake, sometimes using a machine for it. This is repeated many times to be sure the colors of the carpet do not run with detergent and water.
Almost Done: Drying
The last stage before the carpet takes its place on shops is drying. The carpet is let to dry under the sunlight because the natural colors are used in the manufacturing stage, these color’s best way to become stable is drying carpet under the sunlight. But the carpet has a risk to damage on its shape when drying under the sunlight, so the carpet’s all parts should be dried equally.