Iranian machine-made carpets and rugs are woven from various materials. Now I'll discuss the distinction between 100% acrylic machine carpets and percentage carpets (which are a blend of acrylic and BCF) or between 100% BCF carpets and polyester carpets. Acrylic carpets are more durable and have a longer lifespan than BCF, percentage, and polyester carpets. These carpets can be maintained and utilized for over 300 years, but BCF and polyester carpets have a short lifespan. In a very short period of time, they will lose their softness. 
In terms of shortening (swelling), the change in acrylic carpets over time based on the length of usage or wear is negligible or negligible enough to be disregarded, but this issue is observable in other types of machine-made carpets. Thus, with time, the length or width of the carpet will become twisted or reduced. In terms of washing and exposure to light, we observe no changes in acrylic carpets, but this is the case with BCF, mixed, and polyester carpets, causing the carpet's effect and attractiveness to deteriorate rapidly. Acrylic carpets have a strong resistance to direct heat; therefore, one of the characteristics that distinguish acrylic carpets from other carpets is the heat test, which allows you to use a hot iron on the carpet without damaging it, whereas BCF and polyester fibers are susceptible to damage. Due to exposure to heat, the carpets become charred and scuffed, destroying them. Acrylic carpet is not affected by wear, but BCF and polyester undergo corrosion or deterioration over time. Acrylic carpets cannot be compared to % carpets, BCF carpets, or polyester carpets in terms of their enduring beauty. However, one of the downsides of acrylic carpets is that they are not quickly absorbed by nature, whereas BCF and polyester are gradually pulverized, dispersed in space, and absorbed by nature. According to Fiber Year magazine, the production of acrylic fibers increased by 9. 1% in 2013 compared to 2012, while the production of polyester fibers increased by 6.8%. The German company Dralon manufactures 170 tons of acrylic fibers annually, the finer forms of which are utilized for children's apparel, particularly dolls' attire. Despite the fact that certain individuals, particularly in virtual areas, have disseminated allegations that acrylic fibers are harmful, this is the case! In Europe, are children's clothing and toys that can be placed in the child's mouth even while play created with harmful fibers?! As a reminder, it should be stated that due to the initial fluffing of acrylic carpets, they may exacerbate allergy reactions in some individuals. 
Iranian rugs
This section will describe the three types of carpet threads used in Iranian machine-made carpets and rugs. And to conclude, we will examine the carpet that is both the most expensive and the best in terms of the quality of the materials used and the carpet's density: Various types of threads can be discovered in machine-made carpets. Each carpet consists of three distinct types of yarn: pile yarn, the warp yarn, and the weft yarn. 1-pile thread, which is also known as carpet thread This thread is used to weave color knots by wrapping it around the weft thread in the shape of a knot or a U, and it is available in a number of different variants, including the following:
- A) A thread made entirely of pure acrylic
- b) A yarn spun from a combination of acrylic and polypropylene fibers that is a blend of acrylic and polypropylene.
- C) 100% polypropylene (PP or B.C.F.)
- c) polyester or faux silk
2- warp yarn This yarn is spun from a cotton-polyester blend. The quality of the carpet's fibers, as well as the type of yarn used, are crucial elements in determining the carpet's durability and aesthetic appeal. In polypropylene and BCF carpets, however, warp yarn of the same type as pile yarn (BCF yarn) is utilized. This is the reason why these sorts of yarns are less expensive than the type of yarn used in acrylic carpets; thus, this type of yarn is utilized in acrylic carpets more frequently. 3- weft yarn The pile yarn, which can be made of acrylic, polypropylene (BCF), a blend of these two materials, or polyester, is ultimately the most essential aspect in defining the carpet's quality and durability. This holds true regardless of whether or not the carpet has a backing. The most expensive carpets According to the discussion, the carpet that is currently the most expensive is: The 1500 comb carpets are the most gorgeous machine-made carpets in Iran and the rest of the globe. In descending order of elegance are the 1200 comb carpets, 1000 comb carpets, 700 comb carpets, and 500 comb carpets. 
Carpets with a higher density, such as 1500 and 1200 comb, are more elegant, soft, flexible, and beautiful than carpets with a lower density, such as 700 and 500 comb; nevertheless, the diameter (height of pile thread) of carpets with a higher density is smaller than that of carpets with a lower density. In other words, carpets with 700 and 500 combs are more comfortable and significantly lighter than those with 1000 and 1200 combs. Another thing to consider about the most expensive machine-made carpets is that their prices often vary from brand to brand, and these differences are based on the quality level and product pricing guidelines.