Acrylic fabric starts as a petroleum-derived chemical called acrylonitrile, which is polymerized into long molecular chains, dissolved in a solvent, and then forced through tiny holes to form fibers. Those fibers are stretched, crimped, and cut to mimic the look and feel of wool. The entire process transforms a liquid chemical into the soft, lightweight material found in sweaters, blankets, and craft yarn.
From Petroleum to Polymer
Acrylonitrile, a colorless liquid produced from petroleum or natural gas, is the core building block of acrylic fiber. To become a usable textile material, acrylonitrile molecules must be linked together into extremely long chains through a process called polymerization. A chemical initiator triggers the reaction, causing individual molecules to bond end-to-end into a polymer known as polyacrylonitrile, or PAN.
Most commercial acrylic fibers aren’t pure PAN. Manufacturers blend in a small percentage of a second monomer (typically 5 to 15 percent) to improve the fiber’s ability to absorb dye and to make it softer. These added molecules introduce tiny negatively charged sites along the polymer chain, which become critical later in the dyeing stage. If the fiber contained only pure polyacrylonitrile, it would be extremely difficult to color.
Dissolving the Polymer Into a Spinnable Solution
Polyacrylonitrile doesn’t melt cleanly the way polyester does, so it can’t simply be heated and extruded. Instead, the solid polymer is dissolved in a powerful solvent to create a thick, syrupy liquid called a “dope.” Common solvents include dimethylformamide (DMF), dimethylacetamide (DMAc), and dimethylsulfoxide (DMSO). Some manufacturers use salt-based solutions like sodium thiocyanate. The choice of solvent matters because it affects fiber quality and determines which spinning method the factory will use.
Spinning: Turning Liquid Into Fiber
The dissolved polymer is pushed through a spinneret, a metal plate perforated with thousands of tiny holes, to form continuous strands. There are two main ways to solidify those strands into fiber, and each produces a slightly different product.
Wet Spinning
In wet spinning, the polymer solution exits the spinneret directly into a chemical bath (usually water mixed with a coagulating agent). As the solvent diffuses out of each strand and into the bath, the polymer solidifies into a fiber. This method was patented by DuPont in 1946, and their resulting fiber was sold under the brand name Orlon. Wet-spun acrylic fibers have a cross-section shaped like a bean, which contributes to a softer hand feel. Wet spinning can use either organic solvents or salt-based solutions, giving manufacturers more flexibility.
Dry Spinning
Shortly after DuPont’s patent, the German company Bayer developed dry spinning for their brand Dralon. In this process, the polymer solution is extruded into a heated tower where hot air evaporates the solvent, leaving behind solid fibers. Only organic solvents work for dry spinning, with DMF and DMAc being the two options. DMAc is generally preferred because it has a higher flash point, making it safer to handle. Dry-spun fibers have a distinctive bone-shaped cross-section and tend to produce a slightly different texture than wet-spun fibers.
Stretching, Crimping, and Cutting
Fresh-spun acrylic fibers are weak and lack the soft, wool-like character that makes the finished fabric appealing. A series of mechanical steps transforms them.
First, the fibers are washed to remove residual solvent. Then they’re drawn (stretched) to four to ten times their original length. This stretching aligns the polymer chains along the fiber’s axis, dramatically improving tensile strength and elasticity. The drawn fibers are then crimped, a process that introduces tiny zigzag bends along each strand. Crimping is what gives acrylic its characteristic loft and wooly texture, trapping air between fibers for warmth and softness.
Finally, the continuous strands (collected as a thick rope called “tow”) are cut into short staple lengths suitable for spinning into yarn on standard textile machinery. When the cut fibers are heated under tension, cooled, and later immersed in hot water after being spun into yarn, they develop additional bulk that closely resembles woolen yarn. This “heat-setting” step is why acrylic sweaters can feel surprisingly similar to wool at a fraction of the cost.
How Acrylic Gets Its Color
Acrylic fibers are dyed using a class of colorants called basic (cationic) dyes. These dyes dissolve in water and release positively charged color molecules. Remember those negatively charged sites introduced during polymerization? The positively charged dye molecules are attracted to those sites and lock on through ionic bonds, forming a strong, wash-resistant connection.
This ionic bonding mechanism is why acrylic fabrics are known for exceptionally vivid, brilliant colors with high color strength. It’s also why pure polyacrylonitrile without those added comonomers would be nearly impossible to dye. The comonomers essentially create “parking spots” for dye molecules along the fiber.
Global Production Scale
Acrylic fiber production has been gradually declining. Global output was about 1.78 million tonnes in 2019 and dropped to roughly 1.6 million tonnes by 2023, representing just 1.3 percent of the total global fiber market. That makes acrylic a niche player compared to polyester, which dominates synthetic textiles. Most acrylic production is concentrated in Asia, and the fiber remains popular for knitwear, outdoor fabrics, and industrial applications like carbon fiber precursor material.
Environmental Concerns: Microplastic Shedding
Like all synthetic textiles, acrylic sheds tiny plastic fibers during use, washing, and drying. What sets acrylic apart is the volume: research published in the journal Polymers found that acrylic released the most microplastics of the three major synthetic fabrics tested. Acrylic shed roughly 1,428 parts per million (combined washing and drying), compared to about 592 ppm for polyester and 199 ppm for nylon. Acrylic was particularly prone to shedding during tumble drying rather than washing.
These microplastic fibers are small enough to pass through wastewater filters and enter rivers and oceans. If you own acrylic garments, washing in a microfiber-catching bag and air drying instead of using a dryer can meaningfully reduce the number of fibers released. Cold water and gentle cycles also help, since less mechanical agitation means less fiber breakage.