Acrylic fabric is made from a synthetic polymer called polyacrylonitrile, which is derived from petroleum-based chemicals. To be classified as acrylic, the fiber must contain at least 85% acrylonitrile by weight, a compound synthesized from natural gas, oxygen, and nitrogen. The remaining 15% or less consists of other chemicals added to make the fiber easier to dye and process into textiles.
The Chemistry Behind Acrylic Fiber
Acrylonitrile is the building block of acrylic fabric. It’s a small molecule that, through a process called polymerization, links together into long chains to form polyacrylonitrile. This polymer on its own is difficult to work with, so manufacturers blend in a secondary ingredient called a comonomer, typically vinyl acetate or methyl acrylate. These comonomers make up that remaining percentage (up to 15%) and serve a practical purpose: they allow the fiber to absorb dyes evenly and behave better during textile manufacturing.
A related fiber called modacrylic contains between 35% and 85% acrylonitrile. Modacrylic is naturally flame-resistant and shows up in products like faux fur and protective clothing, but it’s a distinct category from standard acrylic.
How Acrylic Fiber Is Manufactured
Once the polyacrylonitrile polymer is created, it needs to be dissolved in a solvent and then reformed into solid fibers. This happens through one of two spinning methods.
In wet spinning, the dissolved polymer is pushed through a device with tiny holes (called a spinneret) directly into a chemical bath. The bath contains a liquid that mixes easily with the solvent but causes the polymer to solidify on contact, forming thin filaments. Think of it like squeezing a syringe of material into a liquid that instantly hardens it into threads.
In dry spinning, the polymer solution is extruded into a heated tower instead. Hot air or gas passes through the tower, evaporating the solvent and leaving behind solid fibers. The evaporated solvent is captured, condensed, and recycled. Before either method begins, the solution is filtered multiple times to remove impurities that could create weak spots or defects in the finished thread.
DuPont developed the first method for spinning acrylic polymer in 1941. By 1950, the company was marketing acrylic fibers under the trade name Orlon, and the material quickly gained popularity as a lightweight alternative to wool.
How Acrylic Compares to Wool
Acrylic was designed to mimic wool’s warmth and softness, and research shows it largely succeeds on the warmth front. Testing at Oregon State University found no significant difference in heat retention between acrylic and wool blankets of the same thickness. The insulating power of a fabric depends primarily on its thickness and how well it holds that thickness over time, not the fiber itself. In other words, a thick acrylic sweater keeps you just as warm as a thick wool one.
Where the two fibers diverge is moisture. Acrylic absorbs very little water, while wool can absorb a significant amount and release it gradually, generating a small amount of heat as it does so. For people who perspire heavily at night or during activity, this low absorbency can make acrylic feel clammy. Wool breathes better in humid conditions.
Acrylic wins on practical convenience. It’s lighter than wool, machine washable and dryable, resistant to moths and mildew, and won’t trigger wool allergies. It also costs significantly less, which is why it dominates the budget end of the knitwear market.
Where Acrylic Fabric Is Used
Acrylic shows up in a wide range of products: sweaters, hats, scarves, socks, blankets, carpets, hand-knitting yarn, craft yarn, stuffed toys, and home furnishings. It’s especially dominant in outdoor textiles. Acrylic accounts for more than 90% of the awning and outdoor furnishing market because it resists UV degradation, mildew, and moisture better than most alternatives. You’ll also find it in upholstery, car soft-tops, and industrial applications like carbon fiber precursors.
Heat Sensitivity and Care
Acrylic’s biggest practical weakness is heat. The fiber can melt or permanently deform at relatively low temperatures, which means you should never iron it on a high setting. If ironing is necessary, use the lowest heat setting with no steam. The same sensitivity applies to dryers: high heat can cause acrylic garments to lose their shape or develop a stiff, shiny surface. Low or medium dryer heat, or air drying, keeps acrylic clothing in better condition over time.
Microplastic Shedding
Because acrylic is a plastic-based fiber, it releases tiny fragments called microfibers every time it’s washed. These fibers are too small to be caught by most washing machine filters and eventually reach waterways. Synthetic fibers like polyester, acrylic, and nylon now represent about 60% of worldwide textile fiber consumption, making laundry a meaningful source of microplastic pollution.
Several factors influence how many microfibers break loose. Using detergent nearly triples the amount released compared to washing without it (about 162 mg per kilogram of fabric versus 60 mg). Warmer water increases shedding by roughly 1.8 times compared to cold water. Longer wash and dry cycles also generate more fibers, with 60-minute cycles releasing about twice as many microfibers as 30-minute cycles. The good news is that shedding decreases substantially over a garment’s life. By the seventh wash, microfiber release drops by about 45% compared to the first wash, and drying releases 67% less. Washing acrylic in cold water on a short cycle is the simplest way to reduce its environmental footprint.
Safety of Finished Acrylic Fabric
Acrylonitrile in its raw, liquid, or vapor form is a hazardous chemical. It’s a known irritant and has been linked to cancer in both animal studies and occupational exposure research. Workplace exposure is tightly regulated, with air concentration limits set at 2 parts per million over an 8-hour day.
For consumers, the risk profile is very different. By the time acrylic fiber has been polymerized, spun, washed, and finished into fabric, the free acrylonitrile has been chemically locked into the polymer chain or removed during processing. Wearing an acrylic sweater is not comparable to handling raw acrylonitrile. The occupational hazards apply to factory workers involved in fiber production, not to people wearing the finished product.