AISHIN is a thermal sock yarn made from 50% cotton and 50% polyester. When the foot gives off water vapor, the cotton fibers absorb it and release a small amount of heat. As a result, the sock feels warmer soon after it goes on. Meanwhile, the polyester half keeps the yarn strong and helps the sock hold its shape wash after wash.
The standard count is 32/1. We can also supply other counts and dye custom shades, so the yarn fits your machine gauge, fabric weight and seasonal palette.
Why This Cotton Polyester Thermal Yarn Suits Winter Socks
Feet keep sweating in cold weather, even when the wearer does not notice it. Most of that moisture leaves the skin as vapor first. Cotton is made of cellulose, and its hydroxyl (-OH) groups bind this vapor. Each time they do, the fiber releases a little heat. That is where the warm feel of AISHIN comes from, so it does not rely on a surface coating.
Polyester behaves differently. It absorbs only about 0.4% moisture, compared with 8.5% for cotton. For that reason, it adds almost no heat of its own. Instead, it brings strength, shape retention and faster drying. This matters because liquid sweat cools a sock as it evaporates, so a sock that stays damp soon feels cold. The 50/50 split therefore keeps the heat effect of cotton without the slow drying of an all-cotton sock.
32/1 Ne standard (about Nm 54 or 166 denier); other counts on request
Heat source
Cotton (cellulose) fibers taking up water vapor
Moisture regain (reference values)
Cotton 8.5%; polyester 0.4%
End uses
Winter socks, thermal socks and warm knit accessories
From First Knitting Trial to Bulk Order
Most new sock styles go through three stages. Each stage answers a different question, so it pays to plan the checks before the first cones arrive.
During the trial, knit AISHIN on your own machine. Then check the handfeel, stitch definition and how the heel and sole look after washing.
In the pilot run, we confirm a shade standard with you while you lock the machine settings. A signed-off standard prevents most color disputes, so later lots knit and look the same.
For bulk orders, we keep lot and shade references on file. As a result, each reorder can be matched to the approved shade.
Wholesale Terms and Pricing
Final pricing for AISHIN cotton polyester thermal yarn depends on count, color depth, order volume and any custom work. To quote accurately, we need your target count, colors, kilograms per color, delivery port and incoterm.
If your winter launch date is fixed, tell us early. We can then check stock, color-matching time and shipping space while your schedule still has room. In addition, each order can ship with an inspection report, and other documents are available for the specification your buyer requires.
Packing and Shipping
Every carton or bag carries the count, color and lot number, so your warehouse can check it in quickly and trace it later. Samples travel by express, while bulk orders go by air or sea.
AISHIN Cotton Polyester Thermal Yarn FAQ
Does AISHIN keep a sock warm all day?
Not through heat generation alone. The cotton releases heat while it takes up vapor, but the effect stops once the fiber is saturated. After that, warmth depends on how much still air the sock traps. A terry cushion sole or a denser knit will therefore feel warmer than a thin single jersey. Telling your customers this up front also keeps their expectations realistic.
Will washing weaken the warm effect?
Washing does not remove it, because the heat comes from the cotton fiber itself rather than from a surface finish. Fabric softener is another matter. It coats the fibers and slows how fast they absorb vapor. So if warmth is a selling point, consider leaving softener off the care label.
How is AISHIN different from WARMPLUS-R?
Both are 32/1 heat-generating yarns, and both draw their warmth from cellulose. WARMPLUS-R blends 60% viscose with 40% acrylic, which gives it a smoother, softer hand. AISHIN pairs cotton with polyester instead, so the sock feels like a familiar cotton sock while the polyester adds strength. When your brief asks for a cotton sock that runs warmer, this cotton polyester thermal yarn is the closer match. For a silkier hand, compare it with our WARMPLUS-R viscose acrylic heat-generating yarn.
Can AISHIN be used in the heel and toe?
It can, although high-wear zones usually need nylon as well. Many mills reinforce the heel and toe with nylon because it resists abrasion better than any other common fiber. AISHIN then runs through the foot and leg, where the warm feel matters most. To pick the right count for your needle setup, see our guide on matching sock yarn count to machine gauge.
How can our lab measure the warm effect?
Labs normally use a humidity-change test such as ISO 16533. The lab conditions the fabric in dry air, then moves it into humid air. Meanwhile, a sensor records how far its temperature rises. Test a knitted sock fabric rather than loose yarn, since knit density changes the result. Tell us which method your buyer accepts, and we will tell you what test data we can supply for your lot.
Can socks made with AISHIN carry an odor-control claim?
Only when a test report supports it. We can share the antibacterial and deodorizing results available for your specification, and your packaging claim should match that report. If odor control is the main selling point, look at our AISHIN Wormwood Microcapsule Deodorant Yarn. It is built for that job on a similar 32/1 cotton polyester base.
