A carding engine feeds raw fiber against a large wire-toothed cylinder 500-600 mm across, where worker and stripper rollers comb it apart, align it into a thin web and condense it into a sliver. Carded sliver gives a softer, fuzzier yarn that suits weft, so yarn meant as warp needs more twist, combed or longer fiber, or a size. The engine also makes dust and lint that burn and damage lungs, so it needs its own ventilated room.
Part of Spinning Frame
Aligning and cleaning fiber on a clothed cylinder to produce the sliver that the roving frame draws out.
A Card Aligns Fiber But Does Not Make It Warp-Strong
The overview describes the engine: a large cylinder of 500-600 mm diameter covered with card cloth (leather with wire teeth bent at 45°), smaller worker and stripper rollers around it, fiber fed in on one side and combed as it passes, a thin web coming off, and the web condensed into a soft untwisted rope called a sliver. The hand version, with two paddle-shaped cards, is in Fiber Preparation.
Carding aligns fibers roughly but leaves many crossing and short ones. That article states the consequence: combed fiber gives a harder, smoother, stronger yarn that suits warp, and carded fiber gives a softer, loftier yarn better for weft and knitting. A card-only frame, as the overview describes, will therefore spin a fuzzier, weaker yarn than a combed one. For warp that gap is closed in three ways: more twist within the warp range (see Twisting), selecting longer fiber for warp, and a size applied when the warp is beamed (Warp Beam). The article on fiber preparation also warns that too much carding breaks fiber length, so more passes are not always better.
What You Need
- Card cloth. The overview gives leather strips with 0.8 mm steel wire teeth, 5-8 teeth per cm. This is the part that is hardest to replace; every tooth is set by hand unless salvaged cloth is available. A hand-card grade scale is given in the fiber article: 72-90 teeth per square inch for coarse fibers and 108-120 or more for fine wool.
- A cylinder, workers and strippers on shafts that turn freely in good bearings (Bearings and Bushings).
- A feed table, a doffer to take the web off and a way to condense it into a sliver.
- A separate room, because of the dust.
Method: Carding A Batch
Step 1: Clean and open the fiber first. Pick out seeds, burrs and grit by hand; foreign matter dulls the wire.
Step 2: Feed a thin, even layer. The sliver is only as even as the feed. Overloading tears fiber and leaves lumps.
Step 3: Take off the web and draw it through a trumpet or between rollers into a sliver of even weight.
Step 4: Check the sliver by weighing a metre; the roving frame will draft it down by the ratio in the overview, which assumes an even starting weight.
Worked Example
The overview’s cylinder, 500-600 mm in diameter, has a circumference of π × 0.5 = 1.57 m to π × 0.6 = 1.88 m. If the cloth is 1 m wide (an assumed width) it covers 1.57 to 1.88 m², which is 15,700 to 18,800 cm². The overview gives 5-8 teeth per cm; if that applies in both directions (the overview does not say), the cloth carries 25 to 64 teeth per cm², so about 390,000 to 1.2 million teeth. Setting that by hand is the reason the overview calls card cloth painstaking. The overview does not give rows; its figure cannot be converted to teeth per square inch to compare with the hand-card grades without measuring a real cloth.
Common Mistakes
- Letting the wire go blunt or bent. Dull teeth tear fiber and leave neps.
- Running the cylinder faster than the feed supports, which beats the fiber instead of combing it.
- Skipping the cleaning, which dulls the clothing and leaves seeds in the yarn.
Safety
The cylinder keeps turning after the drive is off, and its dust burns
The nip between the cylinder and the workers pulls in fingers faster than anyone can react, and a heavy cylinder coasts for a long time after the drive is shifted off. Measure the coast-down on your own engine with a stopwatch, post the figure, and never open a guard until the cylinder has halted. Card wire cuts. Carding fills the air with lint and fine dust that is a respiratory hazard and burns readily; Dust and Respiratory Protection covers coal and rock dust, not cotton, but its measures of ventilating, wetting and limiting shifts transfer. Keep lamps and forges out of the carding room, sweep lint daily, and keep water at hand. Adult work only (Task Assignment by Age).
What’s Next
- Learn next: Roving Frame — drawing the sliver out and giving it just enough twist to handle
- Combine with: Roller Spacing and Gauging — fiber length again sets the roller gauge