Creasing is a permanent or semi-permanent fold line that forms while the fabric is wet, hot and under load. In rope-form dyeing, the fabric is continuously lifted, carried by liquor flow and then stacked again in the drum. Three conditions are behind most creasing problems:
Velvet, suede-like and plush fabrics are more sensitive than flat knits because their value lies in the surface. Pile is easily flattened, bent or pushed in the wrong direction by pressure and friction. A crease that would be almost invisible on a plain jersey can show up as a bright or dark line on velvet, because pile leans differently in the damaged area and reflects light differently.
Beyond appearance, creases affect pile direction, surface texture, hand feel and, in the end, the grade of the finished goods. Many creases cannot be completely removed in finishing, so prevention in the dyehouse is far cheaper than correction afterward.
Not all soft fabrics behave in the same way:
Pile height, fabric thickness, elasticity and fiber composition all influence crease sensitivity. Thick fabrics hold heat and moisture longer. Low-elasticity fabrics do not recover easily from folding. Blends containing spandex, such as nylon/spandex or polyester/spandex, relax and shrink in hot liquor, which changes how the rope sits in the drum.
Overloading is the most common cause of avoidable creasing. When the batch is too heavy for the drum, the rope cannot move freely, dwell time in the stack increases and compression marks appear. Uneven movement is just as harmful: if one section of the rope travels slower, it spends more cycles in the same fold. For delicate fabrics, stable circulation means each part of the rope is lifted, relaxed and re-stacked at a regular rhythm.
Synthetic fibers become more plastic near and above their glass transition range, so folds that form during heating can be set into the fabric. A temperature rise that is too fast, a long hold at the maximum temperature or a sudden cool-down can all reduce dimensional stability and damage the surface. The right profile depends on fiber type, the dye class and the required shade depth, so it should always be confirmed by trials rather than copied from another fabric.
Match the batch weight and fabric length to the machine's recommended operating capacity. For the Yadong MD range, the capacity is listed per model (for example 150–300 kg for MD-1(2)-300), together with the matching liquor volume. Staying inside this range keeps enough free space for the rope to move. Avoid squeezing in extra meters just to finish a lot in one batch.
Select a circulation speed and nozzle condition that suits the fabric: lightweight plush needs gentle transport, while heavier velvet needs enough flow to keep the rope moving without dragging. Check for tangling before heating, feed the rope evenly and watch for localized accumulation in the drum. If the fabric stops traveling at one point, stop and correct it before temperature rises.
Optimize the temperature rise, holding time and cooling procedure for the recipe. The aim is to balance three things: dye penetration, color uniformity and fabric protection. Pushing for speed can create shade variation or creases, while an over-long cycle increases mechanical exposure. A proportional heating and cooling device, which is available as an option on the MD machine, helps make these steps repeatable.
When evaluating a Velvet Dyeing Machine, look at drum geometry, fabric guidance, circulation performance and operating flexibility. Equipment that lets the fabric relax quickly after the lifting stage and does not hold it under a heavy stack will usually reduce compression. For a wider range of machine types, see the Yadong product center.
The Ultra-low Liquor Flow Dyeing Machine, Model MD from Zhejiang Yadong Machinery Co., Ltd is built for dyeing, untwisting, preshrinking and reduction under ultra-low liquor ratio conditions. Its features are described on the product page and are summarized below.
The MD uses a special stepped main-drum structure. After passing the tail, the fabric quickly enters the main drum, where it piles up and creeps forward. According to the manufacturer, this is intended to solve creases caused by long periods of extrusion, to improve the running effect on surfaces that are prone to quality change, and to let the machine run smoothly at high speed with two-strand input. For pile fabrics, the practical value is less time under compression and more controlled mechanical contact.
The machine also has a large-diameter single-drum, double-groove design. It is suited to cloth types with a limited length per piece and improves single-machine utilization. Each fabric groove has an independent guide wheel, so the lifting process does not interfere between the two grooves.
The circulation system moves the rope and keeps liquor flowing through the fabric. The MD combines large-flow nozzles, which help leveling, with a high-head main pump for stable operation. The pump rating rises with the model (30 HP on MD-1(2)-300 up to 75 HP on MD-2(4)-800), and fabric speed is listed as 150–600 m/min. Higher flow is not always better: for super-soft pile, the circulation setting should be matched to the fabric weight and structure, and verified on the actual cloth.
The product page lists suitable fabrics including nylon/spandex, cotton/spandex, polyester/spandex, T/C, T/R, suede velvet and super-soft velvet. Whether a specific fabric runs well still depends on machine configuration and process requirements, which is why a fabric trial is recommended before committing to bulk production.
| Model | MD-1(2)-300 | MD-1(2)-400 | MD-2(4)-600 | MD-2(4)-800 |
|---|---|---|---|---|
| Max. temperature | 140 °C | 140 °C | 140 °C | 140 °C |
| Max. pressure | 4 kg/cm² | 4 kg/cm² | 4 kg/cm² | 4 kg/cm² |
| Liquor (L) | 1200–1800 | 1600–2400 | 2400–3600 | 3200–4800 |
| Capacity (kg) | 150–300 | 200–400 | 300–600 | 400–800 |
| Main pump | 30 HP | 40 HP | 60 HP | 75 HP |
| Fabric speed | 150–600 m/min | |||
Optional systems include a water/steam flowmeter, proportional heating and cooling, proportional dosing, meter-length measuring, a pH control system and a high-temperature washing system. If you also run darker polyester lots or other high-temperature work, compare with the high temperature and high pressure liquid flow dyeing machine, the Model MK and the ultra-low liquor ratio series.
Need help with a specific process problem? The technical support page and the Q&A section are good places to start.
You can learn more about the manufacturer's capabilities on the production equipment section, and read about environmental efforts on the sustainability page. For more articles, visit Yadong News.
Looking for a Velvet Dyeing Machine for your fabrics?
Send your fabric type, width, weight and batch size through our inquiry form, or call 0086-573-87096337. Email: gsj@yadong.com.cn. Address: No. 375, Xichuan Road, Haining City, Zhejiang, China.
