Worsted Yarn Manufacturing Process
A fine smooth yarn spun from combed long staple wool. Worsted yarns are more tightly twisted than the bulkier woolen yarns. The soft, heavy yarn is strong and durable and is often used for sweaters. Worsted yarns are also used for fine dress fabrics and suit materials.
Manufacturing process of the worsted woolen yarns consists of the following steps:
The first step is to get the wool fibers needed for the yarn manufacturing process i.e., sheep shearing. Sheep shearing is the process by which the woolen fleece of a sheep is cut off. Cut-off wool is called fleece. It is also called "grease wool" because of all the oil and lanolin in the wool.
Sheared wool is sorted according to different colors, quality, texture and type. They are sorted into different grades according to these parameters.
Wool taken directly from the sheep is called "raw" or "grease wool". It contains sand, dirt, grease and dried sweat (called suint). The weight of contaminants accounts for about 30 to 70 percent of the fleece's total weight. To remove these contaminants, the wool is scoured in a series of alkaline baths containing water, soap and soda ash or a similar alkali. Rollers in the scouring machines squeeze excess water from the fleece, but fleece is not allowed to dry completely.
Carding is the only process that can untangle and individualize the fibers. After scouring and drying, the vegetable matters still remain in the wool. The bulk of these foreign matters are removed in carding. Carding also achieves intimate mixing of wool fibers, which is only possible with individualized fibers.
The preparative gilling is mainly to align the fibers in a parallel direction, further blend the wool through doubling and to add moisture and lubricants. This is done by using a coarser comb. The main objectives of the gilling machine are to further align the fibers in card sliver and to blend the slivers from different cards. A gilling machine is also known as a gill box, or simply a gill.
Combing is a critical step in worsted processing. Combing process removes short fibers, neps, and impurities (collectively known as noils), further mixes and aligning fibers and forms a continuous rope-like comb sliver.
Finisher gilling is mainly aimed to remove the mild entanglement introduced to the combed sliver.
Drawing is an advanced operation which doubles and redoubles slivers of wool fibers. The process draws, drafts, twists, and winds the stock, making the slivers more compact and thinning them into slobbers. Drawing is done only for worsted process.
Slivers obtained from draw frame are subjected to roving frame to produce rovings. In this process, slivers are drawn out by roving frame and a slight twist is also inserted to form lengths suitable for spinning. Roving can be efficiently spun into yarn on a spinning frame.
Roving is then spun into yarn by giving more twist to yarn.
A huge variety of machinery is used in the different manufacturing processes of the worsted yarn manufacturing. Many companies with their own brand and machine types are available in the market.
Woolen Yarn Manufacturing Process
Wool fiber and hair fiber are the natural hair growth of certain animals and are composed of protein. Protein consists of complex organic compounds containing amino acids. The Great Britain comes first into the story of wool as producer of raw material. The other chief producing countries are Australia, The USSR, New Zealand, Argentina, South Africa, Uruguay and The United States.
Differences between Woollen and Worsted Yarn Manufacturing Process
There is a large difference between the spinning and manufacturing process of both woollen and worsted yarn. These are the two different systems through which different grades of yarns are produced from the wool taken from different animals like sheep, alpaca, rabbits, goats and llama.
Why do fabrics shrink? Shrinkage in Fabrics!
During the manufacturing process of fabric or we call it fabric processing, fabric comes in lot of tension and stretches when it moves from one machine to another which causes stretching in fabric structure and when this tension is removed, and fabric is relaxed it tends to get back in its original structure causing shrinkage.
Acrylonitrile Butadiene Styrene (ABS) Polymers History
Acrylonitrile-Butadiene-Styrene has been available since the 1940's. In attempts to produce bulletproof plastic sheets during the last years of World War II, polymer systems were developed from special butadiene acrylonitrile copolymers and styrene acrylonitrile copolymers with high molecular masses.