SKILLS & KNOW-HOW
How to make a pair of tights - Production phases
Nylon + Elastomer
Nylon is the most used yarn in the actual production of stockings and tights. Nylon is synthesized from oil. The molecules of oil are broken up and then, through a series of processes, rebuilt in very long molecular chains to obtain the nylon polymer.
The polymer is cast at high pressure and temperature (300°C); this fluid substance is filtered and high-speed extruded. The extrusion process is necessary to align the molecules to form a filament.
A thread of nylon is made of a specific number of filaments (or just one in the case of the monofilament nylon). Filaments are humid-air cooled and lubricated; a jet of air interlaces them before they are spooled on the reel at a speed of approximately 300 km/h (in 1940 spinning machines could reach the maximum speed of 1km/h).
The crude nylon yarn is thus obtained: the more numerous and thinner the filaments, the more comfortable and softer the yarn. As it is, however, the yarn is not elastic, therefore it needs to undergo further processing to be used in hosiery.
Yarn manufacturers process the yarn to make it elastic.
Texturing is the necessary process to give volume and elasticity to the thread: a stretched thread lengthens and recover its original shape as the tension disappears. Two methods of texturing are used in hosiery: false twisting, or air jet, and complete twisting.
False twisting allows for a high-volume and elasticity product, though scarcely transparent. It is therefore applied to stretch-type tights.
Texturing by means of twisting makes the thread less voluminous and elastic, but highly transparent, it is then applied to voile or stretch tights and stockings. The spiral's shape is irregular: the filaments are prominent and it is therefore easy to pull the threads of the tights.
Tubular articles are produced.
These will be the legs of the tights. After the yarn has been prepared, it is processed by rotary high-speed machines that allow the combination of various thicknesses and types of yarn and the integration of waistbands, backings and complex designs in just one continuous operation, electronically controlled by a computer.
All the stockings processing styles and designs are created during weaving.
In this phase the tights are given their real shape
The two tubes are assembled together by seams in the area of the bodice. Seams are of great importance, as they determine most of the articles' wearability.
The types of seam which are mostly used are: Automatic seam: it is carried out by computerized systems that join the two tubes together, insert the gusset and sew the toes up.
Flat seam: carried out manually, it is the most comfortable seam, because there is no material overlap. In this case the gusset is inserted by hand.
This step is necessary to eliminate the production wrinkles.
The crude stockings are now Dyed
Dyeing adds the colour to the tights. The more valuable the tights, the more the colour must be applied evenly and without stripes.
Various types of dye are used: disperse dyes for light hues; acid dyes for hues from medium to dark; metal-complex dyes for very dark hues, such as black. Dyeing can be carried out by palette dyeing machine, stacking machines or by tumble dyeing machines running at slow rotary motion.
Finishing is necessary to stabilize the yarn: it is a decisive step for the aspect and for the characteristics of elasticity and recovery of the tights. During this phase additives and any special treatment are added.
After the tights have been dyed, the colour is fixed to the fibre through infra-red lamps, thus preventing any colour bleed when washed or used for the first time.
The tights are given their anatomical shape (foot and leg)
Fixing consists in stretching the lightly damp tights on a leg-shaped metal support and putting them through short bursts of heat in a steam chamber or in a dry oven.
This phase emphasizes all the tights' valuable features: shape of heels, toes, foot and of the moulded bodice as well.
Quality Control and Packing
The next phase after drying and quality control is packing. Before putting them in envelopes or boxes, tights are controlled on a light table or on a shape to detect any imperfection.
Packing can be done by hand or automatically by means of machines.