Burnt-out printing products with its elegant and novel appearance, soft and smooth feel, hanging elegant, colorful unique style, won the praise of consumers. At present, all kinds of burnt-out printing processes and products are designed and implemented by taking advantage of different chemical properties of fibers. Such as polyester-cotton burnt-out products, adhesive/silk burnt-out products, polyester and viscose burnt-out products. But another kind of innovation pure cotton burnt-out product, namely the pure cotton printing hollow fabric has aroused the consumer's attention. This kind of fabric combines the characteristics of burnt-out processing technology and foaming printing technology to realize the cavity by burnt-out technology, while foaming printing prevents the phenomenon of yarn or flocculation during washing and taking. The following is a brief introduction of the processing technology of cotton burnt-out products.

1 process principle

Concentrated sulfuric acid and hydrochloric acid are strong water-absorbing agents, which can be used to dehydrate cellulose fiber of pure cotton fabric, and then corrode and carbonize it by high temperature baking. However, due to the difference of fabric structure specifications, the pure voids will not be resistant to washing and friction, resulting in yarn or floss, thus making the pattern deformation unstable. This problem can be solved if foamed printing and elastic glue printing are introduced in the process.

Foaming printing produces tactile vertical pattern, which can be generally divided into physical foaming and chemical foaming, namely flapping printing and foaming printing. Therefore, its printing pulp can also be divided into physical foaming pulp and chemical foaming pulp. Physical foaming adopts physical foaming slurry, which mainly includes microcapsule preparation and adhesive with low boiling point organic solvent. When printing fabric is baking, the organic solvent in the microcapsule is heated to form bubbles, the volume increases, and the microcapsules are squeezed each other, resulting in irregular overlapping distribution and uneven surface height of printed fabric. Visually, physically foamed printed fabrics have a suede effect and are often referred to as fleece-printing. Chemical foam is the use of chemical foam pulp for printing foam printing, through high temperature so that the foaming agent decomposition, produce a lot of gas, resin layer expansion, raised patterns, so that printed fabric in visual relief effect, this is usually called foam printing. Chemical foaming pulp can be divided into thermoplastic resin foaming pulp and polyurethane vinegar foaming pulp, the latter has the problem of solvent recovery, so the former is generally used. Using the above chemical properties, on the one hand, according to the requirements of customers can give hollow fabric three-dimensional sense, on the other hand, play the function of locking. Elastic glue printing USES high elastic adhesive, with good elasticity and soft feel, suitable for burnt-out printing of pure cotton, polyester-cotton blended, interwoven and core-covered yarn.

2. Determination of process

Hollow and burnt-out printing of pure cotton fabric, does not need to consider the protection of other fibers, only requires enough acid and stable printing color paste, but also consider the impact on foaming pulp.