Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P3/00—Special processes of dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form, classified according to the material treated
  • D06P3/34—Material containing ester groups
  • D06P3/52—Polyesters
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
  • D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/15—Locally discharging the dyes
  • D06P5/151—Locally discharging the dyes with acids or bases

Definitions

• the present invention concerns the field of textile production. More specifically, it concerns a new process for obtaining new and peculiar surface designs through printing on textile products (fabrics or garments) made of polyester or in any case containing polyester fibers.
• Textile printing in general terms, consists of applying printing pastes - containing dyes or pigments - to textile products. This step is followed by one or more stabilization steps, comprising physical and/or chemical treatments having the purpose of stably and locally fixing the dying substances.
• stabilization steps comprising physical and/or chemical treatments having the purpose of stably and locally fixing the dying substances.
• the most widely used printing processes are the direct or application printing (using colored pigments or dying substances belonging to the category of the disperse dyes), the corrosion printing, the resist printing and the thermal transfer printing.
• the printing is not carried out directly on the textile support, but in two steps, firstly printing a support having a perfectly plane and stable surface (release paper) with appropriate colorants, and subsequently transferring the design on the fabric with processes making use of dry heat (sublimation, thermoplasticity), or wet heat (migration, steaming).
• polyester fibers can be saponified by sodium hydroxide. This is sometimes exploited to make the polyester textile products more hydrophilic, and with a feel and a looseness that are more similar to those typical of the natural fibers (namely silk).
• Sodium hydroxide attacks the polyester in the areas of the fiber that are more easily accessible, i. e. in the amorphous ones, and forms some surface cracks.
• the hydrolysis products that are formed in this way (terephthalate and glycol) pass in solution, and thus a first surface degradation stage occurs, known as "decortication", used with the aims mentioned above.
• a second, stronger hydrolysis stage could then bring to the total demolition of the polymeric structure of the polyester, and thus to the total dissolution of the fibers.
• This finishing treatments can be carried out both with continuous and discontinuous processes, among which the DEBACA ® process, developed and patented by the company Montefibre of Milan back in the eighties.
• the process according to the invention consists in applying printing pastes containing high concentrations of strong alkali, such as sodium hydroxide, with appropriate thickening agents, on polyester or polyester-mixed products, in a raw condition or dyed. It is possible to carry out a simultaneous coloration of the product, by applying dyes or pigments via further and different printing cylinders or screens. After the printing step the fabric is dried at high temperature, and then undergoes washing (rope or open wide washing) and neutralization steps.
• strong alkali such as sodium hydroxide
• the process can be applied on textile substrates consisting of woven or knitted fabrics or of manufactured garments, made of polyester or polyester-mixed.
• These substrates can be in any condition and with any superficial appearance (e.g. pile fabrics, with an even surface, made of fancy yarns etc.).
• they can be in a raw condition, bleached, dyed or printed.
• colorant materials and/or pigments resistant to alkaline treatments have been used.
• the sequence of the processing steps can be considered, per se, analogous to a conventional printing process. Therefore, first of all there is a preparation step of the printing paste containing the strong alkali and the other auxiliary components normally present in the traditional printing pastes.
• the paste can then be applied with any known method (screen printing - with manual, semi-automatic or automatic systems -, hollow cylinder rotary printing, cylinder or roller printing), with a speed that may vary as a function of the technique that is used and the desired results. Also the penetration of the printing paste can be adjusted as a function of the effect one wishes to obtain.
• the pattern of the printing matrix, and consequently the design that will be defined on the fabric by the areas with different degradation characteristics can be of any kind, that is, geometrical, flowery, generally fancy.
• a drying step will follow with hot air drying machines, at high temperature (comprised between about 160°C and 185°C) depending on the kind of fabric and, also in this case, of the desired effect. It is at that stage that the actual basic hydrolysis (saponification) of the polyester will be activated.
• the drying step can be carried out at a temperature comprised between about 100°C and 120°C, and then steaming or thermofixing the material at temperatures around 160°C ⁇ 180°C.
• a final washing and neutralizing step will have the aim of washing away the residuals of strong alkali of the printing paste and the products of the hydrolysis (terephthalate and glycol).
• the washing will also be useful for getting away with the unfixed dyeing substances and/or pigments.
• the washing can be carried put with continuous or discontinuous processes, depending on the devices one has available.
• the temperature and other washing conditions are set as a function of the type of printed textile material and of the device in use. All the above mentioned steps are obviously carried out with apparatus fully known of to the person skilled in the art.
• a preferred preparation of a printing paste with strong alkali is expressed by the following recipe.
• Chronological order Products Amount (/kg of paste) 1 Purified water as needed 2
• Strong alkali e.g. sodium hydroxide - aqueous solution 32%) 700 ⁇ 850 g 3/a Synthetic thickening agent (e.g. dispersion of acrylic copolymers in light mineral oil)
• ALCOLPRINT DT-CS ® (Ciba Specialty Chemicals S.p.A.) 35 ⁇ 65 g 3/b
• Natural thickening agent e.g. starch, carboxymethylcellulose, etc. 10 ⁇ 20 g
• the thickening agent has obviously the function of making the paste suitably thick in view of the subsequent use. If needed, wetting substances can be added, as obvious to the skilled person.
• the preparation of the paste will be carried out with the mixing and agitation techniques usual in the field of the textile printing.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Coloring (AREA)
• Treatment Of Fiber Materials (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=38895923

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (2)

Family Cites Families (1)

• 2006
  • 2006-09-27 IT ITFI20060237 patent/ITFI20060237A1/it unknown
• 2007
  • 2007-09-18 EP EP07116696A patent/EP1905889A3/fr not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events