WO2000073567A2

WO2000073567A2 - System and process for dyeing material which is wrapped round rigid supports

Info

Publication number: WO2000073567A2
Application number: PCT/EP2000/005016
Authority: WO
Inventors: Lucio Corbellini
Original assignee: Lucio Corbellini
Priority date: 1999-05-31
Filing date: 2000-05-31
Publication date: 2000-12-07
Also published as: AU5677400A; ITMI991205A1; ITMI991205A0; TW476831B; IT1312586B1; WO2000073567A3

Abstract

A system (11) and process for the treatment and dyeing of material (14) wrapped round hollow rigid supports (13), said supports (13) having through holes along at least a portion of its surface and being inserted inside a surge tank (12) containing a dyebath. The surge tank (12) is connected to a ring circuit (20) having at least one circulation pump (19) to keep the dip circulating. Moreover, there is at least an exchanger (15) for heating the dip and at least a compressed fluid or static pump pressurization device (17), able to maintain a pressure which allows the attainment of higher pressures than those corresponding to the saturated steam pressure.

Description

SYSTEM AND PROCESS FOR DYEING MATERIAL WHICH IS WRAPPED ROUND RIGID SUPPORTS.

The present invention refers to a system and process for the treatment and dyeing of material wrapped round rigid supports. The dyeing of yarns (on reels) and fabrics and other textile material, in general, at lower or higher temperatures to that of saturated steam at atmospheric pressure has always been done on apparatuses equipped with devices which allow the liquid water state to be maintained, also at higher temperatures than the saturated steam at atmospheric pressure .

There are basically two methods with which the known devices allow the attainment of higher temperatures than those of saturated steam at atmospheric pressure: the first uses an air cushion under pressure that guarantees sufficiently high internal surge tank pressures to maintain the liquid state of the dyebath, whereas the second uses a pressure pump that guarantees the liquid state of the dyebath .

In both cases, the static pressure serves the sole function of maintaining the liquid state of the dyebath at the maximum process temperature.

The boiling pressure of the dyeing macnines is therefore such as to allow the attainment of a static pressure which corresponds or is slightly higher to that corresponding to the process temperature thus leaving the difference, between the minimum static pressure consistent with the maximum process temperature and boiling pressure, to the circulation pressure of the process fluid. For this reason the machines are normally of dimensions which can withstand boiling pressures of 5 bars (6, 6.5 and 7 or higher in exceptional cases) and temperatures of 143°C (only higher m exceptional cases) . A typical example of a traditional dip dyeing system includes a surge tank of vertical or horizontal axis, which contains the dip (dyeing liquid) heated by a heating coil m which superheated steam or water circulates . The surge tank is connected to a dip circulation pump and an expansion tank, necessary to offset the increase in dip volume together with the temperature and useful in adding dyes and auxiliary components without having to interrupt the process. In addition, the system has a pressure unit which serves to bring the internal surge tank chamber up to the process pressure as well as checking, adjustment and control devices . The material to be dyed is placed inside the surge tank, wrapped round beams or plastic cops or other suitable supports.

The beams or cops are generally made of cylindrical parts with radial through holes, through which the dip can flow to pass from inside the beam to the outside or vice versa, passing through the fabrics or fibres to be dyed.

As is well-known, the traditional dyeing process on rigid supports involves certain difficulties regarding dye penetration onto the fabrics or yarns with an increase in the density and/or dimensions of the pack, i.e. the material wrapped round the rigid supports may undergo deformations and damage in the presence of high pressure and/or capacities, which adversely affect the quality and use at the subsequent stages; such a phenomenon is particularly marked in well-beaten up fabrics, high density or high deformability reels or extremely delicate yarns for which the dye quality or low cost of the process could be jeopardised.

In any case, a physical limit of the maximum capacity exists which is linked to the material and wrapping characteristics. On the other hand, it is in the clear interests of the dyer to increase such a limit to the highest possible level, so as to reduce the process times.

The aim of the present invention is therefore to eliminate the technical problems encountered, by designing a system and process for the treatment and, in particular, for the dyeing of material wrapped round a hollow rigid support which allows a high quality product to be attained, as regards dye uniformity and conservation of the system pattern and physical/mechanical characteristics of the material.

Another aim of the present invention is to achieve high productivity and, in any case, which is substantially higher than that which is attainable with traditional processes. A further aim of the present invention is to produce a system and process that allows operation at specific capacities which are considerably higher than those known at present and, as a consequence, with proportionately lower process times. The ultimate aim of the invention is to design a process for dyeing materials, m particular yarns or fabrics, wrapped round rigid supports, which is basically simple, safe and reliable, m addition to having relatively limited costs in virtue of the advantages gained.

This and other aims, according to the present invention are achieved by producing a system for the treatment of material wrapped round hollow rigid supports according to claim 1, which may be referred to for purposes of brevity, and a relative process according to claim 2.

Other characteristics of the system and process are set out in the subsequent claims. Advantageously the process, according to the present invention, allows a reduction m the process times and increasing systems productivity and, at the same time, guaranteeing higher quality of treated material, since it reduces deformations determmable by the high specific capacities.

Moreover, it is possible to reduce energy consumption thus favouring the economic and environmental consequences.

The process, according to the invention, also allows the treating and, in particular, the dyeing of different material types, amongst which, chiefly, textile and woody fibres .

Additional characteristics and advantages of a system and a process for the treatment of material wrapped round rigid supports, according to the present invention will be made clear by the following illustrative and unrestricted description, with refererence to the enclosed diagrams in which:

- figure 1 illustrates a first embodiment of a system which carries out a process, according to the present invention, in particular a system for the dyeing of fabrics with air pressurization.

figure 2 illustrates a second embodiment of a system which carries out the process, according to the present invention, in particular a system for the dyeing of fabrics with static pump pressurization.

With particular reference to figure 1, a system is shown which carries out a process for the dyeing of yarns or fabrics wrapped round hollow rigid supports, according to the invention denoted, as a whole, by reference number 11.

The system 11 includes a surge tank 12, inside which is contained a hollow rigid support: or beam 13, around which is wrapped the material to be dyed 14.

The beam 13 consists of a tubular part with through holes along its entire length and equipped with fabric restrainer end flanges 14. Inside the surge tank 12 is situated, in addition, a heating coil type exchanger 15 to heat the dip, while inside the heating coil 15 steam or superheated water circulates, coming from a boiler, not shown for simplification purposes. The surge tank 12 is connected, by piping 16, to an expansion tank 17, that can absorb the dip volume variations resulting from variations in temperature.

The above-mentioned tank 17, is connected, by the connecting valves 24, to a power supply and air pressurization discharge.

In addition, from the tank 17, leads a duct 18 connected to a ring circuit 20, in which a circulation pump 19 is positioned.

The ring circuit 20 has a first branch 20A, which opens inside beam 13 and a second branch 20B which opens into the surge tank 12.

The pump 19 may supply the dip inside the beam 13 (through branch 20A of circuit 20) and sucks up (through branch 20B of circuit 20) the same dip to carry out dyeing according to a traditional process.

The system 11, in short, has an introduction pump 21 connected, by pipe 22A, to tank 17 and, by pipe 22B, to the ring circuit 20, so as to guarantee the introduction of chemical products and subsequently includes a discharge tube 23 from the surge tank 12 and thermoregulation components 30.

According to the process of the present invention, the support or beam 13 is inserted inside the surge tank 12 and afterwards the dyeing fluid and chemical products are introduced.

The dip goes through the material 14 to be dyed, pushed by pump 19, at an absolute capacity which corresponds to a specific capacity and a crossing velocity, which condition the kinetics of the process.

From experimental results received, it can be confirmed that m the case of treatment of yarns of polyester microfllaments on 1.4Kg reels of 160mm in diameter and 290mm in height, at capacities of 901itres/ (mm. x Kg.) the process time was reduced by 20% and, in certain cases, by 30-40% compared to traditional values without impairing the conservation states of the yarn and reel.

Similar results were obtained m the dyeing of knitted fabrics and polyamide lycra for sportswear without jeopardising the conservation state of the beam or fabric.

Such was obtained since the dyeing process has higher static pressures than those found in conventional processes.

In particular, working at static pressures of between 2.7 and 10 bars and, in particular, at 4.5 bars, it was possible to increase capacities up to double the conventional ones (referring to the microbava polyester sample) , without it damaging the yarn or deforming the reel.

The dip temperature reached values between 20°C and 300°C and, in the specific case as is typical in the dyeing of polyester with dispersed dyes, values of between 130° and 135°C.

The process, according to the invention, is basically carried out as indicated below.

After having programmed the process checking devices (not represented in the diagram) and having loaded the material 14, a completely automatic dye cycle is commenced, the first stage of which consists in the filling of surge tank 12 with the process liquid (water) and specific chemical products. The dip is kept moving during the cycle by circulation pump 19, by way of ring circuit 20, and passes through the material 14, thus dyeing it.

Afterwards, the dip passes into the second branch of the circuit 20 to be put into circulation once more, by pump 19.

Any variations in dip volume are absorbed by the expansion tank 17, and the ideal temperature at which to carry out the process is maintained by the heating coil 15.

The stress applied to the material and, hence, its instability and its capacity to withstand bigger capacities increase with increases in the difference between the pressure inside support 13 and the external pressure.

On the other hand, an increase in capacities reduces the dyeing times, resulting in an increase in productivity and a reduction in environmental impact, even if such a capacity increase above the levels normally withstood by materials and garments may cause damage to the material 14 and changes in garment structure, so as to be detrimental to its industrial use ,

In order to remedy the cited drawbacks caused by an increase in absolute capacity, or rather the specific capacity or velocity of the dye fluid, the process has been operated at static pressures higher than those corresponding to the saturated steam pressure at the maximum process temperature, or rather at static pressures higher than those for which traditional machines are normally built, achieving pre- compression of the material on the support.

Due to such a process it is also possible to treat, at the same time, garments with weights and/or densities which are considerably higher than the norm, thus producing equivalent advantageous economic conditions .

A different embodiment of the system 11 which carries out the process, according to the invention, is shown in figure 2 where, the only difference compared to the previously described system is the pressurization method which is of pump type instead of compressed fluid type. The system 11, in such embodiment, has the surge tank 12 in which the beam 13 is housed.

A heating coil 15 is contained inside the surge tank 12 to heat the dip.

The system then includes a pipe 25 leading from the pressurization pump 26 and reaching the surge tank 12 by way of a ring circuit 20.

The pump 19, in turn, keeps the dip in circulation in the ring circuit 20 and by way of the surge tank 12 and the beam 13.

A discharge tube 27 and thermoregulation systems 28 are connected to the surge tank 12.

In practice, it has been proved as a process for the dyeing of yarns and fabrics wrapped round a hollow rigid support, according to the invention, proving especially advantageous since it allows the attainment of quality products and with higher productivity to that which may be achieved with traditional processes.

A process for the dyeing of yarns and fabrics wrapped round a hollow rigid support , conceived as such and which may be subjected to numerous additional alterations and variants, all in keeping with the invention; in addition all the details may be substituted by technically equivalent parts. Finally, the materials used, in addition to the dimensions, may be of any kind depending on technical requirements .

Claims

1. A system (11) for the treatment and dyeing of material (14) wrapped round hollow rigid supports

(13), said supports (13) having through holes along at least a portion of its surface and being inserted inside a surge tank (12) containing a dyebath, said surge tank (12) being connected to a ring circuit (20) which has at least a branch which opens inside the hollow rigid support 13 and a second branch which opens into said surge tank (12), there being at least a circulation pump (19) positioned on said circuit (20) in order to keep the same dip in circulation by way of said ring cicuit (20) and said hollow rigid support (13), in addition there is at least an exchanger (15) for said surge tank for heating said dip and at least a compressed fluid or static pump pressurization device, able to maintain a pressure which is approximately equal to the saturated steam pressure, characterised in that said system and said pressurization device achieve higher pressures to those corresponding to the saturated steam pressure.

2. A process for the treatment and dyeing of yarns or fabrics (14) wrapped round a hollow rigid support

(13), characterised in that it includes at least the following stages in sequence or combination with each other :

• filling of surge tank, containing material to be

treated, with the process liquid;

• heating of said fluid to the process

temperature;

• introduction of chemical products suitable to

treat or dye said material;

• pressurization of said fluid contained in the

surge tank at pressures that are higher than the saturated steam pressure at said process temperature;

• cooling of said fluid contained in the surge

tank;

• depressurization of said fluid;

• discharge of the fluid and said material;

3. A process according to claim 2, characterised in that said process temperature is between 20°C and 300°C.

4. A system (11) according to claim 1, characterised in that said circulation pump (19) operates at capacity values which are higher than traditional values, with reference to the type of material, support and wrapping technique considered.

5. A system (11) according to claim 4, characterised in that said circulation pump (19) operates at capacity values of at least 20% of said traditional values, with reference to the type of material, support and wrapping technique considered.

6. A system (11) and process according to claims 1 and 2, characterised in that said pressurization device operates at static pressures of at least 2.7 bars.

7. A system (11) and process, according to claims 1 and 2, characterised in that said pressurization device operates at static pressures of between 2.7 bars and 10 bars.

8. A system (11) for dyeing yarns or fabrics (14) wrapped round a hollow rigid support (13), with through holes along at least a portion of its surface, where a process is implemented according to claim 2, characterised in that said support (13) is inserted inside a surge tank (12) containing a dyebath under pressure .

9. A process and system as in claims 1 and 2, characterised in that said material to be treated is made up of natural, artificial or synthetic textile fibres in their pure or mixed state.

10. A process and system for dyeing material (14) wrapped round a hollow rigid support (13), as described and illustrated and for the purposes specified.