EP0943026B1

EP0943026B1 - A method for insect-resist treatment of carpets, textiles and insulation products

Info

Publication number: EP0943026B1
Application number: EP97932044A
Authority: EP
Inventors: Steven Andrew Leftly; Peter Edward Ingham; Cynthia Kathleen King
Original assignee: Wool Research Organization of New Zealand Inc
Current assignee: Canesis Network Ltd
Priority date: 1996-07-24
Filing date: 1997-07-24
Publication date: 2003-12-17
Anticipated expiration: 2017-07-24
Also published as: AU3560297A; EP0943026A1; EP0943026A4; AU732690B2; WO1998003718A1

Description

BACKGROUND

This invention involves a method of imparting insect-resistance on carpets, textiles or insulation products which contain wool and/or other animal fibres.

All goods containing wool and other animal fibre components are susceptible to damage caused by insects. Presently these fibre components are treated with insecticides to render them resistant to insect attack.

The most common insecticides used to give wool fibres insect resistance are synthetic pyrethroids, usually permethrin. These are usually applied by adding an aqueous emulsion of the insecticide to wool during scouring, dyeing, tape-scouring or chemical-setting.

The insecticide active is exhausted into and onto the fibres in the above applications. In the case of dyebath application typically 95% of the insecticide is exhausted onto the fibre. With loose wool or yarn scouring application processes, a continuous exhaustion equilibrium is reached being partially dependent on fibre throughput and bowl insecticide concentration. In both the above application processes considerable amounts of effluent containing insecticide are produced.

These effluents are environmentally undesirable in that they may have adverse effects on aquatic organism populations in waters to which the effluent is eventually discharged (usually via sewerage or other waste treatment). This may have an adverse effect on other species down the food chain.
In some geographic areas strict limits are being imposed on the discharge of effluent containing these insecticides. These limits can be such that traditional insect-resist treatment methods as described above, cannot be used if effluent is discharged directly to sewer.
W097/23682 discloses a method of treating carpets or other textiles, the method including the steps of:

incorporating a formulation into a synthetic fibre;
blending the synthetic fibre with wool fibres; and
heating the synethetic fibre and the wool fibres so as to fuse the synthetic fibre onto the wool fibres. The formulation can comprise a fluorosurfactant compound, for example a perfluoro alkyl sulphonate.
The purpose and object of this invention is to overcome the problems of pesticides present in discharge effluents i.e. to produce an alternative to traditional aqueous application methods.

SUMMARY OF THE INVENTION

According to the invention, there is provided a method of protecting wool and other animal fibres from being eaten by insect larvae by treating synthetic fibres or regenerated natural fibres with an insecticide and blending a proportion of this treated fibre with untreated wool or other animal fibre, wherein the proportion of synthetic fibres or regenerated natural fibres in the blend is 5% or less of synthetic fibre or regenerated natural fibre by overall weight of wool or other animal fibre.
The effective insecticide can be permethrin, an insect growth regulator or any other compound having an insect-resist effect.
The insect growth regulator can be RH 5992 (Rohm & Hass) and the insect-resist compound can be Abamectin, Lufenuron (Ciba Geigy), Bifenthrin (FMC Corporation), MGK 264 or a perfluoroalkylsulphonate (3M).

When using the pre-treated fibre to insect-resist wool the aim is to add as little as possible to the overall fibre blend so as to minimise the proportion of synthetic or regenerated natural fibres in the blend.

According to the invention, there is added 5% or less of synthetic fibre by overall weight of wool. Because wool eating insects do not selectively graze wool fibres the pre-treated component effectively protects the whole fibre blend.

A secondary but very important feature of the invention is for the pre-treated fibre to contain a high concentration of insecticide (for example permethrin) to impart insect resistance on the whole fibre blend. The choice of fibre for treatment and the method of insecticide application to the fibre are key features of the invention. Another key factor is that the insecticide treatment is largely fast to subsequent wet processes. This is essential to prevent downstream losses of the insecticide which end up in discharged effluent.

DESCRIPTION OF PREFERRED EMBODIMENTS

The process of application and its inherent properties will be apparent from the following examples.

Example 1

Low-melt bi-component polyester fibre (PES) (LM-51, 15 den, 76 mm - SAM YANG Co Limited) was pre-treated in a bath containing 1 g/l Topsoft (Dylachem - Precision Processors) for 15 minutes at 40°C.

The fibre is then squeezed and added to the application bath which contains:

30% owf Mystox CMP (Catomance) (containing 12% permethrin W/V)
10% owf Dyapol BLF (Yorkshire Chemicals)
pH 4.5 with acetic acid (BDH).

The bath temperature is raised to 55°C and held for 60 minutes.

Fibre is then squeezed and rinsed twice in 40°C rinsewater. The fibre generally takes up about 15% Mystox CMP on weight fibre (owf) (i.e. 1.8% w/w permethrin owf). The dry fibre was blended with wool in the ratio (95% wool/5% PES) to achieve an overall treatment level of about 0.75% Mystox CMP owf (i.e. 0.09% w/w permethrin owf).

The fibre was spun into yarn and then tufted into 10mm cut pile carpet.

The durability of the treatment to shampooing was determined using three shampoo cycles according to the protocol outlined in IWS Test Method 28. A 45°C, 10g/l solution of non-ionic detergent was applied to the carpet using a spray/vacuum cleaner (Kerrick Hydra-Vac). The spray head was moved over the carpet at a speed of 3cm/sec. A second pass was made with vacuum only. The sample was dried at room temperature before the second and third respective cleaning cycles. The amount of permethrin removed was determined using an established HPLC assay technique. The treatment was found to be 94% fast to the shampoo treatment.
The resistance of the carpet to insect attack was determined by using protocol of IWS Test Method 25. The test species used was Tineola bisselliella. 15 larvae of equal size were placed on carpet discs (40mm diameter) in mesh-topped aluminium containers in a controlled environment for fourteen days. Four replicates were used. At the completion of the test the larvae mortalities were determined and carpet damage and weight loss assessed.
100% mortality and low mass losses/damage scores were achieved on all samples, giving a pass result to Wools of New Zealand (WNZ) Test Method 25 protocol.

The above carpet was winch dyed using the following programme:

Auxiliaries	0.2 g/l ALBEGAL FFD	(Ciba Geigy)
	1.5 g/l Sodium acetate	(BDH)
	1.25 ml/l Acetic acid	(BDH)
	1% omw Albegal SET	(Ciba Geigy)
	5% omw Sodium Sulphate	(BDH)
Dyes	0.021 % omw Lanaset Yellow 2R	(Ciba Geigy)
	0.018% omw Lanaset Blue 2R	(Ciba Geigy)
	0.077% omw Lanaset Red 2B	(Ciba Geigy)

Raise bath temperature to 40°C
- add auxilliaries
- circulate 10 mins
- add dyes
Heat to 85°C @ 1°/minute
Hold 30 minutes
Dump bath, rinse
Hydro extract
The overall treatment level was 83% fast to this dyeing.

Example 2

Low-melt bi-component fibre was treated as in Example 1. This loose fibre was tested for treatment fastness to a simulated tape-scour train as follows:

Tape-scouring

Fibre was passed through a series of scour bowls with a roller-squeeze between each one.

Bowl (1) contained 1.5 g/l Teric GN9 (ICl) @ 65°C
Bowls (2), (3) and (4) were clean water rinses @ 65°C

There was 25 second immersion in each bowl followed by a squeeze to hydro-extract the fibre.

The treatment level was 92% fast to this wet process.

Example 3

Low-melt bi-component PES fibre was treated as in Example 1.
This fibre was subjected to a simulated loose-stock dyeing to test for fastness.

Dye bath contained - 0.5% Albegal FFA (Ciba Geigy) omw

1.25 ml/l Acetic acid (BDH)
0.25% Avolan S (Bayer) (omw)

Auxilliaries added to bath @ 50°C
Fibre added to bath and temperature increased to 95°C @ 1°C/hour
Hold at 95°C for 15 minutes
Drop a cold rinse
Fastness to this process was 75%.

Example 4

The low-melt sheath which constitutes about 50% of a bi-component fibre was doped in the melt with 3% permethrin prior to extrusion to produce an insect-resist fibre for blending with wool containing around 1.5% permethrin.

The treated fibre was subsequently blended with wool in the ratio 5%/95% PES/wool as in Example 1 and a similar bioassay carried out to give a pass result in terms of WNZ Test Method 25.

Example 5

Permethrin was added to low-melt polyester fibre at a rate of 1.5% on mass of polymer. The polymer chips were subsequently fed into a hopper, melted then extruded as an homogenous fibre containing about 1.5% insecticide. This was subsequently blended with wool in the ratio 95% wool/5% synthetic as for Example 1. The same level of protection is achieved.

Advantages of the invention are:

1. It eliminates the need to directly insect-proof the wool fibre;

2. It protects wool by incorporating a small proportion of a blend with doped synthetic fibre;

3. It provides a method for treating bi-component fibres with an insect-resist treatment which is substantially fast to subsequent wet processing and cleaning;

4. It provides a method of insect-proofing wool yarns, carpet, textiles, insulation materials or other woollen materials;

5. It provides a method of doping synthetic bi-component or low-melt fibres by exhaust methods;

6. It provides a method of protecting wool products by blending with synthetic fibres doped with pesticide prior to extrusion;

7. It provides a batchwise treatment which does not require effluent discharge between treatments; and

8. It provides a method of insect-proofing wool fibres with little subsequent loss of insect-resist agent during downstream wet processing of dyeing, tape-scouring and chemical setting.

Particular examples of the invention have been described and it is envisaged that modifications and variations can take place without departing from the scope of the appended claims.

Topsoft, Mystox, ALBEGAL, Lanaset, and Avolan may be registered trade marks of their respective proprietors in at least one Contracting State.

Claims

A method of protecting wool and other animal fibres from being eaten by insect larvae by treating synthetic fibres or regenerated natural fibres with an insecticide and blending a proportion of this treated fibre with untreated wool or other animal fibre, wherein the proportion of synthetic fibres or regenerated natural fibres in the blend is 5% or less of synthetic fibre or regenerated natural fibre by overall weight of wool or other animal fibre.
A method as claimed in Claim 1 wherein the synthetic fibres or regenerated natural fibres are treated with permethrin.
A method as claimed in Claim 1 wherein the synthetic fibres or regenerated natural fibres are treated with an insect growth regulator or any compound having an insect-resist effect.
A method as claimed in Claim 3 wherein the insect growth regulator or compound is abamectin, lufenuron, bifenthrin or a perfluoroalkylsulphonate.
An insect-resist treated carpet, textile or insulation product manufactured in accordance with the method as claimed in Claim 1.