GB1574365A

GB1574365A - Felted material

Info

Publication number: GB1574365A
Application number: GB5066/77A
Authority: GB
Original assignee: Bury & Masco Ind
Current assignee: Bury & Masco Ind
Priority date: 1977-02-08
Filing date: 1977-02-08
Publication date: 1980-09-03
Also published as: DE2805057A1; FR2379634B1; FR2379634A1

Description

(54) AN IMPROVED FELTED MATERIAL (71) We BURY & MASCO INDUSTRIES LIMITED, a British Company of P.O. Box 14, Hudcar Mills, Bury, Lancashire BL9 6HD, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention concerns felted materials, that is materials produced from a mass of fibres which have been subjected to a milling and/or fulling operation to cause the fibres to adhere to one another thus to produce a fabric.

Originally felted materials were produced from woollen fibres and one reason why they could be caused to adhere to each other lies in the fact that the fibres have a rough or scale like surface. Such fibres when felted produced a fabric which, while it possessed numerous useful characteristics enabling a relatively wide range of uses to be made of the fabric it also had a number of characteristics which rendered it unusable for some purposes. For example the ability of the material to drape in a pleasing manner after being subjected to the usual felting process was found to be low, additionally the recovery from stretch was also low and the surface texture of the material was limited. These features of the fabric prevented its use, for example, for the production of articles of clothing. Furthermore the material was found to have an unacceptably high shrinkage potential which also mitigated against its use as a clothing or furnishing fabric. Finally the ability of the fabric to recover after being stretched locally was low, that is to say the fabric tends to 'seat'.

While the original forms of felted material have been improved in many respects some of the disadvantages above outlined still exist, even in felts made from blends of fibres of different types, wool fibres always of course being present to enable the felting action to take place during milling and/or fulling. Thus present day felts are still not used widely as the predominating fabric in articles of clothing such as ladies' dresses, men's suits and the like. nor does felt find application in the production of curtains, drapes and the like.

It is an object of the present invention to produce a felted material that does not suffer from the above outlined disadvantages, or at least does not suffer from the disadvantages to an extent such as to prevent its use in the production of articles of clothing, curtains, drapes and the like.

Thus according to one aspect of the present invention there is provided a felted material characterised in that after being subjected to an initial aqueous washing process it exhibits an area shrinkage of less than 5% and has a textured undulating surface.

According to a further aspect of the present invention there is provided a method of producing the said felted material including at least 20% of wool fibres and a proportion of man-made fibres including the steps of carding and blending the fibres, producing a batt and subjecting same to milling and/or fulling sufficient to produce a felt fabric, subjecting said felt fabric to a drying operation under conditions such that the dimensions of the fabric can change thereby. when the drying is completed, to produce a substantially fully shrunk fabric which, due to the differential shrinkage rates of the component fibres exhibits a textured undulating surface.

Preferably the method includes the step of producing a blend of fibres in which the proportion of wool fibres in the blend lies between 40-50%.

In one form of the invention the proportion of wool fibres in the blend is 80%.

Conveniently the final drying step is carried out in a tumble dryer into which heated air is passed while the dryer is rotating.

Conveniently the man-made fibres are of viscose or other synthetic material; the quantity of man-made fibres contained within the blend may lie between 20% and 80%.

Conveniently the man-made fibres are crimped.

The invention will now be described further, by way of example only, with reference to several practical forms thereof.

Stated in general terms one method of producing a felt material in accordance with the invention includes the production of a blend of fibres comprising up to 80% wool fibres and crimped viscose fibres and from this a carded batt of fibres is formed. The so formed batt is subjected to a milling and/or fulling operation in known manner and when the fibres have agglomerated to produce a semi-finished felt the latter while still wet is placed in a tumble dryer to which air at an input temperature of approximately 100" C is fed while the drier is rotated. The felt while being dried in the tumble drier is unconstrained and thus shrinks and compacts to produce a true felt with a textured finish. The textured finish produced consists of raised piles of fibres randomly formed over the whole surface of the material and thus the material exhibits an undulating surface.

The following examples set out in detail some of the methods of producing a felted material according to the invention.

Example I Viscose rayon fibres of staple length two and one half inches and 4.5 denier was blended with 64's count wool. The proportion of fibres in the blend being 63% viscose, 37% wool.

The blend is then carded on a conventional woollen card, the web from the card being cross laid to produce a batt or sheet.

The batt so formed is then hardened on a conventional roller hardener machine as used in the felt industry. The thus hardened or consolidated batt is subjected to milling on a conventional felt rotary milling machine and the greige felt is then dyed in a beam dyeing vessel. The material so formed would, if then treated in the conventional manner be mangled and tentered to produce a uniform felt having the following properties: Weight 138.3 gm/m2 Thickness 0.91 mm Shirley Stiffness 66 degress deflection lengthwise 72 degrees deflection widthwise In contradistinction to this however. the felt from the dyeing vessel is now immersed in water and allowed to shrink in an uncontrolled manner and the shrunk felt is then mangled to reduce the water content to approximately 70% of the dry felt weight. The length shrinkage was found to be 10% and the width shrinkage 20%. The wet felt is now placed in a tumble dryer, set at a temperature of 100" C and tumble dried for one and one quarter hours. After drying, cooling and conditioning back to room conditions the properties of the felt were measured and were found to be as follows: Weight 228 gm/m2 Thickness 2.20 mm Length shrinkage from the original tentered sample = 20% Width shrinkage from the original tentered sample = 31% Shirley Stiffness: 77" deflection in the length direction 79" Deflection in the width direction.

The results tabulated above indicate that the felt produced by the method of the invention exhibit a much reduced stiffness when compared with the original sample, particularly in the length direction and this indicates the improved drape characteristics.

The texture surface of the felt is clearly apparent and can be characterised by measuring the peaks and troughs of the felt surface which can be classed as Amplitude and Wavelength and in addition the density of peaks/unit area was measured.

In the sample produced according to the above example The range of amplitude was 0.5 o 1.5 mm The range of wavelength was 1 < 4 mm The peak density was variable between 10 and 150 peaks/sq inch.

For further comparison purposes the conventional felt referred to above and the textured felt were subjected to after treatment similar to a typical washing/drying cycle as may occur when the fabric is used. The felts were immersed in water at 70" C for fifteen minutes and then dried in an oven at 105 C for thirty minutes and then allowed to condition back to normal room temperature and humidity.

The conventional felt had a length shrinkage of 11% and a width shrinkage of 27%. The textured felt however had a length shrinkage of 1.5% and a width shrinkage of 1.3%.

Example II A hardened, milled, dyed felt was produced in Example 1. After mangling the felt was treated in two ways: one sample of felt was allowed to air dry, another sample was tumble dried as in Example 1. The properties of the felts so treated were then compared. After drying the two samples were measured and the following results were obtained.

Airdried sample Tumble dried sample Weight gm/m2 236 320 Thickness mm 1.82 2.44 Length shrinkage % 8.5 23 Width Shrinkage % 0.1 increase 9.4 Shirley stiffness deflection lengthwise deg. 49 65 Widthwise deg. 65 70 Amplitude of peaks mm -- 0.5 < 1.5 Wavelength of peaks mm -- 1 ) 4 Peak density (peaks/inch2) -- 10 < 150 The results show a significant decrease in stiffness of the tumble dried sample relative to the air dried sample. Both samples were given the same after treatment as in Example 1.

The air dried sample had an area shrinkage of 5% but the tumble dried sample had no measurable shrinkage.

Example Ill Viscose rayon of staple length two and one half inches and 4.5 denier was blended with 70's count wool, the blend being 50iso viscose to 50% wool. The blend was carded on a conventional woollen card and the web wound up on a 60 m frame to produce an unconsolidated fibre sheet 60 m long. The majority of the fibres of the carded sheet were oriented longitudinally of the sheet, that is in the 'length' direction.

The sheet was hardened and milled as in Example 1 and dyed in a conventional fabric dye vessel. The felt was mangled and tentered so that the width was nominally unaltered during heat treatment. This conventional felt had the following properties: Weight = 550 gm/m2 Thickness = = 3.73 mm Shirley Stiffness deflection : lengthwise 3 widthwise 21 A sample of the conventional felt just referred to was then wetted, mangled and tumble dried at 100" C for one and one quarter hours to generate the textured effect. The resultant felt had a surface which contained a mixture of peaks and ridges.

The felt had the following properties: Weight = 722 gm/m2 Thickness = 5.83 mm Shirley Stiffness deflection : lengthwise 28 widthwise 11" Amplitude of peaks 0.5 < 1.5 mm Wavelength of peaks 2 < 3.0 mm Peak density (peaks/sq inch) 10 < 50 The results obtained show that the felt has a much decreased lengthwise stiffness and an increased widthwise stiffness. However, the treated felt exhibits a softer handle and increased drape characteristic than the conventionally produced felt.

Both felts were given the same after treatment as in Example 1. The conventionally produced felt had an area shrinkage of 17% whilst the treated felt exhibited no shrinkage.

The processes described above may be modified if desired. For example, while reference has been made to dyeing of the felt after milling and/or fulling this step may be omitted and the felt transferred to the tumble drier in the undyed state.

It is also possible to remove the semi-finished felt from the milling and fulling machine and dry it, for example if it is desired that the felt be stored before final treatment. Such a felt can subsequently be wetted again and then subjected to the drying process in the tumble drier. Thus it is possible to carry out the manufacturing process in a continuous or discontinuous manner.

It is found that the texture of the finished fabric and the amount of subsidiary felting that takes place in the tumble drier can be varied by, for example, altering the water content of the felt prior to the commencement of the drying process; altering the speed of rotation or size of the drying drum or varying the quantity of fabric placed in the drying drum. In addition, of course, the blend of fibres used, the type and quantity of wool used, the type and quantity of man-made fibres used and the initial density of the semi-finished felt will also serve to modify the final texture of the fabric.

The drape characteristics of the fabric result from the variations in thickness, in both directions of the fabric.

Due to the fact that the drying process uses the shrinkage of the material to produce the texture there is little residual shrinkage capacity in the finished fabric and it is found that the material can be cleaned.

The fabric may be given a shaded or watered effect during dyeing by the correct choice of dyes and the different affinity to dye of the natural and man made fibres in the blend.

WHAT WE CLAIM IS: 1. A felted material characterised in that after being subjected to an initial aqueous washing process it exhibits an area shrinkage of less than 5% and has a textured undulating surface.

2. A method of producing a felted material as claimed in Claim 1 at least 20% of wool fibres and a proportion of man-made fibres, including the steps of carding and blending the fibres, producing a batt and subjecting same to milling and/or fulling sufficient to produce a felt fabric, subjecting said felt fabric to a drying operation under conditions such that the dimensions of the fabric can change thereby, when the drying is completed, to produce a substantially fully shrunk fabric which, due to differential shrinkage rates of the component fibres exhibits a textured undulating surface.

3. A method as claimed in Claim 2 in which the range of proportions of wool fibres in the blend lies between 40-50%.

4. A method as claimed in Claim 2 in which the proportion of wool fibres in the blend is 80%.

5. A method as claimed in Claim 2.3. or 4 in which the man-made fibres are viscose.

6. A method as claimed in any one of Claims 2 to 5 in which the man-made fibres are crimped.

7. A method as claimed in any one of the preceding claims 2 to 6 in which the drying operation is carried out in a tumble dryer into which heated air is passed while the dryer is rotating.

8. A method as claimed in Claim 7 in which the heated air enters the dryer at a temperature of approximately 100"C.

9. A method as claimed in any one of the preceding Claims 2 to 8 in which the semi-finished material is transferred to the drying apparatus direct from the milling and fulling apparatus.

10. A method as claimed in anv one of the preceding claims 2 to 8 in which the semi-finished material is partially dried before transfer to the drying apparatus.

11. A method as claimed in Claim 10 in which the semi-finished material is held on a stenter while being partially dried.

12. A method as claimed in any one of the preceding Claims 2 to 8 in which the semi-finished material is completely dried and is subsequently wetted out before being transferred to the drying apparatus for final drying and shrinking.

13. A felt when produced by the method claimed in any one of the preceding claims.

14. A felted material substantially as hereinbefore described with reference to any one of the foregoing examples.

15. A method of producing a felted material substantially as hereinbefore described with reference to any one of the foregoing examples.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the felt transferred to the tumble drier in the undyed state. It is also possible to remove the semi-finished felt from the milling and fulling machine and dry it, for example if it is desired that the felt be stored before final treatment. Such a felt can subsequently be wetted again and then subjected to the drying process in the tumble drier. Thus it is possible to carry out the manufacturing process in a continuous or discontinuous manner. It is found that the texture of the finished fabric and the amount of subsidiary felting that takes place in the tumble drier can be varied by, for example, altering the water content of the felt prior to the commencement of the drying process; altering the speed of rotation or size of the drying drum or varying the quantity of fabric placed in the drying drum. In addition, of course, the blend of fibres used, the type and quantity of wool used, the type and quantity of man-made fibres used and the initial density of the semi-finished felt will also serve to modify the final texture of the fabric. The drape characteristics of the fabric result from the variations in thickness, in both directions of the fabric. Due to the fact that the drying process uses the shrinkage of the material to produce the texture there is little residual shrinkage capacity in the finished fabric and it is found that the material can be cleaned. The fabric may be given a shaded or watered effect during dyeing by the correct choice of dyes and the different affinity to dye of the natural and man made fibres in the blend. WHAT WE CLAIM IS:

1. A felted material characterised in that after being subjected to an initial aqueous washing process it exhibits an area shrinkage of less than 5% and has a textured undulating surface.