GB2204525A

GB2204525A - Moulding thermally bonded fibrous articles

Info

Publication number: GB2204525A
Application number: GB08809385A
Authority: GB
Inventors: Richard Louis Brucciani
Original assignee: Pal International Ltd
Current assignee: Pal International Ltd
Priority date: 1987-05-09
Filing date: 1988-04-21
Publication date: 1988-11-16
Anticipated expiration: 2008-04-21
Also published as: AU1601788A; GB2204525B; JPS63295750A; EP0291189A2; GB8809385D0; EP0291189A3; GB8711013D0

Description

1 1 1 p 2204525 METHOD AND APPARATUS FOR THE PRODUCTION OF THERMALLY

BONDED PIBROUS ARTICLES This invention concerns a process and apparatus for the production of thermally bonded fibrous articles especially, but not necessarily exclusively, those of textile fibre and of generally shell-like form.

According to the present invention, a process for the production of a thermally bonded fibrous article includes the steps of:- is (a) providing a mould surface having a shalSe corresponding with that of the article to be produced; (b) depositing a layer of loose thermally bondable fibrous mass over said surface and holding it in position thereon; (c) forming an integrated structure by thermally bonding the fibrous mass; and (d) removing the structure from the mould surface.

The fibre mass may comprise of textile fibres and be a mixture of staple fibres of differing kind, one of which has.a lower melt point than the remainder or' may be staple bi-component fibres either alone or mixed with other fibres.

The mould surface may be the outer surface of a mould of male formation or the inner surface of a mould of female formation.

The mould surface may be porous and subjected to suction, firstly to draw a current of fibre charged air against the surface to deposit the fibre mass and hold it in position thereon, secondly to draw heated air through the fibre mass to cause fusion of the melt component thereof, and thirdly to draw cool air through the fibre mass to cause stabilisation thereof. Pressure air may then be applied through the mould surface to displace the moulded structre.

The invention also includes apparatus for carrying out any process as aforesaid.

The invention will be further apparent from the following description, with reference to the single figure of the accompanying drawing, which shows, by way of example only, a diagrammatic cross-section through

4 1 one form.of apparatus for producing articles by one process embodying the invention.

The articles to be produced are hats having a domed centre portion surrounded by a brim.

The apparatus inclu des a mould of male formation having an outer surface 10 whose size and shape correspond with those of the hats to be produced. The wall 10a of the mould which provides the surface 10 is of porous construction and forms a closure to a plenum chamber 11 from which air may be drawn by means of pump 12 or into which air may be supplied by means of pump 13.

The wall 10a whose outer surface 10 may be treated with a release medium such as polytetrafluoroethylene for example, forms a closure to a duct 14 communicating with atmosphere and incorporating electrical resistance heaters 15. The duct is equipped with a door 16.

Loose textile staple fibres may be introduced to duct 14 by a chute 20 extending.from mechanical means 17 arranged to harvest such fibres from a supply hopper 18 thereof and deliver a predetermined mass thereof. The fibre may be staple bi-component fibres having polyethylene and polypropylene components whose melting points are approximately 1350C and 1650C respectively The apparatus is controlled by suitable automatic means which may include a microprocessor to perform the following operational cycle.

is (a) Pump 12 is operated to draw air from duct 14 and through wall 10 whilst means 17 is operated whereby the predetermined mass of fibre is entrained in the resulting air current for deposition and retention on mould surface 10. The arrangement and sizes of pores in the surface 10 are such that the fibre is deposited to conform with a required distribution.

(b) Means 17 is disenabled and heaters 15 are operated whereby heated air having a temperature above 1350C but below 1650C is drawn through the fibre mass to cause fusion of the melt component thereof to produce an integrated structure.

(c) The heaters 15 are switched off whereby cool air is drawn through the structure to stabilise it.

11.

1 1 (d) Pump 12 is stopped and pump 13 operated to displace the completed hat from the mould surface for removal through door 16.

It will be appreciated that it is not intended to limit the invention to the above example onlyr many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof.

Thus, different articles may be produced such as face masks, brassiere cups and so on.

The fibre mass need not be comprised exclusively by bi-component fibres. It can comprise any fibre mixture capable of being thermally bonded to form an integral structure.

Included within the fibre mass may be natural fibres such as of cotton or wool for example or mineral fibres such as of carbon, glass or asbestos for example.

The fibres may be deposited and held on the mould surface by different means such as by centrifugal forces, for example.

The fibres may be preheated whilst in flight and before deposition on the mould surface by operating heaters 15 during the deposition step.

A further mould surface may be provided to engage the fibrous mass on the opposite side from the first mould surface and the two mould surfaces may be heated to effect the thermal bonding step.

The apparatus may comprise a number of stations each adapted for a different process step, the moulds being indexed from station to station.

1

Claims

CLAIMS is 1. A.process for the production of a thermally bonded fibrous

article including the steps of:

(a) providing a mould surface having a shape corresponding with that of the article to be produced; (b) depositing a layer of loose thermally bondable fibrous mass over said surface and holding it in position thereon; (c) forming said layer into an integrated structure by thermally bonding the fibrous mass; and (d) removing the structure from the mould surface.
2. A process according to claim 1 wherein said mould surface is porous and wherein suction is applied to the underside of the surface to draw a current of fibre charged air against the surface to deposit the fibrous mass and hold it in position.
3. A process according to claim 2 wherein the thickness of the fibrous mass over the mould surface is controlled by providing a predetermined mass of fibre during the deposition step and arranging for the arrangement and sizes of the pores in the mould surface to be such as to draw said mass against the mould surface in conformity with a required distribution.
4. A process according to claim 2 wherein the air current is heated to pre-heat the fibres whilst in f light.
5. A process according to claim 1 wherein said mould surface is porous and wherein suction is applied to the underside of the surface to draw a current of heated air through the fibrous mass to effect the thermal bonding step.
6. A process according to claim 1 or claim 2 including the step of providing a further mould surface to engage the fibrous mass on the opposite side from said first mould surface.
7. A process according to claim 6 wherein the two mould surfaces are heated to effect the thermal bonding step.
8. Apparatus for the production of a thermally bonded fibrous article comprising (a) a mould surface having a shape corresponding with that of the article to be produced; X 1k (b) means for depositing a layer of loose thermally bondable fibrous mass over said surface and holding it in position; and (c) means for forming said layer into an integrated stucture by thermally bonding the fibrous mass.
9. Apparatus according to claim 8 wherein said mould surface is porous and wherein means is provided for applying suction to the underside of the surface to draw a current of fibre charged air against the surface to deposit the fibrous mass and hold it in position.
10. Apparatus according to claim 8 wherein said mould surface is porous and wherein means in provided for applying suction to the underside of the surface to draw a current of heated air through the fibrous mass to effect the thermal bonding step.

Published 1988 at The Patent Office, State House, 6BP71 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.