IE880651L - Fibrous moulded body suitable for noise insulation - Google Patents

Description

61 4 0 3 2 The invention concerns a process tor preferably series manufacture of fibrous web-type soft,, basically deformation resistant moulded bodies or moulded mats., in particular for noise protection lining of crane or vehicle cabins or vehicle interiors., from short and/or reprocessed fibres, preferably cotton reprocessed fibres from mining bales., thereby the mixing bales containing the primary material are broken at an input stage and basically teased out to single fibres. Moreover,, the invention concerns a system for the performance of the process using a mixing bale opener for opening and teasing the introduced mixing bales.

The manufacture of moulded components from fibres teased out to fibre web-type formation is known. In one of these processes described in DE-PS 28 45 112 first of all a continuous mat is produced ? which is subsequently cut and compacted. - The processing of such mat sections produces significant difficulties, above all when the moulded sections to be produced show deep mouldings, because the mat sections cannot take up tensile forces.

This disadvantage is supposed to be prevented by a process for the manufacture of fibre mats as the primary material for pressed5 moulded components according to DE-OS 34 03 670. This process involves the mixing of unraveled waste materials with thermo and/or duroplastic binding agents, the mixture then being spread out to a fibre web on a permeable-to-air conveyor belt and the fibre web compacted at increased temperature under pressure to a transportable mat and cut to moulded blank. After a polyester mat or grid has been positioned between two layers of such fibre web? the formation is compacted to the finished moulded component. This process is laborious and expensive and must be broken up into « I 3 numerous manufacturing steps which have to be separated from one s another.

-) The invention therefore describes a process for the manufacture of moulded bodies or moulded mats,, avoiding the above disadvantages 5 and which in particular is self-contained and performed in a continuous manner- The task is realised by a process as described in the introductions which is characterized by the following cooperating properties: leading the teased fibre mass in an air current to a first 10 flocking station; further teasing of the fibre mass as Hell as mixing through and homogenisation in the first flocking station, subsequent teasing of the fibre mass to a fibre web-type formation and deposition o-f the fibre web-type formation on a permeable to air, moving conveyor surface; spraying the fibre ^eb-type formation conveyed on the moving surface with a binding agent in the form of a solution or dispersion and preferably activated by haat and 20 impregnation of the fibre web-typs formation by through suction of the spray through the fibre web-tvpe formation with the aid of underpressure on the reverse of the perforated surface; drying the fibre web-type formation impregnated with binding agent by removal of the solvent in a subsequent drying section; 25 renewed teasing and loosening of the fibre web compacted in the drying process to fibres and subsequent preferably pneumatic conveyance of the fibres into a material buffer,, ■j extraction from the buffer in a suction air current and con- veyaice into the storage hopper in a second flocking unit; dosing the -fibre mi:: coated with binding agent into an air current by means of a roller portioner located after the storage hopper o-f the second -flocking unit and applying the -fibre mi:: as a ■fibre web-type formation onto a permeable-to-air mould under the influence of underpressure., setting the fibre web-type formation by heating to the temperature necessary to activate the binding agent,.

In a preferred further processing method the portioning of the fibre mix in the buffer to single batches is performed at the delivery to the storage hopper for the second flocking chamber and the application thereof subsequent to the roller dosing of the second flocking chamber into the lower section of a permeable-to-air mould under the influence of underpressure. This enables the advantageous process of variation according to a specified program of the local thickness of fibre application into the mould depending on the required properties of the finished product.

After closing the mould the enclosed fibre web is set in the prescribed permanent shape by heating up to requisite temperature for activating the binding agent and then subsequently removing the moulded body after cooling,, A suitable system for the performance of the process according to the invention with a mixing bale opener to open and tease the introduced mixing bales is characterized by the following properties? A delivery pipe equipped with a material blower runs between the mixing bale opener and a first flocking station., which is made up of a feeder shaft and an attached fibre-web-forming flock deliverer; a moveable perforated conveyor surface moving in the direction of travel located under the flock deliverer, which is connected on its rear side with a suction device, which is led back to the -flock deliverer; the perforated conveyor surface under the flock deliverer leads from the flock deliverer to the input of a drying station? a binding agent spray unit is foreseen over the moveable perforated conveyor surface in the area of the suction device; an opener, preferable a mixing roller opener, is located behind the drying station?, a suction pipe located In front of the opener leads to supply shaft buffer and from supply shaft through a second material blower; to a flocking unit, which basically consists of the storage hopper forming the inlet, a dosing device and a flocking trunks a permeable-to-air uptake surface or mould is foreseen under the outlet of the flocking trunk within the range of movement of the trunk openings the reverse side of the uptake surface or mould is connected via a hood and a pipe to a suction blower; the uptake surface or mould can be connected with an appliance for heating and supplying hot air* The supply shaft filled with the teased out fibres after removal of the solvent or dispersion agent of the binding agent solution or dispersion should preferably be equipped with a weighing machine, preferably an automatic portioning weighing machine* This is designed to portion the individual batches, which are consequently delivered by a further material blower into the storage hopper of the second flocking station. From this hopper they are delivered by a roller portioning appliance in a steady flow to the flocking trunk™ The fibre Neb is delivered through the flocking trunk into the lower section of a permeable-to-air mould which is subject to underpressure. In a particular further forming process the local thickness of the applied fibre into the mould can be varied s according to a specified program to meet the required characteristics of the fabricated product- The use of fibres of individual lengths of at least 12 to 14 mm as primary material has proven advantageous.

The outlet of the suction blower located under the rear side of the base of the mould under the hood covering the second flocking station should preferably be led back by a pipe to the storage hopper, preferably to the portioning appliance located belon the storage hopper of the second flocking unit. The fibres and/or 15 binding agent escaping through the perforated mould base are returned to the material flow in this mariner- According to the invention at least two-dimensional movement of the mouth of the trunk is required; preferably the mouthpiece of the flocking trunk can be moved over a three-dimensional Cartesian 20 coordinate system? which enables guiding the mouthpiece of the flocking trunk relatively close to the surface of the moulds, aven for varying application thicknesses, Mhich leads to an improvement of the stability of the mould of the as yet non-solidified fibre ^eb» Guiding the flacking trunk cans for example, be performed 25 pneumatically or by hydraulic cylinder piston units„ In general both the shape and also,,, and in particular,, the movement of the flocking trunk, i.e. its mouthpieces, affecting the application of the fibre material into the mould are of particular importance. According to the invention the mouthpiece of the 30 flocking trunk must be capable of moving longitudinally and diagonally to the mould so that it is possible to realise desired application thicknesses at any location. Preferably the mouthpiece of the flocking trunk should also be capable of vertical movement, i.e. be moved in a three-dimensional Cartesian coordinate system, 35 ^hich is preferably controlled by computer, according to a selected program, or controlled by sensors,, in particular with the aid of an industrial robot. A suitable flacking trunk for the system according to the invention can, for example, be similar in shape to those as represented in Figs. 1 and 2 of DE-PS 24 48 437., which are designed to prevent the -formation of lumps in the processing of fibre webs under the application of liquid binding agents.

The invention shall be described in mare detail on the basis of the enclosed drawing of one of the types of layout of a system in accordance with the invention. The following are showns Fig. 1 Block diagram on layout of a system in accordance with the invention? Fig. 2 view of a production system in accordance with the invention; Fig. 3 section through a strongly schematised flocking station.

The block diagram in Fig. 1 shows the flow of the process according to the invention. The mixing bales 3 are introduced singly to the mixing bale opener„ sphere they are opened; the fibres are teased and separated out. The opened fibres move from the mixing bale opener into a first flocking station 36. Here the fibres are spread to a fibre mat and then sprayed in spray station 9-11 with a solvent,, for example water, or dispersing agent containing a liquified binding agent. Under pressure created on the rear side;, i.e. the other side of the fibre mat facing the spraying device 11 (Fig. 2), ensures suction of the spray through the fibre mat such that the spray impregnates the mat.

The fibre mat impregnated by binding agent then passes through dryer 12. where the solvent or dispersion agent is evaporated off. The now dry fibre matting solidified by the binding agent adhering to the single fibres is now again thoroughly teased open in a subsequent mixing roller opener and then delivered into a supply shaft 409 which also acts as a buffer and — in the case of installation at the base of the supply shaft of a preferably automatic weighing scale 34 and appropriate appliances for controlling supply shaft output — as a batch portioner. The fibre matting with adhering binding agent is then conveyed batchwise to a second proper flocking station 33, where the fibres are introduced to the mould and solidified by hot air from an air heater.

Fig. 2 shows the schematic layout of an example of a design of a system in accordance with the invention. The fibres delivered at the fibre delivery 2 of the bale opener are taken up by the suction connection 4 of a material blower 5 and delivered through a supply pipe 6 to the first flocking station. These are delivered into feed shaft 7 and extracted from the feed shaft at an even rate by a flock deliverer and formed into a fibre mat in a downward-leading and appropriately shaped shaft. The fibre web is positioned at shaft outlet onto a permeable-to-air conveyor belt 9 and conveyed in direction of travel 41. A suction hood 10 is located below the conveyor belt 9 conveying the fibre mat; the suction hood 10 is connected to a suction blower which is not subject to any further description.

A spray unit 11 is located above belt 9 for applying as fine a spray as possible of the binding agent solution or dispersion to the fibre ^eb. The underpressure in hood 10 ensures that the sprayed on aerosol penetrates the loose fibre mat causing impregnation by the binding agent. The result is a practically even distribution of the binding agent over the whole cross-section of the fibre web. The aerosol entering the underpressure side is recycled. s The fibre web delivered from spray station 11 is conveyed by conveyor belt 13 to dryer 12 where it is dried and solidified. It must be pointed out that the temperature in dryer 12 must lie significantly below the activation or melting temperature of the 5 binding agent used.

The solidified strip of fibre web leaving dryer 12 is then again opened out and teased apart in a subsequent mixing roller opener. Suction pipe 39 then takes up the fibres and delivers them to supply shaft 40. which also acts as buffer and weighing store. A 10 preferably automatic weighing machine 34., which also operates the outlet trap located at its outlet,, is foreseen. The fibres with adhering binding agent are taken up batchwise by the suction pipe of a material blower 37 and delivered into the storage hopper of the second (actual) flocking station 33.

The flacking station 33 described in more detail in Fig. 3 consists basically of storage hopper 14. dosing appliance-.15-17 and the moving trunk 19 located within a shroud 18» The fibres with adhering binding agent are fed downwards through dosing appliance 15-17 into closed storage hopper 14 and portioned by dosing appli-20 ance 15-17 in an even current into flacking trunk i9s which applies the fibres according to a specified program to the mould, that is base mould section 28, located on a frame 38 under hood 18 of the flocking station. The base of the mould is perforated and connected via hood 25 and pipe 26 to a suction blower 24. The 25 suction blower creates underpressure in the mould, which sucks and compacts the fibres to the base of the mould. The air sucked from mould 28 and the binding agent and fibres which pass through the perforation of the base of the mould are recycled through connection pipe 27 located between the outlet of suction blower 24 30 and dosing appliance 15-17.

I 0 The base mould 28, filled with the fibres with adhering binding agent* is pushed onto frame 28 for solidification under hood 42 by a hot-air circuit 29-31 from an air heater 28 from hot air feed 30 and hot air return 31, where the upper mould 32 is pressed onto to 5 cover the prescribed base mould. The hot air activates the binding agent,, and after cooling down mould 28, 32 the finished moulded component can be removed- Fig. 3 shows a strongly schematised section through the portioning appliance 15-17 and hood 18 of flocking station 33. At the lower 10 end of storage hopper 14 fit two portioning rollers 16., 17, under which is located with surface contact the foreseen portioning drum 15 with toothing 35. The material deposited in storage hopper 14 is delivered through the devices 15-17 in a steady flow into trunk 19 and from this trunk into the mould, i.e. the base mould 28.

A cylinder piston unit 21 mounted on a bracket 23, itself mounted on shrouding 18, can be seen in Fig„ 3. This unit 21 guides trunk 28 mounted in trunk hanger 20. The figure does not show a second such unit positioned vertically for achieving a two-dimensional swinging movement,, ^hich is the minimum prescription according to 20 the invention. However,, the figure does not show trunk 19 in the most simple rigid form,, but is at least at its lower range moveable in all directions along a horizontal plane such that the preferred movement in a three-dimensional Cartesian coordinate system is g i ven,, I V I r,

Claims (1)

1. lirprocassfar p r ef er ab1y series manufacture of fibrous web-type soft, basically de-formation resistant moulded bodies or moulded mats, in particular -for noise protection lining of crane or vehicle cabins or vehicle interiors, from short and/or reprocessed fibres, preferably cotton reprocessed fibres from mixing bales. whereby the mixing bales containing the primary material are broken at an input stage and basically teased out to single fibres, the process including: leading the teased fibre mass in an air current to a first flocking station; further teasing of the fibre mass as ^ell as miv.ing through and homogenination in the first flocking station,, subsequent teasing of the fibre mass to a fibre web-type formation and deposition of the fibre web-type formation on a permeable to air,, moving conveyor surface; spraying the fibre web-tvpe formation conveyed on the moving surface with a binding agent in the form of a solution or dispersion and preferably activated by heat and impregnation of the fibre web-type formation by through suction of the spray through the fibre web-type formation with the aid of underpressure on the reverse of the perforated surface; drying the -fibre web-type formation impregnated with binding agent by removal of the solvent in a subsequent drying sections renewed teasing and loosening of the fibre web compacted in the drying process to fibres and subsequent preferably pneumatic conveyance of the fibres into a material buffer, extraction from the buffer in a suction air current and convey aice into the storage hopper in a second flocking unit; dosing the fibre mi:: coated mth binding agent into an air current by means of a roller portioner located after the storage hopper of the second flocking unit and applying the fibre mi:', as a fibre web-tvpe formation onto a permeable-to-air mould under the influence of underpressure, end. setting the fibre web-type -formation by heating to the temperature necessary to activate the binding agent. A process according to claim 1£ comprising the portioning of the fibre mix in the buffer to single batches at the delivery to the storage hopper for the second ■flocking chamber and the application thereof subsequent to the roller portioning of the second flocking chamber into the lower section of a permeable-to-air mould under the influence of underpressure. A process accx>rt3ing to claim 2f ccffiprising variation according to pre-sat program of the local thickness of the fibre application into the mould depending on the required properties of the finished product. A process according to one of the claims 1 to 3, cxsEiprising setting the fibre-web matting in the prescribed permanent shape after closing the mould by heating up to requisite temperature for activating the binding agent and subsequently removing the moulded body- A system for tha perfoxntance of the process according to one of the above claims, using a ndscing bale opener to break and open the introduced mixing balesF the system ccnqotrising: a delivery pipe equipped with a material. blcs^ar, the delivery pipe - located between the mixing bale opener arid a first flacking station, which consists of a feeder shaft and an attached fibre web-forming flock deliverer? a moveable perforated conveyor surface moving in direction of travel located! under the flock deliverer., which is coersnected an its rear side 'with a suction devicef which itself is led back to the flock deliverer! the perforated conveyor surface under the flock deliverer leading, from tha flock deliverer to the input of a drying station ; a binding agent spray unit being foreseen over the moveable perforated conveyor surface in the area of the suction device? an opener„ preferably a mixing roller opener being located behind the drying station ; ft ft - ' » 10 15 6, 20 7. 25 8- 14 a suction pipe located before the opener leading to a supply shaft buffer and another leading from supply shaft through a second material blower to a flocking unit, which basically consists of the storage hopper fanaing the inlet, a portioning device and a flocking trunk; a permeable-to-air uptake surface or mould being foreseen under the outlet of the flocking trunk within the range of movement of the trunk opening; the reverse side of the uptake surface or mould being connected via. a hood and a pipe to a suction bloner; and the uptake surface or mould being aswisectable with an appliance for heating and supplying hot a±r„ A system- feecoeding to claim 5 comprising equipping the supply shaft with a weighing machine? preferably an automatic portioning weighing machine, A system according to claim 5 or 6, ccMprising a flocking trunk scuthpiece %»hieh. is moveable in a three-dimensional Cartesian coordinate system. A system according to claim 7, comprising movement of the flacking trunk controlled pneumatically' or by hydraulic cylinder piston units. 15 9. A system according to claim 7 or 8, oatKarising preferably three-dimensional guidance? at the -flocking trunk according to a specified progxeoi or an automatic 5 device guided by sensors. 10. A.systen according to cans of the claims 5 to 9, ccnprising connecting the outlet of the suction blower at the rear side of the uptake surface or mould via a connection pipe £0 to the storage hopper preferably to tha portioning defies located below tha storage hccper of the second flocking unit. 11. A process for preferably series manufacture of fibrous web-type soft, basically deformation resistant moulded 15 bodies or moulded mats according to any preceding claim substantially as hereinbefore' described with reference to and as illustrated in the accompanying drawings. 12. A system according to- claim 5, substantially as herein- 20 before described with reference to and as illustrated in the accompanying drawings. 13- Fibrous web-type soft, basically deformation resistant moulded bodies or moulded mats, whenever manufactured by a process claimed in a preceding claim. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS.