IE61403B1 - Process for 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. - Google Patents

Description

(C) Copyright 1994, Government of Ireland. 4 0 3 The invention concerns a process for 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 mixing bales, whereby 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-F'S 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 pressed, moulded components according to DE-OS 34 03 670. This process involves the mixing of unraveled waste materials with thermo and/or duraplastic 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 numerous manufacturing steps which have to be separated from one another.

The invention therefore describes a process for the manufacture of moulded bodies or moulded mats, avoiding the above disadvantages and which in particular is self-contained and performed in a continuous manner» The task is realized by a process as described in the introduction, which is characterized by the following cooperating properties;, leading the teased fibre mass in an air current tD a first flocking station; further teasing of the fibre mass as well as mixing through and homogenization 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-type 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 section; renewed teasing and loosening of the fibre web compacted in the drying process to fibres and subsequent preferably pneumatic conveygnce of the fibres into a material buffer, extraction from the buffer in a suction air current and con30 veysice into the storage hopper in a second flocking unit; dosing the fibre mix coated with 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 mix 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 ths roller dosing of the second flocking chamber into the lower section of a permeable-toair 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 far 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-farming flock deliverer; a moveable perforated conveyor surface moving in the direc30 tion of travel located under the flock deliverer, which is connected on its rear side with a suction device, which is led back A 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 trunk; 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 opening; 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 web 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 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 below the storage hopper of the second flocking unit. The fibres and/or binding agent escaping through the perforated mould base are returned to the material flow in this manner» 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 coordinate system, which enables guiding the mouthpiece of the flocking trunk relatively close to the surface of the mould, even for varying application thicknesses, which leads to an improvement of the stability of the mould of the as yet non-solidified fibre web. Guiding the flacking trunk can, for example, be performed 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 mouthpiece, affecting the application of the fibre material into the mould are of particular importance» According to the invention the mouthpiece of the 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 flacking trunk should also be capable of vertical movement, i.e. be moved in a three-dimensional Cartesian coordinate system, which is preferably controlled by computer, according to a selected I program, or controlled by sensors, in particular with the aid o-f an industrial robot. A suitable flocking 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 more 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 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, where 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 40, 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 web. The underpressure in hood 10 ensures that the sprayed on aerosol penetrates ths 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.

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 \ j significantly below the activation or melting temperature of the y 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 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) flacking 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 appli20 ance 15-17 in an even current into flocking trunk 19, 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 IB 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 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 and dosing appliance 15-17. .1 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 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 schematized section through the portioning appliance 15-17 and hood 18 of flocking station 33. At the lower 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, which is the minimum prescription according to 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»

Claims (2)

1. i CLAIMS; 1„ Aprocess for preferably series manufacture of fibrous web-type soft, basically deformation resistant moulded bodies or moulded mats, in particular for noise protection lining of 5 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 10 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 well as mixing through 15 and homogenization 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;

2. Q ' 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 25 with the aid of underpressure on the reverse of the perforated surface;