CA1288915C - Method of producing a mat consisting of filament loop aggregations - Google Patents

Abstract

Abstract of the Disclosure In this method of producing a mat consisting of filament loop aggregations, against the step of forming a fisrt filament loop aggregation low in the filament density wherein wherein many filaments made by extruding a thermoplastic synthetic resin out of a die and arranged longitudinally and laterally at intervals are continuously molded, are present on a water surface boiling while keeping a filament tempera-ture close to the temperature at the time of molding by heating while the filament bundle is vertically lowered toward a cooling water surface and are sunk into water in the vertical direction while being con-trolled to be at a speed lower than the filament extruding molding speed, while a high density thermoplastic synthe-tic resin layer is conveyed under heating by a conveyer controlled to be at a feeding speed equal to the sinking speed in water of the above mentioned filament loop aggregation and is sunk into the cooling water along the outside of the filament loop aggregation at the delivery end, said filament loop aggregation and thermo-plastic synthetic resin layer are fused together on their contact surface.

Description

~ 89~ 5 SPECI~ICATION

Tltle of the In~entlon:
METHOD OF PRODUCING A M~T CONSISTING
OF FI~AMENT l.OOP AGGP~EGATIONS

Thls lnvent~on rela~e~ to method of producing a mat conslstlng of fllament loop aggregat-10~5, which is a coarse net-llke developed resilient mat madQ by complLcatedly entangllng synthetic resin monofllaments and more particularly to .. method of produclng a mat con~isting of fllament loop a~gregat-lon~ and adapted to a porch mat of flxed dimention~
~r a fl~or mat formed and laid ln a lomg sheet.
Instead o~ a conrentlonal carpet mat or synthetlc resln mat, there is recently provlded a three-dimenslonal net-like mat conslstlng of synthetic resin monof~lament~ hlgh ln the water permeabllity and qulck dryablllty. Due to such char~cterlstlcs a~ the resill-ency and weather-proofness, such three-dimensional net-llke mat 18 ueed ln many lndoor and outdoor flelds, i~ applled partlculsrly to such water uslng place as, for example, an lnlet and outlet of a bath room or a pool ~lde and 19 appreclated becaus~ lt 18 slmple to wash and dry.

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Also, as this kind of three-dimensional mat is open, the sand and gravels brough when it is trod will drop down ~nd will not remain on the surface.
As water or the like also wlll drop down, the surface can be always kept dry. It i8 thus convenient.
In addition, when such elastic sheet as a synthetic resin sheet, foaming eheet or rubber sheet is pasted to the lower ~urface of such mat, the cushion-lng property as of a mat will be able to be ~ncreased, the ~and and water dropping from the surface will be able to be recel~ed by this sheet pasted to the lower surface and the floor will be able to be prevented from being made dirty directly by the dropping sand and the l~ke, Descript~on of the Pri~r Art;
As disclosed ln the gazette of a Japanese patent publication No.14347/1972, such three-dimensional net-like mat i8 .formed a~ a non-woven fabric wherein many monofilaments made of a thermoplastic synthetic resin are lamlnated whlle belng rubbed and bent, are fused at thelr contaot polnt~ and are cooled to be solidified, The formation of upright loops disclosed in the gazette of a Japanese patent publication No.31222/
1980 and a Japanese patent laid open No.85061/1987 i~

z 2 =

known as a web forming means of the above mentioned flilaments in such non-woven fabric.
Now, in the non-woven fabric formation by the abo~e descr~bed cQnventional means, in ~uch rubbed and bent web formation, the resiliency of the individuà~.
rubbed and bent filament form part itself is low, the rubbed and bent filament~ by this producing means overlap on each other to fall down and, as a result, as the entangled density of the filaments becomes higher, the resiliency of the sheet wlll be lost ~ hu~, when the mat i~ used, the treading touch will be obstructed and, when the mat i8 stored or carried, it will be difflcult to wlnd in the sheet-like mat, much to the inconvenience On the other hand, when the web formation is made loop-~ike, the resiliency of the filament itself in each loop-llke part will be developed but, in the web made of arcuate loops arranged in a sub~tantially fixed form, the respectlve loops are only fused at their intersecting points and the contact point~ between the ad~acent loops, are high ln the lndopendency and are therefore low in the resiliency against treading and, a~ ~ result, no favorable treading touch wlll be obtained.
Summar~ of the Inven_ion:
Therefore, the present lnvention has it as an 3 ~

~.2~ 5 object to provide method of producing a mat wherein a filament web is foarmed of positively closed loops to develop a filament resiliency in each loop part and the degree of the contact f usin~ between the respective loops is made high to be able to develop a strong sheet resiliency.

Description of the Drawln~s.:
The many advantages and features of the present invention can be best understood and appreclated by reference to the accompanying drawings wherein:
~ ig. 1 i8 a side view of Qn essential part showing an embodiment of the apparatus of the present invention;
Fig. 2 i~ a slde view of an essential part showing another embodlment of the method of the present invention; and ~ ig, 3 i8 a ~heet producing process block diagram by using the method of the pre~ent invention.
Detailed Descriptlon of the Inventlon:
According to the present lnventlon, a mat i9 made by overlapplng a three-dlmen~ional aggregatlon o~ upright disarranged loop-like synthetic resln filaments and a ~ynthetic resln layer having very few clearances or no clearance and has many spaces wlthin the three-dlmen~ional aggregation of the ~ilaments ~ 4 ~

~ 5 to develop a cushioning property.
In order to produce such mat, several hot filament~ of a thermoplastic synthetic resin are pressed and extruded through die orifices and are made to fall toward a water surface.
~ he falling hot filaments are heated by such heat sources as ceramic far infrared ray heater3 so as not to be cooled by the atmosphere.
Such hot filaments are easy to make coiled loops on the water surface. Unless the filaments are hot, the loops will become large, Further, in the filaments of a reduced temperature, no coiled loop will be formed but only a channeled rubbed and bent form will be able to be made.
The height from the die mouth end to the water surface i~ 5 to 100 cm. and the heat reduction of the fllaments 19 prevented by making the die mouth end approach the water surface as much as possible.
lhe oriflce diameter of the dle i8 0.3 to ~.5 mm. as an element determlnlng the fllament diameter ln con~ideration of the shrlnkage of the materlal at the time of hardening after being extruded and molded, retains the resiliency and durability of the formed fllaments and prevents the permanQnt set.
A mat sheet consisting of filament aggrega-~ 5 =

s tions of respectlve width~ can be made by arranging thenumbers of orifices corresponding to the widths of 90, 120 and 150 cm. of intended mat sheets with an orifice arrangement of a die of 2 to 6 longitudinal rows at the intervals of 3 to 5 mm. and a pitch of 3 to 5 mm.
in the lateral rows.
~ hat is to say, a hot first filament bundle extruded out of the ~-die of such orifice arrangement is made to fall uprlght toward cooling water and is received by submerged rolls of a rotary peripheral speed well slower than the falling speed to limit the falling speed ln water and to give the filaments a resistance toward the water surface from the above mentioned rolls. Loops having a peripheral length of the filament length corresponding to the difference between the extruding speed of the respective fllaments and the falling speed in water wlll be sequentially continuously described to form a coll-llke flrst fila-ment loop aggregation, In the samQ manner, a second filament bundle falling toward a conveyer present on the water ~urface wlll be prevented by thl~ conveyer from sinking into water and will form loop~ on the water surface to form a ~econd filament loop aggregatlon con~isting of over-lapped coiled loops controlled by the conveying ~peed - 6 =

~ 9~ S

of the conveyer.
At this time~ ~n order to make it ea~y to form loops in the fir~t filament loop aggregation and to make bent irregular loop~, lt i8 effective to keep boiling the cooling water ~urface on which the filament bundle fall 9, Thi3 boiling state vibrates the respective ftlaments wound on the water ~urface. A~ a result, entangled disarranged coiled 1OOPB will be induced on the water surface.
In order to make the boiling state on this water surface, it i8 important to keep the filament~
coming out of the die at a high temperature until the li~uld level. Generally, when the filaments are in contact with the atmosphere, the filament tempera-ture will quickly reduce. The water surface heated by the falling in water of the filament bundle kept at a filament extruding molding temperature~of 200 to 150C, by the above mentioned heating treatment to prevent air cooling in the filaments coming out of the die will be in the boiling state. Therefore, when the cooling water 19 kept at a high temperature of 60 to 80C., thi~ bolling w~ll be made positive.
When the filaments are molded to be coiled loop~ while kept at a hlgh temperature, the fu~ing between the loops will be accelerated. Further, when the cooling water i8 at a hlgh temperature, in case the molded loops are pulled out into the atmosphere by the guide rolls and are sent to the secondary process, they will be able to be ea~ily dried with cool or hot air.
A filament loop aggregation in which the coil density i8 made coarse by increasing the rotation (pulling speed in water) of the rolls in water and the conveyer speed ~ynchroniæed with it and is made high by reducing the pulling speed i~ formed.
On the other hand, even if the thickness width of the hanging first filament bundle i8 not regulated, a three-dimensional formation of coiled loops will be made but the ~i2e of the loops formed on the li~uid surface wlll not be constant. ~herefore, a means of regu~ating the thickness width of the filament bundle functions effectively to form an intended uniform thick-ness coiled loop aggregation.
For the second filament loop aggregation fed onto one outside of the first filament loop aggre-gation, a guide roller iB located ~u~t below the water ~urface on the other out~ide of the first filament loop aggregation to regulate the position cf the first fllament bundle sinking while describing loops and therefore the thickness width of the filament bundle = 8 s in the posltlon on the water surface ~ust above the gulde roller will be regulated a9 related w~th the regulatlon below the water surface.
Such first and second ~llament loop aggrega-tlons are proces3ed ln two parallel place~ and the above mentloned rlrst aggregation 18 formed along one slde surface of the abo~e mentloned second aggregatlon.
In ~uch formatlon, when the above mentloned ~econd aggregatlon 18 heated on th~ slde ~urface to be about the fus~ng temperature, the fllaments on the slde surface wlll soften to maka a 3ynthetlc resln layer of a hlgh denslty by the lateral fall of the loop~, ~ hererore, thls synthetic re~in iayer may be the second fllsment loop aggregat1on ~ormed ln advance a ~ynthetlc res~n ~ack sheet or net-sheet.
In molding ~nthetlc resins, the general tem-perature as of the coollng bath 18 about 50.C. for PE
(polyethylene) and YP (polypropylene), about 10 to 40C.
for PVC (polyvlnyl chloxlde) and about 8~C. for PS
(po~ystyrene).
The surfacQ tenslon of water on PVC (polyv~nyl chlorlde) i8 80 hlgh as to be about 60 to 70 dym,/cm.
that flne ilaments o~ an outslde dlameter less than 1mm. wlll be overlapped in turn above the water ~urface, n 9 D

~ ~ 8~ 9~ S

the coiled loops formed here wlll be laminated in several steps end wlll be cooled in water and there-fore the obJect aggregat~ons coarse ln the loop olearance~
will not be obtained, Therefore, ln order to se~en-tially slnk the colled loops by the fllament bundle on the liquid surface, lt 18 effective to add a ~urface active agent reduclng th~ 8urface tension of the cooling bath.
~ mbodlments of the pre~ent invention ~hall be expla~ned in the followlng:
bodlments:
Fig. 1 is a slde ~iew showlng component parts ln an optimum apparatu8 for embod~ing the present inventlon. ~wo sets of filaments 2a and 2b are to fall vertically toward cooling water 5 while being molded ln the thickness direction (longltudinal d~rec-tion) from a dle 1 extruding a thermoplastic synthetic resln material under pressure.
In the lateral dlrectlon ~front to back direc-tion of the paper 8urface) of the die in thi~ case, many filaments 2a and 2b are to be molded as arranged at predetermined interval6 (pltch of 3 to 5 mm.) in the length 20ne correspondlng to the lateral width of an intended moldlnB-A conveyer 4 present on the water surface is ~ 10 .

arranged ln the falllng zone of the filamentR2b andi8 to be driven at a conveying speed equal to the later described comparatively 910w water sinking speed of the filament loop aggregation.
On the other hand, in the falling zone of the filaments 2a, bar-llke ceramic far infrared ray heaters 3a and 3b are arranged together with reflecting plates 9 80 as to be heating heat sources.
On the fal~ing water surface of the filaments 2a, a guide roller 6 i9 arranged at a predetermined spacing from the delivery end of the above mentioned conveyer 4 90 that the bundle of the filament~ 2a may fall on thè water surface in this clearance and may be led by this roller 6 to sink down~
A pair of feedlng submerged rollers 7a and 7b rotated and driven at a oonstant speed are arranged in water to hold and contract the bundle of the filaments 2a having sunk in the above mentioned water and move it in the cooling water 5. Many engaging pins 8 are erected at intervals on the peripheral surfaae~ of these submerged rollers 7a and 7b. As the rotating peripheral speed of these rollers 7a and 7b rotating at a constant speed is set to be lower than the falling ~peed of the filaments 2a, the filament~ 2a falling at a high s~eed from the die 1 will be decelerated in sinking in water 1 1 =

S

by the above mentioned submerged rollers 7a and 7b and, as a result, will be relaxed by the filament length corresponding to the dlfference betwee.n the falling speed and sinking speed, ~hese relaxations will concentrate in the water surface zone due to the buoy-ancy of the filaments 2a of a small specific gravity.
As a result, the filaments 2a will form loops on the water surface.
That is to say, the filaments 2a extruded out of the die will reach the water surface o~ the cooling water 5 while being kept near the temperature at the time of molding by heating by the above mentioned heaters 3a and 3b in the falling 20ne in air, ~he filament~ 2a having sunk ~n the coollng water 5 will ~uickly lower in the temperature and wlll be hardened, However, these hardened tilament~ 2a will be regulated in the pulling amounts by the submerged rollers 7a and 7b stopped in sliding by the engaging pins 8, therefore the hardened part~ in water will. be sub~ected to resis-tances from the rollers 7a and 7b in water and thereby the soft filaments 2a still at a high temperature ~ust before reaching the water surface will be curved and will be gradually pulled into water while describing 100PB ta form co~led loops.
When the temperature within the bath of this - 12 =

cooling watex 5 is kept at 60 to 80C., the cooling water 5 in the falling position will be locally boiled by heating by the filaments 2a reaching the water surface while at a high temperature. By this boiling, the water surface of that part wlll be waved and greatly rocked and therefore the filaments 2a de~cribing loops on this water surface will be waved and disarranged in xesponse to the rocking of the water surface.
~ herefore, the total surface contact between the ad~acent loops overlapped on the water surface will be obstructed by the concavo-convexe~ by thls dis-arrangement of the disarranged form loops and the contact point parts will be comparatively many.
In such contact part, the loops will be fused with each other between them and will be cooled to be hardened. lherefore, coiled loops having comparatively many fu~ed parts,'between the ad~acent loops will be continuously formed ln turn and a filament loop aggre-gation A in which colled loops a1 are cro~s-linked longitudinally and laterally wlth loop edges overlapping between ad~acent filaments 2a will be formed.
On the other hand, the other corresponding filaments 2b will form on the falling water surface loops by the filament length corresponding to the difference from the extruding, molding an~ falling speed = 13 =

~ .5 at the conveying speed at the conveyer 4 equal to the sinking speed of the filament loop aggregation A regu-lated by the above mentioned submerged rollers 7a and 7b and will be transmitted toward the falling zone of the above mentioned filaments 2a while being laminated in turn to be coiled on the conveyer 4. A filament loop aggregation B high in the filament den~ity will be formed by being fused in the coiled loop overlapping parts by heating by the abo~e mentioned heater 3b while the filaments 2b on this conveyer 4 are conve,yed, will be well softene~ on the surface, will be conyeyed to the dellvery end of the conveyer 4 and will sink into the cooling water 5.
The sinklng zone in water o this aggregation B is located on one out3ide of the falling ~one of the above mentioned filaments 2a. ~he filaments 2a falling between the aggregation B and the guide roller 6 on the opposite side will be regulated in the thicknes~
width by the aggregation B and guide roller 6. Therefore, the size of the loops wlll be formed to be sub~tantially constant and the softened surface of the above mentioned aggregation B and the loops on one side of the aggrega-tlon A will be fused together.
Thereby, there i8 formed a mat material wherein the second filament aggregation B (lnathe ~ 14 _ laterally ~allen dlrection) hlgh ln the density 1~
overla~ped on one slde surface of the first filament a~regatlo~ ~ (ln the uprlght dlrect~on).
By the way, a~ another embodiment, the above mentloned hlgh den~ltly 3econd fllament aggregatlon B
need not always be formed slmultaneou~ly parallelly wlth the aggregation A. As shown in Flg. 2, the a~gre-gation ~ formed ln advance may be fed onto the conveyer 4.
As of a thermplastlc ~ynthetlc resin of a ~igh den~lty, a back sheet made o a ~ynthetic re~in fllm.or net-sheet madc of synthet1c re31n may ~e fed lnstead o~
thls ag~re~atlon B. In tha embodiment shown in the above ment~one~ Plg. 2, tha ~ame mechanl~m part3 as ln the embodlment shown 1~ the a~ove mentioned Ftg. 1 shatl bear respectlvely c~mmon reference numerals~
In these respectivQ embodlmente, the co~veyer 4 has lts conveylng ~urface set to be substantlally flu~h wlth the water qurfacc but may be arranged to have lts conYey1ng surface 80mewhat lncllned to be submerged at the dellvery sidQ tlp.
~ y th~e wag, ln order to pull the colled loops formed on the coollng water surface into water without dl3turblng thelr form, a surface active agent 19 added lnto coollng water 4.

~- î S 8 s Amounts of addltion of the surface active agents per 100 parts of water:
Anion system: Alkylbenzenesulfonate 1 to 0.2 part ~ialkyl~ufosuccinste 1 to ~.0~ "
Nonionic syYtem: Polyoxyethylene nonylphenol ether 1 to 0.1 "
It is effective to add 0.05 to 0.2% dlalkyl-sulfosuccinate which i9 high in the capacity of reducing thesurface tension and in the connecting effect with a 81 i ght amount.
Now, in this kind of apparatus, in order to keep the cooling bath level constant, cooling water is circulated with a pump while being overflowed. In such case, many bubbles will be generated in an aux~liary tank le~el ~etecting e~ectrode and cooling bath and will be disadvantageous in molding. In thl~ re~pect, at the above mentioned effective component concentra-tion of the dialkylsulfosuccinate, many bubbles tend to be generated. Therefore, it can be said to be optimum to add and use preferably 0.05 to 0.2% dialkylsulfo-succinate.
The mat material conYiYting of the thus formed filament loop aggregations A and B may be coated wlth a pla~tiYol made of the same material mixture as of the f'ilament to prevent the bonding strength reduction , 16 =

s and permanent ~et of the ~ilament loop~, The apparatus formatlon therefor 19 shown in ~g. 3, An aggreeat1~n A p~lle~ up from a bath 10 ~f the above mentloned coolln~ water 5 19 fed into a prlmary dryer 12 by a feedlng roller and i8 drled at a low temperature. In th1s drying, th~ aggregat10n A
18 stlll a~out 70C. by the coollng water 5 at a high temperature. Therefore, the water can be comparatively easlly and poslt~vely remoYed by blowing warm wind or the llke.
The dr~ed aggregatlon A 19 ~ed lnto a surface coatlng process part 13 by the above mentloned pla3ti901, 18 processed ln the part 13 by ~uch means as blowing, palntlng or d~pp~n~ t~en fused by high temperature dryln~ ln ~ secondary dryer 14 and 18 wound up on a wlnder 15. A b~ck sheet conslstlng o~ a resln sheet, foamed sheet~ rubber sheet or net-sheet may be used as bonded to the bac~ surfacQ of thl~ aggregatlon A
ln re~ponse to the ob~ect of use of the mat or sheet.
(Formatlon Example 1) Polyvlnyl chlorid~ (PVC)~P-l300)100 parts Plastlclzer DOP Dloctyl phthalste 50 Stablll~er Dl~ut~l tin laurate 2 Csdmlum ~tearate 0.6 part " ~arlum ~tearatQ 0.4 Colorlng agent 0,1 ~ 17 ~

A compound material of the above mentioned mixture i9 molded to be filaments by an extruding molder.
~ he di~tance between the conveyer 4 below the cooling water surface and the guide roller 6 is set to be 15 mm. ~he distance between the guide roller 6 and submerged roller 7a i~ 9 mm. ~he filament molding orifice dlameter o the die 1 i~ 0.8 mm. ~he d~e orifice arrangement i~ of four longitudlnal rows.
~'he clearance between the filament 2b orifice and filament 2a orlflce i3 50 mm, The clearance between the fllaments 2a^is 4 mm. ~helr lateral orifice pitch 8 5 mm. ~he ~tance between the die and cooling water ~urface ~3 5 cm.
~ he die temperature ~ 8 185~C, The die pressure i9 90 kg./cm2. The extruding pressure i~ 190 kg./cm2, The cooling watèr temperature i9 60 to 80C. ~he guide panel temperature is 120C. ~wo ceramic far infrared ray heaters of 2.5 KW each are used. At a molding linear speed of 2m. per minute, loops at a speed of 40 cm. per minute can be made.
In this ~ormation, by only holding the fila-ment bundle in ite thickness width dlrectlon wlth the guide roller~, the front and back surfaces of the aggre-gat~ons can be unifarmed and a mat of a ~1ame~t diameter = 18 =

3 ~ 3~

of 1 mm., loop size of 5 to 10 mm. and thickness of 14 mm. i8 obtained and is made a product through drying and bonding ~teps.
(Formation Example II) When, in the conditions of ~ormation Example I, the filaments 2b are in two rows at a spacing of 4 mm., the filaments 2a are in two rows at a spacing of 4 mm. and the di~tance between the filaments 2a and 2b i9 45 mm, a thick mat of the above mentioned second aggregation layer B part of a fllament diameter of 1 mm., loop ~ze of 5 t~ ~0 mm. and thicknes~ of 14 mm i~
obta~ed.
~Format~on Example III) When, ln the conditions of Formation Example I, the filament~ 2b are in two rows at a spacing of 4 mm., the filaments 2a are in two rows at a spacing of 4 mm., the distance between the filaments 2a and 2b is 4~ mm. and the distance between the conveyer 4 and guide roller 6 is 17 mm., Y 19 =

., a thlck mat of a filament diameter of 1 mm., loop size of 5 to 10 mm. and thickne~ of 16 mm. is obtained.
(Effects of the Invention) Thus, according to the method of the present invention, as an aggregation i8 formed of irregular form loops by windlng filament~ to be coil-like, the indivi-dual closed loops well develop the filament resiliency, are of such lrregular form as a wavy form and are therefore hlgh in the degree of contact fuslng between the ad~acent continuous colled loops and between the loop forming filaments arranged longitudinally and laterally and thu~ a mat high in the bonded degree as a whole can be obta~ned. In the aggregat~on part in which such loop~ are formed in the upright direction, in addltlon to the resiliency of the above mentioned loops themselves, a stiff mat resiliency can be obtainsd by the strength of the bonded degree between these loops The hlgh density thermoplastic synthetic resin layer is high in the strength, particularly, in the tensile strength. ~herefore, according to the method of the present invention, there can be obtained a mat material high in both resiliency and tensile strength and optimum to be used for a porch mat or fioor sheet very high in the treading touch.

In the method of the present inventton, the filaments are lowered onto the water surface while near the molding temperature and, when this water surface is waved by boiling, the loops formed on the water surface will be able to be in such irregular forms as wavy forms and to be contact-fused ln the loop intersecting parts and between the loops.
When the second filament loop aggregation is made a high density thermoplastic synthetic resin layer simultaneously in parallel with the formation of the above described first fllament aggregation low in the filament density, the above mentioned long mat material can be continuously formed. ~owe~er, simply, the above mentioned second aggre~ation or back sheet mater~al formed in advance or net-sheet may be used.
In addition, there are auxiliary effects that, when the filament bundle falling toward the coollng water surface i8 regulated ln hte direction of contracting from outside the width of the thickness directlon of the bundle, the sizes of the respective loops formed of these filaments will be able to be uniformed and, when the contracted width is controlled, the formation of combin-ing the above described upright directed loops and laterally fallen loops will be able to be freely made.
If the distance from the dle to the cooling . .

il 2~

water surface is long, the filament temperature will be reduced by air cooling between them. Therefore, it is desirable to set the distance to be as short as possi~le. However~ if they are to adjacent, the loop formation on the water surface will be disturbed. Therefore, this distance of 5 to 10 cm. is effective.
sy keeping the temperature of the cooling water at a comparatively high temperature of 60 to 80C., a local boil-ing state in which the water surface on which the filaments fall is properly waved by heating by the filaments submerging into water can be automatically obtained. In order to smmooth-ly sink the filaments to prevent the loop forms being disturb-ed, it is effecti~e to ad~ a surface active agent.

_ 22 =

Claims (8)

1. A method of producing a mat consisting of filament loop aggregations characterized in that, against the step of forming a first filament loop aggregation low in the filament density wherein many filaments made by extruding a thermoplastic synthetic resin out of a die and arranged longitudinally and laterally at intervals are continuously molded, are present on a water surface boiling while keeping a filament temperature close to the temperature at the time of molding by heating while the filament bundle is vertically lowered toward a cooling water surface and are sunk into water in the vertical direction while being controlled to be at a speed lower than the filament extruding molding speed, while a high density thermo-plastic synthetic resin layer is conveyed under heating by a conveyer controlled to be at a feeding speed equal to the sinking speed in water of the above mentioned filament loop aggregation and is sunk into the cooling water along the outside of the filament loop aggregation at the delivery end, said filament loop aggregation and thermoplastic synthetic resin layer are fused together on their contact surface.

2. A method of producing a mat consisting of filament loop aggregations according to claim 1 wherein said thermoplastic synthetic resin layer is a second filament loop aggregation high in the filament density formed while sinking is obstructed by said conveyer present on the falling water surface of a second fila-ment bundle formed in parallel with said first filament bundle.

3. A method of producing a mat consisting of filament loop aggregations according to claim 1 wherein said thermoplastic synthetic resin layer is a second filament loop aggregation high in the filament density formed in advance.

4, h method of producing a mat consisting of filament loop aggregations according to claim 1 wherein said thermoplastic synthetic resin layer is a sinthetic resin back sheet or net-sheet.

5. A method of producing a mat consisting of filament loop aggregations according to claim 1 wherein the width in the thickness direction of said first filament bundle is regulated by the synthetic resin layer led by said conveyer on its falling water surface and a guide roller present on the opposite side.

6. A method of producing a mat consisting of filament loop aggregations according to claim 1 wherein the distance from the lower surface of the die to the water surface is in the range of 5 to 10 cm.

7 A method of producing a mat consisting of filament loop aggregations according to claim 1 wherein the cooling water held at a temperature of 60 to 80°C.
is locally boiled by heating by the sinking loops just below the fall of said filaments.

8. A method of producing a mat consisting of filament loop aggregations according to claim 7 or 1 wherein about 0,05 to 0.2% surface active agent dialkyl-sulfosuccinate is added into the cooling water.