AU601331B1 - Mat consisting of filament loop aggregations, and method and apparatus for producing the same - Google Patents

Description

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1 SOur Ref: 273986 5 t: AUSTRALIA 0 1 14ORM Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: 'Applicant(s): Kabushiki Kaisha Risuron Nishiikebukuro 1-chome Toshima-ku Tokyo

JAPAN

ARTHUR S. CAVE CO.

Patent Trade Mark Attornerys Level 10, 10 Barrack Street SYDNEY NSW 2000 Address for Service: Complete specification for the invention entitled "Mat consisting of filament loop aggregations, and method and apparatus for producing the same".

The following statement is a full description of this invention, including the best method of performing it known to me:- 1- 5020 ai mi 1 4 MAT CONSISTING OF FILAMENT LOOP AGGREGATIONS AND METHOD AND APPARATUS FOR PRODUCING SAME 00 0 oo o oeo o s

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Kr 0000 o0 0 0 0 00 0 O or o Background of the Invention: This invention relates to a coarse net-like resilient mat, constructed by entangling synthetic resin monofilaments, and, more particularly, to a mat consisting of a filament loop aggregations adapted for use as a porch mat or a floor mat, formed and laid on a long sheet. This invention also relates to a method and apparatus for producing same.

Instead of conventional carpet mats or synthetic resin mats, a three-dimensional net-like mat consisting of synthetic resin monofilaments, high in the water permeability and of quick drying ability, has recently been embodied. Due to the characteristics of the mat, including the high resiliency and weather-proofness thereof, such a three-dimensional net-like mat is capable of being used in many indoor and outdoor applications, particularly in such places as, for example, a doorway of a bathroom, or, a pool side. In such applications this type of mat is ideal due to it being simple to wash and dry.

Also, due to the construction of the three-dimensional mat, sand and gravel will drop down and will not reyain on the surface thereof. Water or the like will also drop down, and consequently the surface can be always kept dry.

In addition, when such an elastic sheet as a synthetic resin sheet, foaming sheet or rubber sheet is pasted to the lower surface of such mat, the cushioning property of tho mat 1/0233a 2 ol 0 00 0o a 00 o0 0 000 00 0 00 a 0 00 0 004 6.

0 0 0 0 o oa mooo o os is able to be increased, and any sand and water dropping from the surface thereof is able to be received by this sheet and the floor is prevented from becoming dirty and wet.

Description of the Prior Art: Such a three-dimensional net-like mat is formed as a non-woven fabric, wherein many monofilaments of thermoplastic synthetic resin are laminated, and, whilst being twisted are fused at their contact points, cooled and solidified.

The resultant formation is of a plurality upright loops to form a web.

In the non-woven fabric formed by the above described methods the resiliency of the individual filaments is low, and the filaments produced by this method overlap each other, fall down, and, as the entangled density of the filaments becomes higher, the resiliency of the sheet is lost.

On the other hand, when the web formation is made loop-like, the respective loops being only fused at their intersecting points and the contact points between the adjacent loops, the loops are independent and are therefore low in resiliency when trodden upon.

Summary of the Invention: Therefore, the present invention seeks to provide a mat wherein a filament web is formed of positively closed loops such that higher filament resiliency by increased contact fusing between the respective loops is achieved. The present invention also seeks to provide a method and apparatus for producing same.

Description of the Drawings: 000

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A Ci CC CCCC 0233a 3- .~Y2! I I l i. i The many advantages and features of the present invention can be understood and appreciated by reference to the accompanying drawings wherein a preferred embodiment of the invention is shown: Fig. 1 is a side view of an embodiment of the apparatus of the present invention; and, Fig. 2 is a side view showing an example of the mat of the present invention.

I Detailed Description of the Invention: 0090 0 According to the present invention, there is provided, a oo o, 0o mat consisting of upright disarranged loop-like synthetic resin °.44 filaments, which has many spaces to provide cushioning therein.

0 0 o 0° The present invention provides a mat of a multilayer 0 structure, wherein overlapped aggregations, each having coiled loops formed in the upright direction on both the front and .000 0,000 back sides thereof by intermediately providing a high filament o0000o 04 0 density aggregation layer of coiled loops overlapped in the o laterally fallen direction, are provided.

'00 In order to form such a mat, several hot filaments of thermoplastic synthetic resin are pressed and extruded through V(t T-die orifices and are made to fall toward a tank of cooling 064000 water.

A pair of guide rollers are provided below the water, surface, and the filaments are lowered between these rollers.

The falling hot filaments are heated by heat sources such as ceramic infrared ray heaters, such that the filaments are not cooled by the surrounding environment.

Such hot filaments form coiled loops on the water A33a E surface. Unless the filaments are hot, the loops become large.

The height from the mouth end of the T-die to the water surface is preferably 5 to 100 cm, and heat loss of the filaments is prevented by constructing the mouth end of the T-die to be as close as possible to the water surface.

The orifice diameter of the T-die is preferably 0.3 to mm, this diameter determining the filament diameter, which is important to retain the resiliency and durability of the formed filaments and prevent permanent setting thereof.

o oA mat consisting of filament aggregations of various :0o widths can be made by arranging a number of orifices spaced at o Q widths of, for instance, 90, 120 and 150 cm with an orifice onrn o 0o arrangement of a T-die of, for example, 3 to 6 longitudinal rows at the intervals of, say, 3 to 5 mm, and a pitch of, say, 3 to 5 mm in the lateral row.

Oat That is, a hot filament bundle extruded out of the T-die 0001 of such an orifice arrangement is designed to fall towards the S cooling water and be received by submerged rollers which rotate slower than the falling speed of the filament, to consequently limit the falling speed thereof in the water. Loops having a filament length corresponding to the difference between the extruding speed of the respective filament and the falling speed in water will be sequentially continuously formed to be .coil-like on the water surface.

To form such loops into twisted irregular loops, it is effective to boil the cooling water surface.

This boiling vibrates the respective filaments on the water surface. As a result, entangled disarranged coiled loops S 233a A 4III 0'mO! A ?'F are formed in the water surface.

In order to effect the boiling of the water, it is important to keep the filaments coming out of the T-die at a high temperature. When the filaments contact the atmosphere, the filament temperature reduces. The filaments are extruded at a molding temperature of 200 to 150'C, and when the cooling water is kept at a temperature of 60 to 80 0 C, this water tends to be kept boiling.

When the filaments are molded as coiled loops at high 0090 0o temperatures, fusing between the adjacent loops is o0 00 oo accelerated. Further, when the cooling water is kept at an o009 Selevated temperature, and the molded loops are pulled out into 0-40 0.00 o o the atmosphere by the guide rolls and are sent to the secondary 0 0 process described hereinafter, they are easily dried in either cool or hot air.

oA coarser-density filament loop aggregation, is achieved 00.00 0 by increasing the rotation (pulling speed) of the rollers in 0 the water.

oO d If the thickness of the hanging filament bundle is not regulated, a three-dimensional formation of coiled loops will S still be formed. However, the size of the loop formed on the aoae liquid surface will vary. Therefore, by regulating the thickness of the filament bundle, the ability to construct uniform coiled loop aggregations of an intended thickness is possible.

As a pair of guide rollers are just below the water surface and regulate the positions of the filaments while forming loops, the thickness of the filament bundle in the <j233a 6 1Z i Y -IIIIIIOILI-IIII~UnU*^ water just above them will be regulated, related to the regulation below the water surface.

Such filament loop aggregations are shown to be formed in two parallel spacings and, a secondary aggregation is formed along one side surface of the first aggregation.

In such a formation, when the above mentioned aggregation is heated on one side surface at approximately the fusing temperature, the filaments on the side surface will soften and form an aggregation layer of high filament density due to the lateral fall of loops.

roir O In molding synthetic resins, the temperature of the 0 C 0' cooling bath is preferably kept at about 50 0 C for PE 0000 00 4 o (polyethylene) and PP (polypropylene), about 10 to 40°C for PVC (polyvinyl chloride), and about 85 0 C for PS (polystyrene).

The surface tension of water on PVC (polyvinyl chloride) o9, is high, such as 60 to 70 dym/cm, such that fine filaments of 000* °oo an outside diameter of less than 1 mm will be overlapped above o the water surface. The coiled loops formed here will be 00 a laminated in several steps and will be cooled in water and therefore coarse aggregations will not be obtained. Therefore, 0 in order to sequentially sink the coiled loops on the surface, it is effective to add a surface active agent reducing the Isurface tension of the cooling bath.

Embodiments: In Fig. 1 is illustrated side view of a suitable apparatus for embodying the present invention. Two filaments 2a and 2b are provided in spaced apart relationship to supply a thermoplastic synthetic resin material vertically towards a 7- Z) W,0233a "0"U CT? tank of cooling water 5 from a T-die i, the thermoplastic synthetic resin material being extruded under pressure.

In the lateral direction (front to back direction in the drawing) of the T-die, many filaments 2a and 2b may be provided at predetermined intervals (pitch of 3 to 5 mm), corresponding to the lateral width of an intended molding.

In a falling zone, where the filament 2a falls from the T-die i, bar-like ceramic infrared ray heaters 3a and 3b are arranged on each side thereof to effect heating of the filament 2a.

0 In the falling zone of the filament 2a, just below the a 9 surface of the cooling water 5, a pair of guide rollers 4a and 00 0°o°o 4b are arranged in spaced apart relationship such that the bundle of filaments 2a may be guided by these rollers 4a and 4b to sink.

.0 Also, a feeding roller 6, rotated and driven at a 00 2a, having sunk, may be moved in the cooling water 5, held between the feeding roller 6 and the above mentioned guide rollers 4b. As a plurality of engaging pins 8 are provided at intervals on the peripheral surface of this roller 6, and since I0.oa the speed of roller 6 is set at a constant low speed, lower than the falling speed of the filaments 2a, filaments 2a falling from the T-die 1 will be decelerated by the water, and, as a result, slacken by a length proportional to the difference between such falling speed and sinking speed. The slackness in the filaments will result in the filaments 2a forming irregularly shaped loops.

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o o 0o0 0 00 04000 0 0 0 0 o o o o o 9 o o 0 The filaments 2a, extruded out of the T-die 1, will contact the water surface of the cooling water 5 at a temperature substantially equivalent to their molding temperature due to the provision of heaters 3a provided in the falling zone. The filaments 2a, having sunk in the cooling water 5, will quickly lower in temperature and will consequently be hardened. However, these hardened filaments 2a will be regulated in the amount of looping thereof, controlled by the speed of the submerged rollers 6 and the engaging pins 8, such that coil-like loops are formed.

When the overall temperature of cooling water 5 is maintained at 60 to 80 0 C, the cooling water 5 in the falling vicinity of falling position will be locally boiled by heat dissipated by the high temperature filaments 2a. By such boiling, the water surface in that vicinity will be waved and rocked, and therefore, the filaments 2a will be consequently waved and disarranged.

Therefore, the loops will consequently be overlapped on the water surface and will have many contact points with adjacent loops.

The loops will consequently be fused with each other and will be cooled to be hardened. Therefore, coiled loops, having many fused points between the adjacent loops, will be continuously formed, and a filament loop aggregation A in which coiled loops are cross-linked longitudinally and laterally with the loop edges overlapping between adjacent filaments 2, will be formed.

With the above formation defining a first filament loop ooas f t t 00 0 9 aggregation forming step, the aggregation A, moving in the above mentioned cooling water 5, will be engaged with a guide roller 7b, arranged just below the water surface in the falling zone of the other filament 2b, and will be raised upwardly to be exposed on at least one surface thereof above the water surface.

An infrared ray heater 9a is arranged adjacent to the exposed position of aggregation A such that aggregation A may be dried and heated above the surface at a temperature close to the fusing temperature. Therefore, the loops near this heater C will soften and the filaments and will flatten overlap to form a high filament density layer C. This aggregation A will then be directed by guide roller 7b to again be pulled into the cooling water 5. Filaments 2b are provided adjacent the above mentioned heated surface and guide roller 7a.

Another submerged roller 10 is arranged in the sinking zone of the filaments 2b. The filament bundle is moved at a low speed, engaged with engaging pins 8 on the peripheral surface of the roller 10. Once again, since the moving speed of the filament bundle in the water is lower than the falling speed of the filaments 2b falling down from the T-die i, an aggregation B, formed of irregular coil-like loops is obtained. An additional heater 9b is provided in the falling zone of the filaments 2b, having a reflecting plate 11.

The aggregation B will consequently be fused and connected on one side of the heated surface of the above mentioned aggregation A.

Therefore, the product formed is a mat comprised of an /0233a 10 '22 :Y

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A

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h overlapped structure of aggregations A and B consisting of vertically upright loops, and held in the centre thereof by an aggregation layer C of laterally fallen direction loops, as shown in Fig. 2.

The method of forming the above mentioned aggregation layer C is not limited to that described in the above illustrated embodiment. For example, a separately formed aggregation layer C, consisting of laterally fallen loops, may be separately applied to the aggregation layers A or B. Each of the guide rollers 4a, 4b and 7a, 7b may also be arranged so as to be exposed on a part of the peripheral surface above the water surface.

In order to pull the coiled loops, formed on the cooling water surface, into water without disturbing their form, a surface active agent is preferably added into the cooling water p--4 .0 034 0 0 0 0 0 00 00 0 a 0 0t 001 4 4 t' I 1 1 4, 4.

0t The preferred amount of addition of the surface active agents per 100 parts of water is as follows: Anionic system: Alkylbenzenesulfonate: 1 to 0.2 part Dialkylsulfosuccinate: 1 to 0.05 part S Nonionic system: polyoxyethylene nonylphenol ethyl 1 to 0.1 part It is preferable to add 0.05 to 0.2% dialkyl sulfosuccinate, to reduce the surface tension and to effect connecting.

In such an apparatus, to keep the cooling bath water level constant, overflowed cooling water may be circulated with a pump. The generation of a lot of bubbles is disadvantageous AMD 233a 11

SG

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in molding. However, at the above mentioned effective component concentration of dialkylsulfosuccinate, many bubbles tend to be generated. Therefore, it is optimum to add and use preferably 0.05 to 0.2% dialkylsulfosuccinate.

The mat material consisting of the formed filament loop aggregations A and B may be coated with a plastisol of the same material as the filament, to prevent bonding strength reduction and permanent setting of the filament loops.

A backing sheet consisting of a resin sheet, foamed sheet, or rubber sheet, may be bonded to the back surface of the mat material depending upon the use of the product.

Example of a preferred embodiment: 0 oO: Polyvinyl chloride (PVC) (P-1300) 100 parts °a aPlasticizer DOP Dioctyl phthalate 0 Stabiliser Dibutyl tin laurate 2 Cadium stearate 0.6 part barium stearate 0.4 Colouring agent 0.1 A compound material of the above mentioned mixture may be molded to the filaments via an extruding molder.

The distance between the guide rollers 4a and 4b below tir the cooling water surface is preferably set to be about 8 mm.

The distance between the guide roller 4b and submerged roller 6 is preferably 9 mm. The distance between the guide rollers 7a and 7b is about 16 mm. The filament molding orifice diameter is about 0.8 mm. The T-die orifice arrangement is of two longitudinal rows at the intervals of about 5 mm and a lateral orifice pitch of about 5 mm.

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The distance between the T-die and cooling water is preferably 5 cm. The die temperature is preferably 185 0 C. The cooling water temperature is preferably 60 0 C. Four ceramic far infrared ray heaters of 1.5 KW preferably used. At a molding linear speed of about 2 minute, loops at a speed of about 40 cm per minute can formed.

surface about to each are m per be In this formation, by only holding the filament bundle in its thickness width direction with the guide rollers, the front and back surfaces of the aggregation is uniform and the mat shown in Fig. 2 is obtained.

As the extruder die pressure is applied and hot filaments are extruded into air, the finished dimension of the filament is about 0.2 mm thicker than the filament orifice of a diameter of about 0.8 mm of the T-die and a filament coi.l structure of a o000 ot0 ooo 0 00 Q 09

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O diameter of about 1 mm is produ between the guide rollers 7 and the aggregation molded will shr hardened and will be approximat Thus, according to the ma aggregation of irregular coil-i individual loops have a degree irregular form, have a high deg adjacent coiled loopg. Thus a filament bonding is obtained.

ced. Even if the distance S7b is set to be about 16 mm, -ink when the filament is ,ely 13.5 to 14 mmn thick.

.t of the present invention, an ,ike form loops is formed. The of resiliency, and due to their free of contact fusing between mat with a large amount of Due to the resiliency of the above loops obtained by aggregation themselves, a stiff mat of good resiliency is the strength of the bond between these loops. The layer, high in the filament density, is high in 13

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t-i ,/0233a strength, particularly in tensile strength. The consequential effect is to allow sand or water to drop from the upper part )f the mat and, on the other hand, to prevent it from springing up from the lower surface. Therefore, the mat of the present invention, formed of doubly overlapped filament loop aggregations with aggregation layer therebetween, is high in resiliency and tensile strength, and as such, is ideally utilised for a porch mat or floor mat which undergoes a great deal of wear.

When the diameter of the filament is chosen in the preferred ranges hereinbefore discussed, a high strength filament loop is obtained. The mat can however be constructed 0 to be of any desired weight and thickness.

o When the major diameter of the loop of an irregular form is adjusted to be in the ranges hereinbefore discussed, the mat will be of optimum elasticity. If, however, the major diameter of the loop is too large, a shoe tip or the like may catch on and cut the loop and this is not preferable.

In the method of forming the mat or sheet consisting of S filament loop aggregations, the filaments are lowered onto the water surface at temperatures close to the molding temperature, and, when this water surface is waved by the boiling water, the loops formed on the water surface will be in an irregular wavy Sform such as to effect contact-fusing of the adjacent loops.

In addition, when the filament bundle falling toward the cooling water surface is regulated, the sizes of the respective loops formed will be able to b4 controlled and, when the contracted width is also controlled, the formation of uprightly 14 directed loops and laterally fallen loops can be controlled.

If the distance from the T-die to the cooling water surface is large, the filament temperature will be reduced by the air therebetween. It is desirable to set the distance to be as short as possible, however, if it is too short, the loop formation on the water surface will be disturbed. Therefore, a distance of 5 to 10 cm is preferable.

By maintaining the temperature of the cooling water at a temperature of about 60 to 80 0 C, the water surface whereat the filaments fall is boiled. In order to smoothly sink the filaments to prevent the loops forms from being disturbed, it is effective to add a surface active agent.

0 It will be understood by persons skilled in the art that S numerous variations and modifications are envisaged to the present invention. Such variations and modifications should be considered to fall within the scope of the invention as hereinbefore described and as hereinafter claimed.

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Claims (9)

1. A mat comprising: a pair of layer of loop filament aggregations in which irregular form loops of thermoplastic synthetic resin filament are coarsely formed; an intermediate layer of high filament density fused between said pair of layers.

2. A mat as claimed in claim 1 wherein the diameter of said filament is in the range of 0.3 to 1.5 mm

3. A mat as claimed in claim 1 wherein the major diameter of said filament loops is in the range of 3 to 15 mm

4. A method of producing a mat consisting of filament loop aggregations, comprising the steps of: extruding hot filaments of a thermoplastic synthetic resin out of a T-die; lowering said filaments into a tank of cooling water and causing said filaments to sink at a speed lower than the speed at which said filaments are extruded and consequently harden forming an irregular formed loop bundle; raising one side of said bundle out of said cooling water and heating and melting said side of said bundle, increasing the density of said loop filaments to form an intermediate layer of said mat; extruding further hot filaments and lowering same towards said cooling water such that said further hot filaments form a further irregular formed loop bundle fused to said intermediate layer.

A method of producing a mat as claimed in claim 4, A/233a 16 L. -'Q wherein the distance from the lower surface of said T-die to the surface of said tank of cooling water is in the range of to 10 cm.

6. A method of producing a mat as claimed in claim 4 wherein said tank of cooling water is maintained at a temperature of to 80 0 C, and is locally boiled by the heat of said sinking loops.

7. A method of producing a mat as claimed in 4 wherein about 0.05 to 0.2% surface active agent dialkylsulfosuccinate is added into said tank of cooling water.

8. A mat consisting of filament loop aggregations, substantially as herein described with reference to the accompanying drawings.

9. A method for producing a mat consisting of filament loop aggregations, substantially as herein described. An apparatus for producing a mat consisting of filament loop aggregations, substantially as herein described with reference to the accompanying drawings. DATED this 5th day of June, 1990. KABUSHIKI KAISHA RISURON By Its Patent Attorneys ARTHUR S. CAVE CO. S AMD 0233a 17 k