WO1998046670A1

WO1998046670A1 - Manufacturing process for landing mats for judo and playing and the mat obtained accordingly

Info

Publication number: WO1998046670A1
Application number: PCT/YU1998/000005
Authority: WO
Inventors: Jovan Keresic
Original assignee: Jovan Keresic
Priority date: 1997-04-11
Filing date: 1998-02-13
Publication date: 1998-10-22
Also published as: YU14397A; AU6057098A

Abstract

The parallelepiped shaped landing mat core layer is made of small pellets (granules) of soft polyurethane sponge, polyurethane compact material, recycled rubber and shredded bits of leather which are bonded with elastomer (urethane polymer or latex based). This gives the mat the necessary elasticity and a given porousness which ensures its function. The outer sheathing is made of polyvinyl chloride, with a given pattern embossed on its upper side, and a profiled rubber base is glued on the bottom side of the mat allowing it to adhere firmly to the floor. The mixture components are first blended and then poured into a mold where the granules are bound with elastomer. After it sets the core is taken out of the mold and covered with the sheath material. The sheathing can also be placed into the mold before the core mixture is poured into it and pressed into shape with the heated mold cover. This type of landing mat is adequate to the present trends in the evolution of Judo requiring so-called 'fast mats'. It is also important that it absorbs the fall well, attenuates the athlete's sensation of pain and reduces injuries. One of the solutions offered for fixing groups mats together is based on the use of zippers.

Description

MANUFACTURING PROCESS FOR LANDING MATS

FOR JUDO AND PLAYING

AND THE MAT OBTAINED ACCORDINGLY

DESCRIPTION OF THE INVENTION

a) Scope of the Invention

The invention involves sports equipment used in combat sports, primarily in Judo, but can be used as floor covering for other applications. International classification mark for the patent 63B5/18

b) Technical problem

The solution to a technical problem offered by this invention, involves a new approach in landing mat manufacturing, providing the necessary quality application characteristics, relying at the same time on the use of much cheaper raw materials (essentially scrap materials) and ensuring a satisfactory bonding of the mat cover to the core of the mat, and adequate adhesion of the mat to the floor.

c) Technical Circumstances Landing mats are an important part of sports equipment in many sports including Judo. For this particular sport standards exist concerning dimensions, colors, borders and surface patterns reflecting the traditions of Japan where this sport originates from. The following standards apply in Judo: dimensions of the fighting area can range from 8x8 m to 16x16 m and it has a border, and the combat surface must have an embossed pattern consisting of alternating longer vertical and shorter horizontal ribbing. The surface is divided into 1000x1000 mm square modules which are fixed to the floor in various ways. "TATAMI" - the name of the landing mat is also of Japanese origin.

The inner part (core ) of the mat used to be made of dry seaweed or horse-hair, stuffed and pressed into the cover, ensuring the necessary elasticity of the mat and granting a certain absorption of the fall and support to the fighters during the Judo combat.

The outer part (sheathing) was usually made of leather or durable textile with embossed patterns according to Japanese tradition in this sport. The development of new materials, such as new urethane based elastomers has made it possible to manufacture the core of the mat by molding it in one piece which is subsequently covered by a sheathing of synthetic polymer (polyvinyl) with a pattern embossed during the manufacturing of the sheathing itself. This outer cover is glued to the core forming a flat cubelike element used as floor covering for Judo or other applications.

Existing patents covering characteristics and manufacturing processes for landing mats, mainly relate to landing mats used in gymnastics. The specific use of the mats in Judo is covered in Germany by Pat. No. 2649789.

These patents (DE 332034602, Switzerland CH 592022) are characterized by the fact that they cover the use of polymer-porous structures, used in manufacturing the core of the mat. Another group of patents deals with methods of joining individual mats into a unique surface (Germany DE2566843, DE323663202, DE2402335) and the means of fixing them to the floor (Austrian Pat. No. 305116). None of them cover any of the basic elements representing the essence of the invention for which the patent is hereby sought.

d) Essence of the patent

According to this invention, the inner part (core) of the mat consists of granules of chopped polymer materials:

^Polyurethane (up to 90%) The polyurethane hard component obtained through the polymerization of poliole 108 pbw and isocyanate 100 pbw at a temperature ranging between 30°C and 40°C, with mixing at a speed of 5000 rev/sec for 7 seconds.

*Rubber (up to 80%). PRO 223 quality with the following characteristics:

• hardness (° sh - A ) min. 62 ± 5

• snap resistance (N/cm ) min. 1500 • module (%) min. 800

• elongation (%) min. 450

• specific weight (g/cm ) min. 1,12

This type of rubber (recycled) has good mechanical properties and a normal vulcanization speed.

^Leather (up to 50%) quality required by JUS G.B 1.056 namely leather used for molded footwear with the following physical characteristics: • density g/cm^J max. 1 ,20

• snap resistance N min. 150

• snap elongation % min. 35 to 70 Chemical properties:

• humidity % max. 15,0

• ash, over the C₂O₃ content in % max. 2,0

• content of Cr₂O₃, Al₂O₃, ZrO₂ in % min. 0,7

• unbound fat in % min. 6,0

• pH value min. 3,5

• difference in pH values max. 0,7

In view of the type of leather used for molded footwear the recycled material can be can be cowhide, calf leather and horse leather.

* Soft polyurethane sponge, (up to 70%) with the following mechanical and physical properties: standard light sponge and super-soft polyurethane having a specific weight of 25 kg/m³.

a) Standard, soft sponge - white

1. Apparent density specified by JUS GS2.410 - 0,026 g/cm³. 2. Tension resistance specified by JUS GS2.424 - 1,31 kp/cm².

3. Percentile elongation specified by JUS GS2.424 - 251%.

4. Hardness specified by JUS GS2.421 - carrying capacity at 25% to 60% - 8 kp to 14,5 kp.

1. Permanent deformation by compression specified by JUS GS2.423 - 3,1% b) Standard, super-soft sponge - TMS

1. Apparent density specified by JUS GS2.410 - 0,029 g/cm³.

2. Tension resistance specified by JUS GS2.424 - 0,069 kp/cm².

3. Percentile elongation specified by JUS GS2.424 - 154 %.

4. Hardness specified by JUS GS2.421 - carrying capacity at 25% to 60% - 5 kp to 10 kp.

5. Permanent deformation by compression specified by JUS GS2.423 - 4,42% The polymer materials listed above are mixed and bonded by mono-component polymer glue, and in case that a more rapid bonding is desired, double component glue is used, such as the one used in the footwear industry for bonding all types of rubber soles, polyvinyl chloride, polyurethane. Technical data for the polymer glue:

• appearance transparent, colorless

• viscosity, Ford 0,8 / 20°C, S 195 ± 5

• specific weight, 20 C, g/cm 0,85

• dry matter % min. 18 • consumption approx. 200 g/m²

Shredded polymer materials are mixed and bound with a polymer glue to which some 5-10% of hardener has been previously added. After thorough mixing, the entire mass turns into an elastomer and hence an elastic lump. For further processing two procedures can be used: In the first variant, after being mixed the mass is poured into the mold and left there to set for about 10 minutes (depending on the humidity and temperature in the environment). Afterwards the shaped core of the mat is taken out of the mold and covered with an expanded polyvinyl sheath - ET-950, with embossed pattern on the its outer side and having the following properties: Weight of the polyvinyl 950 g/m²

Thickness 1,50 mm

Tear resistance 200 to 360 N

Elongation 30 to 200%

In the other manufacturing procedure the mold is first lined with the polyvinyl sheathing and then the wet mixture is poured into it. Then the mass is pressed down by the lid of the mold (3-6 kg/cm² pressure for 2-4 minutes). The lid has built-in heaters so that the setting of the core takes place under pressure and elevated temperature ranging between 30 ° and 40° C.

Shredded primary materials include elastomers like polyurethane, recycled rubber, leather and soft polyurethane sponge. Gaps between the granules of chopped materials and the bonds between them further enhance the elasticity of the whole system. Since the sheathing is bonded to the core with the same material used to glue granulated basic ingredients, a very functional construction, highly resistant to external stress is obtained.

An additional quality of the invention lies in the fact that all main granulated/shredded materials are recycled thus making the production of the landing mat highly cost-effective.

Along with their use as in Judo and other combat sports, these mats can be successfully used not only in gymnasiums, workout and fitness centers, but also in kindergartens or areas where children learning to walk spend their time.

The problem of fixing the landing mat to the floor is solved by the introduction of a soft rubber base layer with a specific profile: small concave spaces from which air is evacuated by light pressure on the mat. The rubber base dimensions are 920x920mm and its edges are rounded off with a radius r=80- 100mm. The rubber used for the mat base has the following composition:

Rubber mixture:

Component Parts per mass

- Natural rubber (SMR 5) 100,0

- Dibenzithiazyl disulfide 1,2

- N-isoprophyl-N-phenyl-p-phenylenediamine 1,0

- Zinc oxide type 1 50,0

- Black (N 330 HAF) 36,0

- Sulfur 2,5

TOTAL 190,7

The mixture is poured into the mold pre-heated to vulcanization temperature. The vulcanization takes place in a closed press at a temperature of 150± 2° C for 30±1 min. under molding pressure of 3,5 MPa. The rubber slab is up to 3,5 mm thick. Its underside has symmetrical circular cavities φl5-30 mm, with a radius r = 100-150 mm, and the distance between the cavities is 10-15 mm.

Due to the vacuum generated by slight pressure the underside of the rubber base adheres to the parquet or concrete floor thanks to atmospheric pressure. This solves the problem of temporarily fixing the mat to the floor in the room where it is being used. In case that this type of attachment is not appropriate, the group of mats forming the combat area is held together by a border or zipper with one half of it mounted on one mat and the other on the adjacent mat, the closing being effected by pulling the joining element of the zipper.

The embossed pattern on the polyvinyl chloride polymer sheathing, consists of alternating longer vertical (concave), and shorter horizontal (convex) ribbing; pattern groups are separated by a given motif representing the specific mark of this type of Judo landing mats.

The application of aforementioned essential invention principles is illustrated by the following examples:

Example 1

Granules of scrap material - soft polyurethane sponge 16,6%, specific weight 25 kg/m3, hardness 8kp to 14,5 kp.

Granules of scrap compact polyurethane material, 50%, specific weight 0,85g/cm3. Granules of recycled rubber material from old automobile tires 28,4%, specific weight

1,12 g/cm3 and hardness 62 ± 5 0 sh - A

Parts of chopped leather or textile scrap 5%, specific weight 1 ,12 g/cm.3.

All these materials, in listed percentages are to be stirred for 10 minutes in a special receptacle with the addition of polyurethane glue: 3 kg of glue with 1 kg of solvent. The mass is poured manually into a mold with the dimensions 1000x1000x40 mm. After it sets, the core is taken out of the mold and covered by the pre-cut polyvinyl sheath, with a pre-embossed pattern for a given sport. Finally the rubber base (920x920mm) is glued to the bottom of the mat.

Example 2 Granulated polyurethane compact material 50%, specific weight 0,85 g/cm3.

Soft polyurethane sponge 16,6% specific weight 25 kg/m3, hardness 8kp to 14,6kp

Granulated recycled automobile tires 38,4%, specific weight 1,12 g/cm3 and hardness 62 ± 5 0 sh - A Scrap leather 5%, specific density 1 ,20 g/cm3 cut to pieces of about 10 mm are mixed with 3 kg of latex-based glue diluted with 1 kg of appropriate solvent.

The mixture is poured into a press mold 1000x1000x40 mm (already lined with polyvinyl sheath 1,5 mm thick); then the wet mixture is compressed with the upper part of the press (pressure 3-6 kg/cm ) containing built-in heaters that maintain a temperature of about 30°-40°C.

The mass is kept under pressure for 15 minutes, allowing the bonding with the polymer glue which provides the necessary elasticity to the system. The bottom of the mat (positioned face-up in the press) is then covered by a layer of glue to bond the rubber base with the concave cavities. They allow the mat to stick firmly to parquet or other type of floor once the air is pressed out of the cavities.

Tests have been conducted on mats prepared according to the procedure and composition listed in Example 1 and Example 2, and comparisons made with similar specific- purpose mats that did not contain these recycled materials. The following conclusions have been drawn. a) This type of Judo mat belongs to the so-called "fast mats". b) The penetration depth (the mean value was used in the analyses) is 11 mm, which allows the athletes to move faster on the mat, and when they fall, the pressure is quickly distributed over the entire surface by the granules, the energy of the fall being absorbed and the painful sensation reduced.

Tests and measurements of the pulling force for the friction factor have shown that the pulling force averaged about 59N indicating that the mat is less slippery and thus gives the athletes more stability during the exercises and competitions. The tests have been performed by the Materials Testing Institute of Serbia seated in Belgrade on November 5-20th 1997, and are part of report No. 65/97.

Example 3

Landing mats prepared according to the procedure given in Example 1 and Example 2, are attached to adjacent mats with zippers sewn or glued to their edges. Since half of the zipper is fixed to one mat and the other half to the next, mats are attached together by simply closing the zipper.

Example 4

Landing mats whose core has been made according the procedure listed in Example 1 and Example 2, are shaped in a 1000x1000x20 mm mold. Square modules thus obtained are then used to cover the concrete floor (instead of a parquet) and wall-to-wall carpeting is then glued over the mat squares giving an excellent thermally insulated floor for kindergartens and nurseries.

Claims

PATENT CLAIMS

1. Manufacturing procedure for landing mats for Judo and playing, and the landing mat obtained with these manufacturing processes, characterized by the initial elastomer materials : soft polyurethane sponge, specific weight 25 kg/m³ constituting up to 70% of the mass, polyurethane polymer constituting up to 90% of the mass, recycled rubber constituting up to 80% of the mass having a specific weight of 1,12 g/cm³ shredded into granules ranging between 5 and 10 mm, to which scrap leather chopped into particles ranging between 1 and 2 mm are added and constituting up to 50% of the mass having a specific density of 1,20 g/cm ; the mixture is then blended with polyurethane elastic bonding agent, specific weight 0,85 g/cm diluted with a suitable solvent so that the wet mixture after adequate homogenization is poured into a square-shaped mold previously lined with a 1,5 mm thick polyvinyl sheath; finally the bottom part of the mat is covered by a 3mm thick rubber base having the dimensions of 920x920mm and specific circular cavities (╧å25mm, radius r= 125mm) spaced at 12mm, thus forming a robust and firm structure.

2. The landing mat according to the Claim is characterized by the fact that after being blended the granulated material mixture is poured into a mold, pre-lined with a polyvinyl sheath, then pressed (at 3-6 kg/cm²) with the upper lid of the mold with built-in heaters for

2-4 minutes thus shaping the mat at a temperature of 35 - 40┬░C.

3. The landing mat according to the Claim is characterized by the rubber base with appropriate concave cavities which is glued to the bottom of the core after the mixture sets as specified in Item 1; the base allows the mat to firmly adhere to the parquet floor by simply evacuating air from the cavities.

4. The landing mat specified in this Claim under Item 1. is characterized by the fact that individual mat modules are attached by zippers mounted along the sides of the modules. Since half of the zipper is fixed to one edge of the mat and the other half to the next, the simple closing of the zipper attaches the mats thus forming a compact surface.

5. The landing mat specified in this Claim under Item 1. is characterized by the fact that a square block less thick than the one used for combat competitions can be utilized as a module for creating a low-priced floor covering suitable for various applications e.g. in kindergartens and nurseries.