JPS62500442A - Coated abrasive sheet material with superior base material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] explanation Technical field FIELD OF THE INVENTION This invention relates to superior substrates for coated abrasive products.

Background technology Coated abrasive products are a general category of abrasive products that include abrasives that are bonded to at least one surface. Particularly as having a base sheet with a layer of abrasive material consisting of grains and a binder. be marked. Substrates for coated abrasives can be made from a variety of materials depending on the product requirements. Manufactured. Generally not used under high stress locations and with smaller diameter abrasive sheets. Products that require ease of tearing to manufacture generally require weaker materials such as paper and non-woven fabrics. Manufactured from a solid base material.

If stronger substrates are required, woven fabrics, leather, plastic films and metal films can be used. Use stronger substrates such as sheet metal. Strong, stretch-resistant substrates typically include Manufactured from vulcanized fibers, woven fabrics and laminates containing these materials.

Very important areas requiring strong, stretch-resistant coated abrasives are appropriately sized elongated (2) Coated abrasive material typically manufactured by joining the ends of IJ Tsuzo This is the production of an abrasive belt that is a continuous loop. However, useful coatings on belts The use of woven fabrics to impart strength and stretch resistance to abrasive substrates has its drawbacks. Ru.

Such woven substrates are expensive. This is because the weaving operation requires a weaving device and This is because it requires the use of new working hours. Furthermore, when the woven fabric is stretched, the sinusoidal of the yarn by weaving operations which tend to reduce the amplitude and yet allow a limited amount of elongation. Not completely stretch resistant due to typical sine wave generation. In addition, the warp fibers are made of cotton fibers. By crossing the intersection, the surface of the fabric is finished with an abrasive belt. The many protrusions often found on the surface of (indicated by long scratches) occurs.

Disclosure of invention Although the present invention is relatively easy to manufacture, it is necessary to To provide a coated abrasive sheet material with strong strength and excellent stretch resistance.

The superior abrasive sheet materials of the present invention are bonded to at least one major surface thereof. In addition, the binder and abrasive grains were added to (a) the flexible sheet and (b) Stretch resistance of a large number of closely spaced non-weft yarns glued to one side of a flexible sheet; It is characterized by comprising longitudinally aligned coplanar continuous filament reinforcing yarns.

The term "weftless" refers to a fabric without weft or filler threads, which is traditional in woven fabrics. It means that. The term "weftless" refers to the threads of adjacent threads that are not bonded to each other as in cloth. are distinct and individual threads, although at least some of them touch each other. is intended.

The threads may be glued to both sides of the flexible sheet. is self-adhered to the substrate on the surface It's okay. Preferred coated abrasive sheet materials include reinforcing threads and further covering the reinforcing threads. the main body of the flexible sheet facing the surface containing the nonwoven web adhered to the surface of the flexible sheet; Contains an abrasive layer adhered to the surface. This preferred embodiment provides a basis for woven material. Surface protrusions typically associated with coated abrasives made using abrasive materials are avoided.

Other preferred embodiments provide the nonwoven web with a layer of thermoplastic adhesive material covering the yarns. by replacing the plastic film glued to the

A preferred flexible sheet is a first polymeric thermoplastic material, preferably polyethylene. a first layer of terephthalate and a second polymeric thermoplastic material, preferably ethyl Most preferably the ratio of lenterephthalate and ethylene isophthalate is 80: 20 copolyesters with a lower thermoplasticity than that of the first polymeric thermoplastic material. a coextruded film having a second layer of a second polymeric thermoplastic material having a plastic softening temperature; Including film.

The threads are made of glass and polyethylene terephthalate, polyvinyl alcohol, and resin. High modulus organic thermoplastics such as nylon, nylon and other high modulus thermoplastic materials a continuous filament made from a filament-forming material selected from the group consisting of Preferably, it contains a runt.

Brief description of the drawing The invention will be further described with reference to the accompanying drawings in which like reference numerals indicate like parts. Yes, and FIG. 1 shows a flexible sheet suitable for use as a substrate for the coated abrasive sheet material of the present invention. Highly enlarged cross-sectional view of the material. FIG. 2 shows a coated abrasive sheet material according to the invention and a coated abrasive as an abrasive coating. FIG. Figure 3 shows that continuous filament reinforcing yarn is used as an abrasive coating for the same flexible sheet material. A highly enlarged cross-sectional view of another embodiment of a coated abrasive sheet material of the present invention on a major surface. Adashi, FIG. 4 shows another coated abrasive sheet material according to the invention similar to that shown in FIG. A highly enlarged cross-sectional view of the embodiment, and FIG. 5 is a schematic diagram of a method of manufacturing a coated abrasive sheet material of the present invention.

Referring to the drawings, FIGS. 2-4 show the types of coated abrasive sheet materials of the present invention. The embodiments are shown below. With reference to FIG. having a surface layer 23 of plastic adhesive material and having a large number of closely spaced non-weft yarns; A flexible sheet 22 comprising coplanar continuous filament reinforcing threads 24 arranged in the longitudinal direction. a substrate 21 containing and preferably a conventional manufacturer's adhesive 26 and a sandsize bond. It includes an abrasive layer 25 that includes abrasive grains 28 bonded therein by an adhesive that includes an adhesive 27. 2 shows a coated abrasive sheet material 20. The base material also has a fryer 0 layer 29. Can be primed to promote excellent adhesion.

FIG. 6 shows a thermoplastic adhesive material on the abrasive layer 25 and at least one major surface thereof. A flexible sheet 32 having a surface layer 33 of and an abrasive layer 25 of the flexible sheet 32 A filament yarn partially embedded and bonded in a layer 33 of thermoplastic material between The coated abrasive sheet of the present invention is identified by the reference numeral 30, comprising a substrate 31 comprising 24. 2 shows another embodiment of the sheet material.

FIG. 4 is similar to that shown in FIG. 2, but with thermoplastic adhesive material covering thread 24. A preferred coated polishing according to the invention comprises a layer 41 of non-woven fabric adhered to the surface of the layer 23 of A rubbing sheet material 40 is shown.

FIG. 1 can be used for the superior coated abrasive sheet material of claims 2 to 4. A flexible sheet material comprising a thermoplastic layer 23 on one major surface of a flexible sheet 22 10 is shown.

FIG. 5 illustrates a preferred method of manufacturing the coated abrasive sheet material shown in FIG. 4 according to the present invention. show. A flexible sheet material 10 of the type shown in FIG. (with an inner thermoplastic layer 23) and is unwound from the inner thermoplastic layer 23 and passed over the idler roll 52. and towards the heated nip rolls 53 and 54, with these nip rolls 53 and 54, The flexible sheet material 10 is combined in the nip and removed from the roll 60 to the idler roll. Non-woven fabric 61 (forming the bottom layer) and yarn spool fed over the thread 62 Reinforcing yarns 71 (top layer and bottom layer) supplied from 70 and arranged with a comb 72 (disposed between) to form a top layer to produce a composite sheet 55. then This composite sheet 55 is passed under a coating station 56 where the sheet 55 is Preferably, extrusion coating with Zolaimer to provide a base coated composite sheet 57, This primer composite sheet 57 passes through a primer curing station 58 and The sheet is passed over the roller roller 59 and reversed. Next, apply the undercoat composite sheet. Manufacturer's adhesive is applied through roll coater 63 to provide uniform coverage of abrasive grains 65. The electrostatic abrasive coater passes over the section 64, and then the loop It passes through a drying device 66. The abrasive coated dry sheet is then coated with sandsize adhesive. It runs through a covering station 67, runs through a loop drying device 68, and becomes a roll 69. A finished product 40 is provided that can be rolled up for storage or cut to size for use.

Reinforcing threads suitable for use in the coated abrasive sheet materials of the present invention are Substantially any conventional stretch resistance having an adequate tensile strength to give an acceptable degree of It may also be a continuous filament yarn. Base material strength requirements can vary; There is some variation in the yarn strength requirements. Generally requires a high tensile strength substrate The application requires stronger threads.

Reinforcing threads are necessary to impart stretch resistance to the resulting product without reducing the strength of the described base material. The composition tends to be slightly flat. This type of flattening improves the surface smoothness of the base material. Desirable for maximizing sex.

Typical, useful yarns have approximately 50 to 200 filaments per yarn strand. Consisting of a bundle of continuous filaments with threads. Continuous filament yarn Most of its individual filaments extend substantially the length of the land. i.e., more than about 90%). The material forming the stretch-resistant, highly elastic, strong yarn is , generally preferred. A suitable yarn filament with the required stretch resistance and strength is , polyester (e.g. polyethylene terephthalate), polyamide (e.g. nylon and aromatic polyamides (such as iron 6), rayon, polyvinyl It can be formed from alcohol, etc.

Various inorganic materials also provide useful threads. The preferred thread is glass thread. Formed from fibers. Such threads are known by the trademark “Fiberglas”. available from Owens Corning Company under las ) J.

Glass fiber yarn is applied to glass filament, this glass filament yarn coated and lubricated against abrasive contact to reduce filament breakage during processing. It may also contain a chemical treatment agent called sizing. Thread filaments are unsolved May include heating to obtain a more uniform product that processes more smoothly than twisted yarn. . The yarn fibers are twisted a predetermined number of times per unit of length, and the direction of twist is Tabletically, it is typically identified as the designation "S" or "z". preferred gala The thread weighs approximately 2 kg/Ian to 9 kg/Ax.

The currently preferred yarn is polyethylene, preferably from 100 denier to 2.000 denier. Manufactured from high modulus polyesters such as lenterephthalate. thread like this is commercially available.

The flexible sheet material preferably has a smooth surface and sufficient strength to withstand processing conditions. plastic films, non-woven webs (e.g. paper) with It can be made of any flexible material such as. Preferred flexible sheet materials are polymeric fibres. It's Lum. Examples of such preferred polymeric films include oriented (preferably biaxially oriented, heat cera), it-lyethylene terephthalate, nylon and and oriented polyolefins such as polyethylene, polyzolopylene and polybutylene. There is a film made by Other film-forming polymers can also be used.

A preferred flexible sheet is [available under the trade name Mylar J] Oriented polyethylene terephthalate film or ``Scotch Parr'' (ScotchPar) Polyethylene terephtha available under the trade name J. Made of rate film. Such films are typically extruded and then stretched. It is stretched or stretched to produce a crystalline structure resulting from the orientation of the polymer molecules. stretching The film is strong, thin, and soft, yet taller and narrower than the intermediate amorphous film. temperature range.

Other useful films include polyesters with polyester bonds in the polymer backbone. polybasic fats, especially polybasic aromatic acids and cycloaliphatic alcohols. There is an aliphatic alcohol polyester film. Equivalent polyester like this The film consists of terephthalic acid and 1,4-bis(hydroxymethylene)cyclohexane. It is formed from a polymer of xane. Also, oriented linear polyamide films are also very is in good condition.

Film thickness is generally 0.0251 mm depending on film strength and processing conditions. It is within the range of RN~0.1751m. Thickness 0-025 im ~ 0.25111 Polyethylene terephthalate films with a

The flexible sheet preferably has a flexible sheet covering at least one major surface thereof. Both materials include a layer of plastic polymeric material that softens upon heating at low temperatures.

Useful thermoplastic polymeric materials include olefin-acrylate copolymers, e.g. An example is ethylene acrylic acid copolymer. A preferred thermoplastic material is polyethylene Copolymer consisting of 80 parts of terephthalate and 20 parts of polyethylene inphthalate It's ester. The thermoplastic layer typically has a thickness of about 0.001 rta to 0.5I IIm.

A preferred flexible sheet comprises polyethylene terephthalate and the copolyester. Coextrusion of monolithic thermoplastic copolyester onto a polyethylene terephthalate base layer by producing a composite coextruded film with a transparent surface layer. this Such flexible sheets are typically oriented and heat set to achieve the desired strength. Get the feeling.

Reinforcement threads and flexible sheets can be adjusted in response to temperature or humidity changes or depending on the application. with similar contraction and expansion rates, or for other reasons, with different contractions or expansions. preferably chosen to avoid wrinkles or other distortions caused by .

The nonwoven web is preferably included in the coated abrasive sheet material of the present invention to Protect the threads and use coated abrasive sheet material as an abrasive belt to minimize slippage. If necessary, provide a friction surface on the side opposite the abrasive side. . Any nonwoven web that provides the structure with a suitable coefficient of friction and yet adheres well to the threads can be used. Can be used. Typical nonwoven webs are most typically up to about 5 cm in length, preferably Shaped from short staple fibers of polymeric material with a length of 0.5 cm to 10 cm. will be accomplished. Useful fibers are relatively fine, up to 50 denier, preferably about 1 denier. denier to 20 denier. Preferred fibers have good thermal stability, i.e. Additionally, this fiber is stable up to about 200° C. and provides fusion to the structure.

Short-fiber nonwovens are preferred, but other webs such as spunwoven nonwovens may be used. Web structures can also be used.

Suitable polymers for forming the fibers of the nonwoven web include polyesters, e.g. Ethylene terephthalate, polyalkylene (e.g. polyethylene, polypropylene) polyamide (e.g. nylon), rayon, cotton and other similar fibers. There is strength. Mixtures of copolymers and fibers can also be used.

The preferred nonwoven web herein is polyethylene terephthalate having a low melting point copolymer sheath. Made from a stasol fiber with a length of approximately 4 tenier and 3 cm having a tallate core. be done.

The thermoplastic layer can be heated and coated using another coating technique using liquid coating methods or by the application of a granular thermoplastic binder material that softens when thermally calendered. Can be applied by Granular thermoplastic binder materials can be applied to flexible sheets or Can be applied directly to the yarn and can be applied to part or all of the yarn surface and the adjacent surface of the flexible sheet. softens under sufficient heat and pressure to wet the surface and, upon cooling, between the thread and the surface of the sheet. to form a bond. Useful liquid binder materials include acrylic or styrene. - There are latexes such as those of butadiene resin.

The substrate of the present invention consists of a preformed nonwoven web that is placed between two heat calender rolls. Preferably, the material is manufactured by supplying the reinforcing yarn and the flexible film together with the reinforcing yarn and the flexible film.

In such methods, the material softens when heated in the nip of the calender rolls. from fibers that, in their softened state, become sticky enough to act as adhesive for the structure. Preferably, a formed nonwoven web is used.

Preferred nonwoven webs are for example -(Rando-Webber) It can be formed on a web forming device like J machine. Wear. Such non-woven wool with a weight of 0.06ki9/m2~0.6 kg/~2 I found the web to be useful.

In a preferred method, a calendar roll rolls the heat softenable fibers of the nonwoven web. Softening temperature, typically about 100°C to 300°C, preferably about 130°C Heated to ~160°C. Sufficient pressure to obtain adequate formation of the product, typically is a typical processing speed of about 1.5 m/min to 90 m/min, preferably 1.5 m/min. Approximately 2 kg/cm ~ 50 kli' at m/min ~ 6 m/min / cm (preferably 2 kg/cm to 6 kg/cm) as force L/7 Add between the rolls.

The reinforcing threads are spaced from each other at intervals of approximately 1 thread/cm width to 25 threads/cm width depending on the denier. , and is flattened by contact with the nip roll to increase the covered area. Preferably, surface irregularities are reduced. per unit width, small denier yarn is larger denier It is also typical to use more thread rolls. Typically, about 100 deni Approximately 2 to 25 threads per cm width are used for the threads, while about 2000 denier threads are used per cm width. Typically, 91 to 5 threads per cm width are used for the threads of the roll.

The flexible film used in the substrate of the present invention is typically bent down, if necessary, to provide a special When using rigid non-stick polymeric materials such as polyethylene terephthalate, Improves the adhesion of conventional coating resins. Various priming techniques are available in the industry. Known.

The abrasive layer of the coated abrasive sheet material is utilized in the manufacture of conventional coated abrasive sheet materials. applied by conventional coating techniques. In such a method, various The abrasive grains can be mixed with any of a variety of conventional grains typically used in coated abrasive products. Use a combination drug. Useful and useful abrasive grains include aluminum oxide and charcoal. Silicon oxide, decroite, zirconia, diamond, melting or soluke9 technology synthetic abrasive materials such as those formed by, mixtures of these, non-abrasive There are mixtures with grinding materials. Useful conventional abrasive binders include phenolic resins , urea-formaldehyde resin, glue, etc.

example The invention is further described with reference to the following examples, in which all parts are by weight, unless otherwise specified. It will be explained in detail.

The substrate for the coated abrasive material was heated to 138°C and subjected to a nip pressure of 5 kg/linear cm and nip of two smooth steel calender rolls at a processing speed of 3 m/min. At the same time, table fiber [product name "Melty"] available below], web weight 50,! 9/m2, and “run” a nonwoven web produced by a ``Downipper'' web forming machine; (b) Supplied from the beam, and with a spacing of 910 lines per 2-54 cm width. 500 denier polyester reinforced fillant yarn introduced into the nip [Product name] Celanese (available under J type 787) and (C) It has a thickness of 0.12 mm and has an ethylene acrylic acid primer. Primed (100% solids) by extrusion and UV treatment. (applied by adhering and priming to polyethylene terephthalate film) Primed poly, primed with Renacrylic acid primer 0-02m Place the ethylene terephthalate film with the primed side down and away from the threads. and with a thread between the nonwoven web and the polyethylene terephthalate film, Manufactured by supplying.

The substrate is coated with a conventional abrasive coating composition consisting of abrasive grains and a bonding agent on its primed side. It is coated with material and formed into an endless belt, and is F-3 value (force at 3% extension) 75 lb, / 1 nch using a tension test device (13-4kl?/Cm) and final tensile strength 1601bs, /line 1nc The coated abrasive sheet was found to have h ('l F3-6 kg/cm) generates sheet material. Abrasive belts can be used successfully to abrade wood panels, and It was found to give acceptable cutting performance without excessive stretching or slippage. This test , 15.2 cm x 762 cm surface running at 1680 surface m/min. This was done using an Oakley J-stroke sander. . A pine plate (38cm x 61cm) was coated with graphite using a hand lever. A sanding finish was achieved by applying pressure with a back-up pad. bell The tension on the top was provided by 27.3 kg of pure air pressure.

The substrate for the coated abrasive sheet material was used at 4 lines/cm of each other as described in Example 1. Non-woven web and polyester reinforcing yarn laminated together with filament yarns The resulting laminate was manufactured using polyethylene terephthalate 0.12W. IL thick layer and first coated with ethylene acrylic acid primer 0-02111. 80:20 ethylene terephthalate primed on a polyethylene terephthalate surface. Talate: 0-1'2 with 0.02+am thick layer of ethylene isophthalate The copolyester side of the +ol coextruded film was thermally calendered. obtained A coated abrasive is prepared by coating a coated substrate with a conventional abrasive composition on its primed surface. This coated abrasive product was tested on an endless surface on a belt sander. Good results were obtained as a route.

The coated abrasive substrate is laminated with the nonwoven web and reinforcing yarns described in Example 1 to form a laminate. This laminate was then coated with an ethylene acrylic acid primer on both sides. Laminated to 0-12n polyethylene terephthalate film primed to 0.02m1 did. The exposed primed polyethylene terephthalate film surface is then coated with a binder. and abrasive grains to produce a coated abrasive sheet product. The coated abrasive sheet product was cut and then formed into an abrasive belt. belt The test was successful.

The base material for coated abrasive sheet products is 0.3 twist sold by Oakens Corning Company under the filament yarn Polymerized single strand, untwisted glass filament yarn of type 110 with /Cm It was manufactured by using it in place of ester yarn. This base material is Tested with a "Ron" tensile testing device, the tensile strength was 18 kg/cm at 2 inches extension and breaking. A flexible substrate according to the present invention having a point tensile strength of about 40 kg/cm "A" weight paper as sheet, sera from 10 threads/2.54 cm beam Needs Type 787 Polyethylene Terephthalate Low Shrinkage High Elasticity 500 Denier and ethylene acrylic acid (trade name “Dow J DAF 899 EAA”) manufactured using thermoplastic film (available from Chemical Company) . Press down the assembled part with the paper on top, the thread in the middle and the adhesive film on the bottom. The product was passed through two calender rolls heated to about 128°C under 9/cm. The parts were glued together. Apply paint to the paper surface of the composite material using a coating bar on the obtained base material. Applying speed 26. ! 9/m2 to 30, phenolic resin hardness at 9/m2 Apply a 70% fabrication coat and then grader 150 oxidizer evenly over the coated surface. 80% of the aluminum abrasive! Spray at i' / m2 ~ 100 & / m2, Coating was done by precuring for 1 hour at 88°C. solid content 60 chihue Apply the size coating of Knoll resin to the abrasive grain coated surface at a rate of 50 g/　m2~60　g/ m2 and then harden the coated sheet for 6 hours at 110°C. It became.

The resulting coated abrasive product can be used to sand wood panels in place of "A" weight paper. , Rubber latex impregnation agent [Product name: Kimberly-Clark (Kimberly-Clark)] C1ark) Kimberly-Clark Kannoguny under JC-5188+5 Munsing Paper Divis except that "A" weight paper saturated with ion) was used. The method described in Example 5 was repeated. A substrate was prepared as described in Example 5 and then A coated abrasive product was obtained.

3.81 cm, made of 1.2 denier polyethylene terephthalate fiber, heavy Amount 3-4 j! / m2 (Thailand 7'510 as Celanese Corporation Eastman Kodak Company Product name: Eastman ``East Bond.''

(Eastobond) Powder polyester available under JF A-252 Stell adhesive was sprinkled to give about 0.05% to about 0.5% additive by weight. child The sprinkling web was manufactured by Celanese Corporation as yarn type 787. 5.9 pieces/c of 500 denier polyethylene terephthalate yarn available at 0,089 ynx (3,5 mil) polyethylene pre-placed at intervals of m It was placed on a terephthalate film. These layers were heated to 149°C. 12 seconds using a step press with a 20 cm x 20 am platen. pressed to produce a well-bonded laminate useful as a substrate for coated abrasives. .

Minnesota Mining and Manufacturing to replace polyester powder Product name from Alling Company: “Scotch Coat (5cotchkote R)” The procedure of Example 7 was followed except that a granular epoxy resin powder available under 213 was used. The web is then pressed onto a polyethylene terephthalate film over the yarn. A laminate according to the invention was obtained that is useful as a substrate for coated abrasives.

Eastman "Eastbond" FA-252 powder polyester on both sides in advance 0.089 (6.5 mil) polyethylene terephthalate sheet with adhesive On top of the film, six 500 denier polyethylene terephthalate threads (type 787 , available from Celanese Corporation). This thread is about 6. 35 mm apart, and also with adhesive-coated tape before placing it on the film surface. and held it in place. Two sheets of this structure were each coated with a release agent in advance. Place it between two sheets of paper, press it for 15 seconds using a step press, and then heat it to 149°C. 0Ilff) to produce a laminate useful as a substrate for coated abrasives.

international search report Enter NNEX Tw THE I) ITERNATIONAL 5EARCHRE PORT　NINTERNATIONAL　APPLICATKON　No, PCT/υS 85101825 (SA 10840) FR-A-2095 85None tJS-A-2880080Nona US-2292991Non.

υ! 1-A-301J79S NoneU3-A-3333372None tJS-A-3136614None

Claims (9)

[Claims] 1. an abrasive layer including a bonding agent and abrasive particles adhered to at least one major surface; An improved coated abrasive sheet material having a flexible substrate comprising: , (a) flexible sheet and (b) Stretch resistance of a large number of closely spaced non-weft yarns adhered to one side of the flexible sheet. , an improved coating featuring longitudinally aligned coplanar continuous filament reinforcing yarns. Covered abrasive sheet material. 2. further comprising the abrasive layer adhered to the substrate on its main surface containing the reinforcing threads; A coated abrasive sheet material according to claim 1, characterized in that: 3. said adhesive bonded to said base material on its main surface containing said reinforcing yarn; The coated abrasive sheet material of claim 1 further characterized by an abrasive layer. 4. A nonwoven wafer is bonded to the surface layer of the flexible sheet and covers the reinforcing threads. 4. The coated abrasive sheet material of claim 3 further comprising: 5. the flexible sheet comprises a first layer of a first polymeric thermoplastic material and a first layer of a first polymeric thermoplastic material; a second polymeric thermoplastic material having a lower thermoplastic softening humidity than the polymeric thermoplastic material of further characterized by comprising a coextruded film having a second layer of plastic material; A coated abrasive sheet material according to claim 1. 6. the first thermoplastic polymeric material is polyethylene terephthalate; and the second thermoplastic polymeric material is made of polyethylene terephthalate and polyethylene. Claims further characterized in that the copolyester is a copolyester of ntrephthalate. Coated abrasive sheet material of paragraph 5. 7. a polymeric material adhered to the surface of the flexible sheet over the reinforcing threads; The coated abrasive sheet material of claim 3 further comprising a sheet of fee. 8. The thread is selected from the group consisting of glass and highly elastic organic polymeric thermoplastic materials. Contains continuous filaments made from loose filament-forming materials. The coated abrasive sheet material of claim 1, further characterized in: 9. The highly elastic organic polymeric thermoplastic material is polyethylene terephthalate, polyethylene terephthalate, furthermore that it is selected from the group consisting of vinyl alcohol, rayon, and nylon. The coated abrasive sheet material of claim 8 characterized in .