KR20080067327A - Glass fiber bundles for mat applications and methods of making the same - Google Patents

Abstract

Dried bundles of chopped glass fibers that may be used in mat forming applications is provided. The chopped glass fiber bundles (42) are formed of individual glass fibers (12) positioned in a substantial parallel orientation. The dried chopped glass fiber bundles may be prepared by applying a size composition to attenuated glass fibers, splitting the fibers to obtain a desired bundle tex, chopping the wet glass bundles to a discrete length, and drying the wet glass bundles in a dielectric oven, a Cratec(R) oven, or a rotating tray oven. Alternatively, the dried chopped glass bundles may be prepared by sizing attenuated glass fibers, passing the sized fibers through a heat transfer chamber where air heated by a bushing is drawn into the heat transfer chamber to dry the glass fiber bundles, splitting the dried, sized glass fiber bundles to obtain a desired bundle tex, and chopping the dried bundles of glass fibers. The sizing composition includes : one or more film-forming agents selected from the group consisting of a polyrethane film-former, an unasturated polyester or an epoxy resin.

Description

Glass fiber bundle for mat and manufacturing method therefor {GLASS FIBER BUNDLES FOR MAT APPLICATIONS AND METHODS OF MAKING THE SAME}

FIELD OF THE INVENTION The present invention relates generally to nonwoven fiber mats, and more particularly to chopped glass fibers that can be used as a substitute for glass forms that have been used in conventional mat forming applications, in particular wet mat forming applications. Relates to a dry bundle. Also provided is a method of forming a dry bundle of chopped glass fibers.

Generally, glass fibers are formed by drawing molten glass into a filament through a bushing or orifice plate and then applying to the filament an aqueous sizing composition comprising a lubricant, a coupling agent and a film forming binder resin. The sizing composition protects the fibers from interfilament friction and improves compatibility between the glass fibers and the matrix comprising the glass fibers used. After application of the sizing composition, the wet fibers can be gathered into one or more strands, cut and collected. The chopped strands may comprise hundreds or thousands of individual glass fibers. The collected chopped glass strands can then be packaged in the wet state as wet chopped fiber strands (WUCS) or dried to form dry chopped fiber strands (DUCS).

Wet chopped fibers are generally used in wet treatments where the wet chopped fibers are dispersed in a water slurry comprising surfactants, viscosity modifiers, antifoams and / or other chemical agents. The slurry comprising the chopped fibers is then stirred so that the chopped fibers are dispersed throughout the slurry. The slurry comprising the fibers is placed on a moving screen where most of the water is removed to form a web. The binder is then added and the resulting mat is dried to remove the remaining water and to cure the binder. The nonwoven mat formed is an assembly of dispersed individual glass filaments.

Dried chopped strands are generally used in dry treatments, where the dry strands are blown and cured on a conveyor or screen to form mats. For example, dried chopped strands are suspended in air, collected as loose webs on screens or perforated conveyors, and then cured to form mats of randomly oriented bundles.

Fiber mats formed by wet and dry treatments are very suitable as reinforcements for many types of applications. In order for the final laminate to have satisfactory physical properties, it must include a sufficient amount (weight) of glass reinforcement. Although the bundles of fibers in the dry mat provide a high glass content, making dried chopped strands is expensive because the strands are generally dried and packaged in individual steps before they are cut. Thus, it is desirable to use less expensive glass forming platforms that achieve increased glass content in composites that require high impact strength.

Bundles of dried chopped fibers have already been produced. In the following, some examples of processes for forming a bundle of such dried chopped fibers are described.

Schaefer US Pat. No. 4,024,647 discloses a method and apparatus for drying and transporting chopped glass strands. The glass filaments are tapered through the orifices of the bushings and coated with a lubricant binder and / or size. The filaments are gathered into one or more strands and then cut. The wet chopped fibers then fall onto the first vibratory conveyor. The vibration of the first vibrating conveyor keeps the cutting strands in the fiber bundles by preventing the bundles from sticking together. The chopped strand is then passed to a second vibratory conveyor and passes through a heating zone, where the cutting strand is heated to lower the moisture content to less than 0.1% by weight. Then, the cutting strand of the desired length is transferred to the collection package through the forming portion of the second vibrating conveyor.

US Patent No. 5,055,119 to Flautt et al. Describes an energy efficient process and apparatus for forming glass fiber bundles or strands. Glass fibers are formed from molten glass exiting the heated bushing. The fibers are moved downwards and sizing is applied to the glass fibers by an applicator. In order to dry the glass fibers, air is passed from below the bushing down the bushing, where the air is heated by the heat of the bushing. The heated air enters the chamber through which the glass fibers pass. The heat transfer contact causes the water or solvent of the sizing composition to evaporate. Then, the dried fibers are collected in a bundle. The bundle can be cut later.

US Patent No. 6,148,641 to Blough et al. Describes a method and apparatus for making dried chopped strands from a supply of continuous fiber strands. In the described method, the fiber strand is cut in the cutting assembly, the strand cut from the discharge assembly is discharged into a transition chutte directly connected to the drying chamber, the cutting strand is collected in the drying chamber, and the strand is removed from the drying chamber. By at least partially drying, chopped fiber strands are made from one or more continuous strands.

And a chopped strand glass mat was formed by using the wet process, which included the glass bundles found in the dry process and the individual fibers found in the wet process. Some examples of these mats are described below.

US Pat. Nos. 4,112,174 and 4,129,674 to Hannes et al. Disclose glass mats consisting of a web of monofilament fibers and an elongated glass fiber bundle interspersed in a random orientation pattern throughout the web. The glass fiber bundles preferably contain about 20 to 300 monofilaments. The fiber mat is formed by a wet process. In order to keep the glass fiber bundles in bundle form in the slurry during the mat forming process, the bundles are coated with water or another liquid insoluble binder.

U.S. Patent Nos. 4,200,487 and 4,242,404 to Bodoc et al. Describe glass mats comprising individual glass filaments and elongated glass fiber elements. The elongated glass fiber element is formed from a bundle of glass fibers that, when the slurry is agitated, slide separately and become longitudinally connected. It was claimed that the glass fiber elements contributed to the high strength properties of the mat and that the individual filaments provide the uniform density required for the injection of asphalt in the manufacture of shingles. The mat is formed by a wet process.

US Patent No. 6,767,851 to Rokman et al. And US Patent Application 2002/0092634 disclose nonwoven mats in which at least 20% of the fibers are present as fiber bundles having about 5 to 450 fibers per bundle. In a preferred embodiment, at least 85% of the fibers in the mat are in the form of bundles. The fibers are fixed in the bundle by sizing that is substantially insoluble in water such as epoxy resin or PVOH. The bundle may comprise at least 10% reinforcing fibers, such as glass fibers. The mat can be manufactured by a foam or water process.

Despite the presence of such dried chopped glass bundles and fiber bundle-containing mats, there is still a need in the art for a cost effective and efficient process for increasing glass fiber content due to the use of wet glass mats.

It is an object of the present invention to provide chopped glass fiber bundles that can be used as a replacement for conventional glass foams used in mat forming applications. The chopped glass fiber bundles are formed of a plurality of individual glass fibers located in an orientation substantially parallel to each other. The glass fibers used to form the chopped fiber bundles may be any kind of glass fibers. Although reinforcing fibers such as natural fibers, mineral fibers, carbon fibers, ceramic fibers, and / or synthetic fibers may be present in the chopped glass fiber bundles, it is preferred that all of the fibers in the chopped glass fiber bundles are glass fibers. The fibers may comprise one or more film formers (polyurethane film formers, polyester film formers, and / or epoxy resin film formers, etc.), at least one lubricant, and at least one silane coupling agent (aminosilane or At least partially coated with a size composition comprising methacryloxy silane coupling agent, and the like. The size of the glass fibers is filamented during the subsequent processing steps to form a mat that maintains the bundle integrity during the formation and subsequent processing of the glass fiber bundles and imparts an aesthetic appearance to the final product. To help.

오븐 (Owens Corning 사로부터 이용가능) 과 같은 유동층 오븐, 또는 회전식 트레이 열적 오븐과 같은 오븐에서 건조되어 절단 유리 섬유 다발을 형성한다.It is also an object of the present invention to provide a method of forming a chopped glass fiber bundle that can be used as an alternative to conventional glass foams used in mat forming applications. At least one film former (polyurethane film former, polyester film former, and / or epoxy resin film former, etc.), at least one lubricant, and at least one silane coupling agent (aminosilane or methacryl) Size composition comprising an oxy silane coupling agent, etc.) is applied in a conventional manner to the thin glass fibers. The sized glass fibers can be divided into glass fiber strands comprising any number of individual glass fibers. It is preferable that a glass fiber bundle has a bundle tex of 20-200 g / km. The glass fiber strands can then be cut and dried into wet chopped glass fiber bundles to solidify or cure the sizing composition. Preferably, the wet bundle of fibers is a conventional dielectric (RF) oven, Cratec

It is dried in a fluid bed oven, such as an oven (available from Owens Corning), or in an oven, such as a rotary tray thermal oven, to form chopped glass fiber bundles.

오븐 (Owens Corning 사로부터 이용가능) 과 같은 유동층 오븐, 또는 회전식 트레이 열적 오븐에서 더욱 건조된다.It is also an object of the present invention to provide a method of forming a chopped glass fiber bundle using a heat transfer chamber to thermally dry a sized wet glass fiber. At least one film former (polyurethane film former, polyester film former, and / or epoxy resin film former, etc.), at least one lubricant, and at least one silane coupling agent (aminosilane or methacryl) A size composition comprising an oxy silane coupling agent, etc.) is applied to the tapered glass fibers by the bushing. The sized glass fibers can then be passed through a heat transfer chamber where air heated by the bushings enters the heat transfer chamber, substantially drying the sizing on the glass fibers. The dried glass fibers exiting the heat transfer chamber may be divided into glass fiber strands comprising any number of individual glass fibers. It is preferable that a glass fiber bundle has a bundle tex of 20-200 g / km. Prior to cutting the glass strands into chopped glass fiber bundles, the glass strands can be gathered together in a single tow. In one exemplary embodiment, the chopped fiber bundle is a conventional dielectric (RF) oven, Cratec

It is further dried in a fluid bed oven, such as an oven (available from Owens Corning), or in a rotary tray thermal oven.

An advantage of the present invention is that chopped glass fiber bundles can be formed at a faster rate than conventional air-laid processes. Increasing the manufacturing speed of chopped glass fiber bundles can produce more output and additional products that can be sold to consumers.

Another advantage of the present invention is that chopped glass fiber bundles can be formed at low manufacturing costs since the wet glass fibers do not need to be dried and cut in individual steps.

Another advantage of the present invention is that little or no fuzz occurs in the final chopped strand mat according to the wet fibers used to form the chopped glass fiber bundles.

These and other objects, features and advantages of the present invention are described in the detailed description below. However, it should be clearly understood that the drawings are for illustrative purposes only and do not prescribe the limitations of the invention.

Considering the following detailed description of the invention with reference to the accompanying drawings, the advantages of the invention will become apparent.

1 is a schematic diagram of a cut strand bundle according to an exemplary embodiment of the present invention.

2 is a flow diagram illustrating the steps of an exemplary process for forming a glass fiber bundle according to at least one embodiment of the present invention.

3 is a schematic diagram of a processing line for forming dried chopped strand bundles according to one exemplary embodiment of the present invention.

4 is a schematic diagram of a processing line for forming dried chopped strand bundles according to at least one other exemplary embodiment of the present invention.

5 is a schematic diagram of a processing line for forming a cut strand mat using a cut strand bundle according to the present invention.

FIG. 6 is a graph of laminate tensile strength in the machine direction and in the transverse direction for a conventional cut strand mat and a cut strand mat using a dried cut glass fiber bundle according to the present invention.

FIG. 7 is a graph of laminate tensile modulus in the machine and transverse directions for a conventional cut strand mat and a cut strand mat using a dried cut glass fiber bundle according to the present invention.

FIG. 8 is a graph of laminate flexural strength in the machine and transverse directions for a conventional cut strand mat and a cut strand mat using a dried cut glass fiber bundle according to the present invention.

FIG. 9 is a graph of laminate flexural modulus in the machine and transverse directions for a conventional cut strand mat and a cut strand mat using a dried cut glass fiber bundle according to the present invention. FIG.

10 is a graph of tensile strength in the machine direction for laminates formed using dried chopped glass fiber bundles according to the present invention.

11 is a graph of tensile strength in the transverse direction for laminates formed using dried chopped glass fiber bundles according to the present invention.

12 is a graph of IZOD notched impact strength of bulk molding compounds consisting of glass fibers sized with a sizing composition according to the invention to control at 0 °.

FIG. 13 is a graph of Izod notch impact strength of a bulk molding compound consisting of glass fibers sized with a sizing composition according to the present invention for control at 90 °.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein.

In the drawings, the thicknesses of lines, layers and regions may be exaggerated for clarity. Like reference numerals in all the drawings indicate like elements. The terms "top", "bottom", "side", "top", "bottom" and the like are used here for illustrative purposes only. When an element is represented as being on another element, it may be directly to or against the other element, or an intervening element may be present. The terms "sizing", "size", "sizing composition", and "size composition" may be used interchangeably herein. The terms "strand" and "bundle" may also be used interchangeably.

The present invention relates to chopped glass fiber bundles that can be used as a substitute for conventional glass foams used in mat forming applications and to processes for forming such chopped glass fiber bundles. An example of a chopped glass fiber bundle according to the invention is shown schematically in FIG. 1. As shown in FIG. 1, the chopped glass fiber bundles 10 are formed of a plurality of individual glass fibers 12 (having a diameter 16 and a length 14). The individual glass fibers 12 are positioned in an orientation that is substantially parallel to each other in a tightly woven or " bundle " form. The expression "substantially parallel" as used herein indicates that the individual glass fibers 12 are parallel or nearly parallel to each other. The chopped glass fiber bundles according to the present invention are suitable for the formation of chopped strand mats (CSM), the formation of sheet forming compounds (SMC), bulk molding compounds (BMC), hand lay-up applications, and spraying -up) can be used for applications. And, chopped glass fiber bundles can be used to make preforms for use in resin transfer molding (RTM) or tissue reaction injection molding (SRIM). In tissue reaction injection molding, the dried chopped glass fiber bundles 10 are blown onto the screen to have the shape of the desired part, such as a truck bed or an auto door inner.

유리 섬유), 울 유리 섬유, 또는 이들의 조합과 같은 임의의 종류의 유리 섬유일 수 있다. 적어도 한 바람직한 실시형태에서, 유리 섬유는 습식용 절단 스트랜드 유리 섬유 (WUCS) 이다. 습식용 절단 스트랜드 유리 섬유는 본 기술분야에 공지된 종래 프로세스에 의해 형성될 수 있다. 습식용 절단 스트랜드 유리 섬유는 약 5 ∼ 약 30 % 의 습분 함량을 갖 는 것이 바람직하고, 약 5 ∼ 약 15 % 의 습분 함량을 갖는 것이 더욱 바람직하다.The glass fibers used to form the chopped fiber bundles include A-type glass fibers, C-type glass fibers, E-type glass fibers, S-type glass fibers, ECR-type glass fibers (eg, available from Owens Corning). Advantex

Glass fibers), wool glass fibers, or a combination thereof. In at least one preferred embodiment, the glass fibers are wet chopped strand glass fibers (WUCS). Wet chopped strand glass fibers can be formed by conventional processes known in the art. It is preferable that the wet chopped strand glass fibers have a moisture content of about 5 to about 30%, and more preferably have a moisture content of about 5 to about 15%.

로서 판매되고 있음) 등) 와 같은 다른 강화 섬유를 사용하는 것은 본 발명의 범위 내에 속하는 것으로 생각된다. 여기서 사용되는 것처럼, 용어 "천연 섬유"는 줄기, 씨, 잎, 뿌리 또는 인피부 (bast) 를 포함하는 (그러나 이에 국한되지 않음) 식물의 임의의 부분에서 추출된 식물 섬유를 가리킨다. 섬유 다발에 합성 섬유가 포함되면, 섬유 다발로 형성되는 매트는 더욱 유연해지거나 작은 반경에의 순응성 (conformability) 이 커지게 된다. 또한, 합성 섬유의 사용은 이후 처리에서 매트 바인더로서 작용하여, 절단 유리 섬유 다발 (10) 을 함께 유지하고 절단 스트랜드 매트를 형성할 수 있다. 그러나, 다발 (10) 내 모든 섬유가 유리 섬유인 것이 바람직하다.In the fiber bundle 10, natural fibers, mineral fibers, carbon fibers, ceramic fibers, and / or synthetic fibers (polyester, polyethylene, polyethylene terephthalate, polypropylene, and / or polyparaphenylene terephthalamide (Kevlar

Use of other reinforcing fibers, such as, for example). As used herein, the term “natural fiber” refers to plant fibers extracted from any part of a plant, including but not limited to stems, seeds, leaves, roots or basts. When synthetic fibers are included in the fiber bundles, the mats formed from the fiber bundles become more flexible or have greater conformability to small radii. In addition, the use of synthetic fibers can serve as a mat binder in subsequent processing, holding the chopped glass fiber bundles 10 together and forming a chopped strand mat. However, it is preferable that all the fibers in the bundle 10 are glass fibers.

In one exemplary embodiment, schematically illustrated in FIG. 2, the process for forming the chopped glass fiber bundles 10 forms glass fibers to form the chopped glass fiber bundles (step 20), and the size composition of the glass fiber (Step 22), splitting the fibers to obtain the desired bundle tex (step 24), cutting the wet fiber strands into individual lengths (step 26), and drying the wet strands (step 28). .

As shown in greater detail in FIG. 3, glass fibers 12 may be formed by tapering a stream of molten glass material (not shown) exiting the bushing or orifice 30. The tapered glass fibers 12 may have a diameter of about 8 to about 23 microns, preferably 10 to 16 microns. After the glass fibers 12 are drawn out of the bushing 30, an aqueous sizing composition is applied to the fibers 12. The sizing can be applied by the application roller 32 shown in FIG. 3 or by conventional methods, such as by spraying the size directly onto the fibers (not shown). The size protects the glass fiber 12 from breaking during subsequent processing, helps to suppress inter-filament wear, and ensures the integrity of the strands of the glass fiber, such as the interconnection of the glass filaments forming the strands.

In addition, in the present invention, the size of the glass fibers 12 maintains bundle integrity during the formation and subsequent processing of the glass fiber bundles 10, such as a wet process for forming a chopped strand mat (CSM). In this process, the glass fiber bundles 10 are added to the white water slurry and stirred. The slurry is then placed on a moving screen where most of the water is removed to form a web, a binder is added, and the web is dried to remove the remaining water and to cure the binder. Unlike conventional glass bundles, the chopped glass fiber bundles 10 sized with the size composition described below remain in the bundle form or substantially in the bundle form during the formation of the chopped strand mat. In at least one exemplary embodiment, the fibers 12 in the bundle 10 may be sized with a sizing composition such that a predetermined amount of the fibers 12 are dispersed in the slurry from the fiber bundle 10 while stirring. In addition, the size composition of the glass fibers 12 aids in the filamentation of the bundle 10 in subsequent processing steps to form a mat that imparts an aesthetic appearance to the final product.

Another example where the size of the glass fibers maintains bundle integrity during processing is when molding sheet molding compounds (SMC). In the molding of the sheet molding compound, the matched metal die is loaded (filled) with the sheet molding compound or bulk molding compound (BMC). When the metal die is closed and heated so that the sheet molding compound (or BMC) can flow and fill the die to form the desired part, the glass fiber bundle 10 preferably has bundle integrity. However, if the glass fiber bundle 10 separates into single fibers in the die before the flow is complete, the individual glass fibers form agglomerates and incompletely fill the die, resulting in a defective part. On the other hand, after the sheet or bulk molding compound is flowed and the die is filled, the glass fiber bundle 10 is then filamentated, thereby "telegraphing" or "fiber print" (glass fiber bundle 10 on the part surface). It is desirable to reduce or even prevent the occurrence of the contour). Thus, the size of the glass fibers 12 aids in filamentation of the chopped glass fiber bundles 10 during the subsequent processing steps (such as forming a chopped strand mat formed from the glass fiber bundles 10) to form an aesthetic final product.

The size composition applied to the glass fibers 12 may include one or more film formers (polyurethane film formers, polyester film formers, and / or epoxy resin film formers, etc.), at least one lubricant, and at least one Silane coupling agent (aminosilane or methacryloxy silane coupling agent). If desired, weak acids such as acetic acid, boric acid, metaboric acid, amber acid, citric acid, formic acid, and / or polyacrylic acid may be added to the size composition to aid in hydrolysis of the silane coupling agent. The size composition may be applied to the glass fibers 12 at a loss of burn (LOI) of about 0.05 to about 2.0% in the dried fibers. LOI can be defined as the percentage of organic solid material accumulated on the glass fiber surface.

The film forming agent is a material which improves the adhesion between the glass fibers 12 and consequently improves the strand integrity. Suitable film formers for use in the present invention include polyurethane film formers, epoxy resin film formers, and unsaturated polyester resin film formers. Specific examples of film formers include polyurethane dispersions such as Neoxil 6158 (commercially available from DSM); Polyester dispersions such as Neoxil 2106 (available from DSM), Neoxil 9540 (available from DSM) and Neoxil PS 4759 (available from DSM); And PE-412 (available from AOC), NX 9620 (available from DSM), Neoxil 0151 (available from DSM), Neoxil 2762 (available from DSM), NX 1143 (available from DSM) ), AD 502 (available from AOC), Epi Rez 5520 (available from Hexion), Epi Rez 3952 (available from Hexion), Witchbond W-290 H (available from Chemtura), and Witcobond W Epoxy resin dispersions such as -296 (available from Chemtura). The film former (s) may be present in the size composition at about 5 to about 95 weight percent of the active solids in size, preferably at about 40 to about 80 weight percent of the active solids.

The size composition also includes one or more silane coupling agents. The silane coupling agent enhances the adhesion of the film former (s) to the glass fibers 12 during the subsequent treatment and reduces the degree of baffle or broken fiber filaments. Examples of silane coupling agents that can be used in the size composition of the present invention can be characterized by amino, epoxy, vinyl, methacryloxy, ureido, isocyanato and azamido functional groups. have. Suitable coupling agents for use in the size composition are, for example, γ-aminopropyltriethoxysilane (A-1100 available from General Electric) and methacryloxypropyltriethoxysilane (A-174 available from General Electric) Commercially available as The silane coupling agent may be present in the size composition in an amount of about 5 to about 30 weight percent of the active solids in the size composition, more preferably about 10 to about 15 weight percent of the active solids.

And the size composition may comprise at least one lubricant to facilitate manufacture. The lubricant may be present in the size composition in an amount from about 0 to about 15 weight percent of the active solids in the size composition. Preferably the lubricant is present in an amount of about 5 to about 10 weight percent of the active solids. Although any suitable lubricant may be used, specific examples of suitable lubricants for use in the size composition include stearic ethanolamide (available from AOC) sold under the name Lubesize K-12; PEG 400 MO, monooleate ester having about 400 ethylene oxide groups (commercially available from Cognis); And Emery 6760 L, polyethylenimine polyamide salt (commercially available from Cognis).

It has been found that certain chemical groups in combination are particularly effective at keeping the chopped glass fiber bundles 10 in bundle form during subsequent processing. For example, urethane-based film forming dispersions (such as γ-aminopropyltriethoxysilane (sold as A-1100 by General Electric) in combination with aminosilane) may be bundled together in a size composition. It is effective to maintain. It has also been found that the addition of additives such as polyurethane-acrylic alloys to the urethane-based sizing compositions helps to maintain bundle integrity.

And epoxy-based film forming dispersions in combination with epoxy curatives are effective sizing compositions for use in the present invention. In particular, epoxy based film formers such as Epi-Rez 5520 and epoxy curing agents such as DPC-6870 available from Resolution Performance Products, in particular methacryloxypropyltriethoxysilane (commercially available as A-174 from General Electric) In combination with methacryloxy silane such as) to form an effective sizing composition.

It has also been found that unsaturated polyester resin film formers are effective in forming useful sizing compositions. For example, unsaturated polyester resin film formers such as PE-412 (unsaturated polyester in styrene emulsions in water) or Neoxil PS 4759 (available from DSM) are effective sizes for use in the present invention. Unsaturated polyester film formers may be used alone or in combination with a benzoyl peroxide curing catalyst such as Benox L-40LV (Norac Company, Inc.). The benzoyl peroxide curing catalyst promotes curing (crosslinking) of the unsaturated polyester and makes the film surrounding the glass fibers waterproof.

Sizing compositions include antifoams, such as Drew L-139 (available from Drew Industries, a subsidiary of Ashland Chemical), antistatic agents, such as Emerstat 6660A (available from Cognis), surfactants such as Surfyno 465 (available from Air Products) , Conventional additives such as Triton X-100 (available from Cognis) and / or thickeners. The additive may be present in the size composition in trace amounts (eg, less than about 0.1 weight percent of active solids) up to about 5 weight percent of active solids.

After the glass fibers 12 have been treated with the sizing composition, they are collected and split into fiber strands 36 having the specified desired number of individual glass fibers 12. A splitter shoe 34 divides the tapered and sized glass fibers into fiber strands 36. The glass fiber strands 36 may pass through a second splitter shoe (not shown) before being cut. The specific number of individual glass fibers 12 (and therefore the number of divided pieces of glass fibers 12) present in the fiber strands 36 varies depending on the particular use of the chopped glass fiber bundles 10. For example, if the bushing has 4000 orifices for thinning the glass fibers, in order to obtain a glass fiber bundle comprising 100 fibers, it is necessary to divide the thin glass fibers into 40 paths. The bundle tex of such particular bundle of glass fibers depends on the diameter of the glass fibers forming the bundle. In the above example where the fiber bundle comprises 100 individual glass fibers, if the fiber diameter of the glass fibers is 12 microns, the resulting bundle tex is 29. If the bundle diameter is 16 microns, the resulting bundle tex is 51 g / km. The glass fibers 12 are preferably divided into fiber bundles having a specific number of individual fibers to have a bundle tex of about 20 to about 200 g / km, preferably about 30 to about 50 g / km.

The fiber strands 36 are transferred from the collection shoe 38 to the cutter 40 / coat (cot, 60) combination, where the combination has a length of about 0.125 to about 3 inches, preferably about 0.25 to about 1.25 inches. Having a wet chopped glass fiber bundle 42. The wet chopped glass fiber bundles 42 may fall onto the conveyor 44 (foraminous conveyor, etc.) for delivery to the drying oven 46. Alternatively, the wet chopped glass fiber bundles 42 can be collected in a container (not shown) for later use.

오븐 (Owens Corning 사로부터 이용가능) 과 같은 유동층 오븐, 또는 회전식 트레이 열적 오븐과 같은 오븐 (46) 에서 건조된다. 그리고 나서, 건조된 절단 유리 섬유 다발 (10) 은 수집 컨테이너 (48) 에 수집될 수 있다. 예시적인 실시형태에서, 자유수 (free water, 즉, 절단 섬유 다발 (42) 의 외부에 있는 물) 의 약 99 % 초과 (또는 약 99%) 가 제거된다. 그러나, 건조 오븐 (46) 에 의해 실질적으로 물 전부가 제거되는 것이 바람직하다. 여기서 사용되는 "실질적으로 물 전부" 라는 표현은 섬유 다발 (42) 의 자유수 전부 또는 거의 전부가 제거됨을 나타낸다.The bundle 42 of sized wet chopped fibers is then dried to cure or solidify the sizing composition. Preferably, the wet bundle of fibers 42 is a conventional dielectric (RF) oven, Cratec, for forming the chopped glass fiber bundles 10.

It is dried in a fluid bed oven, such as an oven (available from Owens Corning), or in an oven 46, such as a rotary tray thermal oven. The dried chopped glass fiber bundles 10 can then be collected in a collection container 48. In an exemplary embodiment, more than about 99% (or about 99%) of free water (ie, water outside the chopped fiber bundle 42) is removed. However, it is preferable that substantially all of the water be removed by the drying oven 46. The expression "substantially all of the water" as used herein indicates that all or almost all of the free water of the fiber bundle 42 is removed.

In at least one exemplary embodiment, the wet bundle 42 of glass fibers is dried in a conventional dielectric (RF) oven. The dielectric oven includes electrodes that are spaced apart from each other, which produce an alternating high frequency electric field between the electrodes with successive opposite charges. A wet bundle of glass fibers 42 passes between the electrodes and through an electric field, where an alternating high frequency electric field excites water molecules and molar energy of the molecules is sufficient to evaporate water in the wet cut fiber bundles 42. Raise to level.

Dielectric drying of the bundle 42 of wet glass fibers enhances fiber to fiber bonding and reduces bundle to bundle adhesion. The dielectric energy evenly penetrates the wet bundles 42 of the chopped glass fibers and allows the water to evaporate quickly, helping to keep the wet glass bundles 42 separated from each other. And with the dielectric oven, the wet glass fiber bundle 42 can be dried, without the dynamic method of fiber stirring conventionally required in order to remove moisture from a wet fiber. This omission of agitation reduces or eliminates the friction or wear of fibers commonly observed in conventional fluidized bed and tray drying ovens due to the high air flow rate in the oven and the physical motion of the fiber material in the bed. And, the omission of agitation greatly increases the dielectric oven's ability to hold the glass fibers in bundles and does not filament the glass fiber strands as in aggressive conventional heat treatments.

오븐과 같 은 유동층 오븐 또는 회전식 트레이 오븐에서 건조될 수 있다. Cratec

건조 오븐 및 회전식 트레이 오븐 모두에서, 습식 절단 유리 섬유 다발 (42) 은 건조되고, 섬유 상에 있는 사이징 조성물은 제어된 온도를 갖는 고온의 공기 유동을 이용하여 응고된다. 그리고 나서, 건조된 섬유 다발 (10) 은, 절단 유리 섬유 다발 (10) 이 수집되기 전에 롱 (long), 버플 볼 및 바람직하지 않은 다른 물질을 제거하기 위해, 스크린 위로 전달된다. 그리고, Cratec

과 회전식 트레이 오븐에서 일반적으로 발견되는 높은 오븐 온도는 사이즈를 매우 높은 레벨의 경화로 재빨리 경화시킬 수 있고, 이는 조숙한 필라멘트화의 발생을 감소시킨다.In another embodiment, the wet cut glass fiber bundles 42 are Cratec

It may be dried in a fluid bed oven, such as an oven, or in a rotary tray oven. Cratec

In both the drying oven and the rotary tray oven, the wet chopped glass fiber bundles 42 are dried, and the sizing composition on the fibers is solidified using a hot air flow having a controlled temperature. The dried fiber bundles 10 are then transferred over the screen to remove longs, baffle balls and other undesirable materials before the chopped glass fiber bundles 10 are collected. And Cratec

The high oven temperatures commonly found in rotary tray ovens can quickly cure the size to a very high level of hardening, which reduces the occurrence of premature filamentation.

In the second embodiment of the present invention schematically shown in FIG. 4, the glass fibers 12 are tapered from the bushing 30. The aqueous sizing composition described in detail above is applied to the tapered glass fibers 12 to form the wet sized glass fibers 50. The sizing can be applied by an external application roller 32 or by conventional methods such as spraying the size directly onto the glass fiber 12 (not shown). Positioning the size applicator in the heat transfer chamber 52 is believed to be within the scope of the present invention. The wet sized glass fibers 50 then enter the heat transfer chamber 52 and ambient air flows into the upper end 54 of the heat transfer chamber 52 from around the bushing 30.

As shown in FIG. 4, the heat transfer chamber 52 is disposed below the size applicator 32 so that the air flowing into the upper end 54 of the heat transfer chamber 52 is heated by the maximum heat generated by the bushing 30. The upper end 54 of the heat transfer chamber 52 is positioned sufficiently close to the bushing 30. The heat transfer chamber 52 is then disposed essentially around the sized glass fiber 50 such that heated air evaporates the water or solvent present in the size composition of the wet glass fiber 50. The heat transfer chamber 52 extends downward from the size applicator 32 a distance sufficient to dry or substantially dry the sized wet glass fibers 50. In a preferred embodiment, the moisture content of the glass fibers 50 is less than about 0.05%. The wet glass fibers 50 cause the heat transfer chamber 52 to move through the heat transfer chamber 52 and emerge as dried glass fibers 56 in the chamber 52. Such adiabatic procedures are described in US Pat. No. 5,055,119 to Flautt et al.

The dried size glass fibers 56 are then collected and split into a specific desired number of dried fiber strands 58 of individual glass fibers 12. The splitter shoe 34 divides the dried size glass fibers 56 into dried fiber strands 58, which can then be gathered by a gather shoe 38 into a single toe 59 for cutting. have. Splitter shoe 34 may be positioned internally (not shown) within heat transfer chamber 52 to split the wet glass fibers 50 into strands before exiting heat transfer chamber 52. In such a situation, the collection shoe 38 may or may not be located in the heat transfer chamber 52. In addition, the splitter shoe 34 may be positioned between the size applicator 32 and the heat transfer chamber 52 to split the glass fibers 12 before entering the heat transfer chamber 52 (not shown).

오븐 (Owens Corning 사로부터 이용가능) 과 같은 유동층 오븐, 또는 회전식 트레이 열적 오븐으로의 운송을 위한 컨베이어 (도시 안 됨) 상에 놓일 수 있다.The toe 59 of the bonded glass fiber strands can be cut by a combination of conventional coat 60 and cutter 40 to form a dried chopped fiber bundle 10. As noted above, the dried chopped fiber bundles 10 may have a length of about 0.125 to about 3 inches, preferably about 0.25 to about 1.25 inches. In at least one preferred embodiment, the dried size glass fibers 56 are dried bundles 58 of fibers having a bundle tex of from about 20 to about 200 g / km, preferably from about 30 to about 50 g / km. Divided into. The dried chopped glass fiber bundles 10 may be dropped into the collection container 48 for storage or placed on a conveyor for inline formation of the chopped strand mat (this embodiment is not shown). In another embodiment, the dried chopped fiber bundles 10 can be dried in order to dry further in conventional dielectric (RF) ovens, Cratec.

It may be placed on a fluid bed oven, such as an oven (available from Owens Corning), or on a conveyor (not shown) for transportation to a rotary tray thermal oven.

In use, the dried chopped glass fiber bundles 10 can be used in the chopped strand mat 84 as shown in FIG. 5. The dried chopped glass fiber bundles 10 may be provided to the conveyor 62 by a storage container 60. The dried chopped glass fiber bundles 10 are placed and stirred in a mixing tank 64 containing various surfactants, viscosity modifiers, antifoams, and / or other chemical agents to form chopped glass fiber bundle slurries (not shown). do. The slurry can be delivered through a machine chest 66 and a constant level chest 68 to further disperse any fibers selectively released from the chopped glass fiber bundles 10 by the size composition. The glass fiber bundle slurry can then be transferred from the constant level chest 68 to the head box 70, where the slurry is deposited on a moving screen or porous conveyor 74 and most of the water from the slurry Removed to form a web 72. Water may be removed from the web 72 by conventional vacuum or air intake systems (not shown in FIG. 5). The binder 76 is then applied to the web 72 by the binder applicator 78. Then, the binder-coated web 80 passes through the drying oven 82 to remove the remaining water and to cure the binder. The formed nonwoven chopped strand mat 84 coming from the oven 82 includes a randomly dispersed glass fiber bundle. The nonwoven cut strand mat 84 may be wound on a winding roll 86 for later use.

The binder may be an acrylic binder, styrene acrylonitrile binder, styrene butadiene rubber binder, urea formaldehyde binder or mixtures thereof. Preferably, the binder is a standard thermosetting acrylic binder formed of polyacrylic acid and at least one polyol (eg, triethanolamine or glycerin). Examples of suitable acrylic binders for use in the present invention include plasticized polyvinylacetate binders such as Vinamul 8831 (available from Celene) and modified polyvinyl acetates such as Duracet 637 and Duracet 675 (available from Franklin Internatinoal). Acetate is included. The binder selects conventional additives (dyes, oils, fillers, colorants, UV stabilizers, coupling agents (eg, aminosilanes), lubricants, wetting agents, surfactants, and / or antistatic agents, etc.) to improve process and product performance. It may include.

There are a number of advantages provided by the chopped glass fiber bundles 10 of the present invention. For example, the chopped glass fiber bundles 10 can be formed at very high speeds, especially when compared to glass bundles formed by conventional airlaid processes. Increasing the manufacturing speed of chopped glass fiber bundles can produce more output and additional products that can be sold to consumers. And since the fibers do not need to be dried and cut in individual steps, chopped glass fiber bundles can be formed at low manufacturing costs.

And, using the chopped glass fiber bundles 10 to form chopped strand mats in the above wet process provides a mat having a substantially uniform distribution of glass (aerial density) and white in appearance. In addition, the use of wet fibers to form chopped glass fiber bundles is advantageous because no or little buzz occurs in the final chopped strand mat.

While the invention has been described in outline, it will be further understood through the specific specific examples set forth below for purposes of illustration only and not exclusive or restrictive unless otherwise indicated.

Yes

Example 1: Formation of dry cut fiberglass bundles

As outlined below, a sizing composition shown in Tables 1 to 4 was prepared in a bucket. To prepare the size composition, about 90% water and acid (s), if present in the size composition, were added to the bucket. The silane coupling agent was added to the bucket and the mixture was stirred for a time during which the silane could hydrolyze. After hydrolysis of the silane, a lubricant and a film former were added to the mixture with stirring to form a size composition. The size composition is then diluted with the remaining water to obtain a target mixed solid of about 4.5% mix solids.

TABLE 1 Polyurethane Size Composition A

Component of Size Composition % By weight of active solids W290H ^(a) 83.64 A-187 ^(b) 1.12 A-1100 ^(c) 4.68 A-100 ^(c) 9.95 Lubesize K-12 ^(e) 0.06

^(a) Polyurethane Film Forming Dispersion (Cognis)

^(b) Epoxy Curing Agent (Resolution Performance Products)

^(c) γ-aminopropyltriethoxysilane (General Electric)

^(d) Polyurethane-acrylic alloys (Cognis)

^(e) stearic ethanolamide (AOC)

TABLE 2 Polyurethane Size Composition B

Component of Size Composition % By weight of active solids W296 ^(a) 491.76 A-187 ^(b) 6.79 A-1100 ^(c) 25.86 PEG 400 MO ^(d) 2.21

^(a) Polyurethane Film Forming Dispersion (Chemtura)

^(b) Epoxy Curing Agent (Resolution Performance Products)

^(c) γ-aminopropyltriethoxysilane (General Electric)

^(d) Polyurethane-acrylic alloys (Cognis)

^(e) Monooleate esters (Cognis)

TABLE 3 Epoxy Size Composition A

Component of Size Composition % By weight of active solids ER 5520 ^(a) 46.15 DPC-6870 ^(b) 46.15 PEG 400 MO ^(c) 3.08 A-174 ^(d) 4.62

^(a) Epoxy Resin Film Forming Dispersion in Water (Resolution Performance Products)

^(b) Epoxy Curing Agent (Resolution Performance Products)

^(c) monooleate esters (Cognis)

^(d) methacryloxypropyltrimethoxysilane (General Electric)

Table 4 Epoxy Size Composition D

Component of Size Composition % By weight of active solids ER 3546 ^(a) 47.20 DPC-6870 ^(b) 47.20 PEG 400 MO ^(c) 0.88 A-174 ^(d) 4.72

^(a) Epoxy Resin Film Forming Dispersion (Resolution Performance Products)

^(b) Epoxy Curing Agent (Resolution Performance Products)

^(c) monooleate esters (Cognis)

^(d) methacryloxypropyltrimethoxysilane (General Electric)

Each size is applied to the E-glass in a conventional manner (roll type applicator, etc.) as described below. The E-glass is tapered into 13 μm glass filaments through a 75 lb / hr bushing with a 2052 hole tip plate attached. The filaments are collected and divided into 16 paths, yielding 128 filaments per bundle of fiberglass and a bundle tex of about 43 g / km. The glass fiber bundles are then cut to a length of about 1.25 inches by a mechanical coat-cutter combination and collected in a plastic pan. The chopped glass fibers contain about 15% forming moisture. This moisture in the chopped glass fiber bundles is removed in a dielectric oven (40 MHz, Radio Frequency Co.) to form dried chopped glass fiber bundles.

Example 2: Cutting with dried cut glass fiber bundles Strand  Formation of mat

A dry chopped fiber bundle formed according to the procedure of Example 1 was used to form four chopped glass mats. The dry chopped fiber bundles (including the above-described size compositions shown in Tables 1 to 4, respectively) are suspended in a 250 gallon mixing tank, and suitable additives (surfactant, dispersant, etc.) are added thereto while stirring to cut the chopped glass fiber bundle slurry. Formed. The components (other than water) of the white water slurry are shown in Table 5.

TABLE 5

White water ingredients Volume (ppm) Drewfloc 270 ^(a) 400-900 Surfynol 465 ^(b) 50 to 200 Drew L-139 ^(c) 5 to 25 Nalco 7330 ^(d) 1 to 5

^(a) Anionic Polyacrylamides (available from Drew Industries)

^(b) Nonionic Surfactants (available from Air Products)

^(c) Defoamer (available from Drew Industries)

^(d) biocide (ONDEO Nalco)

The glass slurries were each placed on a moving chain, where most of the water was removed by vacuum to form a web. A plasticized polyvinylacetate mat binder was added to the glass web (Vinamul 8831 by Helene) by a weir (curtain coater). The web was then passed through a pressurized air oven at 450 ° F. for 30 seconds to remove residual water from the web, cure the binder, and form a chopped glass mat. As a result of measuring the basis weight of the mat, it was about 1 oz / ft ² . It was also found that the binder was present at 5.0 wt% in the mat. The mat was pure white and showed good pore density visually. And the chopped glass mat exhibited a dry tensile strength of 30 lb in the machine direction (MD) and 25 lb in the transverse direction (CD).

Laminates were made with a chopped glass mat having a polyester resin (AOC R937) and catalyzed with an Attofina DDM9 catalyst (2-butanone peroxide). To facilitate comparison, the laminates comprising the chopped glass fiber bundles of the present invention all had a thickness substantially equal to the 3 oz / ft ² basis weight. Mimicking hand layup, the laminate was formed in a hydraulic press at nominal temperature (120 ° F.) and pressure for 30 minutes. For 14 in ² laminates, the lower end of the press range pressure was 10,000 lb, which is approximately 50 psi. The laminate is post-cured for 2 hours in an oven at 200 ° F. before mechanical testing.

Laminates comprising the chopped glass fiber bundles of the present invention were tested for tensile strength and flexural strength. Tensile strength was determined according to the experimental procedure of ASTM D5083, and flexural strength was determined according to the experimental procedure of ASTM D790. Comparative mats are shown in Table 6.

TABLE 6

Comparison mat Explanation M723A 1 oz / ft ² cutting strand mat from Owens Corning M8643 1 oz / ft ² electrically drawn grade continuous filament mat from Owens Corning M8610 1 oz / ft ² general purpose filament mat from Owens Corning

Mechanical tests of laminates comprising the chopped glass fiber bundles of the present invention showed that the laminates of the present invention exhibited nearly equivalent performance compared to standard chopped strand mats (M723A) and surprisingly M8643 and M8610, continuous filament mats (CFM). The result of the comparative test is shown to FIGS. 6-9.

Example 3: heat transfer Chamber  Formation of Used Dry-cutting Fiberglass Bundles

Each of the sizes shown in Tables 1-4 was prepared and applied in a conventional manner to E-glass tapered with 13 μm glass filaments in a 75 lb / hr capacity bushing with a 2052 hole tip plate. The sized fibers are divided into 16 paths to obtain 128 filaments per glass fiber bundle, passed through a heat transfer chamber, where the air heated by the maximum heat generated by the bushing to dry the glass fiber bundles into the heat transfer chamber. Inflowed. The dried glass fiber bundles had a bundle tex of about 43 g / km. The dried glass fiber bundles were collected in one toe and cut into lengths of 1.25 inches with a mechanical coat-cutter combination. The cut glass fibers were collected in a plastic pan. The glass fibers contained 0% forming moisture.

Example 4: heat transfer Chamber  Cutting using dry cut glass fiber bundles formed using Strand  Formation of mat

A dry chopped fiber bundle formed according to the procedure described in Example 3 was used to form four chopped glass mats. The dry chopped fiber bundles (each containing the different size compositions listed in Tables 1 to 4) are suspended in a 250 gallon mixing tank, and suitable additives (surfactant, dispersant, etc.) are added thereto while stirring to cut the chopped glass fiber bundle slurry. Formed. The components (other than water) of the white water slurry are shown in Table 7.

TABLE 7

White water ingredients Volume (ppm) Drewfloc 270 ^(a) 400-900 Surfynol 465 ^(b) 50 to 200 Drew L-139 ^(c) 5 to 25 Nalco 7330 ^(d) 1 to 5

^(a) Anionic Polyacrylamides (available from Drew Industries)

^(b) Nonionic Surfactants (available from Air Products)

^(c) Defoamer (available from Drew Industries)

^(d) biocide (ONDEO Nalco)

The glass slurries were each placed on a moving chain, where most of the water was removed by vacuum to form a web. A plasticized polyvinylacetate mat binder was added to the glass web (Duracet 675 from Franklin International) by a weir (curtain coater). The web was then passed through a forced air oven at 450 ° F. for 30 seconds to remove remaining water from the web, cure the binder, and form a chopped glass mat. As a result of measuring the basis weight of the mat, it was about 1 oz / ft ² . It was also found that the binder was present at 5.0 wt% in the mat. On visual observation, the mat was pure white and was found to exhibit good pore density visually. And the chopped glass mat exhibited a dry tensile strength of 32 lb in the machine direction (MD) and 27 lb in the transverse direction (CD).

Laminates were made with a chopped glass mat having a polyester resin (AOC R937) and catalyzed with an Attofina DDM9 catalyst (2-butanone peroxide). To facilitate comparison, the laminates comprising the chopped glass fiber bundles of the present invention all had a thickness substantially equal to the 3 oz / ft ² basis weight. Mimicking hand layup, the laminate was formed in a hydraulic press at nominal temperature (120 ° F.) and pressure for 30 minutes. For 14 in ² laminates, the lower end of the press range pressure was 10,000 lb, which is approximately 50 psi. The laminate is post-cured for 2 hours in an oven at 200 ° F. before mechanical testing. Mechanical tests of laminates comprising the chopped glass fiber bundles of the present invention show that the laminates of the present invention have nearly equivalent performance compared to standard chopped strand mats (M723A) and surprisingly M8643 and M8610, continuous filament mats (CFM) (see Table 6). Indicated.

Example 5: Cutting with dried cut glass fiber bundles Strand  Tensile Strength of Laminates Made of Mat

A dry chopped fiber bundle formed according to the procedure described in Example 3 was used to form four chopped glass mats as described in Example 4 above. The dry chopped fiber bundles sized with the polyurethane size composition A (Table 1) were suspended in a white water slurry comprising the components shown in Table 7 in a 250 gallon mixing tank. The glass slurries were each collected on a moving chain, where most of the water was removed by vacuum to form a web. A plasticized polyvinylacetate mat binder was added to the glass web (Duracet 675 or Duracet 637 from Franklin International) by a weir (curtain coater). The web was then passed through a forced air oven at 450 ° F. for 30 seconds to remove water remaining from the web, to cure the binder, and form a chopped glass mat.

Laminates were prepared from chopped glass mats according to the procedure described in Example 4 above. The various samples tested (samples 1-7) are shown in Table 8. Sample 1 and Sample 2 included Duracet 637 as a binder, and Sample 3 and Sample 4 included Duracet 675 as a binder. Laminates were tested for tensile strength in the machine direction (MD) and transverse direction (CD). The results are shown in Table 10 and Table 11. As a result, the laminate exhibits a bias in the machine direction. This skew phenomenon is in contrast to mats produced according to conventional airlaid processes, which show no or almost no skew. The bias in the machine direction is advantageous for laminates because the cutting strand mat is inherently stronger in the direction that the consumer pulls off the roll. As a result, larger rolls can be produced. And, because of the additional strength, the consumer can pull the chopped strand mat off the roll at a faster rate and less likely to tear the mat. Furthermore, according to the data, laminates formed from chopped glass fiber bundles sized with size composition A exhibit better strength compared to the comparative object.

TABLE 8

Sample Description of Cutting Strand Mat One 0.5 oz / ft ² , 6 ply 2 1.5 oz / ft ² , 2-ply 3 0.5 oz / ft ² , 6 ply 4 1.5 oz / ft ² , 2-ply 5 M723A (3 plies of 1 oz / ft ² ) for comparison 6 M723A-2 (6 layers of 0.5 oz / ft ² ) for comparison 7 M723A-3 (2 layers of 1.5 oz / ft ² ) for comparison

Example 6: various Sizing  Formation of Bulk Molding Compound Using Composition

A quarter inch (1/4 ") chopped glass fiber sample was prepared from a bulk molding compound having the composition shown in Table 8.

TABLE 9 Bulk Molding Compound Composition

ingredient pph (Parts Per Hundred) Polyester Resin E-342 ^(a) 60 Thermoplastic P-713 ^(b) 40 tBPB ^(c) 1.5 Calwhite ^(c) 200 Zinc stearate ^(e) 4

^(a) unsaturated polyester resin (AOC)

^(b) thermoplastic (AOC)

^(c) tert-butylperbenzoate catalyst

^(d) Calcium Carbonate (Cabot)

^(e) Release Agent (Aldrich Chemical Co.)

The bulk molding compound compositions of Table 8 were prepared from various experimental glasses sized at 20 wt% with various sizing compositions. Various experimental glass fibers are shown below as Sample 1-Sample 10. The charge was placed in a 12 inch x 18 inch tool and molded at 10,000 psi, 265 ° F. for 5 minutes. The laminates were tested for resistance to notched impact strength according to ASTM D256 in the 0 ° and 90 ° directions. The results are shown in Tables 12 and 13. As a result, glass fibers sized with experimental size compositions exhibited at least comparable performance. The result was unexpected because at least comparable impact strength was achieved by drying the glass fibers for a short time (30 minutes) as compared to the conventional process of drying the glass for at least 20 hours.

Sample 1-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried in a thermal oven at 265 ° F. for 6 hours.

Sample 2-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried in an RF oven for 30 minutes and then in a thermal oven at 265 ° F. for 1 hour.

Sample 3-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried in an RF oven for 30 minutes and then in a thermal oven at 265 ° F. for 2 hours.

Sample 4-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried in an RF oven for 30 minutes and then in a thermal oven at 265 ° F. for 2 hours.

Sample 5-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried for 30 minutes in an RF oven and then in a thermal oven at 265 ° F. for 2 hours.

Sample 6-Polyurethane Size Composition A (Table 1) was added to the glass fibers and dried in an RF oven for 30 minutes and then in a thermal oven at 265 ° F. for 2 hours.

Sample 7-Polyurethane Size Composition B (Table 2) was added to the glass fibers and dried in an RF oven for 30 minutes, with no post heating.

Sample 8-Epoxy Size Composition A (Table 3) was added to the glass fibers and dried in an RF oven for 30 minutes with no post heating.

Sample 9-Epoxy Size Composition A (Table 3) was added to the glass fibers and dried in an RF oven for 20 minutes with no post heating.

Sample 10-Polyurethane Size Composition B (Table 2) was added to the glass fibers and dried in an RF oven for 20 minutes with no post heating.

Sample 12-Controlled Bulk Molding Compound (BMC) Dry Cutting Strand (101C from Rio Claro, Brazil; Owens Corning)

The foregoing has described the invention for this purpose in general and in connection with specific embodiments. Although the invention has been described as what is considered to be the preferred embodiment, a wide range of modifications known to those skilled in the art can be made within the general disclosure. The scope of the invention is defined by the claims set forth below.

Claims (20)

As chopped glass fiber bundles 42 for use in mat forming applications, A plurality of substantially parallel glass fibers 12 positioned in a bundle orientation, wherein the glass fibers are sized to maintain the plurality of glass fibers in the bundle orientation during formation and subsequent processing of the glass fibers in the bundle orientation. At least partially coated with the composition, The sizing composition, At least one film former selected from the group consisting of a polyurethane film former, an unsaturated polyester film former and an epoxy resin film former; At least one silane coupling agent; And A chopped glass fiber bundle comprising at least one lubricant. The chopped glass fiber bundle of claim 1, wherein the plurality of glass fibers have a bundle tex of about 20 to about 200 g / km. The chopped glass fiber bundle of claim 1, wherein the glass fiber is a wet chopped strand glass fiber. The chopped glass fiber bundle of claim 1, wherein the film former is a polyurethane film former and the sizing composition further comprises a polyurethane-acrylic alloy. The chopped glass fiber bundle of claim 1, wherein the film former is an epoxy resin film former and the sizing composition further comprises an epoxy curative. The chopped glass fiber bundle of claim 1, wherein the film former is an unsaturated polyester film former and the sizing composition further comprises a benzoyl peroxide curing catalyst. The method of claim 1, wherein the at least one film former is present in the sizing composition in an amount of about 80 to about 95 weight percent of the total solids, and the at least one silane coupling agent is present in the sizing composition. Chopped glass fiber bundles, wherein the at least one lubricant is present in the sizing composition in an amount of about 0.1 to about 2 weight percent of total solids. The chopped glass fiber bundle of claim 1, wherein the at least one silane coupling agent is selected from the group consisting of an aminosilane coupling agent and a methacryloxy silane coupling agent. The chopped glass fiber bundle of claim 1, wherein the sizing composition filaments the glass fiber into the bundle orientation during subsequent processing to form an aesthetic final product. As a method of forming the chopped glass fiber bundles 42, At least one film former selected from the group consisting of a polyurethane film former, an unsaturated polyester film former and an epoxy resin film former; At least one silane coupling agent; And applying a sizing composition comprising at least one lubricant to the plurality of tapered fiber bundles 12, Dividing the plurality of glass fibers into glass fiber strands 36 comprising a predetermined number of glass fibers, Cutting the glass fiber strands to form wet cut glass fiber bundles having individual lengths, and Drying the wet chopped glass fiber bundles in a drying oven selected from the group consisting of a dielectric oven, a fluid bed oven, and a rotary tray thermal oven to form chopped glass fiber bundles. The method of claim 10, wherein the predetermined number of glass fibers of the glass fiber strands is a number sufficient to provide a bundle tex of about 20 to about 200 g / km. The method of claim 10, further comprising placing the wet chopped glass fibers on a conveyor prior to the drying step. The method of claim 10, wherein at least about 99% of the water outside of the wet chopped glass fiber bundles is removed from the drying oven. The method of claim 13, The oven is the dielectric oven, The drying step includes passing the wet chopped glass fiber bundles through continuously oppositely charged electrodes located in the dielectric oven to evaporate water in the wet chopped fiber bundles without agitation of the wet chopped fiber bundles. Comprising, a method of forming a cut glass fiber bundles. The method of claim 13, wherein the wet chopped fiber bundles are dried in a fluidized bed and the sizing composition on the glass fibers is solidified using a hot air flow having a controlled temperature. As a method of forming the chopped glass fiber bundles 42, At least one film former selected from the group consisting of a polyurethane film former, an unsaturated polyester film former and an epoxy resin film former; At least one silane coupling agent; And applying a sizing composition comprising at least one lubricant to the plurality of fiber bundles 12 tapered by bushings; Passing a plurality of sized glass fibers through a heat transfer chamber, into which the air heated by the bushing enters into the heat transfer chamber to substantially dry the plurality of sized glass fibers to form dried glass fibers; Dividing the dried glass fibers into glass fiber strands (36) comprising a predetermined number of the dried glass fibers; And Cutting the glass fiber strands to form chopped glass fiber bundles having individual lengths. 17. The method of claim 16, further comprising gathering the glass fiber strands into a single toe prior to cutting the glass fiber strands. The method of claim 16, wherein the predetermined number of glass fibers of the glass fiber strands is a number sufficient to provide a bundle tex of about 20 to about 200 g / km. 17. The chopped glass fiber of claim 16, further comprising heating the chopped glass fiber bundle in a drying oven selected from the group consisting of a dielectric oven, a fluid bed oven, and a rotary tray thermal oven to further dry the chopped glass fiber bundle. How to form a bundle. 17. The method of claim 16, wherein the dividing step occurs before the dry glass fibers exit the heat transfer chamber.

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