CA1090521A - Method for producing fiber-reinforced polymer foam - Google Patents
Method for producing fiber-reinforced polymer foamInfo
- Publication number
- CA1090521A CA1090521A CA261,823A CA261823A CA1090521A CA 1090521 A CA1090521 A CA 1090521A CA 261823 A CA261823 A CA 261823A CA 1090521 A CA1090521 A CA 1090521A
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- Canada
- Prior art keywords
- layer
- foam
- fibrous layer
- liquid
- foamable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
- Reinforced Plastic Materials (AREA)
- Molding Of Porous Articles (AREA)
- Moulding By Coating Moulds (AREA)
- Laminated Bodies (AREA)
Abstract
METHOD FOR PRODUCING FIBER-REINFORCED POLYMER FOAM
ABSTRACT OF THE DISCLOSURE:
Flexible or rigid polymer foam reinforced with fibers such as glass fibers or synthetic fibers is produced by supplying at least one fibrous layer downwardly, supplying facing members downwardly adjacent the layer from the opposite sides thereof at a certain angle, feeding a foamable resinous liquid, for example, two-component type polyurethane, polyisocyanurate or polyoxazolidone foam-forming liquid to the opposite surfaces of the layer, pass-ing the layer and the facing members through a gap which is narrower than the thickness of the layer to compress the layer and to enable the foamable liquid to penetrate into the layer, and allowing the foamable liquid to foam under restricted or unres-tricted conditions. Foam in which fibers are uniformly distribut-ed has improved physical and chemical properties, such as cushion-ing properties, strength, compressive strain and flame-resistance.
ABSTRACT OF THE DISCLOSURE:
Flexible or rigid polymer foam reinforced with fibers such as glass fibers or synthetic fibers is produced by supplying at least one fibrous layer downwardly, supplying facing members downwardly adjacent the layer from the opposite sides thereof at a certain angle, feeding a foamable resinous liquid, for example, two-component type polyurethane, polyisocyanurate or polyoxazolidone foam-forming liquid to the opposite surfaces of the layer, pass-ing the layer and the facing members through a gap which is narrower than the thickness of the layer to compress the layer and to enable the foamable liquid to penetrate into the layer, and allowing the foamable liquid to foam under restricted or unres-tricted conditions. Foam in which fibers are uniformly distribut-ed has improved physical and chemical properties, such as cushion-ing properties, strength, compressive strain and flame-resistance.
Description
52~
BACKGROUND OF THE INVENTION:
This invention relates to a method for continuously producing a body of fiber-reinforced polymer foam.
In the prior art, fiber-reinforced polymer foam products are obtained by dispersing chopped glass fibers in a polymer foam. For example, Japanese Patent Publication No. 469/1969 discloses a fiber-reinforced polymer foam produced by mixing short fibers having a length of less than 5 mm in a urethane foam-forming liquid and then allowing the foamable liquid to foam. In this method, however, addition of the glass fiber8 results in only for the increase in quantity and only a slight reinforcing effect may be expected.
Glass fibers are required to have a length of more than 10 mm, preferably more than 20 mm, to obtain a reasonable reinforcing effect by the addition of glass fibers. When such longer fibers are actually added to and ~ixed with a urethane foam-forming liquid, fibers are intertwined each other during the mixing so that the fibers may not be dispersed uniformly ; in the foamable liquid and hence in the foam. A considerably irregular distribution of the fibers in the foam results.
Various-methods were proposed to solve the above drawback. Among these useful is a spray process in which chopped fibers are sprayed simultaneously with spray foaming.
One method is disclosed in Japanese Patent Publication No.
8386/1972, which requires to spray a foamable material in the vertical direction on a plate placed horizontally. Chopped fibers are supplied substantlally at right angles to the flow of spraying foamable material. Another method is known from Japanese Patent Unexamined Publication No. 21360/1975, in which the spraying of chopped fibers is performed in the same direction as the spraying of foamable material, while a plate to ,..
~sz~
be sprayed may be held not only at the horizontal position, but also at any angular position. The formation of a random web and the foaming are simultaneously performed on the plate.
These methods, however, have disadvantages that a foamable material cannot penetrate in portions where fibers are inter-twined to a large extent and thus many voids are formed when a larger content, for example, about 10% of fibers is desired, and that they are expensive because the loss of foamable material and fibers is large due to scattering and droppinq.
A further method is known in which a glass fiber layer is impregnated with a urethane foam-formlng liquid before foaming. For example, a method for continuously making a fiber-reinforced foam body disclosed in U.S. Pat. No. 3,867,494, comprises distributing a urethane foam-forming liquid over the upper surface of a glass fiber layer which is moved horizontally, applying another fibrous layer thereon, compressing the resulting composite layer to enable the foamable material to penetrate into the fibrous layers, and restricting the extent of the foaming of the foamable material. This method can provide an improved foam in which a larger amount of fibers are comparatively uniformly distributed as compared with the above-mentioned spray foaming method. The loss of fibers and foamable material is very slight. However, the following problems still remain unsolved.
(a) Since a foamable material is distributed to the inner surface of a lower fibrous layer placed at the horizontal position, another fibrous layer is superposed on the inner surface of the lower layer with the foamable material there-between and compressive force is then applied to enable the foamable material to penetrate into the fibrous layers, the penetration of the foamable material throughout the fibrous 105~0521 layers, particularly into the upper fibrous layer is insufficient.
(b) Since the foamable material supplied on the horizontal fibrous layer is not easily spread due to poor fluidity, a uniform distribution of the foamable material is achieved with difficulty. Further, a uniform penetration of the foamable material into the fibrous layer cannot be attained even after the compression, resulting in a nonuniform product.
(c) The foamable material penetrates to a least extent into a single fibrous layer large in thickness, for example, of more than 50 mm, so that a thick product cannot be obtained.
~ d) After the cream time of the foamable material, an increase in viscosity and the foaming of the foamable material prevent its penetration into the fibrous layers so that a foam containing fibers uniformly cannot be obtained.
~herefore, this method is unsuitable for the production of a foam from a foamable material havinq a short cream time.
Regardless of these disadvantages, the latter method disclosed in the above U.S. Patent has been found to be more advantageous than the former method, or the spray foaming method in some aspects. The inventors have made an extensive investigation on the latter method in order to eliminate ` the above-described drawbacks, and have accomplished the present invention.
SUMMARY OF THE INVENTION:
According to the invention there is provided a method for producing a body of fiber-reinforced polymer foam comprising the steps of (a) continuously supplying at least one fibrous layer having an apparent density of 0.001-0.lg/cm3, substantially vertically downwardly, (b) supplying a facing member downwardly ad;acent each extreme outer surface of the fibrous layer at an anqle of not less than 0 degree and less I~G521 than 90 degrees to the vertical to superpose each member on eachside of the fibrous layer, (c) simultaneously with the step ~b), distributing a foamable resinous liquid downwardly from the opposite sidesOf the fibrous layer in each space defined between the fibrous layer and the facing members, (d) passing the fibrous layer and the facing members superposed thereon through a gap which is narrower than the thickness of the fibrous layer to enable the foamable liquid to penetrate and disperse in the fibrous layer uniformly, and (e) allowing the foamable liquid to foam under restricted or unrestricted conditions.
It is therefore an advantage of this invention, at least in the preferred forms, that it can provide an improved method for continuously and efficiently producing any kind of foamed products having different shapes such as thick foamed products and cylindrical foamed coverings in which the loss of fibers and a foamable material is substantially negligible, a fibrous layer is uniformly impregnated with the foamable material so that uniformly foamed products can be obtained, and even a liquid foamable material having a short cream time may advantageously be used.
The facing members may both be of a flexible material or one may be of a flexible material and the other of the rigid material.
The foamable liquid may be distributed between the layers and between the fibrous layers and surface members if two or more layers are used.
The fibrous layer should be supplied downwardly so that the foamable liquid may easily reach the intersections between the fibrous layer and the members within a short period I~CSZ~
of time.
Important characteristics of the present invention can be summarized as follows. The fibrous layer positioned between two facing members is downwardly and continuously supplied together with the members. Simultaneously the foamable liquid is supplied from the opposite surfaces of the fibrous layer. The resulting laminate of the fibrous layer and the facing members is passed through a gap which is narrower than the thickness of the layer. Since the layer is held approximately vertically, the foamable liquid flows downwardly within a short perlod of time and rapidly reaches the inter-sections between the layer and the facing members. During passing through the narrow gap, the foamable liquid penetrates rapidly and uniformly throughout the layer from the opposite sides thereof under the influence of compressive force. An improved productcontainillg fibers uniformly in foam is obtained after the foaming.
Further, by supplying the foamable liquid from both sldes of the fibrous layer, the foamable liquid is dispersed into the fibrous layer within a shorter period of time than foamable liquid supplied from one side of the fibrous layer, and the foamed body contains fibers uniformly even if the fibrous layer is thick.
The essential features of the present invention will now be described in detail.
The fibrous layer which may be used in the present invention includes layers of any kind of fibrous materials, for example, cottonwool (or cotton batting)-like, porous materials consisting of intertwined organic or inorganic fibers and capable of forming into a sheet or plate by reason of handlability. Generally, fibrous materials which can be 5Zl directly used as a filler for mattresses or bedclothes, a - cushioning material, or a thermal insulating material are favor-able. Dense fabrics such as carpet are unsuitable. The preferable range of the apparent density of the fibrous layer varies depending on the type and fineness of component fibers, but may generally be from 0.001 to 0.1 g/cm3. Particularly, the apparent density may preferably fall in the range from 0.005 to 0.05 g/cm3, with a slight variation in accordance with the intended servlce of the products. For example, fillers of polyester fibers for bedclothes have an apparent density of about 0.005-0~02 g/cm , insulating materials of glass fibers about 0.005-0.1 g/cm3, and- palm rock about 0.1 g/cm3.
No particular restriction is imposed on the kind of fibers which can constitute the layer according to the present invention. Any desired fibers of organic and inorganic type may be used. For example, included are inorganic fibers such as glass fiber, aluminum fiber, iron fiber and roc~ wool, and organic fibers such as natural fiber, synthetic fiber and artificial fiber. Examples of organic fibers are fibers made of synthetic high-molecular substances such as polyvinyl chloride, polyvinylidene chloride, nylon, aromatic nylon, polyethylene terephthalate, polyvinyl acetal, polyvinyl alcohol, ; phenol-formaldehyde polycondentsates, polyacrylonitrile, etc., artificial fibers such as rayon, acetate, etc., and natural fiber such as cotton, flax, wool, fur, palm fiber, etc.
According to the present invention the fibrous layer is compressed to impregnate the layer with the liquid foamable material. It is desirable for the f~brous layer to resume its original thickness after the impregnation is complete. To this end, fibers may preferably have a high elastic recovery.
However, the elastic recovery is not critical, because the foamable - lQ~GSZl material which has penetrated into the fibrous layer expands together with the fibers during foaming. Consequently, foam in which fibers are uniformly distributed may be obtained as long as the foamable material has a low foaming magnification.
The fineness, length and degree of intertwinement of the fibers may suitably chosen depending on the intended service of the products. The fineness of fibers may preferably, but not critically, fall in the range of about 1 - 50 deniers.
Finer fibers, for example, of 0.5 denier or thicker fibers, for exampie, palm and flax fibers may also be employed.
The length of fibers may vary within a very wide range so far as they can be formed into a cottonwool-like mass and preferably fall in the range of, for example, about 10 - 100 mm. Longer fibers, for example, of 300 mm or more in length may also be employed provided that they are crimped.
Among the above-described fibers constituting the fibrous layer, synthetic fibers, particularly nylon Vinylon j ~Trade Mark,) acryl and polyester fibers are especially desir-! able in view of the reinforcement ef~ect, while glass wool and rock wool are desirable in view of the flame-retardant effect.
The fibrous layer is interposed between the facing members according to the present invention. The facing material may include two kinds of materials, a flexable material and a rigid material. Examples of the flexible material are paper, woven and non-woven fabrics of various fibers, films and sheets of plastics, and sheets and foils of metals-such as aluminum.
The member of the rigid material are, for example, boards of different rigid materials such as woodboard, plywood, asbestosboard~ plaster board, aluminum board, iron board, plastics board, etc., and pipes such as iron pipe, aluminum pipe, plastics pipe, etc. The manner of supplying the facing ~Q9C521 members according to the present invention wilI be described below with reference to the drawings.
The foamable liquid which can be used in the process of the present invention designates a li~uid material capable of forming a cellular polymer foam by a chemical foaming unaer suitable conditions. Examples of the polymer foam made from the foamable liquid are polyurethane, polyisocyanurate, poly-oxazolidone, carbodiimido, polyamide, p~ ide, pyranyl, epoxy, phenol and urea foams and com~inations thereof. In general, the foamable liquid consists of two or more liquid components which are mixed with each other to form a flexible or rigid poly-mer foam with the formation of a polymer and the generation of gas occurring substantially at the same time. The preferable foams made from the foamable liquid are polyurethane foams, poly-isocyanurate foams and polyoxazolidone foams.
It is commercially most important that a foam`can be ` obtained simply by mixing liquid components with each other without any particular external heating. The above-described foams can meet this requirement. Some of phenol foams are, however, prepared by adding a foaming agent to powder resol and heating the resulting mixture. This kind of foamable materials are not liquid so that they will hardly penetrate into the fibrous layer. Such foamable materials are thus unsuitable for the present invention. A phenol foam-forming liquid consisting of two liquid components can be employed in the method of the present invention.
The preparation of the above-described foams is well known and described in the literature.
The invention will now be described in greater detail and be explained with reference to a few embodiments and the accompanying diagrammatic drawings, in which ~WC521 Figs. 1 to 5 are schematic illustrations of different embodiments of carrying out the invention, respectively, Fig. 6 is a schematic front view of a modified example of compressive rolls which can be used in the invention, and a cross-sectional view of the rolls taken on the line A - A, Fig. 7 is a schematic perspective view of an apparatus for continuously producing a foam body according to the invention, Fig. 8 is a schematic front view of another apparatus according to the invention, Fig. 9 is a schematic plane view showing means for restricting foaming place in the foaming zone, Fig. 10 is a schematic front view of a further appar-atus according to the invention, Figs. 11 to 13 are schematic illustrations of different embodiments in which a foam covering is provided on a pipe according to the inventionj respectively, Figs. 14 to 15 are perspective views showing different methods of winding a foam layer on a pipe, respectively, Fig. 16 is a schematic front view showing means for restricting the foaming of a foamable layer wrapped around a pipe, Fig. 17 is a cross-sectional view of the vanes shown in Fig. 16 taken on the line B - B, ~ igs. 18 to 19 are perspective views of examples of the product according to the invention, respectively and Fig. 20 is a schematic flow sheet of an apparatus for producing a foam body suitable as a cushion.
~ eferring to the drawings, Figs. 1 to 5 shown schematic views illustrating different embodiments of the present invention, respectively. In these Figures, corresponding parts having the same function are designated by the same numeral.
_g_ In Figs. 1 to 5, numeral 1 represents a fibrous layer (to be referred to simply as "layer", hereinafter) which is supplied downwardly. Members of a flexible facing material 4 and 5 are supplied to the opposite surfaces of the layer 1 and the layer and the members are passed through a pair of rolls
BACKGROUND OF THE INVENTION:
This invention relates to a method for continuously producing a body of fiber-reinforced polymer foam.
In the prior art, fiber-reinforced polymer foam products are obtained by dispersing chopped glass fibers in a polymer foam. For example, Japanese Patent Publication No. 469/1969 discloses a fiber-reinforced polymer foam produced by mixing short fibers having a length of less than 5 mm in a urethane foam-forming liquid and then allowing the foamable liquid to foam. In this method, however, addition of the glass fiber8 results in only for the increase in quantity and only a slight reinforcing effect may be expected.
Glass fibers are required to have a length of more than 10 mm, preferably more than 20 mm, to obtain a reasonable reinforcing effect by the addition of glass fibers. When such longer fibers are actually added to and ~ixed with a urethane foam-forming liquid, fibers are intertwined each other during the mixing so that the fibers may not be dispersed uniformly ; in the foamable liquid and hence in the foam. A considerably irregular distribution of the fibers in the foam results.
Various-methods were proposed to solve the above drawback. Among these useful is a spray process in which chopped fibers are sprayed simultaneously with spray foaming.
One method is disclosed in Japanese Patent Publication No.
8386/1972, which requires to spray a foamable material in the vertical direction on a plate placed horizontally. Chopped fibers are supplied substantlally at right angles to the flow of spraying foamable material. Another method is known from Japanese Patent Unexamined Publication No. 21360/1975, in which the spraying of chopped fibers is performed in the same direction as the spraying of foamable material, while a plate to ,..
~sz~
be sprayed may be held not only at the horizontal position, but also at any angular position. The formation of a random web and the foaming are simultaneously performed on the plate.
These methods, however, have disadvantages that a foamable material cannot penetrate in portions where fibers are inter-twined to a large extent and thus many voids are formed when a larger content, for example, about 10% of fibers is desired, and that they are expensive because the loss of foamable material and fibers is large due to scattering and droppinq.
A further method is known in which a glass fiber layer is impregnated with a urethane foam-formlng liquid before foaming. For example, a method for continuously making a fiber-reinforced foam body disclosed in U.S. Pat. No. 3,867,494, comprises distributing a urethane foam-forming liquid over the upper surface of a glass fiber layer which is moved horizontally, applying another fibrous layer thereon, compressing the resulting composite layer to enable the foamable material to penetrate into the fibrous layers, and restricting the extent of the foaming of the foamable material. This method can provide an improved foam in which a larger amount of fibers are comparatively uniformly distributed as compared with the above-mentioned spray foaming method. The loss of fibers and foamable material is very slight. However, the following problems still remain unsolved.
(a) Since a foamable material is distributed to the inner surface of a lower fibrous layer placed at the horizontal position, another fibrous layer is superposed on the inner surface of the lower layer with the foamable material there-between and compressive force is then applied to enable the foamable material to penetrate into the fibrous layers, the penetration of the foamable material throughout the fibrous 105~0521 layers, particularly into the upper fibrous layer is insufficient.
(b) Since the foamable material supplied on the horizontal fibrous layer is not easily spread due to poor fluidity, a uniform distribution of the foamable material is achieved with difficulty. Further, a uniform penetration of the foamable material into the fibrous layer cannot be attained even after the compression, resulting in a nonuniform product.
(c) The foamable material penetrates to a least extent into a single fibrous layer large in thickness, for example, of more than 50 mm, so that a thick product cannot be obtained.
~ d) After the cream time of the foamable material, an increase in viscosity and the foaming of the foamable material prevent its penetration into the fibrous layers so that a foam containing fibers uniformly cannot be obtained.
~herefore, this method is unsuitable for the production of a foam from a foamable material havinq a short cream time.
Regardless of these disadvantages, the latter method disclosed in the above U.S. Patent has been found to be more advantageous than the former method, or the spray foaming method in some aspects. The inventors have made an extensive investigation on the latter method in order to eliminate ` the above-described drawbacks, and have accomplished the present invention.
SUMMARY OF THE INVENTION:
According to the invention there is provided a method for producing a body of fiber-reinforced polymer foam comprising the steps of (a) continuously supplying at least one fibrous layer having an apparent density of 0.001-0.lg/cm3, substantially vertically downwardly, (b) supplying a facing member downwardly ad;acent each extreme outer surface of the fibrous layer at an anqle of not less than 0 degree and less I~G521 than 90 degrees to the vertical to superpose each member on eachside of the fibrous layer, (c) simultaneously with the step ~b), distributing a foamable resinous liquid downwardly from the opposite sidesOf the fibrous layer in each space defined between the fibrous layer and the facing members, (d) passing the fibrous layer and the facing members superposed thereon through a gap which is narrower than the thickness of the fibrous layer to enable the foamable liquid to penetrate and disperse in the fibrous layer uniformly, and (e) allowing the foamable liquid to foam under restricted or unrestricted conditions.
It is therefore an advantage of this invention, at least in the preferred forms, that it can provide an improved method for continuously and efficiently producing any kind of foamed products having different shapes such as thick foamed products and cylindrical foamed coverings in which the loss of fibers and a foamable material is substantially negligible, a fibrous layer is uniformly impregnated with the foamable material so that uniformly foamed products can be obtained, and even a liquid foamable material having a short cream time may advantageously be used.
The facing members may both be of a flexible material or one may be of a flexible material and the other of the rigid material.
The foamable liquid may be distributed between the layers and between the fibrous layers and surface members if two or more layers are used.
The fibrous layer should be supplied downwardly so that the foamable liquid may easily reach the intersections between the fibrous layer and the members within a short period I~CSZ~
of time.
Important characteristics of the present invention can be summarized as follows. The fibrous layer positioned between two facing members is downwardly and continuously supplied together with the members. Simultaneously the foamable liquid is supplied from the opposite surfaces of the fibrous layer. The resulting laminate of the fibrous layer and the facing members is passed through a gap which is narrower than the thickness of the layer. Since the layer is held approximately vertically, the foamable liquid flows downwardly within a short perlod of time and rapidly reaches the inter-sections between the layer and the facing members. During passing through the narrow gap, the foamable liquid penetrates rapidly and uniformly throughout the layer from the opposite sides thereof under the influence of compressive force. An improved productcontainillg fibers uniformly in foam is obtained after the foaming.
Further, by supplying the foamable liquid from both sldes of the fibrous layer, the foamable liquid is dispersed into the fibrous layer within a shorter period of time than foamable liquid supplied from one side of the fibrous layer, and the foamed body contains fibers uniformly even if the fibrous layer is thick.
The essential features of the present invention will now be described in detail.
The fibrous layer which may be used in the present invention includes layers of any kind of fibrous materials, for example, cottonwool (or cotton batting)-like, porous materials consisting of intertwined organic or inorganic fibers and capable of forming into a sheet or plate by reason of handlability. Generally, fibrous materials which can be 5Zl directly used as a filler for mattresses or bedclothes, a - cushioning material, or a thermal insulating material are favor-able. Dense fabrics such as carpet are unsuitable. The preferable range of the apparent density of the fibrous layer varies depending on the type and fineness of component fibers, but may generally be from 0.001 to 0.1 g/cm3. Particularly, the apparent density may preferably fall in the range from 0.005 to 0.05 g/cm3, with a slight variation in accordance with the intended servlce of the products. For example, fillers of polyester fibers for bedclothes have an apparent density of about 0.005-0~02 g/cm , insulating materials of glass fibers about 0.005-0.1 g/cm3, and- palm rock about 0.1 g/cm3.
No particular restriction is imposed on the kind of fibers which can constitute the layer according to the present invention. Any desired fibers of organic and inorganic type may be used. For example, included are inorganic fibers such as glass fiber, aluminum fiber, iron fiber and roc~ wool, and organic fibers such as natural fiber, synthetic fiber and artificial fiber. Examples of organic fibers are fibers made of synthetic high-molecular substances such as polyvinyl chloride, polyvinylidene chloride, nylon, aromatic nylon, polyethylene terephthalate, polyvinyl acetal, polyvinyl alcohol, ; phenol-formaldehyde polycondentsates, polyacrylonitrile, etc., artificial fibers such as rayon, acetate, etc., and natural fiber such as cotton, flax, wool, fur, palm fiber, etc.
According to the present invention the fibrous layer is compressed to impregnate the layer with the liquid foamable material. It is desirable for the f~brous layer to resume its original thickness after the impregnation is complete. To this end, fibers may preferably have a high elastic recovery.
However, the elastic recovery is not critical, because the foamable - lQ~GSZl material which has penetrated into the fibrous layer expands together with the fibers during foaming. Consequently, foam in which fibers are uniformly distributed may be obtained as long as the foamable material has a low foaming magnification.
The fineness, length and degree of intertwinement of the fibers may suitably chosen depending on the intended service of the products. The fineness of fibers may preferably, but not critically, fall in the range of about 1 - 50 deniers.
Finer fibers, for example, of 0.5 denier or thicker fibers, for exampie, palm and flax fibers may also be employed.
The length of fibers may vary within a very wide range so far as they can be formed into a cottonwool-like mass and preferably fall in the range of, for example, about 10 - 100 mm. Longer fibers, for example, of 300 mm or more in length may also be employed provided that they are crimped.
Among the above-described fibers constituting the fibrous layer, synthetic fibers, particularly nylon Vinylon j ~Trade Mark,) acryl and polyester fibers are especially desir-! able in view of the reinforcement ef~ect, while glass wool and rock wool are desirable in view of the flame-retardant effect.
The fibrous layer is interposed between the facing members according to the present invention. The facing material may include two kinds of materials, a flexable material and a rigid material. Examples of the flexible material are paper, woven and non-woven fabrics of various fibers, films and sheets of plastics, and sheets and foils of metals-such as aluminum.
The member of the rigid material are, for example, boards of different rigid materials such as woodboard, plywood, asbestosboard~ plaster board, aluminum board, iron board, plastics board, etc., and pipes such as iron pipe, aluminum pipe, plastics pipe, etc. The manner of supplying the facing ~Q9C521 members according to the present invention wilI be described below with reference to the drawings.
The foamable liquid which can be used in the process of the present invention designates a li~uid material capable of forming a cellular polymer foam by a chemical foaming unaer suitable conditions. Examples of the polymer foam made from the foamable liquid are polyurethane, polyisocyanurate, poly-oxazolidone, carbodiimido, polyamide, p~ ide, pyranyl, epoxy, phenol and urea foams and com~inations thereof. In general, the foamable liquid consists of two or more liquid components which are mixed with each other to form a flexible or rigid poly-mer foam with the formation of a polymer and the generation of gas occurring substantially at the same time. The preferable foams made from the foamable liquid are polyurethane foams, poly-isocyanurate foams and polyoxazolidone foams.
It is commercially most important that a foam`can be ` obtained simply by mixing liquid components with each other without any particular external heating. The above-described foams can meet this requirement. Some of phenol foams are, however, prepared by adding a foaming agent to powder resol and heating the resulting mixture. This kind of foamable materials are not liquid so that they will hardly penetrate into the fibrous layer. Such foamable materials are thus unsuitable for the present invention. A phenol foam-forming liquid consisting of two liquid components can be employed in the method of the present invention.
The preparation of the above-described foams is well known and described in the literature.
The invention will now be described in greater detail and be explained with reference to a few embodiments and the accompanying diagrammatic drawings, in which ~WC521 Figs. 1 to 5 are schematic illustrations of different embodiments of carrying out the invention, respectively, Fig. 6 is a schematic front view of a modified example of compressive rolls which can be used in the invention, and a cross-sectional view of the rolls taken on the line A - A, Fig. 7 is a schematic perspective view of an apparatus for continuously producing a foam body according to the invention, Fig. 8 is a schematic front view of another apparatus according to the invention, Fig. 9 is a schematic plane view showing means for restricting foaming place in the foaming zone, Fig. 10 is a schematic front view of a further appar-atus according to the invention, Figs. 11 to 13 are schematic illustrations of different embodiments in which a foam covering is provided on a pipe according to the inventionj respectively, Figs. 14 to 15 are perspective views showing different methods of winding a foam layer on a pipe, respectively, Fig. 16 is a schematic front view showing means for restricting the foaming of a foamable layer wrapped around a pipe, Fig. 17 is a cross-sectional view of the vanes shown in Fig. 16 taken on the line B - B, ~ igs. 18 to 19 are perspective views of examples of the product according to the invention, respectively and Fig. 20 is a schematic flow sheet of an apparatus for producing a foam body suitable as a cushion.
~ eferring to the drawings, Figs. 1 to 5 shown schematic views illustrating different embodiments of the present invention, respectively. In these Figures, corresponding parts having the same function are designated by the same numeral.
_g_ In Figs. 1 to 5, numeral 1 represents a fibrous layer (to be referred to simply as "layer", hereinafter) which is supplied downwardly. Members of a flexible facing material 4 and 5 are supplied to the opposite surfaces of the layer 1 and the layer and the members are passed through a pair of rolls
2, 3 for laminating the layer and the members and compressing them on each other and through another pair of auxiliary rolls 6, 7 (Fig. 1). A foamable liquid is supplied at 8 and 9 from the opposite sides of the layer 1. Fig. 2 shows the same arrangement as Fig. 1 except that a pair of rolls 6, 7 are omitted. In Fig. 3, instead of rolls, guide members 11 and 12 defining a slit therebetween are placed in a facing relation for laminating, introducing downward and compressing the layer ; and the members. In Fig. 4, one of the facing members is the member S of the flexible material, while the other is a member 10 of a rigid material.
In a correct sene, the foamable liquid is directed to each inner surface of the facing members 4 and 5 and then carried by the members to the intersections of the layer 1 and the members 4 and S.
The layer 1 is supplied from above, that i8, down-wardly in the vertical direction or slightly obliquely. The layer 1 is preferably supplied substantially vertically downwardly to achieve the sufficient penetration of the foamable resinous liquid into the layer. ~owe~er, the layer 1 may be supplied obliquely, for example, at an angle of generally less than 30 degrees and at most 45 degrees to the vertical line so long as the foamable liquid can be supplied without hindrance. The facing members 4 and 5 are supplied at the same speed as the layer from the opposite sides of the layer.
That is, the layer is sandwiched in the facing members. The facing members 4 ard 5 have an oblique relation to the layer 1.
The vertical line and the members 4 and 5 intersect at angles ~ and ~^,respectively, which may be the same or different and be selected within the range of 0 - 90 degrees (Fig. 1) excluding 90 degrees. If the angle ~ or ~' between the layer and the member exceeds 90 degrees, a smooth, effective downward flow of the foamable liquid accompanied by the layer is prevented and part of the foamable liquid is wasted. Therefore, the angle ; should be less than 90 degrees. As the angle is smaller, the flow of the foamable liquid is more smooth. However, the pro-vision of a pipe for supplying the foaming liquid is restricted more or less when the angle is too small. As a result, the angle may preferably ~e selected within the range of 4 - 86 degrees, especially 30 - 60 degrees.
Another embodiment of the arrangement for supplying the facing members ls shown in Fig. 5.- First the facing members 4 and 5 are supplied in a parallel and close relation to the layer 1. Next, the members are once extended outwardly and then returned toward the layer via a pair of auxiliary rolls to define free triangular spaces where the pipes for supplyinq the foamable liquid can be provided at 8 and 9.
Thereafter, the members 4 and 5 are superposed on the layer 1 through a pair of rolls 2', 3' for laminating the facing members to the layer and then to another pair of rolls 6, 7 for compressing them. This arrangement saves the space that the apparatus occupies.
The facin~ member is supplied so as to abut onto each surface of the layer. When two or more layers are used, the facing members are superposed on the opposite extreme outer surfaces of a composite layer consisting of two or more 1~19CS21 layers. The facing members which receive the foamable liquid serve for preventing the leakage or draining out of the foamable liquid which is distributed to the opposite sides of the downwardly moving layer, and help the foaming liquid reach the intersections between the layer and the members and spread over the layer. The facing member may be of a material capable of being integrally bonded to the foam or easily released from the foam, depending on the intended service of the products. The facing members to be superposed on the opposite sides of the layer may both be of a flexible material or one may be of a flexible material and the other may be of a rigid material.
The latter case is shown in Figs. 4, lO and ll.
It is required to supply the foamable liquid to the layer from the opposite sides thereof. When only one layer is supplied as shown in Figs. l to 5, the foamable liquid is supplied at 8 and 9 between the layer and the members. The foamable liquid shouId be supplied between the layers as well as between the extreme outer layer and the member when two or more layers are used. The place where the foamable liquid is supplied is not restricted to one stationary position. A
nozzle for supplying the foamable liquid may be reciprocated transversely to the layer when a layer has a large width.
An elongated slit-like nozzle the len~th of which corresponds to that of the layer may also be used. The tip of the nozzle may preferably be positioned near the intersection of the layer and the member. In order that the foamable liquid may rapidly reach the intersection of the layer and the member and uniformly penetrate into the layer under the influence of compressive force, the foamable liquid should be supplied onto the opposite surfaces of the layer not only from the opposite sides thereof, but also in the downward direction.
` l~CS2~
The supply of the foamable liquid may be directed to eitherthe layer or the members. It may, however, be rather pre-ferable to supply the foamable liquid to the facing members first and uniformly distribute over the members prior to making contact with and penetrating into the layer, because more uniform penetration can be expected than otherwise.
After the foamable liquid has been supplied, the layer and the facing members superposed thereon are forcedly passed through a gap narrower than the thickenss of the layer to com-press the layer and the members and to penetrate the foamableliquld into the layer. When the layer and the members are passed through the gap, either a pair of rolls 2, 3 (Fig. 2) or two pairs of rolls 2, 3 and 6, 7 (Fig. 1) may be used. A
pair of rolls 2', 3' for lightly pressing them to superpose the layer and the members and another pair of rolls 6, 7 for strongly compressing them may also be used (Fig. 5). Alter-natively, a pair of gulde members 11, 12 defining a tapered slit may be used instead of rolls IFig. 31. As the gap defined between the guide members tapers, occluded air within the layer is successively and completely forced out or removed upward so that the obtained product may not involve any underimpregnated portion. Means for providing a gap is not restricted to the above embodiments.
The distance across the gap may generally be 2 to 70 %, preferably 5 to 30 %, of the thickness of the layer. An exact distance in each case may suitably be selected within the above range depending on the density of the fibrous layer used and the desired physical properties of the intended product. The penetration of the foamable liquid into the layer is insufficient at a larger distance exceeding the above-described range, while the liquid is squeezed out at a smaller distance below the lower limit, resulting in a lacking amount of the liquid impregnated.
Generally,cylindrical rolls are used to define a gaptherebetween. The cylindrical roll need not necessarily have a uniform circular periphery. Rolls may be corrugated in the longitudinal direction and juxtaposed each other so as to engage with each other as shown in Fig. 6. Slit-defining guides may also be corrugated. The use of such deformed rolls or guides may facilitate the penetration of the foamable liquid into the layer.
The above-described roll or guide may be made of any desired material. Iron, aluminum, rubber and plastics are suitable for the roll, while iron, aluminum and plastics are suitable for the guide.
The layer impregnated with the foamable li~uid which has passed the gap and in which foaming has not been initiated is flexible and can be bent in any shape like wet towel. This enables to form or mold the layer into a body having any desired shape such as flat plate, plate having a recessed or curved surface, cylinder, semicylinder or the llke. Upon forming the layer into such a particular shape, a device for restricting foaming which has an interior surface corresponding to the desired shape may be used. Sometimes foaming may advantageously be carried out without using such a restricting device.
Fig. 7 is a schemattc perspective view showing an apparatus which may be used in the present invention when foaming is carried out in free space.
Rolls, nozzles 8, 9 for supplying the foaming liquid and guide members 11, 12 defining a gap are arranged as described above. Below the gap is placed an endless belt conveyor 16.
In the apparatus shown, the layer 1 is continuously moved downwardly at a constant speed and at the same speed thefacing members 4 and 5 are supplied downwardly in an oblique relation to the layer 1. Nozzles 8 and 9 which reciprocate transversely supply the foamable liquid downwardly at a constant flow rate. As the layer 1 moves downwardly and the facing members 4 and 5 advance obliquely downwardly, the foamable liquid is rapidly carried by the facing members to the position of the guide members 11 and 12. It is to be noted that the foamable liquid is supplied to each surface of the layer 1. As the layer 1 is passed through the gap between the guide members and success-ively compressed due to the taper of the gap,occluded air is removed in an upward direction and the foamable liquid uniformly penetrates into the whole layer.
The layer 1 and the facing members 4, 5 which have passed the guide members 11, 12 are led on the conveyor 16 via the guide roll 13. The foaming li~uid is allowed to foam under non-res-tricted conditions on the conveyor 16. A foamed and cured body 15 is obtained, which can be cut to a desired size by a knife or other cutting means 14. Upon the use of facing members of silicone coat~d release paper, a fiber-reinforced foam without the facing members may be obtained. If facing members are of aluminum foil or kraft paper, a fiber-reinforced foam with the facing members attached thereon may be obtained.
Fig. 8 is a schematic front view showing another apparatus in which foaming is carried out under restricted condi-tions. A caterpiliar type device 17 for restricting foaming is provided above the conveyor 16. The use of the restricting device 17 may result in a flat product having a constant thickness. It is possible to control the thickness of a product or the thickness of a skin layer of foam by suitably adjusting the distance between the conveyor 16 and the restricting l~C521 device 17.
During the operation of this apparatus, the members 4and 5 are pulled forwardly by a driving machine (not shown) so that to compress the body during foaming is exerted. Such pressure is not favorable at the initial stage of foamln~. A
supporting bar 2a is provided behind the compressive roll 2 before the facing member 4 reaches the caterpillar belt 17, which bar takes up the member 4 and removes it from the layer 1. A rotary roll or a perforated pipe for blowing pressurized air may be used instead of the supporting bar 2a. A suction means for drawing the member by the action of reduced pressure may also be used.
A foam body whichh~s emerged from the apparatus shown in Fig. 8 has a flat upper and a flat lower surface, bu~ has rough side edges. It is necessary to cut and remove the rough side edges upon finishing. As a result, the yield of a product is reduced and the disposal of cut edge waste must be considered.
Fig. 9 is a schematic plan view showing an apparatus to be incorporated in the foaming zone, in which the above drawbacks may be eliminated. In the figure a device for res-tricting foaming to be provided at right above the conveyor 16 is omitted for clarity.
Along either side of the conveyor 16 for carrying the layer on which foaming is performed, separate caterpillar type devices for restricting foaming 18 and 19 are provided. DurLng operation belts of the devices 18 and 19 run at the same speed as the belt of the conveyor 16. At the positions where the restricting devices lB and 19 face the side edges of the layer or the foam, respectively, two sheets of release paper 20 and 21 are fed so as to interpose between the restricting device and the side edge of the layer. The surfaces of the restricting SZl devices 18 and 19 which are made contact with the side edges ofthe foam, respectively, may be flat to produce a foam body having flat side surfaces. The surfaces may be regularly recessed or corrugated so that the resulting products may engage with each other at their sides when arrayed side by side. In the latter case, a number of products may be connected in the width direction to meet the requirement of large width.
Fig. 10 is a schematic front view of a still further apparatus for carrying out the present invention. In this embodiment, one facing member 5 is made of a flexible material and the other facing member 10 is made of a rigid material.
Furthermore, the facing member 10 has been cut into a number of pieces having a certain length and these facing pieces are successively fed by means of conveyors 22 and 23. To prevent the foaming liquid from leaking frOm an opening between adjoining p$eces, the pieces have previously been connected by inserting urethane foam therebetween and a sheet of release paper 24 which is fed from a release paper roll 25 placed below the conveyor 23 is supplied between the conveyor belt and the facing pieces 10.
The li~uid-impregnated layer will have completed foaming during the passage along the conveyor 16 and the caterpillar type device 17 for restricting foaming. Thereafter, the resulting continuous foam body is cut at the connection between the pieces, obtaining a number of products having the fiber-reinforced polymer foam on the piece of rigid facing member.
Figs. 11, 12 and 13 show different embodiments accord-ing to the present invention in which a fiber-reinforced polymer foam is provided on the peripheral surface of a pipe, respectively.
Numeral 26 is a pipe to be covered with a foam. In the embodiment shown in Fig. 11, the pipe 26 serves not only as one of facing members interposing the layer 1 therebetween, gCS21 but also as one of rolls for defining a gap through which thelayer is passed. Numeral 27 is a roll for releasing and guiding the facing member 5, provided that the facing member S is made of a releasable, flexible material. Since foaming has not been initiated at the time when the member 5 and the layer 1 reach the roll 27, the member S can easily be released. As a result, only the layer impregnated with the foamable liquid is applied or wound on the peripheral surface of the pipe 26. Foaming is carried out under unrestricted conditions on the pipe.
In Fig. 12, both the facing members 4 and 5 are made of a releasable, flexible material. After the foaming liquid has sufficiently penetrated into the layer 1 with the aid of guide members 11 and 12, the facing members 4 and 5 are released from the layer which is then wound on the pipe 26. Foaming is commenced and completed on the pipe. A pipe covered with foam is obtained.
The arrangement shown in Fig. 13 is similar to that in Flg. 12 except that the facing member 4 is not released, but is wound on the pipe 26. The facing member 4 is not stuck to the surface of the pipe 26 so that the resulting cylindrical product consisting of the facing member and the foam may be removed freely in the longitudinal direction and be used as a pipe covering.
Fig. 14 shows how to-wind the foam body on the pipe in the arrangement in Fig. 13. It is assumed that the layer and the foam body 15 has a relatively small width. By moving the pipe 26 in its longitudinal direction and in a transverse direction to the continuous feed of the foam body 15 and rotating the pipe in a synchronous manner, the foam body is wound on the pipe 26 in a spiral manner. Of course, the winding of the foam body or the layer on the pipe ln Figs. 11 and 12 can be carried out in a similar manner.
1~9G52~
The procedure in which the layer is wound on the pipe to obtain the pipe integrally covered with foam or the layer is wound on the pipe with release paper interposed there-between and the wound layer is removed from the pipe to obtain a pipe covering, is not restricted to the embodiment shown in Fig. 14. For example, an impregnated layer having the width corresponding to the circumference of a pipe may be produced by means of the apparatus shown in Fig. 7. Prior to foaming, the impregnated layer is transferred by means of a conveyor and a pipe is placed on the layer, the flow direction of the layer being parallel to the longitudinal direction of the pipe.
The layer is deformed by means of a suitable means so as to enclose the pipe therein. Finally, foaming is initiated.
This wrapping procedure is shown in Fig. 15.
A further embodiment is shown in Figs. 16 and 17, in which a fiber-reinforced polymer foam body is provided on a pipe and foaming is carried out under restricted conditions. Fig.
16 is a schematic front view of a restricting device in the foaming zone and Fig. 17 is a schematic vertical cross section of the device shown in Fig. 16 taken on the line B - B. A
foam~ng liquid impregnated layer may be prepared by means of the apparatus shown in Fig. 7. On the non-foamed impregnated layer is placed a pipe 26 with its longitudinal direction parallel to the flow direction of the layer and then the layer is wrapped on the pipe so as to enclose the latter by using a suitable means as shown in Fig. 15. Thereafter, the pipe with the enclosing layer is introduced into the input of the device shown in Fig. 16.
The device shown in Fig. 16 comprises a pair of caterpillar type means for restricting foaming 28 and 29 placed one on the other. The vanes of the caterpillar have a l~C5Z~
semi-circular recessed portion at its outer edge so that a substantially circular space is defined between the adjoining vanes when two caterpillars 28 and 29 engage each other. During the passage of the pipe and the layer wrapped thereon through the restricting means, foaming is completed and a cylindrical foamed body having a smooth and uniform diameter is obtained.
It is to be noted that the foam coating is omitted for clarity in Fig. 16.
The pipe covering which is produced in the above-described manner according to the present invention has importantcharacteristics that it can be produced more easily in mass production than the pipe covering produced by the conventional mold method, and that it is more excellent in deformation resistance and surface smoothness than the pipe covering produced by the conventional block slicing method.
Figs. 18 and 19 are perspective views of examples of the product obtained according to the present invention. A
corrugated foam plate ~Fig. 18) and a cylindrical foam rod (Fig. 19) may~be produced in the above-described manner by impregnating a layer with a foamable liquid, passing the impregnated layer through a device for restricting foaming which has a given interior configuration, and allowing to foam.
Fig. 20 is a schematic flow sheet for producing a foam body suitable for a bucket seat cushion to be mounted in a car or a seat cushion of a chair.
In this embodiment, a number of pieces 30 cut out from a fibrous layer at constant intervals are successively supplied instead of a continuous long fibrous layer. Facing members 4 and 5 of a releasable, flexible material are fed at the same speed as the pieces and a foamable liquid is simultaneously appl~ed~at 8 and 9. Upon passing between guide members 11 and 12, the lO~CSZ:l `
fibrous piece 30 is compressed and thoroughly impregnated withthe foamable liquid. The facing members 4 and 5 are separately released in the course of transfer of the impregnated pieces 33.
That is, the facing member 4 is removed and taken up on a reel 31 and the facing member 5 is also recovered via a guide roll 32. The impregnated pieces 33 without the facing members are placed one by one in each of molds 34 which are successively moved along a belt conveyor Inot shown). On the top of each mold 34 which has received the impregnated fibrous piece 33 10 is placed a lid 35. Foaming is initiated in the interior of the mold and a foamed body 36 is formed in accordance with the shape of the mold. The foamed body 36 is removed from the mold and is r~eady for use.
A foam body produced in the above-described manner may have any desired shape and be used in various purposes.
For example, a foam body of rigid urethahe foam or isocyanurate foam may be used as an external wall for housing, a core of a curtain wall and a partition wall for building, an external wall for an outdoor refrigerator, a thermal insulating material for a tank or a pipe for storing or supplying cryogenic liquid such as liquified oxygen, nitrogen and natural gas. A foam body of flexible urethane foam may advantageously be used as a cushioning material for a vehicle seat and sofa.
As obvious from the above, by supplying a fibrous layer downwardly, supplying facing members downwardly adjacent the layer at an angle of less than 90 degrees to the vertical line, and supplying a foamable liquid downwardly from the opposite sides of the layer according to the present invention, the following noticeable effects can be attained.
(a) The fibrous layer is effectively and thoroughly impregnated with the foamable liquid. That is, the penetration of the foamable l~gCS21 liquid is uniform and completed within a short period.(b) The impregnation is very easy even when a foamable liquid is highly reactive, for example, an isocyanurate foam-forming liquid.
(c) The impregnation is uniform and very rapid even when the fibrous layer is thick. It is possible to produce a uniform and thick foam body.
(d) The content of fibers in the foam can easily be adjusted.
Accordingly, a foam body having a high flexural strength and 10 a high compressive strength can be obtained.
~e) A flame-resistant or flame-retardant composite material can be obtained by using glass wool as a layer. For example, a self-extinguishing foam and a semi-fire-retardant foam are obtained by using a combustible urethane foam-forming liquid and a isocyanurate foam-forming liquid, respectively. (The self-extinguishing and semi-fire-retardant properties are defined by ASTM D-1692-68 and JIS A 1321, respectively.) ~f) A pipe surrounded with a thermal insulating material, and a pipe covering as well as a plate-like foam body can easily 20 and continously be produced.
(g) A foam body having a small coefficient of linear expansion can be obtained, which is very suitable as a cryogenic insulating material because no crack is formed.
(h) A flexible foam body improved in tensile strength, tearing strength, repeated compression strain and cushioning properties can also be produced.
The following examples are included merely to aid in the understanding of the invention, and variations may be made by one skilled in the art without departing from the spirit and 30 scope of the invention. All parts are by weight.
SZl Example 1:
A flexible urethane foam reinforced with polyesterfibers is produced in this example.
(a) The formulation of a urethane foam-forming liquid.
Component A: tolylene diisocyanate (2,4-compound/2,6---~ compound.
= 80/20) 34.5 parts Component B: glycerol-based polyoxypropylene triol (molecular weight 3,000) 100 parts water 2.5 parts tricholoromonofluoromethane 5.0 parts silicone surfactant 2.0 parts Dabco-33LV* 0.1 part stannous octoate 1.3 parts * trademark, manufactured by Air Products Co., a mixture of triethylenediamine/dipropylene gylcol 11~3) Mixing ratio of partA/part B = 100/111 Temperature : 17C
Cream time (at room temperature 23C) : 28 sec.
Rise time lat room temperature 23C) : about 3 min.
Foam density upon unrestricted foaming : 0.049 g/cm ~b) Apparatus The apparatus shown in Fig. 7 is used. The slit defined between the guide members 11 and 12 has a width of S0 mm at the top, a width of 7.0 mm at the bottom and a length of 150 mm.
(c) Polyester fiber layer Polyester cottonwool commercially available as a filler for bedclothes and having a density of 0.01 g/cm3 is heated for a short time in an oven at 150C to reduce the density of 0.005 l~CS21 g/cm3. The heat-treated cotton is formed into a strip-like fibrous layer having a width of about 30 cm and a thickness of about 4 cm.
(d) Preparation of foam A silicone coated release paper sheet of 30 cm in width is supplied to each side of the above-described fibrous layer in the apparatus shown in Fig. 7. The layer and the release paper sheets are downwardly fed at a speed of 240 cm/min.
through the slit. The components A and B are mixed and fed at a flow rate of 3,360 g/min. This flow is separated into two which are supplied to the release paper sheets or the intersections between the layer and the sheets, respectively.
After the layer has passed the slit, the resulting laminate is led to the caterpillar type conveyor. Foaming is carried out under unrestricted conditions to obtain a foam body having a width of about 20 cm and a thickness of about 14 cm.
After curing, physical properties of the resulting foam are determined. For comparison, physical properties 20 of a foam containing no fiber are also shown in Table 1.
l~C521 -~ Table 1 Product ~A) of Comparative Increment the invention product (B) percentage**
containing containing fibers no fibers (~) 10 Density g/cm3 0 050 2 Compressive strength (75%2compression), 250 210 19 g/cm Cushioning proper-ties (Sag factor) 3.43 2.52 36 Tensi~e strength, Xg/cm 1.35 0.93 45 Tearing strength, Kg/cm 1.70 ~ 0.60 183 Elongation, % 75 85 12 Repeated compression permanent strain*, % 2.0 3.7 46 * JIS K 6401 - 1974 *~ All percentages are calculated in terms of (A - B)/B
except that the percentage for repeated compression permanent strain is calculated in terms of IB - A)~B because a lower value is preferable in the case of the strain.
As apparent from Table 1, the product of the invention, when compared with the comparative product, exhibits not only higher strength and cushionlng properties, but also an improved resistance to fatigue. Such excellent properties cannot be expected for the conventional flexible urethane foam. The product of the invention is very suitable as a cushioning material.
5Zl~- Example 2:
A rigid urethane foam reinforced with glass fibers is produced in this example.
The formulation of a urethane foam-forming liquid is as follows.
Component A: polymeric isocyanate (PAPI, Trade Mark, manufactured by The Upjohn Co., amine e~uivalent 133.5)112 parts Çomponent B: sucrose-based polyether polyol (hydroxy value 450)lO0 parts trichloromonofluoromethane 40 parts silicone surfactant2.0 parts diethylene g~ycol solution of triethylenediamine (33%)2.0 parts Foaming properties:
Cream Time : 30 sec.
Rise Time : 3 min.
Foam density upon unrestricted foaming : 0.032 g/cm3 The apparatus used is the same as in Example l. Two sheets of silicone coated release paper of about 30 cm in width are superposed on the opposite sides of a glass fiber layer having a thickness of about 5 cm, a width of about 30 cm and a density of about 0.01 g/cm3. The layer and the sheets superposed thereon are passed downwardly through a slit having a width of 6.0 mm at the narrowest at a speed of 240 cm/min. The components A and B are mixed and fed at a flow rate of 2,400 g/min. This flow is separated into two which are supplied to the release paper sheets or the intersections between the layer and the sheets, respectively. After the layer has passed the slit, the resulting laminate is led between the caterpillar type conveyor and a restricting device spaced apart 100 mm from the ~C521 conveyor surface. Foaming is carried out under the restrictedconditions, obtaining a rigid foam body having a width of about 20 cm, a thickness of 10 cm and a density of 0.052 g/cm3.
Although this kind of urethane foam initself is combustible, the glass fiber-reinforced urethane foam produced according to the above proced~re is evaluated as self-extinguish-ing according to the test method of ASTM D-1692-59T.
Example 3:
A urethane-modified isocyanurate foam reinforced with glass fibers is produced in this example.
The formulation of a foamable liquid and its foaming properties are as follows.
Component A: Polymeric isocyanate (amine equivalent 133.5)140 parts Component B: sorbitol-based polyether polyol (hydroxyl value 550) 33 parts trichloromonofluoromethane 25 parts silicone surfactant2.Oparts potassium acetatel.Oparts Foaming properties:
Cream time : 25 sec.
Rise time : 80 sec.
Foam density upon unrestricted foaming : 0.035 g/cm3 The foaming conditions and the apparatus used are the same as in Example 2. The resulting foam has a density of 0.042 g/cm3. Fire-retardant properties are tested according to JIS A
1321. The results are Td THETA 81 and CA 46. Any deformation and crack which are undesirable with respect to fire resistance are not observed. The foam is evaluated as Class II of flame-retardance according to the above-described JIS test method.
In a correct sene, the foamable liquid is directed to each inner surface of the facing members 4 and 5 and then carried by the members to the intersections of the layer 1 and the members 4 and S.
The layer 1 is supplied from above, that i8, down-wardly in the vertical direction or slightly obliquely. The layer 1 is preferably supplied substantially vertically downwardly to achieve the sufficient penetration of the foamable resinous liquid into the layer. ~owe~er, the layer 1 may be supplied obliquely, for example, at an angle of generally less than 30 degrees and at most 45 degrees to the vertical line so long as the foamable liquid can be supplied without hindrance. The facing members 4 and 5 are supplied at the same speed as the layer from the opposite sides of the layer.
That is, the layer is sandwiched in the facing members. The facing members 4 ard 5 have an oblique relation to the layer 1.
The vertical line and the members 4 and 5 intersect at angles ~ and ~^,respectively, which may be the same or different and be selected within the range of 0 - 90 degrees (Fig. 1) excluding 90 degrees. If the angle ~ or ~' between the layer and the member exceeds 90 degrees, a smooth, effective downward flow of the foamable liquid accompanied by the layer is prevented and part of the foamable liquid is wasted. Therefore, the angle ; should be less than 90 degrees. As the angle is smaller, the flow of the foamable liquid is more smooth. However, the pro-vision of a pipe for supplying the foaming liquid is restricted more or less when the angle is too small. As a result, the angle may preferably ~e selected within the range of 4 - 86 degrees, especially 30 - 60 degrees.
Another embodiment of the arrangement for supplying the facing members ls shown in Fig. 5.- First the facing members 4 and 5 are supplied in a parallel and close relation to the layer 1. Next, the members are once extended outwardly and then returned toward the layer via a pair of auxiliary rolls to define free triangular spaces where the pipes for supplyinq the foamable liquid can be provided at 8 and 9.
Thereafter, the members 4 and 5 are superposed on the layer 1 through a pair of rolls 2', 3' for laminating the facing members to the layer and then to another pair of rolls 6, 7 for compressing them. This arrangement saves the space that the apparatus occupies.
The facin~ member is supplied so as to abut onto each surface of the layer. When two or more layers are used, the facing members are superposed on the opposite extreme outer surfaces of a composite layer consisting of two or more 1~19CS21 layers. The facing members which receive the foamable liquid serve for preventing the leakage or draining out of the foamable liquid which is distributed to the opposite sides of the downwardly moving layer, and help the foaming liquid reach the intersections between the layer and the members and spread over the layer. The facing member may be of a material capable of being integrally bonded to the foam or easily released from the foam, depending on the intended service of the products. The facing members to be superposed on the opposite sides of the layer may both be of a flexible material or one may be of a flexible material and the other may be of a rigid material.
The latter case is shown in Figs. 4, lO and ll.
It is required to supply the foamable liquid to the layer from the opposite sides thereof. When only one layer is supplied as shown in Figs. l to 5, the foamable liquid is supplied at 8 and 9 between the layer and the members. The foamable liquid shouId be supplied between the layers as well as between the extreme outer layer and the member when two or more layers are used. The place where the foamable liquid is supplied is not restricted to one stationary position. A
nozzle for supplying the foamable liquid may be reciprocated transversely to the layer when a layer has a large width.
An elongated slit-like nozzle the len~th of which corresponds to that of the layer may also be used. The tip of the nozzle may preferably be positioned near the intersection of the layer and the member. In order that the foamable liquid may rapidly reach the intersection of the layer and the member and uniformly penetrate into the layer under the influence of compressive force, the foamable liquid should be supplied onto the opposite surfaces of the layer not only from the opposite sides thereof, but also in the downward direction.
` l~CS2~
The supply of the foamable liquid may be directed to eitherthe layer or the members. It may, however, be rather pre-ferable to supply the foamable liquid to the facing members first and uniformly distribute over the members prior to making contact with and penetrating into the layer, because more uniform penetration can be expected than otherwise.
After the foamable liquid has been supplied, the layer and the facing members superposed thereon are forcedly passed through a gap narrower than the thickenss of the layer to com-press the layer and the members and to penetrate the foamableliquld into the layer. When the layer and the members are passed through the gap, either a pair of rolls 2, 3 (Fig. 2) or two pairs of rolls 2, 3 and 6, 7 (Fig. 1) may be used. A
pair of rolls 2', 3' for lightly pressing them to superpose the layer and the members and another pair of rolls 6, 7 for strongly compressing them may also be used (Fig. 5). Alter-natively, a pair of gulde members 11, 12 defining a tapered slit may be used instead of rolls IFig. 31. As the gap defined between the guide members tapers, occluded air within the layer is successively and completely forced out or removed upward so that the obtained product may not involve any underimpregnated portion. Means for providing a gap is not restricted to the above embodiments.
The distance across the gap may generally be 2 to 70 %, preferably 5 to 30 %, of the thickness of the layer. An exact distance in each case may suitably be selected within the above range depending on the density of the fibrous layer used and the desired physical properties of the intended product. The penetration of the foamable liquid into the layer is insufficient at a larger distance exceeding the above-described range, while the liquid is squeezed out at a smaller distance below the lower limit, resulting in a lacking amount of the liquid impregnated.
Generally,cylindrical rolls are used to define a gaptherebetween. The cylindrical roll need not necessarily have a uniform circular periphery. Rolls may be corrugated in the longitudinal direction and juxtaposed each other so as to engage with each other as shown in Fig. 6. Slit-defining guides may also be corrugated. The use of such deformed rolls or guides may facilitate the penetration of the foamable liquid into the layer.
The above-described roll or guide may be made of any desired material. Iron, aluminum, rubber and plastics are suitable for the roll, while iron, aluminum and plastics are suitable for the guide.
The layer impregnated with the foamable li~uid which has passed the gap and in which foaming has not been initiated is flexible and can be bent in any shape like wet towel. This enables to form or mold the layer into a body having any desired shape such as flat plate, plate having a recessed or curved surface, cylinder, semicylinder or the llke. Upon forming the layer into such a particular shape, a device for restricting foaming which has an interior surface corresponding to the desired shape may be used. Sometimes foaming may advantageously be carried out without using such a restricting device.
Fig. 7 is a schemattc perspective view showing an apparatus which may be used in the present invention when foaming is carried out in free space.
Rolls, nozzles 8, 9 for supplying the foaming liquid and guide members 11, 12 defining a gap are arranged as described above. Below the gap is placed an endless belt conveyor 16.
In the apparatus shown, the layer 1 is continuously moved downwardly at a constant speed and at the same speed thefacing members 4 and 5 are supplied downwardly in an oblique relation to the layer 1. Nozzles 8 and 9 which reciprocate transversely supply the foamable liquid downwardly at a constant flow rate. As the layer 1 moves downwardly and the facing members 4 and 5 advance obliquely downwardly, the foamable liquid is rapidly carried by the facing members to the position of the guide members 11 and 12. It is to be noted that the foamable liquid is supplied to each surface of the layer 1. As the layer 1 is passed through the gap between the guide members and success-ively compressed due to the taper of the gap,occluded air is removed in an upward direction and the foamable liquid uniformly penetrates into the whole layer.
The layer 1 and the facing members 4, 5 which have passed the guide members 11, 12 are led on the conveyor 16 via the guide roll 13. The foaming li~uid is allowed to foam under non-res-tricted conditions on the conveyor 16. A foamed and cured body 15 is obtained, which can be cut to a desired size by a knife or other cutting means 14. Upon the use of facing members of silicone coat~d release paper, a fiber-reinforced foam without the facing members may be obtained. If facing members are of aluminum foil or kraft paper, a fiber-reinforced foam with the facing members attached thereon may be obtained.
Fig. 8 is a schematic front view showing another apparatus in which foaming is carried out under restricted condi-tions. A caterpiliar type device 17 for restricting foaming is provided above the conveyor 16. The use of the restricting device 17 may result in a flat product having a constant thickness. It is possible to control the thickness of a product or the thickness of a skin layer of foam by suitably adjusting the distance between the conveyor 16 and the restricting l~C521 device 17.
During the operation of this apparatus, the members 4and 5 are pulled forwardly by a driving machine (not shown) so that to compress the body during foaming is exerted. Such pressure is not favorable at the initial stage of foamln~. A
supporting bar 2a is provided behind the compressive roll 2 before the facing member 4 reaches the caterpillar belt 17, which bar takes up the member 4 and removes it from the layer 1. A rotary roll or a perforated pipe for blowing pressurized air may be used instead of the supporting bar 2a. A suction means for drawing the member by the action of reduced pressure may also be used.
A foam body whichh~s emerged from the apparatus shown in Fig. 8 has a flat upper and a flat lower surface, bu~ has rough side edges. It is necessary to cut and remove the rough side edges upon finishing. As a result, the yield of a product is reduced and the disposal of cut edge waste must be considered.
Fig. 9 is a schematic plan view showing an apparatus to be incorporated in the foaming zone, in which the above drawbacks may be eliminated. In the figure a device for res-tricting foaming to be provided at right above the conveyor 16 is omitted for clarity.
Along either side of the conveyor 16 for carrying the layer on which foaming is performed, separate caterpillar type devices for restricting foaming 18 and 19 are provided. DurLng operation belts of the devices 18 and 19 run at the same speed as the belt of the conveyor 16. At the positions where the restricting devices lB and 19 face the side edges of the layer or the foam, respectively, two sheets of release paper 20 and 21 are fed so as to interpose between the restricting device and the side edge of the layer. The surfaces of the restricting SZl devices 18 and 19 which are made contact with the side edges ofthe foam, respectively, may be flat to produce a foam body having flat side surfaces. The surfaces may be regularly recessed or corrugated so that the resulting products may engage with each other at their sides when arrayed side by side. In the latter case, a number of products may be connected in the width direction to meet the requirement of large width.
Fig. 10 is a schematic front view of a still further apparatus for carrying out the present invention. In this embodiment, one facing member 5 is made of a flexible material and the other facing member 10 is made of a rigid material.
Furthermore, the facing member 10 has been cut into a number of pieces having a certain length and these facing pieces are successively fed by means of conveyors 22 and 23. To prevent the foaming liquid from leaking frOm an opening between adjoining p$eces, the pieces have previously been connected by inserting urethane foam therebetween and a sheet of release paper 24 which is fed from a release paper roll 25 placed below the conveyor 23 is supplied between the conveyor belt and the facing pieces 10.
The li~uid-impregnated layer will have completed foaming during the passage along the conveyor 16 and the caterpillar type device 17 for restricting foaming. Thereafter, the resulting continuous foam body is cut at the connection between the pieces, obtaining a number of products having the fiber-reinforced polymer foam on the piece of rigid facing member.
Figs. 11, 12 and 13 show different embodiments accord-ing to the present invention in which a fiber-reinforced polymer foam is provided on the peripheral surface of a pipe, respectively.
Numeral 26 is a pipe to be covered with a foam. In the embodiment shown in Fig. 11, the pipe 26 serves not only as one of facing members interposing the layer 1 therebetween, gCS21 but also as one of rolls for defining a gap through which thelayer is passed. Numeral 27 is a roll for releasing and guiding the facing member 5, provided that the facing member S is made of a releasable, flexible material. Since foaming has not been initiated at the time when the member 5 and the layer 1 reach the roll 27, the member S can easily be released. As a result, only the layer impregnated with the foamable liquid is applied or wound on the peripheral surface of the pipe 26. Foaming is carried out under unrestricted conditions on the pipe.
In Fig. 12, both the facing members 4 and 5 are made of a releasable, flexible material. After the foaming liquid has sufficiently penetrated into the layer 1 with the aid of guide members 11 and 12, the facing members 4 and 5 are released from the layer which is then wound on the pipe 26. Foaming is commenced and completed on the pipe. A pipe covered with foam is obtained.
The arrangement shown in Fig. 13 is similar to that in Flg. 12 except that the facing member 4 is not released, but is wound on the pipe 26. The facing member 4 is not stuck to the surface of the pipe 26 so that the resulting cylindrical product consisting of the facing member and the foam may be removed freely in the longitudinal direction and be used as a pipe covering.
Fig. 14 shows how to-wind the foam body on the pipe in the arrangement in Fig. 13. It is assumed that the layer and the foam body 15 has a relatively small width. By moving the pipe 26 in its longitudinal direction and in a transverse direction to the continuous feed of the foam body 15 and rotating the pipe in a synchronous manner, the foam body is wound on the pipe 26 in a spiral manner. Of course, the winding of the foam body or the layer on the pipe ln Figs. 11 and 12 can be carried out in a similar manner.
1~9G52~
The procedure in which the layer is wound on the pipe to obtain the pipe integrally covered with foam or the layer is wound on the pipe with release paper interposed there-between and the wound layer is removed from the pipe to obtain a pipe covering, is not restricted to the embodiment shown in Fig. 14. For example, an impregnated layer having the width corresponding to the circumference of a pipe may be produced by means of the apparatus shown in Fig. 7. Prior to foaming, the impregnated layer is transferred by means of a conveyor and a pipe is placed on the layer, the flow direction of the layer being parallel to the longitudinal direction of the pipe.
The layer is deformed by means of a suitable means so as to enclose the pipe therein. Finally, foaming is initiated.
This wrapping procedure is shown in Fig. 15.
A further embodiment is shown in Figs. 16 and 17, in which a fiber-reinforced polymer foam body is provided on a pipe and foaming is carried out under restricted conditions. Fig.
16 is a schematic front view of a restricting device in the foaming zone and Fig. 17 is a schematic vertical cross section of the device shown in Fig. 16 taken on the line B - B. A
foam~ng liquid impregnated layer may be prepared by means of the apparatus shown in Fig. 7. On the non-foamed impregnated layer is placed a pipe 26 with its longitudinal direction parallel to the flow direction of the layer and then the layer is wrapped on the pipe so as to enclose the latter by using a suitable means as shown in Fig. 15. Thereafter, the pipe with the enclosing layer is introduced into the input of the device shown in Fig. 16.
The device shown in Fig. 16 comprises a pair of caterpillar type means for restricting foaming 28 and 29 placed one on the other. The vanes of the caterpillar have a l~C5Z~
semi-circular recessed portion at its outer edge so that a substantially circular space is defined between the adjoining vanes when two caterpillars 28 and 29 engage each other. During the passage of the pipe and the layer wrapped thereon through the restricting means, foaming is completed and a cylindrical foamed body having a smooth and uniform diameter is obtained.
It is to be noted that the foam coating is omitted for clarity in Fig. 16.
The pipe covering which is produced in the above-described manner according to the present invention has importantcharacteristics that it can be produced more easily in mass production than the pipe covering produced by the conventional mold method, and that it is more excellent in deformation resistance and surface smoothness than the pipe covering produced by the conventional block slicing method.
Figs. 18 and 19 are perspective views of examples of the product obtained according to the present invention. A
corrugated foam plate ~Fig. 18) and a cylindrical foam rod (Fig. 19) may~be produced in the above-described manner by impregnating a layer with a foamable liquid, passing the impregnated layer through a device for restricting foaming which has a given interior configuration, and allowing to foam.
Fig. 20 is a schematic flow sheet for producing a foam body suitable for a bucket seat cushion to be mounted in a car or a seat cushion of a chair.
In this embodiment, a number of pieces 30 cut out from a fibrous layer at constant intervals are successively supplied instead of a continuous long fibrous layer. Facing members 4 and 5 of a releasable, flexible material are fed at the same speed as the pieces and a foamable liquid is simultaneously appl~ed~at 8 and 9. Upon passing between guide members 11 and 12, the lO~CSZ:l `
fibrous piece 30 is compressed and thoroughly impregnated withthe foamable liquid. The facing members 4 and 5 are separately released in the course of transfer of the impregnated pieces 33.
That is, the facing member 4 is removed and taken up on a reel 31 and the facing member 5 is also recovered via a guide roll 32. The impregnated pieces 33 without the facing members are placed one by one in each of molds 34 which are successively moved along a belt conveyor Inot shown). On the top of each mold 34 which has received the impregnated fibrous piece 33 10 is placed a lid 35. Foaming is initiated in the interior of the mold and a foamed body 36 is formed in accordance with the shape of the mold. The foamed body 36 is removed from the mold and is r~eady for use.
A foam body produced in the above-described manner may have any desired shape and be used in various purposes.
For example, a foam body of rigid urethahe foam or isocyanurate foam may be used as an external wall for housing, a core of a curtain wall and a partition wall for building, an external wall for an outdoor refrigerator, a thermal insulating material for a tank or a pipe for storing or supplying cryogenic liquid such as liquified oxygen, nitrogen and natural gas. A foam body of flexible urethane foam may advantageously be used as a cushioning material for a vehicle seat and sofa.
As obvious from the above, by supplying a fibrous layer downwardly, supplying facing members downwardly adjacent the layer at an angle of less than 90 degrees to the vertical line, and supplying a foamable liquid downwardly from the opposite sides of the layer according to the present invention, the following noticeable effects can be attained.
(a) The fibrous layer is effectively and thoroughly impregnated with the foamable liquid. That is, the penetration of the foamable l~gCS21 liquid is uniform and completed within a short period.(b) The impregnation is very easy even when a foamable liquid is highly reactive, for example, an isocyanurate foam-forming liquid.
(c) The impregnation is uniform and very rapid even when the fibrous layer is thick. It is possible to produce a uniform and thick foam body.
(d) The content of fibers in the foam can easily be adjusted.
Accordingly, a foam body having a high flexural strength and 10 a high compressive strength can be obtained.
~e) A flame-resistant or flame-retardant composite material can be obtained by using glass wool as a layer. For example, a self-extinguishing foam and a semi-fire-retardant foam are obtained by using a combustible urethane foam-forming liquid and a isocyanurate foam-forming liquid, respectively. (The self-extinguishing and semi-fire-retardant properties are defined by ASTM D-1692-68 and JIS A 1321, respectively.) ~f) A pipe surrounded with a thermal insulating material, and a pipe covering as well as a plate-like foam body can easily 20 and continously be produced.
(g) A foam body having a small coefficient of linear expansion can be obtained, which is very suitable as a cryogenic insulating material because no crack is formed.
(h) A flexible foam body improved in tensile strength, tearing strength, repeated compression strain and cushioning properties can also be produced.
The following examples are included merely to aid in the understanding of the invention, and variations may be made by one skilled in the art without departing from the spirit and 30 scope of the invention. All parts are by weight.
SZl Example 1:
A flexible urethane foam reinforced with polyesterfibers is produced in this example.
(a) The formulation of a urethane foam-forming liquid.
Component A: tolylene diisocyanate (2,4-compound/2,6---~ compound.
= 80/20) 34.5 parts Component B: glycerol-based polyoxypropylene triol (molecular weight 3,000) 100 parts water 2.5 parts tricholoromonofluoromethane 5.0 parts silicone surfactant 2.0 parts Dabco-33LV* 0.1 part stannous octoate 1.3 parts * trademark, manufactured by Air Products Co., a mixture of triethylenediamine/dipropylene gylcol 11~3) Mixing ratio of partA/part B = 100/111 Temperature : 17C
Cream time (at room temperature 23C) : 28 sec.
Rise time lat room temperature 23C) : about 3 min.
Foam density upon unrestricted foaming : 0.049 g/cm ~b) Apparatus The apparatus shown in Fig. 7 is used. The slit defined between the guide members 11 and 12 has a width of S0 mm at the top, a width of 7.0 mm at the bottom and a length of 150 mm.
(c) Polyester fiber layer Polyester cottonwool commercially available as a filler for bedclothes and having a density of 0.01 g/cm3 is heated for a short time in an oven at 150C to reduce the density of 0.005 l~CS21 g/cm3. The heat-treated cotton is formed into a strip-like fibrous layer having a width of about 30 cm and a thickness of about 4 cm.
(d) Preparation of foam A silicone coated release paper sheet of 30 cm in width is supplied to each side of the above-described fibrous layer in the apparatus shown in Fig. 7. The layer and the release paper sheets are downwardly fed at a speed of 240 cm/min.
through the slit. The components A and B are mixed and fed at a flow rate of 3,360 g/min. This flow is separated into two which are supplied to the release paper sheets or the intersections between the layer and the sheets, respectively.
After the layer has passed the slit, the resulting laminate is led to the caterpillar type conveyor. Foaming is carried out under unrestricted conditions to obtain a foam body having a width of about 20 cm and a thickness of about 14 cm.
After curing, physical properties of the resulting foam are determined. For comparison, physical properties 20 of a foam containing no fiber are also shown in Table 1.
l~C521 -~ Table 1 Product ~A) of Comparative Increment the invention product (B) percentage**
containing containing fibers no fibers (~) 10 Density g/cm3 0 050 2 Compressive strength (75%2compression), 250 210 19 g/cm Cushioning proper-ties (Sag factor) 3.43 2.52 36 Tensi~e strength, Xg/cm 1.35 0.93 45 Tearing strength, Kg/cm 1.70 ~ 0.60 183 Elongation, % 75 85 12 Repeated compression permanent strain*, % 2.0 3.7 46 * JIS K 6401 - 1974 *~ All percentages are calculated in terms of (A - B)/B
except that the percentage for repeated compression permanent strain is calculated in terms of IB - A)~B because a lower value is preferable in the case of the strain.
As apparent from Table 1, the product of the invention, when compared with the comparative product, exhibits not only higher strength and cushionlng properties, but also an improved resistance to fatigue. Such excellent properties cannot be expected for the conventional flexible urethane foam. The product of the invention is very suitable as a cushioning material.
5Zl~- Example 2:
A rigid urethane foam reinforced with glass fibers is produced in this example.
The formulation of a urethane foam-forming liquid is as follows.
Component A: polymeric isocyanate (PAPI, Trade Mark, manufactured by The Upjohn Co., amine e~uivalent 133.5)112 parts Çomponent B: sucrose-based polyether polyol (hydroxy value 450)lO0 parts trichloromonofluoromethane 40 parts silicone surfactant2.0 parts diethylene g~ycol solution of triethylenediamine (33%)2.0 parts Foaming properties:
Cream Time : 30 sec.
Rise Time : 3 min.
Foam density upon unrestricted foaming : 0.032 g/cm3 The apparatus used is the same as in Example l. Two sheets of silicone coated release paper of about 30 cm in width are superposed on the opposite sides of a glass fiber layer having a thickness of about 5 cm, a width of about 30 cm and a density of about 0.01 g/cm3. The layer and the sheets superposed thereon are passed downwardly through a slit having a width of 6.0 mm at the narrowest at a speed of 240 cm/min. The components A and B are mixed and fed at a flow rate of 2,400 g/min. This flow is separated into two which are supplied to the release paper sheets or the intersections between the layer and the sheets, respectively. After the layer has passed the slit, the resulting laminate is led between the caterpillar type conveyor and a restricting device spaced apart 100 mm from the ~C521 conveyor surface. Foaming is carried out under the restrictedconditions, obtaining a rigid foam body having a width of about 20 cm, a thickness of 10 cm and a density of 0.052 g/cm3.
Although this kind of urethane foam initself is combustible, the glass fiber-reinforced urethane foam produced according to the above proced~re is evaluated as self-extinguish-ing according to the test method of ASTM D-1692-59T.
Example 3:
A urethane-modified isocyanurate foam reinforced with glass fibers is produced in this example.
The formulation of a foamable liquid and its foaming properties are as follows.
Component A: Polymeric isocyanate (amine equivalent 133.5)140 parts Component B: sorbitol-based polyether polyol (hydroxyl value 550) 33 parts trichloromonofluoromethane 25 parts silicone surfactant2.Oparts potassium acetatel.Oparts Foaming properties:
Cream time : 25 sec.
Rise time : 80 sec.
Foam density upon unrestricted foaming : 0.035 g/cm3 The foaming conditions and the apparatus used are the same as in Example 2. The resulting foam has a density of 0.042 g/cm3. Fire-retardant properties are tested according to JIS A
1321. The results are Td THETA 81 and CA 46. Any deformation and crack which are undesirable with respect to fire resistance are not observed. The foam is evaluated as Class II of flame-retardance according to the above-described JIS test method.
Claims (13)
1. A method for producing a body of fiber-reinforced polymer foam comprising the steps of (a) continuously supplying at least one fibrous layer having an apparent density of 0.001-0.1 g/cm3, substantially vertically downwardly, (b) supplying a facing member downwardly adjacent each extreme outer surface of the fibrous layer at an angle of not less that 0 degree and less than 90 degrees to the vertical to superpose each member on each side of the fibrous layer, (c) simultaneously with the step(b), distributing a foamable resinous liquid downwardly from the opposite sides of the fibrous layer in each space defined between the fibrous layer and the facing members, (d) passing the fibrous layer and the facing members superposed thereon through a gap which is narrower than the thickness of the fibrous layer to enable the foamable liquid to penetrate and disperse in the fibrous layer uniformly, and (e) allowing the foamable liquid to foam under restricted or unrestricted conditions.
2. A method according to claim 1 wherein said fibrous layer is made of glass fibers having an apparent density of 0.005 - 0.1 g/cm3, a fineness of 1 - 50 deniers and a length of 10 - 100 mm.
3. A method according to claim 1 wherein said fibrous layer is made of synthetic fibers having an apparent density of 0.005 - 0.1 g/cm3, a fineness of 1 - 50 deniers and a length of 10 -100 mm.
4. A method according to claim 1 wherein said foamable liquid is a polyurethane foam-forming liquid.
5. A method according to claim 1 wherein said foamable liquid is a polyisocyanurate foam-forming liquid.
6. A method according to claim 1 wherein said foamable liquid is a polyoxazolidone foam-forming liquid.
7. A method according to claim 1 wherein said gap through which the fibrous layer and the facing members superposed thereon are passed has a distance of 2 - 70 % of the thickness of the fibrous layer.
8. A method according to claim 1 wherein said angle to the vertical line at which said facing member is supplied is 30 - 60 degrees.
9. A method according to claim 1 wherein said fibrous layer is a synthetic fiber layer and said foamable liquid is a flexible urethane foam-forming liquid..
10. A method according to claim 1 wherein said foamable liquid is distributed from the opposite sides of the fibrous layer downwardly to the corresponding facing members in the spaces defined between the fibrous layer and the facing members.
11. A method according to claim 1 wherein said facing member to be supplied to the extreme outer surface of the fibrous layer is of a flexible material.
12. A method according to cla1m 1 wherein a facing member of a flexible material is supplied to one of the extreme outer surfaces of the fibrous layer and a facing member of a rigid material is supplied to theother surface.
13. A method according to claim 12 wherein said facing member of a rigid material is a pipe.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50114525A JPS5936574B2 (en) | 1975-09-22 | 1975-09-22 | Method for continuously manufacturing fiber reinforced plastic foam |
| JP114525/1975 | 1975-09-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1090521A true CA1090521A (en) | 1980-12-02 |
Family
ID=14639925
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA261,823A Expired CA1090521A (en) | 1975-09-22 | 1976-09-22 | Method for producing fiber-reinforced polymer foam |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5936574B2 (en) |
| CA (1) | CA1090521A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011013516A1 (en) | 2010-03-10 | 2011-12-15 | Basf Se | Method for manufacturing mold part e.g. A-column, in cladding part in body construction of automobile, involves processing mold part, where preferential direction of foaming lies perpendicular to propagation direction of foaming material |
| WO2019219614A1 (en) * | 2018-05-17 | 2019-11-21 | Covestro Deutschland Ag | Method for preparing composite materials made of polyethylene fibers having an ultra-high molecular weight and cross-linked polyisocyanates |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55103928A (en) * | 1979-01-31 | 1980-08-08 | Matsushita Electric Works Ltd | Production of plate of glass fiber-reinforced resin |
| JPS5831716A (en) * | 1981-08-20 | 1983-02-24 | Sumitomo Chem Co Ltd | Continuous manufacture of prepreg sheet |
| KR20000070441A (en) | 1997-01-23 | 2000-11-25 | 선스타 기켄 가부시키가이샤 | Two-pack urethane foam composition, and two-pack urethane foam composition packing apparatus and method |
| JP2003103551A (en) * | 2001-09-27 | 2003-04-09 | Araco Corp | Molded object constituted of woody fiber material and method for manufacturing the same |
| JP7322631B2 (en) * | 2019-09-24 | 2023-08-08 | トヨタ紡織株式会社 | Method for manufacturing vehicle interior material |
-
1975
- 1975-09-22 JP JP50114525A patent/JPS5936574B2/en not_active Expired
-
1976
- 1976-09-22 CA CA261,823A patent/CA1090521A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011013516A1 (en) | 2010-03-10 | 2011-12-15 | Basf Se | Method for manufacturing mold part e.g. A-column, in cladding part in body construction of automobile, involves processing mold part, where preferential direction of foaming lies perpendicular to propagation direction of foaming material |
| WO2019219614A1 (en) * | 2018-05-17 | 2019-11-21 | Covestro Deutschland Ag | Method for preparing composite materials made of polyethylene fibers having an ultra-high molecular weight and cross-linked polyisocyanates |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5238577A (en) | 1977-03-25 |
| JPS5936574B2 (en) | 1984-09-04 |
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