JPH0516344B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a multilayer molded foam composite product and its manufacturing method.

[Prior art]

It is often desirable to make products from flexible foam materials. For example, when assembling or manufacturing simple, non-raised rectangular cushions, ready-made foams that can be purchased in any desired size are used. However, flexible foams are elastic. When it is bent, twisted, or curved, the flexible foam tends to return to its original shape.

Such a form cannot be easily deformed into a desired shape, such as an arcuate profile.

Depending on the application, it is necessary to make products with complex non-linear shapes, and in such cases, traditional manufacturing methods
It is not possible to use ready-made rectangular form blocks. Rather, such conventional methods require cutting of flexible foam blocks to produce such shaped foam products.

For example, to conventionally manufacture products with pointed protrusions, such as edge protrusions on foam sheet cushions, a rectangular form is typically fabricated for use as a cushion base. Prepare the blocks. The second rectangular block placed on top of the first block is cut along the edge of the cushion to match the sharp rounded protrusion on the edge of the cushion. Cutting the foam in this example is tedious and time consuming. Furthermore, when it is desired to create a complex shape or a large number of bends and curves, it becomes difficult to cut the foam. This typically requires special cutting tools and special skills to use them. Also, such cutting operations significantly increase costs and reduce the efficiency of mass production of foam products.

Also, by using molds, flexible foam products having multiple bends and curves can be manufactured. Of course, in this case it is not possible to obtain cheap ready-made forms for manufacturing the product. Rather, the foam-forming compound is injected into a mold with suitable frames, webs, or other design features to create the shape of the flexible foam product. However, this makes the manufacturing process significantly more expensive.

[Summary of the invention]

The present invention relates to a method of making a three-dimensional shaped article consisting of two or more parts of soft foam. The invention is particularly suitable for producing complex shapes from ready-made foam sheets, which cannot otherwise be achieved using soft foams of this type. After selecting each appropriate foam section, an intermediate layer of adhesive is applied to the adjacent surfaces of the joint sections.
After joining the parts, the product is transformed into the selected shape. Allow the adhesive to cure while holding the product in this selected shape. After this hardening, the product retains its shape without returning to its previous position under the stress.

Although it is not necessary to apply a vacuum to form the article, a vacuum can also be used to hold the textile and/or vinyl material in place during placement and molding.

By providing additional layers or sections of flexible foam and/or reducing the thickness of the foam sections, the internal resultant forces that prevent the product from returning to its unstressed state can be increased. . This further ensures that the product retains its shape permanently.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing molded foam products using readily available, off-the-shelf flexible foam materials that can be deformed into desired shapes. Other objects and advantages of the method of the present invention and the manufactured products formed thereby will become apparent from the following detailed description and drawings. In the drawings, the same reference numerals indicate the same parts throughout.

〔Example〕

The present invention relates to molded composite foam products and methods of manufacturing such products. To produce a molded foam product according to the method of the invention, appropriate portions 10, 12 of foam material are selected in connection with FIG. These parts are rectangular in shape and are, for example, in the nature of ready-made flexible foam that can be purchased at any foam store. The range of densities of flexible foams suitable for use in the present invention is from about 8.01 to 80.1 kg per cubic meter (from about 0.5 lbs. to at least 5 lbs. per cubic foot).
It is. However, others may be used as appropriate for the particular application.

In the embodiment of the invention shown in FIG. 1, the first portion 10 and second portion 12 of flexible foam are rectangular layers of prefabricated foam. After selecting the first and second portions of appropriate dimensions, at least one of the portions is coated with adhesive 1 along its surface 14.
3 and this surface is treated with the surface 16 of the other part.
It is joined with. However, to make the bond more permanent and complete along the adjacent interfaces of the joint, both joint surfaces may be treated with adhesive, or the foam layer may be completely saturated with adhesive. good. The adhesive used can be either hard or soft depending on the application. Suitable hard adhesives include hard urethane adhesives, epoxy adhesives, hard latex adhesives, and the like, as shown in US Pat. Nos. 4,373,057 and 4,395,530. Suitable soft adhesives include soft urethane adhesives such as those shown in the aforementioned patents, soft latex adhesives, contact cements, and the like. These surfaces are then joined by applying inward pressure, pressing the surfaces tightly together. The surfaces are joined and pressed together by hand or with a hydraulic press.

The composite multilayer product is then deformed along the bonded adhesive interface as follows. That is, the individual layers are successively placed in a suitable mold, after which the mold is closed and the product is held in the mold until the adhesive hardens. During the adhesive curing process,
Apply enough pressure to form and hold the contour, i.e., indentation, etc.

It should be noted that the shape of the product is not limited to the normally elastic flexible foam section, ie the foam layer. Thus, the product can be layered and bent as desired to create various contours and shapes. For example, by using the method of the present invention, simple arcuate profiles with smooth, interlocking curvatures can be easily formed. Other shapes with a strict radius of curvature can also be formed, such as a horseshoe. Similarly, L-shaped and S-shaped
A curve, or multiple curves, can also be formed.
Furthermore, the curvature or profile is not limited to curving along a single axis. Rather, three-dimensional contours and shapes can be formed as well.

Once the product is formed into the desired shape, it is held in that shape while the adhesive dries. For example, when forming a product into a desired shape by pressing the product into a mold having the desired shape, the product is held in the mold until the adhesive hardens. Thus, when the cured product is removed from the mold, it retains the desired shape.
The reason for this is that the compressive and tensile forces generated in the foam layer due to deformation do not cancel each other out. Rather, the part is bent and stretched along the adhesive interface,
The compressive and tensile forces caused by compression result in a resultant force that causes the product to maintain its deformed shape after curing, rather than allowing the flexible foam to return to its initial unstressed state. is maintained.

If necessary, the product is hot pressed in a mold according to well-known methods by those skilled in the art to facilitate shaping the product into the desired shape or to provide rapid curing.

Referring now to FIG. 2, a cross-section of an S-shaped composite foam article made in accordance with the method of the present invention is shown. The invention is not limited to using only two sections of flexible foam. Molded articles using a suitable adhesive coating 20 sandwiched between layers 18 may also be used. When multi-layered, the thickness of adjacent parts, ie, adjacent layers, becomes thinner, so that the shape of the cured product can be better maintained. Furthermore, if desired depending on the use,
The covering material 22 can also be adhesively fixed to the outer surface of the product. Suitable covering materials that can be used in the present invention include:
These materials are well known in the art and include woven and non-woven fabrics, vinyl, other flexible plastic films, leather, and the like. The same adhesive used to bond the flexible foam sections together can also be used to attach the covering material to the surface of the foam product;
Other suitable adhesives known in the art may also be used. Of course, if necessary, the cover material can be attached to the product by hot pressing the cover onto the product when the product is hot pressed in the mold.

By using the method of the present invention, other features can also be simultaneously incorporated into multilayer foam products. Thus, as shown in FIG. 3, a hinge line or bend line 24 can be formed, for example, by cutting the line deeply into the product at any location to emphasize different designs. Such bend lines are formed by pressing a steel rule into the surface of the product at the desired location and to the desired depth.

It is also possible to add a decorative pattern to the product, for example as shown in FIG. In this embodiment of the invention, a plurality of bend lines 24 are formed by using a steel ruler with hand bending and deformation, or by using a mold or mechanical frame and bending device as an additional process step.
Designs and decorative patterns such as contours 25 and contours 25 can be indented and contoured.

Additionally, as shown in FIG. 5, additional multiple sheets of flexible foam 26 and inserts such as insert members 28 may be incorporated into the product to further emphasize the design and make the pad even more comfortable. You can also do it.

In another embodiment of the invention, the molded article is molded in a rigid shell of, for example, ABS plastic or fiberglass. An adhesive layer is then placed between the product and the shell and the two are glued together. between two or more parts of a composite product,
By placing the rigid material, a rigid support structure is formed, which also maintains the desired product shape.

It is also clear that various embodiments of products made according to the method of the invention can include supports and other features that enhance the design. For example, between the foam layers or on top of the foam layers, spring bodies, rigid foams, rigid inserts, additional foams, mesh materials, cloths, or padding may be included.

It is also clear that each layer of the product can have the same contour or a diverging contour, giving the product different contours and different layers. The mold for forming the product may be configured with a variety of raised texturing tools, such as die tools, photoetch plates, wire patterns, and the like. Therefore, any design can be formed on the cover material or support material simultaneously with molding and curing of the product. The molds can also be constructed to have thermal adhesive means, such as decals or trims, in place during curing. Products manufactured according to the method of the invention also include:
In other words, it can also be made using a vacuum forming mold to deepen the contour. This vacuum forming mold allows the use of thicker cover materials that are difficult to form, as well as heavier support materials (such as ABS shells).

Additionally, if desired, one or more of the foam layers and/or adhesives may be modified to impart further desired characteristics to the finished product.
Such desirable features include improved acoustic insulation, flame resistance, and providing a different feel to the finished product. Thus, the characteristics of the finished product can be modified by adding one or more additives, such as acoustic modifiers, flame retardants, and smoke-reducing materials, to alter the surface and dimensional properties of the foam. It can be changed as desired.

In particular, acoustic modifiers can be added to the adhesive during the manufacturing process. Representative materials suitable for such purposes are alumina (bauxite),
Magnesium carbonate, lead powder and other dense materials. The exact amount to add is less critical and depends primarily on the desired level of sound isolation.

Adding dense materials such as such materials to the adhesive rather than to the foam creates friction and is desirable to cause the foam to break during manufacturing.

Regarding flame retardant materials, a typical flame retardant material used in foam is Fyrel manufactured by Stauffer Chemical Company.
Liquid flame retardants such as CEF and tricresyl phosphate. Such a substance is added to the foam by placing the substance on a roller and running the foam through the roller.
Allows liquid to be evenly distributed and absorbed into the foam. The amount is not critical and depends on the desired end use.

If a solid flame retardant material is used, such as a halogenated hydrocarbon such as decrolane with the addition of antimony oxide, such material may be added to the adhesive during manufacturing, as in the case of the acoustic modifier described above. Mix. Again, the amount of solid combustion retardant material to be added is less critical and generally depends on the end use of the product.

A suitable smoke-reducing material is alumina and calcium hydroxide, which is mixed into the adhesive; the mixture is approximately 300% foam by weight; The ratio is about 3:1 to 4:1.

If it is desired to change the surface and size characteristics of the foam, for example to give the foam a rubbery feel, a urethane elastomer can be applied to the foam using a roller. A suitable mixture for that purpose is 100 parts of Mobay's Multrinol 3901 and 9 parts of Upjohn's Isonate 143L, which in weight ratio is Apply it to the foam so that it is about 50-300%.
The elastomer is applied to the foam by coating the surface of the foam with elastomeric material by running the foam past an elastomer-coated roller.

The effect of including such adducts as described above is that
This means that only one grade of foam needs to be stored. Typically, when it is desired to manufacture products with different properties, different types of foams with the desired finished product properties are required. However, with the present invention, forms can be tailored to specific needs without having to wait for a supplier to make and/or ship a custom form. The substrate form can have greater and more uniform pull and break strength than the custom form attached to it. For example, special combustion low smoke foams typically
It does not have sufficient tensile strength to withstand conventional coatings and manufacturing methods. Furthermore, by using the method of the invention, several different modifiers can be installed in one step or in several successive steps. This method allows the use of substances that do not mix well with each other.

Obviously, other embodiments, other materials, other designs, and other steps may be incorporated into the method without departing from the spirit and scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a two-layer molded flexible foam product having a contoured shape made according to the method of the present invention, and FIG. FIG. 3 is a cross-sectional view of a multilayer molded flexible foam article made in accordance with the present invention having deep welt lines; FIG. FIG. 5 is a cross-sectional view of a multilayer moldable flexible foam product having multiple ridges and contours made in accordance with the present invention; FIG. FIG. 2 is a cross-sectional view of a flexible foam. 10, 12... Foam material part, 13... Adhesive, 14, 16... Surface.

Claims (1)

Claims: 1. (a) a first foam portion; (b) a first foam portion having at least one surface adapted to conform to the contour of the surface of the first foam portion so as to be adhesively bonded into a single product; (c) disposed between said bonded surfaces and said first
1. A foam composite product comprising adhesive means for adhesively joining a foam portion and a second foam portion, the foam portions being held in a permanently elastically deformed state. 2. A foam composite product according to claim 1, characterized in that the shape of the product is formed by at least one arcuate contour. 3. Claim 2 comprising a flexible covering material adhesively bonded to the surface of the product.
Foam composite products as described in Section. 4. The foam composite product of claim 3, wherein the product includes a raised pattern on selected portions of the surface of the product. 5. (a) providing a first part of a flexible foam having a surface to be bonded to another part; (b) providing a first part of a flexible foam having a surface to be joined to said surface of said first part; (c) treating either or both of the surface of the first portion and the surface of the second portion with a suitable adhesive; and (d) treating the surface of the first portion and/or the surface of the second portion with a suitable adhesive; bonding the surfaces of the second portion; (e) deforming the bonded first and second portions into a selected shape; and (f) curing the adhesive, forming a flexible foam. A method of forming a multilayer molded foam article wherein the joined first and second portions remain elastically deformed and retain a selected shape. 6. between said steps (b) and (c), the step of providing at least one additional portion of flexible foam having a surface that joins with the surface of said second portion of flexible foam; 6. A method as claimed in claim 5, characterized in that reinforcement is provided to permanently hold the multilayer molded foam product in the selected deformed shape. 7. The process of deforming the joined first part and second part and the process of curing the adhesive,
6. A method as claimed in claim 5, including the steps of placing the joined parts in a suitable mold and curing the adhesive within the mold. 8. Claim 7, characterized in that it includes a step of pressing the product with heat within the mold.
The method described in section. 9 preparing a covering material to cover the surface of said product, treating said covering material with a suitable adhesive, applying said covering material to said product, while hot pressing said product in said mold. 9. A method of forming a multilayer molded foam product as claimed in claim 8, including the additional step of simultaneously heat pressing said cover onto said product. 10. The method of claim 8, including the additional step of placing mesh material between two adjacent sections of the article at least one location between the sections to strengthen the article. 11. The method of claim 8 including the additional step of attaching a fixture to the article for attaching the article to a support member. 12. Claim 8 comprising the additional step of disposing a substantially rigid material between at least two portions of the article to provide a rigid support structure for enhanced retention of the selected shape of the article. Method described. 13. Claim 12, characterized in that said substantially rigid material is ABS plastic.
The method described in section. 14. The method of claim 12, wherein the virtually rigid material is glass. 15. The method of claim 5, further comprising the step of adding at least one acoustic modifier to the adhesive before treating the surfaces to be joined with the adhesive. 16. The method of claim 15, wherein the acoustic modifier is selected from the group consisting of alumina, magnesium carbonate, and lead powder. 17. The method according to claim 5, comprising the step of adding a combustion retardant substance. 18. The flame retardant material is a liquid flame retardant material that is applied to the foam by placing it on a roller and running the foam through the roller, thereby applying the flame retardant material to the foam. 18. The method of claim 17, characterized in: 19. The method of claim 18, wherein the liquid flame retardant material is selected from the group consisting of tricresyl phosphate and fireall CEF. 20. The method of claim 17, wherein the flame retardant is a solid flame retardant that is incorporated into the adhesive before the surfaces to be joined are treated with the adhesive. 21. The method of claim 20, wherein the solid combustion material is selected from the group consisting of antimony oxide and halogenated hydrocarbons. 22. The method of claim 5, further comprising the step of adding a smoke-reducing substance to the adhesive before treating the surfaces to be joined with the adhesive. 23. The method of claim 22, wherein the smoke reducing material is alumina and calcium hydroxide in a ratio of about 3:1 to 4:1. 24. The method of claim 5, further comprising the step of applying a urethane elastomer to modify the surface and size properties of the foam. 25. Claim 24, wherein the urethane elastomer is applied to the surface of the front foam by running the foam through a roller coated with the elastomer.
The method described in section. 26. A method of forming a multilayer molded foam article, comprising: (a) providing a multilayer elastic foam; (b) treating the surface of said layer with a suitable adhesive; and (c) treating the adhesive-treated portion with a suitable adhesive. (d) deforming the bonded multilayer product such that the shape of the product is formed by at least one arcuate profile; and (e) curing the adhesive to adhesively secure adjacent layers of elastic foam. a method of forming a multilayer molded foam article, the bonded article retaining its deformed shape without elastically returning to its original unstressed state.