GB2207080A

GB2207080A - Moulding composite articles

Info

Publication number: GB2207080A
Application number: GB08813182A
Authority: GB
Inventors: David Brian Fisher
Original assignee: Camatic Pty Ltd
Current assignee: Camatic Pty Ltd
Priority date: 1987-06-04
Filing date: 1988-06-03
Publication date: 1989-01-25
Also published as: GB8813182D0

Abstract

A soft toy or other product has an external skin of latex or synthetic rubber which is preformed and which is subsequently filled with a foamable material such as polyurethane, the foaming step being effected within a die. The external skin can be formed in a die into which the foamable material is then introduced, or else the skin is removed after formation and placed in another die into which the foamable material is introduced. The skin is made by dipping a former or by rotational or gravitational casting. The product may include an internal strengthening frame.

Description

I,,MP,RQVRD MOULDED PRODUCT This invention relates to an improved moulded product and, specifically, to moulded products which have a relatIvely soft feel0 but yet, which have a tough and resilient outer layer.

The invention is particularly suitable for the manufacture of soft toys and it is in this aspect that it will be described, but it will be appreciated that it can also be readily applied to the manufacture of other products, such as, for example, cushions and pillows.

Soft toys for children must meet several requirements.

The first of these is that they must have a relatively tough outer layer so as to maintain the Imerior of the toy and, at the same time, this layer must be non-toxic and, should the interior of the toy include anv toxic material, must also be impervious.

A desiderata would be that the outer layer would be of skin tone, both In feel and in colour.

It Is the object of the present invention to manufacture a product which has these characteristics.

in its broadest sense, we provide a product having an outer skin of latex or synthetic rubber and an interior which is of a synthetic plastics foam. such as a polyurethane foam.

The invention includes the method of making such a product which comprises forming an outer skin of a flexible resilient material, such as latex or synthetic rubber, introducing into the moulded skin a plastics material which can be foamed to a flexible foam and effecting foaming of the material so as to fill the outer skin.

In order that the invention can be more readily understood, we shall describe the manufacture of a toy using the concept of the invention.

In the embodiment to be described, the toy has two components, a body and a head and, in such an arrangenqent, the invention relates to the formation of the body from the neck down. It is possible to use the invention to provide a complete toy or other article and this will be described further later.

The outer skin of the toy is preferably of latex and, certainly, is of some flexible resilient material which is non-toxlc and which has good physical properties as far as tearing or other damage is concerned and may be of the order of 0.01 to 0.03 cm thick and, in a preferred form of the invention, we use a thickness of 0.018 cm.

The skin can be formed by any conventional method of forming latex and, specifically, it could be formed in a rotational mould, by dipping procedures or In an enclosed mould into which liquid latex can be poured and the excess subsequently removed.

A dipping process is preferred for production as dipping permits the latex to be air cr oven dried and for the solvents to be rapidly removed therefrom, whereas, if the other processes are used, it is more difficult to ensure rapid curing.

It can also be difficult, using the enclosed processes, to provide a skin which Is satisfactory as, for ease in rcmovinn the skin from moulds, it would be preferred that the mould be spilt, but this would normally cause flashing on the skin, and this is unacceptable for quality toys.

The other alternative is to form the skin in a closed mould and it will then be appreciated that the skin has to be withdrawn through the neck aperture, which can be extremely difficult If dipping is used there is a former having the shape and size of the body to be formed which former is dipped a number of times into a latex solution until the required thickness is'achieved.

Also, If dipping is used, the former can be arranged to have negative details formed thereon and the skin can be adapted to be used inverted, that is that the skin can be stripped from the form so that the inside becomes outwardly directed and, In this way, an extremely Rood surface with very high definition can be achieved.

As far as the urethane is concerned, we prefer to use a cold cure moulded high resilient polyurethane which is MDI and polyether polyol based.

If the skin is rotationally formed in a split mould, it is possible to introduce the monomer mixture into the mould whilst the skin Is still in position therein but, practically, we prefer to locate the skin into a polyurethane moulding die and to then infect the monomer mixture into the skin within the die.

It may be preferred to provide a strengthening frame within the doll and. such frames, which may be made of plastics or metal can be articulated to simulate particular forms of limb or body movements.

The latex from whizz the skin is made has sufficient elasticity to enable the neck of the doll to be dilated so that the frame can pass therethrough and to be located within the skin and the frame may be provided with certain extensions to effect proper location and to provide a support so that the frame is correctly held relative to the skin.

These extensions may be provided with rounded or extended surfaces to act analyst the inside of the skin.

Each skiniframe assembly Is located Into a die and the monomer mixture is dispensed from high pressure machinery Into the skin in the die.

As the polyurethane formed foams, so the whole of the die space is occupied and the polyurethane acts as a backfill and supports the latex skin by applying a pressure thereto and, because of the adhesive properties of polyurethane, the foam is intimatelY bonded to the skin and to the frame.

After curving4 the doll Is removed from the mould and the whole of the torso, arms and legs of the doll Is formed and a head can be connected to the neck openin .

It will be seen that the doll of the present invention has an external skin which can approach. in touch, the skin of a person and can also be coloured to match the colour of human skin.

The density of the foam, which can be controlled by the quantity of monomers incorporated, and the actual formulation of these, can be such as to give the required feel and the articulated skeleton, if used, can provide movement only at the joints and thus, again, simulate movements bY a human.

The arrangement also provides an arrangement whereby the skin, when formed4 can have creases to permit ready movement and the use of the polvthene, other with the latex, permits such movement without any form of tuckering or unwanted folds when movement of the limb is effected.

If required, the skin, before being placed in the mould to receive the urethane or the doll, after completion, may be passed between rollers, at least one of which has needle like spikes so as to form the surface of the skin wlth pore like formations.

It will be seen that a doll made using the process of the invention can have a good feel for a child as the skin has a texture very similar to that of normal skin and the pressure of the polyurethane against the skin gives a sensation to touch similar to that of muscles beneath the skin.

If a central frame is provided, this can also ensure that the movement of the limb closely simulates a natural movement.

At the same time, the toy meets the basic requirements of safety In that the outer laver is Strong and continuous and resists damage whilst, at the same time, 15 completely non-toxic If sucked or chewed.

Whilst we have described herein a toy made with a latex outer layer and a foamed polyurethane interior, it will be appreciated that, by using these products, toys havlng very different characteristics can be formed simply by controlling the thickness of the outer layer and the density of the foam.

It is possible usIng the invention to make a complete toy or other article.

Because of the resilience of the latex skin It is possible to form slits or thi like therein which can permit venting of the air from the skin whilst the foam is forming, which slits subseciuently close to Provide a complete toy or other article which has not apparent breaks therein.

Also, whilst we have described the Invention as being particularly applicable to the manufacture of soft toys, there are also other areas where it has applications.

One such Is in the manufacture of cushions and pillows.

In each case. the provision of an impervious tough, but non-toxic outer layer can be most desirable and the ability to vary the stiffness of the product is also of great value.

Claims

WE CLAIM:

1. A method of making a product which comprises forming an outer skin of a flexible resilient material, such as latex or synthetic rubber, Introducing into the moulded skin a plastics material which can be foamed to a flexible foam and effecting foaming of the material so as to fill the outer skin.

2. A method of making a product as claimed in claim I wherein the skin is formed on a former. It is stripped therefrom and placed in a mould, the material which can be foamed is introduced into the skin in the mould and the material, when foaming, back-fills the skin to produce the product.

3. A method as claimed in claim 2 wherein the former has surface variations negative to that, when the skin is removed therefrorn, and the skin Is inverted, the surface variations are clearly defined.

4. A method as claimed in claim 1 wherein the skin is made by rotational casting or other technique in a dosed mould and wherein the skin Is removed from the mould before the mixture which can be foamed Is introduced into the skin.

5. A method as claimed in claim 1 wherein the skin is made by rotational casting or other technique in a dosed mould and wherein the mixture which can be foamed is introduced into the mould before the skin is removed therefrom.

S. A method as claimed in any preceding claim wherein the materIal which can be foamed is compatible with the material of the skin so that, on foaming. this becomes adhesively secured to the skin.

7. A method as claimed in any preceding claim wherein there Is an Internal frame which is located in the skin before the material which can be foamed is Introduced. the frame acting to provide definition or control of relative movement of portions of the product.

8. A method as claimed In any preceding claim wherein the outer skin is perforated with a number of small diameter holes either before or after the formIng steP is taken.

9. A method as claimed In any one 'of the preceding claims wherein the material to be foamed comprises a high resilience polyurethane which is MDI and polyether polyol based.

10. A product made by the method of any one of the preceding claIms.

11. The product of claim 10 being a soft toy, a pillow or a seat or back member.

12. A product as claimed in claim 10 being a soft toy in which the' skin is latex and has a thickness in the range of 0.10 cm to 0,30 cm.

13. A soft toy as claimed In claim 12 having an Inner frame which comprises a skeleton which is articulated to permit specific movements of portions of the toy.

14. A product having an outer skin of a flexible resilient materlal such as latex or synthetic rubber which is formed separately and a body of flexible foam material therein, the foam material being closely adjacent the skin.

15. A product as claimed in claim 14 wherein the foam material is foamed in sItu and back-fills the skin.

16. product as claimed in claim 15 wherein the adhesive properties of the foam material causes it to become adhesively secured to the skin.

17. A product as claImed in any one of claims 14 to 17 wherein there is an Internal skeleton which b articulated to permit specific movement of the product.

18. A product as claimed in any one of claims 14 to 17 wherein the product Is a soft toy.