MOULDED PRODUCTS FROM A FLOWABLE MATERIAL

The present invention relates to a mould, a mould part, a method of producing a plurality of moulded products from a flowable material and a moulded product formed from a flowable material. Background

Moulding is used in many different industries to produce products with a specific size and shape. The size and the shape of the moulded product are determined by the size and shape of the mould from which it is formed. Moulding typically involves filling a cavity in a mould with a flowable material and then allowing the flowable material to solidify by cooling. Some materials used for making such moulded products shrink on cooling. Shrinkage on cooling may cause the main body of the moulded product to contract inwardly away from the inner walls of the cavity in the mould, resulting in a moulded product which is smaller than the cavity in the mould. Alternatively, shrinkage on cooling may cause the material in the mould to contract outwardly away from the centre of the cavity in the mould, and therefore form a void within the moulded product. Such a void within the moulded product may form a channel to the surface of the moulded product and may constitute a significant defect to the moulded product.

If either of the modes of shrinking described above occur in the moulding process to a significant extent, the moulded products are likely to be defective. For example, if significant shrinkage inwardly away from the inner walls of the cavity occurs then the moulded product would be smaller than the desired moulded shape. Alternatively, if significant shrinkage outwardly away from the centre of the cavity in the mould occurs then defects in the form of either an internal void or an open channel in the moulded product may be produced, providing products having an undesired weight and/or shape and/or a significant structural weakness. These problems are particularly evident when moulds are used to simultaneously form a plurality of moulded products which are intended to have a uniform size, shape and weight.

It is an aim of embodiments of the present invention to provide a mould, a mould part, a moulded product or a method of producing a plurality of moulded products that addresses at least one disadvantage of the prior art, whether identified here or elsewhere, or to provide an alternative to existing moulds, mould parts, moulded products or methods of producing a plurality of moulded products.

Summary of the invention

According to the present invention there is provided a mould, a mould part, a moulded product and a method of producing a plurality of moulded products from a flowable material as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

According to a first aspect of the present invention there is provided a mould comprising a plurality of cavities for receiving a flowable material and at least one reservoir for receiving the flowable material, wherein the cavities are arranged in communication with the at least one reservoir such that the flowable material can flow from the at least one reservoir into the cavities.

The cavities may suitably be any size or shape. Suitably the cavities are substantially spherical. Suitably the cavities are spherical. Suitably the cavities are substantially spherical and have a diameter of at least 1 cm, for example at least 2 cm, suitably at least 3 cm. Suitably the cavities are substantially spherical and have a diameter of up to 10 cm, for example up to 7 cm, suitably up to 5 cm. Suitably the cavities are substantially spherical and have a diameter of between 3.25 cm and 4.25 cm.

Suitably the cavities of the plurality of cavities have substantially the same size and shape. Suitably the mould comprises a substantially flat lower surface for standing the mould on a substantially flat surface during a process of filling the cavities in the mould.

In a moulding method using the mould of the first aspect, a flowable material can be moved into the plurality of cavities under a force. Suitably a flowable material can be pumped into the plurality of cavities. Alternatively a flowable material can flow under gravity into the plurality of cavities.

Suitably the plurality of cavities comprises at least one filling hole to allow the introduction of a flowable material into the cavities. Suitably the plurality of cavities comprises more than one filling hole. Suitably each of the cavities in the plurality of cavities comprises at least one filling hole, but preferably only one filling hole. Suitably the filling hole or holes are arranged in an upper region of the plurality of cavities or in an upper region of each cavity. Suitably the filling hole or holes are accessible from an upper face of the mould.

The cavities are arranged in communication with at least one reservoir. Suitably the at least one reservoir is arranged substantially above the plurality of cavities.

Above is intended to refer to the relative position when the mould is placed on a substantially flat surface in a position suitable for a process of filling the cavities in the mould to be carried out.

Suitably the plurality of cavities is arranged in communication with a single reservoir. Suitably the plurality of cavities comprises a group of cavities which are each arranged in communication with a single reservoir. Suitably the plurality of cavities comprises a first group of cavities which are each arranged in communication with a first reservoir and a second group of cavities which are each arranged in communication with a second reservoir. Suitably the plurality of cavities comprises more than one group of cavities which are each arranged in communication with a single reservoir, wherein each group of cavities is arranged in communication with a separate reservoir.

Suitably the mould comprises a plurality of cavities wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir. In embodiments wherein the plurality of cavities is arranged in communication with a single reservoir or wherein the plurality of cavities comprises a group of cavities which are each arranged in communication with a single reservoir, that reservoir suitably has a volume of up to the total volume of the plurality of cavities. Suitably the single reservoir has a volume of up to one half of the total volume of the plurality of cavities. Suitably the single reservoir has a volume of at least one tenth of the total volume of the plurality of cavities. Suitably the single reservoir has a volume of at least one quarter of the total volume of the plurality of cavities. Suitably the single reservoir has a volume of approximately one third of the total volume of the plurality of cavities.

In embodiments wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir, those reservoirs suitably have a volume of up to the volume of one of the cavities. Suitably the reservoirs have a volume of up to one half of the volume of one of the cavities. Suitably the reservoirs have a volume of at least one tenth of the volume of one of the cavities. Suitably the reservoirs have a volume of at least one quarter of the volume of one of the cavities. Suitably the reservoirs have a volume of approximately one third of the volume of one of the cavities.

The plurality of cavities and the at least one reservoir suitably communicate through an opening in a cavity. Suitably the plurality of cavities and the at least one reservoir communicate through an opening in more than one cavity. Suitably the plurality of cavities and the at least one reservoir communicate through an opening in each cavity. Suitably the opening or openings in the cavity or cavities communicate to the at least one reservoir directly. Alternatively the opening or openings in the cavity or cavities communicate to the at least one reservoir through a channel. The opening or openings in the cavity or cavities which communicates to the at least one reservoir may suitably be a separate opening to the filling hole. Suitably the plurality of cavities are arranged in communication with the at least one reservoir through a filling hole in a cavity. Suitably the plurality of cavities are arranged in communication with the at least one reservoir through a filling hole in more than one cavity. Suitably the plurality of cavities are arranged in communication with the at least one reservoir through a filling hole in each of the cavities.

Suitably a flowable material can be moved from the at least one reservoir into the plurality of cavities under a force. Suitably a flowable material can be pumped from the at least one reservoir into the plurality of cavities. Alternatively a flowable material can flow under gravity from the at least one reservoir into the plurality of cavities.

Suitably the filling hole or holes are arranged in the upper part of the cavity or cavities and the at least one reservoir is arranged above the plurality of cavities. Suitably a flowable material can flow under gravity from the at least one reservoir, through the filling hole or holes and into the plurality of cavities. Suitably substantially all of the at least one reservoir is arranged above the filling hole or holes in the plurality of cavities. Suitably all of the at least one reservoir is arranged above the filling hole or holes in the plurality of cavities.

In some embodiments, the at least one reservoir is arranged above the cavities and has a shape which allows substantially all of a flowable material contained in the at least one reservoir to flow under gravity into the plurality of cavities. Suitably the at least one reservoir is arranged above the cavities and has a shape which allows substantially all of a flowable material contained in the at least one reservoir to flow under gravity from the at least one reservoir, though the filling hole or holes and into the plurality of cavities. Such embodiments may be advantageous compared to a mould wherein the reservoir has a shape which prevents a portion of a flowable material contained in the reservoir from flowing under gravity into the plurality of cavities, due to a reduction in the wastage of the flowable material during a moulding process. Such embodiments are particularly advantageous when the value of the flowable material is high compared with alternative flowable materials and/or the flowable material is difficult to recover from the reservoir and use in a subsequent moulding process. In some embodiments, the at least one reservoir has a shape which at least partially follows the shape of an upper region of the cavities in the mould, beneath the reservoir. Suitably the reservoir comprises a base surface above the cavities and this base surface has a shape which at least partially follows the shape of an upper region of the cavities. That is, at least a part of the base surface is generally parallel to an inner surface of the cavities. The shape of the base surface which at least partially follows the shape of an upper region of the cavities in the mould may provide a reservoir wherein a portion of a flowable material contained in the reservoir cannot flow under gravity into the plurality of cavities. Such embodiments may be advantageous due to an improvement in the manufacture of the mould, for example by injection moulding, compared to the manufacture of a mould which allows substantially all of a flowable material contained in the at least one reservoir to flow under gravity into the plurality of cavities. For example, a mould with a reservoir which has a shape which at least partially follows the shape of an upper region of the cavities in the mould may have a more consistent thickness than alternative embodiments and therefore suffer fewer defects during manufacture using an injection moulding process.

In some embodiments the filling holes have cylindrical walls. In other embodiments the filling holes have inclined walls, for example countersunk walls, narrower at the cavity side and wider at the reservoir side. The intention is to minimise the presence of pips or knobs of material on the moulded end products.

Suitable flowable materials include liquids, compositions, dispersions, solutions, colloids, foams, semi-solids and emulsions. Suitably the flowable material is only flowable at a temperature above room temperature. Suitably the flowable material becomes a solid or a semi-solid at room temperature. Alternatively the flowable material may become a solid or semi solid at a temperature lower than room temperature.

Suitably the flowable material is a viscous, sticky liquid.

Suitably the flowable material is a detergent composition. Suitably the flowable material comprises at least one surfactant.

Suitably the flowable material is a material which shrinks on cooling, in the liquid phase or when solidifying. Suitably the flowable material shrinks on cooling by contracting inwardly away from the inner walls of the cavities in the mould. Suitably the flowable material shrinks on cooling by contracting outwardly away from the centre of the cavities in the mould, forming a void.

Suitably the plurality of cavities and the at least one reservoir of the mould according to this first aspect can be filled with a flowable material which shrinks on cooling. Suitably the flowable material contained within the at least one reservoir of the mould can flow into a void in the cavities produced by the shrinkage of the flowable material within the cavities. In embodiments wherein the mould comprises a plurality of cavities arranged in communication with a single reservoir and/or wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir, the reservoir and/or reservoirs may retain heat more effectively than moulds comprising a single cavity and a single reservoir. This improved retention of heat may allow a flowable material in the reservoir and/or reservoirs to remain in a flowable state for longer by cooling more slowly compared to a flowable material in a reservoir of a mould comprising a single cavity and a single reservoir. The longer the flowable material remains in a flowable state, the more effective it may be at flowing into a void formed in the cavities by shrinkage of a flowable material within the cavities. This advantage may be greater for the embodiments wherein the mould comprises a plurality of cavities arranged in communication with a single reservoir than in embodiments wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir.

Suitably the mould provides moulded products of a desired size, shape and weight which would not have been possible using a mould without the reservoir due to the shrinkage of the flowable material on cooling.

Suitably the mould comprises two mould parts. Suitably the two mould parts are a lower mould part and an upper mould part. Suitably the lower mould part comprises a substantially flat lower face for resting on a substantially flat surface. Suitably the lower mould part comprises a plurality of recesses in an upper face of the lower mould part.

Suitably the upper mould part comprises a plurality of recesses in a lower face of the upper mould part. Suitably the plurality of recesses in the lower face of the upper mould part corresponds to the plurality of recesses in the upper face of the lower mould part. Suitably the upper mould part and the lower mould part can be joined together such that the recesses of the upper mould part are in register with the recesses of the lower mould part to form the plurality of cavities in the mould.

Suitably the upper mould part is provided with the at least one reservoir arranged in communication with the plurality of recesses in the upper mould part. Suitably the upper mould part is provided with a filling hole or holes for the plurality of cavities. Suitably the plurality of recesses in the upper mould part and the plurality of recesses in the lower mould part are substantially hemispherical. Suitably the substantially hemispherical recesses in the upper mould part and the lower mould part can be joined together to form a plurality of substantially spherical cavities in the mould.

Suitable materials from which the mould, upper mould part and lower mould part may be constructed include metals and polymer materials which have suitable properties of chemical and heat resistance and dimensional stability. Suitable metals include steel and aluminium and zinc alloys. Suitable polymer materials include polycarbonate. Suitably the mould is constructed from polycarbonate.

Suitably the mould may be provided with a heating arrangement for heating the at least one reservoir. Suitably the heating arrangement can provide heat to a flowable material in the at least one reservoir to maintain the flowable material in a flowable state whilst a flowable material in the plurality of cavities at least partially solidifies.

Suitably the mould of this first aspect may be used to produce a plurality of moulded products which have a substantially consistent size, shape and mass. Suitably the mould may be used to produce a plurality of such moulded products more efficiently than a mould having a single cavity or a plurality of moulds each having a single cavity.

In embodiments wherein the mould comprises a plurality of cavities arranged in communication with a single reservoir, the cavities and the reservoir may be filled from a dispenser arranged during a filling process at a single position above the reservoir. Therefore such moulds may allow a more efficient filling process than would be possible using a mould wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir and/or moulds comprising a single cavity and a single reservoir.

When a flowable material shrinks on cooling in the cavities of the mould, slight variations in the rate and/or extent of shrinkage of the material in different cavities may produce slight variations in the size and/or amount of voids in the cavities and therefore cause variations in the amount of flowable material which flows into the voids. In embodiments wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir and/or moulds comprising a single cavity and a single reservoir, the reservoirs can be provided with more flowable material than would be necessary if the rate and/or extent of shrinkage of the material was completely consistent, to account for this variation. In embodiments wherein the mould comprises a plurality of cavities arranged in communication with a single reservoir, providing the reservoir with more flowable material than would be necessary if the rate and/or extent of shrinkage of the material was completely consistent may not be required. The variation in the rate and/or extent of shrinkage of the material in different cavities can be accounted for by providing flowable material from the single reservoir, the cavities requiring less material to fill the voids compensating for the cavities which require more material to fill the voids. Therefore the use of the mould comprising a plurality of cavities arranged in communication with a single reservoir may require less flowable material to form a plurality of moulded products than a mould wherein each of the cavities in the plurality of cavities is arranged in communication with an individual reservoir and/or moulds comprising a single cavity and a single reservoir. This is particularly advantageous when the flowable material is expensive and/or difficult to manufacture and/or process.

According to a second aspect of the present invention there is provided a mould part comprising a plurality of recesses and at least one reservoir, wherein the plurality of recesses are arranged in communication with the at least one reservoir such that a flowable material can flow from the reservoir into the recesses.

The suitable features of the mould part of this second aspect are as defined in relation to the mould of the first aspect. The suitable features of the mould part of this second aspect are as defined in relation to the upper mould part described in relation to the first aspect. According to a third aspect of the present invention there is provided a method of producing a plurality of moulded products from a flowable material, using a mould according to the first aspect, the method comprising the steps of:

(a) at least partially filling the plurality of cavities with a flowable material; (b) at least partially filling the at least one reservoir with a flowable material such that the flowable material in the reservoir can flow into the cavities to supplement the flowable material in the cavities;

(c) allowing the flowable material to at least partially solidify; and

(d) opening the mould to remove the moulded products from the mould. Suitably the method involves the production of a plurality of moulded products from a flowable material which shrinks on cooling. Suitably the method involves the production of a plurality of moulded products from a flowable material which shrinks on cooling by contracting inwardly away from the inner walls of the cavities in the mould. Suitably the method involves the production of a plurality of moulded products from a flowable material which shrinks on cooling by contracting outwardly away from the centre of the cavities in the mould.

Suitably step (a) involves heating a material in order to provide the flowable material. For example, step (a) suitably involves melting a solid or semi-solid material to provide a flowable material.

Suitably step (a) involves substantially filling the plurality of cavities with a flowable material. Suitably step (a) involves filling the plurality of cavities with a flowable material.

Suitably step (a) involves allowing the flowable material to pour from above the cavities through an opening into the plurality of cavities.

Suitably step (a) involves at least partially filling the plurality of cavities with a flowable material through at least one filling hole in the plurality of cavities. Suitably step (a) involves at least partially filling the at least one reservoir with a flowable material and allowing that flowable material to flow into the plurality of cavities to at least partially fill the plurality of cavities.

Step (b) involves at least partially filling the at least one reservoir with a flowable material. Suitably the at least one reservoir is provided with a volume of flowable material of up to the total volume of all the cavities arranged in communication with that reservoir, suitably up to one half of the total volume. Suitably the at least one reservoir is provided with a volume of flowable material of at least one tenth of the total volume of all the cavities arranged in communication with that reservoir, suitably at least one quarter. Suitably the at least one reservoir is provided with a volume of flowable material of approximately one third of the total volume of all the cavities arranged in communication with that reservoir.

Suitably the flowable material used in step (b) is the same as the flowable material used in step (a). Alternatively the flowable material used in step (b) is different to the flowable material used in step (a).

Suitably step (a) and step (b) are carried out in one consolidated step. For example, flowable material is suitably introduced into the plurality of cavities and/or the at least one reservoir until the plurality of cavities and the at least one reservoir are at least partially filled with flowable material.

Suitably the flowable material is introduced into the plurality of cavities and/or the at least one reservoir from a dispenser arranged during the filling process at a single position above the plurality of cavities and the at least one reservoir.

Alternatively the flowable material is introduced into the plurality of cavities and/or the at least one reservoir from a dispenser which moves during the filling process to different positions above the plurality of cavities and the at least one reservoir.

Step (c) involves allowing the flowable material to at least partially solidify. Suitably step (c) involves allowing the flowable material to substantially solidify. Suitably step (c) involves allowing the flowable material to solidify. Step (c) suitably involves cooling the flowable material in the plurality of cavities. Suitably step (c) involves allowing a flowable material with a temperature greater than room temperature to return to room temperature. Suitably step (c) involves exposing the flowable material in the plurality of cavities to a temperature lower than room temperature. Suitably step (c) involves actively cooling the flowable material in the plurality of cavities. Alternatively step (c) involves passive cooling of the flowable material to room temperature.

Suitably step (c) causes the flowable material to substantially solidify in the plurality of cavities. Suitably step (c) causes the flowable material to solidify in the plurality of cavities.

Suitably step (c) involves allowing the flowable material to flow under gravity from the at least one reservoir into the cavities as the flowable material in the cavities at least partially solidifies. Alternatively step (c) involves pumping the flowable material from the at least one reservoir into the cavities as the flowable material in the cavities at least partially solidifies.

Suitably step (c) involves maintaining the flowable material in the at least one reservoir in a flowable state whilst the flowable material in the plurality of cavities at least partially solidifies. Suitably the flowable material in the at least one reservoir is maintained in a flowable state whilst the flowable material in the plurality of cavities substantially solidifies, suitably whilst the flowable material in the plurality of cavities solidifies. Maintaining the flowable material in the at least one reservoir in a flowable state suitably involves heating the flowable material. Step (d) involves opening the mould to remove the moulded products from the mould. Suitably step (d) involves removing the moulded products from the mould. Suitably the moulded products removed from the mould are substantially solid.

Suitably the moulded products produced by the method of this third aspect are solid products or semi-solid products which are able to be handled. Suitably the moulded products are solid products. Suitably the moulded products are substantially spherical. Suitably the moulded products are spherical.

Suitably the moulded products are substantially spherical and have a diameter of at least 1 cm, for example at least 2 cm, suitably at least 3 cm. Suitably the moulded products are substantially spherical and have a diameter of up to 10 cm, for example up to 7 cm, suitably up to 5 cm. Suitably the moulded products are substantially spherical and have a diameter of between 3.25 cm and 4.25 cm.

Suitably the moulded products have a mass of up to 200 g, for example up to 100 g, suitably up to 50 g. Suitably the moulded products have a mass of at least 5 g, for example at least 10 g, suitably at least 20 g. Suitably the moulded products have a mass in the range of 30- 40 g.

Suitably the moulded products have a substantially consistent size, shape and mass.

Suitably the moulded products are formed from a solid or semi-solid detergent composition. Suitably the moulded products comprise at least one surfactant.

According to a fourth aspect of the present invention there is provided a moulded product produced using a mould according to the first aspect of the present invention; by using a mould part according to the second aspect of the present invention; or by using the method according to the third aspect of the present invention.

The suitable features of the moulded product of this fourth aspect are as defined in relation to the first and third aspects. Suitably the moulded product is formed from a material which shrinks on cooling. Suitably the moulded product is formed from a material which shrinks on cooling by contracting inwardly away from the inner walls of the cavities in the mould. Suitably the moulded product is formed from a material which shrinks on cooling by contracting outwardly away from the centre of the cavities in the mould.

Suitably the moulded product is part of a plurality of moulded products.

Moulds, mould parts, moulded products and methods of producing a plurality of moulded products according to the present invention may overcome at least one disadvantage of the prior art.

Moulds, mould parts and methods of producing a plurality of moulded products according to the present invention may be used to provide moulded products which are free or substantially free of defects caused by a flowable material shrinking on cooling by contracting inwardly away from the inner walls of the cavities in the mould.

Moulds, mould parts and methods of producing a plurality of moulded products according to the present invention may be used to provide moulded products which are free or substantially free of defects caused by a flowable material shrinking on cooling by contracting outwardly away from the centre of the cavities in the mould. Moulds, mould parts and methods of producing a plurality of moulded products according to the present invention may be used to provide moulded products which have an improved consistency of size, shape and weight compared to moulded products produced by known methods using flowable materials which shrink on cooling.

Moulds, mould parts and methods of producing a plurality of moulded products according to the present invention may be used to provide moulded products which have an improved structural integrity compared to moulded products produced by known methods using flowable materials which shrink on cooling.

Brief description of the drawings For a better understanding of the invention, and to show how example embodiments may be carried into effect, reference will now be made to the accompanying drawings in which:

Figure 1 is a perspective view from above of a mould comprising a plurality of cavities, according to the first aspect;

Figure 2 is a top plan view of the mould of Figure 1 , showing cross-section line 3; Figure 3 is a cross section view taken through the mould of Figure 1 and Figure 2, along line 3; Figure 4 is a perspective view of the top face of the upper mould part of the mould of Figures 1 -3;

Figure 5 is a perspective view of the bottom face of the upper mould part of the mould of Figures 1 -3; Figure 6 is a perspective view of the top face of the lower mould part of the mould of Figures 1 - 3;

Figure 7 is a perspective view from above of the mould of Figure 1 after filling with a flowable material; and

Figure 8 is a perspective view of the respective mould recesses of the top and bottom halves of the mould of Figure 1 , after moulding and opening of the mould.

Detailed description of the example embodiments

Figure 1 shows a mould (100) formed from an upper mould part (1 10) and a lower mould part (120) which are held together by fixing arrangements (130). Defined between the upper (1 10) and lower (120) mould parts are a plurality of cavities (1 1 1). The cavities (1 1 1) are substantially spherical. The cavities (1 1 1) are arranged in four rows, each row comprising five cavities (1 1 1 ). Fixing arrangements (130) comprise bolts (131) which pass through the lower mould part (1 10) and the upper mould part (120). Washers (132) and wingnuts (133) are threaded onto the bolts (131) and tightened to fasten the upper (1 10) and lower (120) mould parts together. The plurality of cavities (1 1 1) can be seen most easily in Figure 3 and are spherical, being defined by opposed hemispheres in the upper mould part (1 10) and in the lower mould part (120). The mould (100) comprises a top face (1 15). The top face (1 15) of the upper mould part (1 10) is provided with four reservoirs (1 12). Each of the reservoirs (1 12) is arranged in communication with a row of five cavities (1 1 1). A filling hole (1 14) provides a communication between each of the cavities (1 1 1) and the reservoirs (1 12). The reservoirs (1 12) are arranged substantially above the cavities (1 1 1) and are suitable for retaining a flowable material above the cavities (1 1 1) when the cavities (1 1 1) are substantially full of a flowable material. The reservoirs (1 12) are open at the top face (1 15) of the upper mould part (1 10) and are suitable for receiving a flowable material when said flowable material is dispensed from above the reservoirs (1 12). The volume of each of the reservoirs is approximately one third of the total volume of a row of five cavities. The portion of reservoir (1 12) above the filling hole of a cavity (1 1 1 ) communicates to the portion of the reservoir above an adjacent cavity through a channel (1 13). The upper (1 10) and lower (120) mould parts are constructed from a chemical and heat resistant, dimensionally stable material. In this embodiment the upper (1 10) and lower (120) mould parts are constructed from polycarbonate.

Figure 3 shows a cross section of the mould (100) along line 3 as shown in Figure 1 . Mould (100) is formed by fastening upper mould part (1 10) and lower mould part (120) together in a face to face relationship, with the respective hemispheres of the mould parts aligned to form the spherical cavities (1 1 1). Figure 3 shows a row of five adjacent cavities (1 1 1 ), each with a filling hole (1 14) and each arranged in communication with the reservoir (1 12) through the filling holes (1 14). The cavity (1 1 1) comprises an inner surface (1 16). Reservoir (1 12) comprises a base surface (1 12a) which has a shape which partially follows the shape of the upper region of the cavities (1 1 1) in the mould. That is, a part of the base surface (1 12a) is generally parallel to the inner surface (1 16) in the upper region of the cavities (1 1 1 ). The shape of the base surface (1 12a) provides regions (1 12b) where flowable material contained in the reservoir (1 12) cannot flow under gravity into the cavities (1 1 1 ). The shape of the base surface (1 12a) is a compromise between maximising an amount of flowable material in the reservoir (1 12) which can flow into the cavities (1 1 1) under gravity and facilitating the manufacture of the mould (100) by injection moulding.

In this embodiment the filling holes have cylindrical walls. In another embodiment the filling holes have inclined walls, for example countersunk walls, narrower at the cavity side and wider at the reservoir side. The intention is to minimise the presence of pips or knobs of material on the moulded end products. Figure 4 shows the upper face (1 15) of the upper mould part (1 10). The portion of reservoir (1 12) above the filling hole (1 14) of a hemispherical recess (1 1 1 a) is in communication with the portion of a reservoir (1 12) above an adjacent cavity through a channel (1 13). Upper mould part (1 10) comprises four fixing holes (140) for receiving a fixing arrangement to allow the upper mould part (1 10) to be firmly and accurately attached to a lower mould part to form a complete mould.

Figure 5 shows a lower face (1 17) of the upper mould part (1 10) shown in Figure 4. The lower face (1 17) comprises twenty hemispherical recesses (1 1 1 a) arranged in four rows of five, and each comprising a filling hole (1 14). In use the hemispherical recesses are intended to be aligned with complementary hemispherical recesses in a lower mould part and are intended to form substantially spherical cavities when the upper mould part (1 10) and a lower mould part are aligned and fixed together. To facilitate alignment and fixing of the upper mould part (1 10) to the complimentary lower mould part, the upper mould part (1 10) is provided with four apertures (1 19) for receiving a peg arranged on a complimentary lower mould part.

Figure 6 shows the upper face (1 18) of a lower mould part (120). Lower mould part (120) comprises twenty hemispherical recesses (1 1 1 b) arranged in four rows of five. The hemispherical recesses are intended to be aligned with complimentary hemispherical recesses in an upper mould part, such as that shown in Figure 5, to form substantially spherical cavities in a complete mould. To facilitate alignment and fixing of the lower mould part (120) to an upper mould part, fixing pegs (121) are provided on the lower mould part (120). In use, the four fixing pegs (121) enter complimentary apertures on an upper mould part, such as the apertures (1 19) shown in Figure 5, in order to facilitate the alignment and fixing of the lower mould part (120) to an upper mould part through contact of the upper face (1 18) of the lower mould part (120) and the lower face of an upper mould part to form a complete mould comprising twenty substantially spherical cavities. The lower mould part (120) also comprises four fixing holes (140) suitable for alignment with four fixing holes on a complimentary upper mould part, such as that shown in Figure 5, when the lower mould part (120) and the upper mould part are joined together to form a complete mould.

Figure 7 shows the mould (100) of Figure 1 comprising twenty cavities (not shown) arranged in four rows of five cavities, each row of five cavities being provided with a reservoir (1 12). The mould shown in Figure 7 has been filled with a flowable material (150) which has filled each of the twenty cavities and has substantially filled each of the five reservoirs (1 12).

Figure 8 shows the upper mould part (1 10) as shown in Figure 5 and a lower mould part (120) as shown in Figure 6. The upper mould part (1 10) and the lower mould part (120) have been separated after being used to form a plurality of moulded products (160). Each hemispherical recess (1 1 1 b) of the lower mould part (120) comprises a substantially spherical moulded product (160) formed by the solidification of a flowable material.

In use, the upper mould part (1 10, Figure 4) is attached to the lower mould part (120, Figure 6) by lowering the lower face (1 17, Figure 5) of the upper mould part (1 10) onto the upper face (1 18) of the lower mould part (120) such that the alignment pegs (121 , Figure 6) on the lower mould part (120) enter the apertures (1 19, Figure 5) in the upper mould part (1 10). Fixing bolts are then passed through the fixing holes (140, Figure 6) in the lower mould part (120) and through the fixing holes (140, Figure 4) in the upper mould part (1 10). The fixing bolts are then provided with washers (133) and wingnuts (132) as shown in Figure 1 which are tightened to firmly join the upper mould part (1 10) and the lower mould part (120) together to form a complete mould (100, Figure 1) comprising twenty substantially spherical cavities. In order to form a plurality of moulded products using the mould (100), the following procedure may be followed. Each cavity of the mould (100) is filled with a flowable material through filling holes (1 14). Further flowable material is then added to each of the four reservoirs (1 12) to provide the filled mould (100) as shown in Figure 7. The volume of flowable material added to each reservoir is approximately one third of the total volume of the five cavities arranged in communication with that reservoir. The flowable material is then allowed to cool in the cavities. As the flowable material cools and shrinks, further flowable material is drawn into the cavities from the reservoir and thereby prevents defects forming in the moulded products. Once the flowable material has sufficiently solidified within the cavities, the wing nuts (132), washers (133) and fixing bolts (131) are removed. The upper mould part is then separated from the lower mould part to give a lower mould part (120, Figure 8) comprising a plurality of moulded products (160) as shown in Figure 8. The moulded products (160) may then be removed from the lower mould part (120).

Example 1

A plurality of substantially spherical moulded products were produced from composition A (a transparent soap composition) shown below in Table 1 :

Table 1

Each of the components of composition A were mixed and melted together at 1 10 °C to give molten composition A. The molten composition A was poured into each of three rows of five cavities in the mould shown in Figures 1 -8, to exactly fill each of the cavities.

The reservoir of each row was further provided with molten composition A such that the reservoir above the cavities was filled with a volume of molten composition A approximately equal to one third of the total volume of the five cavities in the row. The molten compositions in the mould were then allowed to cool in air for fifteen minutes and were further cooled in a freezer for one hour. The mould was then opened by separating the upper mould part from the lower mould part and the moulded products were inspected.

The moulded products of each row were substantially spherical with no internal or external defects caused by shrinkage of the molten material on cooling. The moulded products had a consistent size, shape and weight.

Example 2

A plurality of substantially spherical moulded products were produced from composition B (a high melting soap composition) shown below in Table 2:

Table 2

Each of the components of composition B were mixed and melted together at 1 10 °C to give molten composition B. The method of Example 1 was repeated to form moulded products from composition B which were substantially spherical with no internal or external defects caused by shrinkage of the molten material on cooling. The moulded products had a consistent size, shape and weight.

Example 3

A plurality of substantially spherical moulded products were produced from composition C (a synthetic detergent soap composition) shown below in Table 3: Table 3

Each of the components of composition C were mixed and melted together at 1 10 °C to give molten composition C. The molten composition C was poured into each of three rows (rows X, Y and Z) of five cavities in the mould shown in Figures 1 -8, to exactly fill each of the cavities.

The reservoir of row X was not provided with any further molten composition C. Therefore the reservoir of row X did not contain any of the molten composition C.

The reservoir of row Y was further provided with molten composition C such that the reservoir above the cavities was filled with a volume of molten composition C approximately equal to one third of the total volume of the five cavities in the row.

The reservoir of row Z was further provided with molten composition C which also comprised a blue dye such that the reservoir above the cavities was filled with a volume of blue-dyed molten composition C approximately equal to one third of the total volume of the five cavities in the row. The molten compositions in the mould were then allowed to cool in air for fifteen minutes and were further cooled in a freezer for one hour. The mould was then opened by separating the upper mould part from the lower mould part and the moulded products were inspected.

The moulded products of row X exhibited substantial defects in the form of large cavities in the centre of the moulded products. The moulded products of row Y were substantially spherical with no internal or external defects caused by shrinkage of the molten material on cooling. The moulded products in row Y had a consistent size, shape and weight. The moulded products in row Z showed a blue colouration in the centres of the moulded products.

The presence of the blue dye in the centre of the moulded products of row Z in Examples 3 and the presence of a cavity in the moulded products of row X show that the molten composition C had shrunk on cooling towards the internal surface of the cavities and away from the centre of the cavity. This shrinking action caused the molten composition in the reservoir to be drawn into the cavities and fill the void left by the shrinking molten composition in the cavity. Without wishing to be bound by theory, we believe that this mode of shrinking is partly caused by the affinity of the molten material such as composition C for the inner surface of the mould cavities. This affinity for the inner surface of the mould cavities caused the molten composition C to shrink on cooling by contracting outwardly away from the centre of the cavity instead of contracting inwardly away from the inner walls of the cavity.

Although preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.