GB2613634A - Ecological wood pulp and paper disposable indoor slippers - Google Patents

Abstract

A method of finish forming moulded wood pulp disposable indoor slippers into a single moulding; and a method of finish forming and integrating a moulded wood pulp sole into a pair of disposable indoor slippers with a naturally waxed paper upper. Also provided is a method of laminating numerous moulded wood pulp preforms together using natural plant-based adhesives; and a production method utilising a moulded preform sole, finished through press over-curing with natural plant-based waxes to achieve a smooth finish, and incorporating a tread pattern into the bottom of the sole.

Description

Description

INTRODUCTION TO THE INVENTION

A method of finish forming moulded wood pulp disposable indoor slippers into a single moulding comprising of the completed footwear. Secondly a method of finish forming and integrating a moulded wood pulp sole into a pair of disposable indoor slippers ostensibly having a naturally waxed paper upper.

Production method using a moulded fibre product as an oversize preform, finished through press over-curing (co-curing) with natural plant based wax to achieve a silky smooth vamp finish that may be decorative or smooth, while during the same impression imprinting a tread pattern into the sole to improve grip.

And a method of laminating numerous moulded wood pulp preforms together using natural plant based adhesives, or simply bonded by the forming process through reliance upon the natural lignin and cellulose present within the pulp. The process being completed through press over-curing (co-bonding) as described herein.

Considerations relating to improving the mechanical properties and water resistance of the constituent parts of the aforementioned ecological disposable indoor slippers. Natural processing additives may be combined with natural antidegradants that will lend themselves to recycling or upon C\I disposal natural decomposition.

What is proposed is a holistic approach to reducing the environmental impact of disposable indoor slippers used in the home or hospitality sector. The fibre used always being wood pulp combined with other plant based natural products. The objective is that used slippers are returned to the (3) manufacturing plant for recycling so they can be recycled up to 6 times. All binders, adhesives and C\J antidegradants to be natural.

BACKGROUND OF THE INVENTION

The present invention relates to the finish press forming a moulded fibre product preform into indoor slippers as a single homogeneous moulding and is particularly applicable to the commercial hospitality sector, where disposable slippers are supplied as a standard guest amenity.

Existing disposable indoor slipper products are constructed with a high proportion of mixed synthetic materials: polyurethane foams, woven polyesters, rubbers and polyvinyl chloride vegan leathers. Single use products with constituent parts that will persist in the environment for many years.

Disadvantages may be discovered in all existing products and what may look like natural waxed paper slippers can be found to have been realised through reinforcing a plastic vamp material with wood fibres, forming a plastic wood fibre composite. Upon further deconstruction the ubiquitous polyurethane foam beneath a polyvinyl chloride vegan leather sole, may be discovered. Once again the conclusion can be drawn that the product is almost completely constructed of mixed plastics, making recycling problematic. Alternatives products made wholly or partly from animal products present alternative ethical dilemmas for the hospitality sector.

Therefore the difficulty encountered in obtaining disposable indoor slippers that minimise the environmental and ethical impact may be achieved by constructing them as a single homogeneous or laminated waxed wood pulp moulding. Surpassing the existing flexible [Hydrazine] foamed polymer derivatives of the traditional wooden clog.

Historically the production of moulded pulp fibre products involved a water suspension of fibres being deposited onto a screened formation mould. Vacuum being used in order to consolidate the fibres onto the formation mould, developing shear strength while removing excess water. Finally the mould tool may be closed with what may be referred to as the transfer mould (depending on the process), pressure and heat may be applied removing more water. A somewhat soggy product is then de-moulded and oven cured at temperatures ranging between approximately 175°C and 200°C to enable the fibres to bond together. The exact process temperatures are dependent upon the pulp composition and constituents used, the upper temperature is more suited to raw wood pulp without additives.

The International Moulded Fibber Association (IV FL) categorizes moulded fibre products (MFPs) into four categories, Types 1 through 4: Thick Wall, Transfer Moulded, Thermoformed, and Processed. Warranting specific consideration is the current state of the art for Thermoformed MFP where the maximum achievable thickness for this process is quoted by the IMFA as 4 mm.

The production of wax paper starts with a similar water suspension of wood fibres as the MFP process. However, the pulp is deposited onto a flat screen, vacuum again used to consolidate the fibres and remove excess water. Then the pulp is then passed through heated rollers where pressure and heat C\I are used to enable the fibres to bond together. Waxing is completed by spraying a small quantity of C\I wax as a fine mist onto both sides of the paper and again passing the paper through heated rollers.

SUMMARY OF THE INVENTION

CJ With a view to mitigating the foregoing disadvantages, the present invention is a method of creating a homogeneous or laminated wood pulp moulding through extensively adapting the traditional clog design to accommodate a closed two part mould tooling philosophy. This has been achieved through modifying the features of a traditional clog, while creating a design more suited to its role of disposable indoor slipper. In comparison to the traditional clog design the raised toe cap, sole waist (or shank) and heal counter have been removed. While the unique clog style collar has been extended to blend with the inner sole. In order to reduce weight the sole thickness has also been reduced. Resulting in a unique design solution that recognises the very different mechanical properties exhibited by a waxed press over-cured wood pulp. In its broadest aspect the above product design adaptation and revised method of finish forming moulded wood pulp disposable indoor slippers into a single moulding comprising of the completed footwear is described.

In the simplest manifestation a disposable wood pulp slipper, based on the product design adaptation as given, is manufactured using the thermoforming process, accepting the limitations in wall thickness (4 mm). In this manifestation the finished product is not laminated in any way and is simply a monolithic moulding. A would pulp preform is created using a screened formation mould but before the preform enters the thermoforming tooling an additional reduction and control over the water content are anticipated, through partial oven curing. After partial oven curing the addition of a wax mist to the preform is as described according to a further aspect as below. Because considerably less water will be held within the preform as it transfers to the heated closed mould tooling an improved surface finish will be achieved.

According to a further aspect of the invention, a method of laminating numerous wood pulp preforms together using natural plant based constituents, through press over-curing (co-bonding). Multiple layers of the preforms may be dried and a plant based adhesive then being applied to the adherends. The adherends are masked if and when the waterproofing wax mist is applied to the preform(s) as described according to a further aspect as below. The current thickness limitation of the thermoforming process (4 mm) can be multiplied by the number of plies, therefore if a 2 ply construction were used the wall thickness may be increase to 8 mm. The advantage of laminating moulded wood pulp preforms before press over-curing is that thicker finished products are achievable with greatly improved mechanical properties. It may also be assumed that increasing the thickness of the slipper sole will have a positive improvement in comfort. It is also envisaged that a laminated wood pulp sole may be incorporated into a more conventional slipper construction method, both as inner and outer sole.

Secondly as a derivative of the above manifestations a method of finish forming and integrating a moulded wood pulp sole into a pair of disposable indoor slippers ostensibly having a naturally waxed paper upper is envisaged. This form of the present invention approaches slipper construction in a more conventional way. A waxed paper vamp being sandwiched between the wood pulp moulded sole and a die cut inner sole. A plant based adhesive then being applied to the adherends and the assembly is co-cured in a thermoforming mould tool.

According to a further aspect of the above inventions, a production method using a moulded pulp C\I product as an oversize preform, finished through press over-curing (co-curing) with natural plant based wax to achieve a silky smooth vamp finish that may be decorative or smooth, while during the same impression imprinting a tread pattern into the sole to improve grip. Again the water resistance of the finished slippers will be created by coating exterior of the partly dried preform with a thin film of plant based [soya] wax, before it enters the closed mould tool.

C\J Advantageously, the invention designs and processes lend themselves to very high production rates, in comparison to congenital slipper manufacturing. While considerations relating to improving the mechanical properties and water resistance of the constituent parts of the aforementioned ecological indoor slippers may be achieved through waxing. Combined with other natural processing additives and natural antidegradants that will lend themselves to recycling or upon disposal natural decomposition. These and other objects, features and advantages are accomplished according to the instant invention by providing a clog product design adaptation combined with using a waxed moulded pulp product will achieve a silky smooth finish that may be decorative or smooth, while during the same impression imprinting a tread pattern into the sole to improve grip. While a 'foot' impression may be applied to a wood pulp inner sole to improve comfort. Adapting the design features of the traditional wooden clog design in an innovative way to suit the aforementioned new and innovative production method. The improvement in surface finish, tensile strength and surface hardness achieved by the above process being needed as part of the technology transition from egg boxes and waxed paper to waxed wood pulp footwear.

What is proposed is a holistic approach to reducing the environmental impact of indoor slippers used in the home or hospitality sector.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a side view of a house slipper showing the adaptations to the traditional clog design; item 1 is the toe cap; item 2 is the vamp; item 3 is the collar; and item 4 sole.

FIG. 2 is an adaptation of an indoor slipper in side view, showing an example of laminating the screened formation mould preform within a thermoforming mould tool; item 1 is based on the preform used to create the slipper in FIG. 1; item 2 is the additional perform used to increase the sole thickness.

FIG. 3 shows an example of a laminated wood pulp indoor slipper sole, note the thickness may be much greater than existing technology will allow and that a waxed paper vamp may be inserted to the top of ply 1 or between plies land 2; item 1 is ply 1; item 2 is ply 2; and item 3 is ply 3: FIG. 4 is a side view of a house slipper showing an adaptation where a wood pulp sole is combined with a waxed paper vamp; item 1 is the waxed paper vamp; item 2 is the wood pulp sole; and item 3 is the wood pulp inner sole: FIG. 5 is a rotated side view of an indoor slipper showing the mould tool arrangement with a stepped split line; item 1 is the upper mould tool; item 2 indicates a typical draft angel; item 3 is the tooling C\I split line; item 4 is the slipper cavity from FIG. 1; and item 5 is the lower mould tool.

(3) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. land 2 show the manner in which a traditional clog may be adapted to suit the new production method described herein.

With regards to the dimensions given a single ply may be any thickness from 1 mm to 4 mm, the upper size being the current technology limitation A difficulty encountered in thermoforming or press forming a conventional clog is the limitation on material thickness. To mitigate this problem, the invention provides a method of laminating a preforms created with a screened formation mould through first partly oven curing before waxing and then thermoforming with an adhesive.

The preferred embodiment of the invention is shown in FIG. 2. It will be clear to the person skilled in the art that various modifications may be made to the described preferred embodiment without departing from the scope of the invention as set forth in the appended claims. In particular, it is not essential to form the clog with a closed toe.

The extension in thickness as shown in FIG. 2 is not simply limited to the underside of the sole, the additional preform may be extended so that any part of the slipper may be increased in thickness. It is also envisaged that various shaped preforms may be combined so that the number of plies in any area may be controlled, for example to create an inner sole shaped to the foot for added comfort.

FIG. 3 shows how a laminated wood pulp slipper sole may be constructed from multiple layers. This additional thickness allows for additional comfort, because a foot shape may be moulded to the inner sole and additional grip as a more pronounced tread pattern may be added.

FIG. 4 shows how a laminated wood pulp slipper sole may be combined with a more conventional vamp, though in this example the vamp is envisaged as being waxed paper.

FIG. 5 shows how the mould tooling needs to be designed, notice how the tooling split line is stepped and also follows the profile of the collar. The mould tool parting is arranged in a way that ensures that a draft angle is available to the entire product, from heel to inner sole to toe to vamp. The generous draft angels follow the natural shape of the foot and combined with the wax coating allow for easy removal of the finished slipper form the tooling.

It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific forms shown.

Claims (9)

1. Claims 1. An adaptation to the traditional clog design to allow manufacturing of a disposable indoor slipper using wood pulp formed into a single homogeneous moulding.
2. 2. The improvement of claim 1, wherein: Additional preforms are added to the mould tooling in order to increase the part thicknesses where required through laminating.
3. 3. The improvement of claim 2, wherein: A disposable slipper sole is constructed through laminating wood pulp preforms to increase the thickness of the sole.
4. 4. The improvement of claim 3, wherein: The inner sole is moulded to the shape of a foot to improve comfort.
5. S. The improvement of claim 3, wherein: Allowing a deeper tread to be incorporated improving grip on wet surfaces for example.
6. 6. The improvement of claim 2, wherein: The clog shape is deconstructed into a wood pulp sole and waxed paper upper.
7. 7. The improvement of claim 6, wherein: The clog shape is deconstructed into a medium density wood fibre sole and waxed paper upper that is moulded into shape with heat and pressure (not a folded design more random crease).
8. 8. The improvement of claim 3, wherein: Said clog moulding is comprised partly of a natural cellulose foam moulding faced with waxed paper.
9. 9. The improvement of claims 1 to 8, wherein: The wood pulp is replaced with a medium density wood fibre.