FR2711622A1 - Shock protection element, manufacturing method and device for using the method - Google Patents

Abstract

The invention relates to a method of manufacturing a shock protection element for an object of any shape, the said element being made from paper pulp or similar and intended to surround the said object whilst contacting it at points. The invention also relates to a device for using the method and to a shock protection element.

Description

 The invention relates to a method of manufacturing impact protection elements for an object of any shape, as well as a device for implementing said method. The invention also relates to such impact protection elements.

 We already know in the state of the art noibreuz products allowing protection against shocks.

 We can note the sheets of corrugated cardboard which are produced by calendering. Corrugated cardboard provides effective protection against impact, but it cannot easily be adapted to objects of any shape.

 Also known are packages of food products made from paper pulp, such as egg cartons. However, the manufacturing processes for such packages are relatively complex. We can in particular refer to patents U8-A-1,697,24o, GB-1,137,131 and FR-A-1,399,753. All these methods require a mold carrier wheel. Due to their rotation, the machines are complex, in particular as regards the feeding systoles. In addition, changing the molds on the wheel is a relatively long operation.

 These packages are rigid enough, so they cannot be adapted to objects of any kind. For each high data product, a specific tool must be designed. These tools are of complex construction, which results in a considerable cost and manufacturing time.

 Protective elements are also known which consist either of a cellular foam or else of a flexible plate plastic material, trapping air bubbles.

 These protective elements have the advantage of being easily adaptable to the shape of the object to be protected.

 However, these elements have drawbacks in terms of recycling.

 Indeed, these protective elements made of plastic, most often have to be laminated on a support made of a different material, in particular cardboard, to give them strength and rigidity.

 It is therefore difficult to recycle the products used, the separation between the plastic material and the paper material being difficult, if not impossible. These conventional protective materials also require the massive use of whole plastic and constitute polluting waste.

 The object of the invention is therefore to solve the problems posed by the products of the state of the art by proposing a method of manufacturing an element of protection against impacts, for an object of any shape, said method being a simplified implementation and using a rapid and inexpensive manufacturing mold. This process makes it possible to obtain a protective element which easily adapts to the shape of the object to be protected or which is already adapted to the shape of this object, this element being moreover recyclable.

 The method according to the invention makes it possible to manufacture protective elements from paper pulp or the like which are intended to surround the object to be protected by ensuring spot contact.

 Throughout the description, "point contact" is understood to mean a contact which is not made over the entire surface of the object but only over surfaces of size very much smaller than the total surface of the object. .

The process includes
- a shaping step in which we apply
pulp in a mold, in the shape of said element
protective and having a honeycomb structure, and
at room temperature, an overpressure of the
outer side of the mold relative to the active part of the
mold,
- a drying step, in which the
heat to the element previously comforts in the mold
and we maintain a vacuum on the outside of the mold
relative to the active part of the mold, during the two stages, the mold is fixed and substantially horizontal, and the active part of the mold directed upwards.

 In a first embodiment, the active part of the mold has the form of a plate.

 The method thus makes it possible to obtain a protective element which is shaped around the object to be protected, during its use.

 In a second embodiment, the active part of the mold has the shape of the internal wall of a component of said protective element, said internal wall having a relief substantially opposite to that of the part of the object that the component is intended to protect, said component being intended to cooperate with at least one other component to form said protective element.

 The method then makes it possible to obtain a protective element which adapts to the shape of the object to be protected, when the different components cooperate with each other.

 In a particular embodiment, said components of the protective element are made in one piece, with a single mold.

 In a preferred mode, the method is carried out continuously. This is particularly interesting for the manufacture of plate-shaped protective elements.

 Advantageously, the intensity of the overpressure maintained during the shaping step is chosen so as to obtain a substantially homogeneous and uniform layer of paper pulp on the active part of the mold.

 According to a first embodiment, during the drying step, heat is supplied to the protection element by infrared radiation, producing a temperature in particular between 100 ° C. and 2900 ° C.

 According to a second embodiment, during the drying step, heat is provided to the protective element by heating gases which are sucked through the element due to vacuum, said hot gases being at a temperature in particular between 100 ° C. and 290 ° C.

 The choice of this temperature range ensures the shortest and most complete drying of the protective element possible.

 Thus, all the stages of the manufacturing process are carried out until the molded and dried part is removed from the mold, using the same tool for molding, or conformation, and drying.

 In order to limit handling and to adapt to all shapes of parts, the paper protection element is released from the mold by injection of compressed air through the mold, after drying.

 Alternatively, and in order to achieve cost savings, maintenance and handling for the elements, said elements can, in particular when they are large, be removed from the mold by means of a suction suction device, which optionally allows the same suction source to be used as for the other process steps.

 The invention also relates to a device for implementing this method.

 According to the invention, the mold is made of a porous and non-hydrophilic material.

 Preferably, the material resists thermal shock due to the passage of steam when the drying is obtained by suction of hot gases so that the lifetime of the mold is relatively long. For the same purpose, it is preferable to choose a material which does not oxidize.

 This material can be composite.

 The invention finally relates to a shock protection element for an object of any shape, this element having the advantage of adapting or of already being adapted to the shape of the object and of being completely recyclable .

 Thus, the impact protection element is made of paper pulp or the like and has with said object a contact face of honeycomb structure, which ensures point contact between said object and said element when the latter surrounds said object. .

 In an alternative embodiment, said element has the form of a sheet having a honeycomb structure which is, during its use, shaped around said object to be protected.

 In another alternative embodiment, said element consists of at least two components, the internal wall of each component having a relief substantially opposite to that of the part of the object that the component is intended to protect, said components being intended to cooperate with each other to provide a central cavity corresponding substantially to the dimensions of the object to be protected, the walls of said cavity having a honeycomb structure.

 In a particular embodiment, said components constitute a single piece.

 Preferably, said honeycomb structure consists of a succession of patterns, such as a cone or a hemisphere, possibly truncated.

The invention will be better understood and other objects, advantages and characteristics thereof will appear more clearly on reading the following description, made with reference to the accompanying drawings, in which
- Figure 1 shows an implementation device
of the process according to the invention,
- Figures 2a and 2b show a first pattern of
honeycomb structure for a protective element according to
the invention, seen from the side and from above,
- Figures 3a and 3b show a second pattern, in
side and top view,
- Figures 4a and 4b show a third pattern, in
side and top view and
- Figures 5 to 8 show, seen in section,
examples of cellular structure patterns for
protective elements according to the invention.

 FIG. 1 shows an example of a device for implementing the method of manufacturing impact protection elements. This device essentially comprises a mold 1, placed on a fixed support 2. The mold is arranged substantially horizontally, the active part 3 of the mold being directed upwards.

 In the example illustrated in Figure 1, the active part 3 of the mold has the form of a plate.

 The mold 1 is not necessarily fixed, it can also be arranged on a system such as a conveyor, ensuring its translation in a substantially horizontal plane.

Such a device is used when it is desired to implement the method according to the invention, continuously.

 The mold 1 is made of a porous gas material.

 In addition, the active part 3 of the mold has a honeycomb structure which consists of a succession of patterns, each pattern here having substantially the shape of a hemisphere. With reference to the other figures, other examples of honeycomb structure will be described.

 The method of manufacturing a protective element includes a shaping step and then a drying step.

The shaping step consists of
- to apply, manually or by means
automatic, an appropriate amount of pulp
in mold 1,
- to maintain, at room temperature, an overpressure of the
outer side of the mold 1 relative to the active part 3
of the mold.

 The intensity of this overpressure is chosen so as to prevent the paper pulp from being deposited in the thinner zones 6 of the mold, due to the gravity, and thus to maintain a uniform and homogeneous layer of paper pulp on all the active part 3 of the mold.

The drying step consists of
- to establish a depression on the outer side 5 of the mold
relative to the active part 3 of the mold,
- to bring heat to element 4 beforehand
shaped in the mold.

 This vacuum can for example be obtained by means of a vacuum pump and a conduit opening out at the rear of the mold 1. These devices are not illustrated in FIG. 1.

 In addition, heat can be brought to the room by infrared radiation, producing in particular a temperature between 100 and 2900C. The radiation value can be appropriately determined so that the part is heated without the mold being heated. This allows it to be effectively protected against thermal shock.

 One can also dry the element 4 in the mold 1 by sucking hot gases 7, through the element 4 and the mold 1, the gas flow being directed from the top to the bottom of the mold, as illustrated by FIG. 1 .

 This suction of hot gases can for example be obtained by means of a heating device placed above the mold and heating gases which are sucked in due to the vacuum. Such a device is not shown in FIG. 1. The gases used are preferably constituted by ambient air.

 Thus, the heating device heats the air to a temperature preferably between 1000 and 290 "C and the hot air 7 is set in motion through the mold 1 and the element 4, shaped in the mold , thanks to the said pump mounted at the end of the suction duct This allows the shaped element 4 which is still in the mold to be dried.

 Due to the depression, the paper pulp is fixed in the mold. Indeed, the mold is not hermetic to the pressure but it is impermeable to the paper pulp which cannot therefore be driven further by the depression. The paper pulp thus takes the form imposed by the mold, while being dried due to the temperature of the radiation or the air sucked in.

 Finally, the element 4 is removed from the mold. This can be obtained by a distribution of compressed air, this compressed air circulating in the same way as the air sucked in by the pump but in the opposite direction, and expelling the element 4 from the mold 1 The demolding can also be obtained by a suction device by suction cup which is placed at least on the internal face 8 of the element 4 and by displacement of the suction cup (s) on said part.

 Preferably, the mold 1 is made of a non-hydrophilic material.

 It is subjected to significant thermal shock when drying is ensured by suction of hot gases. To increase its service life, it is therefore preferable to make it from a material resistant to thermal shock.

 For the same purpose, this material does not oxidize.

 Preferably, the mold 1 can be made of a composite material so that it can be produced quickly.

 The device for implementing the method according to the invention is very simplified compared to known devices, in particular for the production of egg cartons. In particular, the mold can be produced quickly and at low cost and it can also be changed very quickly.

 The mold being arranged so that its active part 3 is directed upwards, the intensity of the gas suction established during the drying step is much lower than that which is necessary in the systems for the manufacture of boxes. eggs, which include a rotating mold wheel and do not use gravity.

 The protective element which is obtained after demolding constitutes a relatively flexible sheet. It can therefore be easily shaped around the object that one wishes to protect against impact.

 In addition, the honeycomb structure that has the internal face 8 of the protective element ensures spot contact with the object to be protected and thus effective protection against shocks.

 Variants of the honeycomb structure will be described with reference to the other figures.

 This element 4 consists only of paper pulp or assimilated and it is therefore easily recyclable.

 Thus, not only does this protective element not require the use of plastic material, but it also makes it possible to use composite papers, notably originating from the recovery of old paper.

 The manufacturing method according to the invention has been described with regard to a device making it possible to obtain a protective element in the form of a sheet, this element then being shaped around the object to be protected, during its use.

 One can also consider implementing the method according to the invention to produce a protective element whose shape is previously adapted to that of the object to be protected.

 In this case, the protective element consists of at least two components which can cooperate with each other by providing a central cavity. The internal wall of each component has a relief substantially opposite to that of the part of the object that the component is intended to protect and facing which it is intended to be placed. The shape of the components is determined so that this cavity substantially corresponds to the dimensions of the object to be protected.

The walls of the cavity have a honeycomb structure which is in contact with the object to be protected, when the components of the protective element cooperate with each other.

 These components can in particular fit into each other.

 Such protective elements can be designed for any products, such as cameras or decorative objects.

 Each component of a protective element of this type is obtained from a mold, the active part of which has the shape of the internal wall of the component.

 The protective element can also be made in one piece, the two components being for example articulated with respect to each other. Only one mold is necessary.

 The manufacture of such protective elements, in sheet or preformed form, is relatively simple and inexpensive insofar as the manufacture of corresponding molds entails relatively low costs compared to conventional molds.

 As indicated above, the method according to the invention can be implemented continuously, which further reduces the cost of manufacturing protective elements.

 With reference to the other figures, examples of patterns of honeycomb structures for protective elements according to the invention will be described.

 As illustrated in FIGS. 2a and 2b, this pattern can consist of a cone, the contact between the protective element and the object to be protected then being substantially punctual. This pattern can also be constituted by a truncated cone, as shown in Figures 3a and 3b. Contact with the elements to be protected is then ensured by surfaces 10.

 Figures 4a and 4b show a pattern in the form of a cone having edges 17, the contact between the protective element and the object to be protected being produced by surfaces 11, of substantially square section.

 As shown in Figure 1, the pattern can be constituted by an element of substantially semispherical shape. With reference to FIG. 5, this element can be slightly truncated, the contact with the element to be protected being effected by means of surfaces 12.

 Referring to Figure 6, the pattern can be constituted by a protrusion in the form of a sugar loaf, the contact is then made along lines.

 The pattern can also consist of a protuberance having a slight central depression 15, as illustrated in FIG. 7. The reliefs 13 and 14, on either side of the depression 15, ensure contact with the product to be protected .

 Referring now to FIG. 8, the pattern may consist of a protuberance of substantially square section, contact with the product to be protected being ensured by means of surfaces 16.

 These different examples of patterns of cellular structures for a protective element according to the invention illustrate the nature of the contact between the protective element and the product to be protected against impact, this contact having been defined as a "point contact". As was previously explained, this contact is effectively substantially punctual; it can also be carried out by means of surfaces of reduced size compared to the total surface of the object to be protected.

 The examples which have just been illustrated are in no way limiting, and one can envisage all kinds of forms which can ensure "point contact".

 The reference signs inserted after the technical characteristics mentioned in the claims, have the sole purpose of facilitating the understanding of the latter, and in no way limit their scope.

Claims (14)

CLAIM8  1. A method of manufacturing an impact protection element for an object of any shape, said element being made of paper pulp or the like and intended to surround said object by ensuring spot contact, said method comprising  a shaping step in which paper pulp is applied in a mold (1), in the shape of said protective element (4) and having a cellular structure, and an overpressure of the material is maintained at room temperature outer side (5) of the mold (1) relative to the active part (3) of the mold (1),  - A drying step, in which heat is supplied to the element (4) previously shaped in the mold (1) and a vacuum is maintained on the outside (5) of the mold (1) relative to the active part (3) of the mold, during the two stages, the mold is substantially horizontal and the active part (3) of the mold directed upwards.  2. Method according to claim 1 characterized in that the active part (3) of said mold has the form of a plate.  3. Method according to claim 1 characterized in that the active part (3) of said mold has the shape of the internal wall of a component of said protective element, said internal wall having a relief substantially opposite to that of the part of l object that the compound is intended to protect and said component being intended to cooperate with at least one other component to form said protective element.  4. Method according to claim 3, characterized in that said components are made in one piece, with a single mold.  5. Method according to one of claims 1 to 4 characterized in that it is implemented continuously.  6. Method according to one of claims 1 to 5, characterized in that the intensity of the overpressure maintained during the shaping step is chosen so as to obtain a substantially homogeneous and uniform layer of paper pulp on the active part (3) of the mold (1).  7. Method according to one of claims 1 to 6, characterized in that during the drying step, heat is provided to the protective element (4) by infrared radiation, producing a temperature in particular between 1000 and 2900C.  8. Method according to one of claims 1 to 6, characterized in that, during the drying step, heat is supplied to the protective element (4) by heating gases (7) which are drawn into the through the element due to the vacuum, said hot gases (7) being at a temperature in particular between 100 ° C. and 2900 ° C.  9. Method according to any one of claims 1 to 8, characterized in that after the drying step, the element (4) is released from the mold (1) by injection of compressed air through the mold, or by means of a suction device with suction cup.  lo. Device for implementing the method according to one of claims 1 to 9, comprising a mold, characterized in that said mold (1) is made of a non-hydrophilic porous material.  11. Device according to claim 10, characterized in that said material resists thermal shock and does not oxidize.  12. Device according to one of claims 10 or 11, characterized in that said material is composite.  13. Impact protection element for an object of any shape, said element being made of paper pulp or the like and having with said object a contact face (8) of cellular structure, which ensures point contact between said object and said element when the latter surrounds said object.  14. Protective element according to claim 13 characterized in that said element has the form of a sheet having a honeycomb structure which is, when in use, shaped around said object to be protected.  15. Protective element according to claim 13, characterized in that said element consists of at least two components, the internal wall of each component having a relief substantially opposite to that of the part of the object that the component is intended for. protect, said components being intended to cooperate with each other to provide a central cavity corresponding substantially to the dimensions of the object to be protected, the walls of said cavity having a honeycomb structure.  16. Protective element according to claim 15, characterized in that said components constitute a single piece.  17. Protective element according to one of claims 13 to 16 characterized in that said honeycomb structure consists of a succession of patterns, such as a cone or a hemisphere, possibly truncated.