FR2673886A1 - METHOD AND DEVICE FOR DECORATING A PIECE MADE BY INJECTION AND DECORATED PIECE THUS PRODUCED. - Google Patents

Abstract

Method for the decoration of a part (1) of plastic material made by injection in a mould (2) wherein: a) with the mould (2) being open, there is removably fixed to a male injection portion (4), a self-carrying, thin, deformable decorative element (3) which is applied to the internal face (5) of a female portion (6) of the mould (2); b) the mould (2) is then closed; c) then, the material of the part (1) is injected, the decorative element (3) is displaced and deformed with the flow (12) of injected material in order to detach it from the male portion (4) and to apply it to the internal face (5); d) the mould (2) is opened and the part (1) is ejected.

Description

METHOD AND ARRANGEMENT FOR DECORATING A REALIZED PIECE
BY INJECTION AND DECORATED PART THUS PRODUCED
The invention relates to a method and a device for decorating a part produced by injection and a decorated part thus produced.

 We already know the technique called "in-mold" or decoration in the mold. According to this technique, a part produced by injection is decorated by means of a transfer film supporting the decoration, this film having a detachable film once the part is injected.

The state of the art is also illustrated by the following documents: JP-A-2 171 223, US-A-4 948 654,
JP-A-2 158 315, JP-A-2 059 307, JP-A-6 226 8700 and JP-A-5 614 6717.

 The inventor posed the problem of making a decoration of the "Chinese lacquer" type and found that the classic "in-mold" technique as it was known was not well suited to this problem.

 An object of the invention is therefore to resolve and produce a decoration of the "Chinese lacquer" type on a piece of injected plastic.

To this end, the invention proposes, according to a first aspect, a method of decorating a part based on plastic material produced by injection into a mold.
characterized by the fact that
a) with the mold in the open state, a thin decorative element, in the form of a sheet, self-supporting, deformable perpendicular to its plane, cut locally and removably at a male injection part thereof. so that it can be deformed and applied & flat, without wrinkles on the internal face of a female part of the mold;
b) then the maie and female parts are made to cooperate to bring the mold to the closed state;
c) then, the mold being in the closed state, gradually, the constituent material of the part is injected into the mold, the mold is filled, the decorative element is moved and deformed with the flow of injected material to detach it of the male part and apply it flat generally on the internal face of the female part;
d) then, once the part has been produced, the mold is brought to the open state and the part is ejected from the mold;
so that the decorative element is included on the piece, the junction between them being smooth.

According to other characteristics of this process
- A sheet is used as a decorative element essentially comprising paper forming a support substrate.

 - Use is made of a decorative element having a decorative pattern or appearance towards its external face.

 - A decorative element cut out is used to form a pattern or give a decorative appearance to the piece.

 - The decorative element & the male injection part are sucked in locally and removably by suction, mechanical attachment, magnetic attraction.

 - More particularly, the decorative element is fixed to the male injection part by mechanical attachment by means of at least one lug cooperating with a hole, a slot, a local hollow deformation of the decorative element. This removable attachment is made in the immediate vicinity of an injection zone, which is a median zone of the male part of the mold in correspondence with a median zone of the decorative element, the part of the decorative element in line with the injection area being substantially full.

 - A decorative element originally substantially flat or pre-formed is used.

 - A mold is used with a substantially horizontal opening axis and a decorative element originally extending substantially vertically.

According to a second aspect, the invention provides a device for decorating a plastic-based part produced by injection into a mold
including
- a mold having a male part and a female part which can be moved between a closed state and an open state, thanks to the opening & closing means, the male part being provided with at least one injection conduit opening into the cavity by the two male and female parts;
- And means for injecting the plastic material which can be associated with the injection pipe;
characterized in that the male part comprises means for attaching a decorative element, active when the mold is in the open state and passive when the mold is in the closed state and the injection means are put in action.

According to other characteristics of this device
- The attachment means are located in the immediate vicinity of the injection area.

 - The attachment means are located in the protruding middle area of the male part.

 - The attachment means are mechanical, magnetic, pneumatic.

 - The attachment means are mechanically operated and include at least one lug.

 - The lug has an axial length substantially equal to the thickness of the decorative element used.

 - In the closed state of the mold, the lug is moved away from the internal face of the female part.

 According to a third aspect, the invention provides an injected part, made of plastic material having a decorative element, produced by the method or device previously described.

 Such a part is for example used as packaging, packaging or packaging or packaging element for cosmetics, beauty products, medicines, etc.

The invention will be better understood from the following description with reference to the drawings in which
- Figure 1 is an axial sectional view of a mold of the device according to the invention, in the closed state, the injection of the material of the part being made and the decorative element being in place
- Figure 2 is an axial sectional view along a plane perpendicular to the section plane of Figure 1
- Figure 3 is an enlarged view of part A of Figure 1
- Figures 4 and 5 are two views respectively from above and in perspective of decorated pieces according to the invention
- Figures 6 and 7 are two views comparable to Figure 1 showing the mold In the open state respectively without and with decorative element.

 The invention relates to a method and a device for decorating a plastic part 1 produced by injection into a mold 2.

 The invention also relates to the part 1 provided with a decorative element 3 obtained by the method or the device.

The process includes the following successive steps
a) with the mold 2 in the open state, a thin decorative element 3, leaf-shaped, self-supporting, deformable perpendicular to its plane, cut so that it can be deformed and applied flat, without folds on the internal face 5 of a female part 6 of the mold 2
b) then the male 4 and female 6 parts are made to cooperate in order to bring the mold 2 to the closed state; ;
c) then, the mold 2 being in the closed state, gradually, the constituent material of the part 1 is injected into the mold 2, the mold 2 is filled, the decorative element 3 is moved and deformed with the flow 12 of injected material to detach it from the male part 4 and apply it flat generally on the internal face 5 of the female part 6
d) then, once the part 1 has been produced, the mold 2 is brought to the open state and the part 1 is ejected from the mold 2
The implementation of this process is such that the decorative element 3 is included on the part 1, the junction between them being smooth.

 The process which has just been described implements a device comprising the mold 2 with its male 4 and female 6 parts movable between a closed state and an open state, along an opening-closing axis 7; by means of opening - closing.

 The male part 4 is provided with at least one injection conduit 8 which opens into the cavity 9 formed by the two male and female parts 4 and 7 in the closed state. This cavity 9 defines the shape, the dimension and the limits of the part 1 injected. This conduit 8 opens into the cavity 9 in an injection zone 10.

 The device also comprises means for injecting the plastic material which can be associated with the injection conduit 8 (not shown).

 The device finally comprises the other means usually known from the state of the art for this type of device: heating, cooling, ejection, etc.

 This device is such that the male part 4 comprises hooking means 11 for a decorative element 3, active when the mold 2 is in the open state and passive when the mold 2 is in the closed state and the means injection are implemented.

 The part 1 can be intended to be used as packaging or conditioning or element of packaging or conditioning for cosmetics, beauty products, medicines or the like.

 The injectable plastic and therefore constituting the part 1 is typically that used for this kind of application.

 The part 1 may have a dimension of the order of a centimeter, or even less, or several centimeters, or even of the order of more than ten centimeters. Its thickness can be between around 1 & 5 millimeters.

 Such a part 1 can have radii of curvature of the order of or several tens of centimeters.

 By local attachment of the decorative element 3 to the male part 4 is meant the fact that the decorative element 3 is fixed to the male part 4 in a limited manner and not over its entire surface.

 The decorative element 3 is qualified as thin because its thickness is a fraction of that of the part 1.

For example, this thickness is of the order of 1/10 to 5/10 of a millimeter.

 The decorative element 3 is called a sheet because its thickness is substantially constant and its length dimension (perpendicular to its thickness) generally greater, or even very substantially greater than its thickness.

 The decorative element 3 is qualified as self-supporting because it is able, only maintained by the attachment means 11 and in the absence of external constraints other than its own weight, to maintain itself with a certain held, without sagging.

 However, the decorative element 3 is deformable in particular under the effect of sufficient external stresses such as those resulting from the mechanical forces arising from the application of the flow of material during injection. This deformation is said to be perpendicular to the plane of the decorative element (although the latter is not necessarily plane) in order to signify that it resembles that of a sheet that is folded or rolled.

 It should be noted that it is essentially the flow 12 of injected material coming from the conduit 8 which causes the displacement, at least locally, of the decorative element where it was previously maintained by the means 11. This same flow also causes, in the envisaged embodiment, the detachment of the decorative element 3 from the means 11.

 As mentioned, the decorative element 3 is arranged so that it can be deformed from its original state when it is associated with the male part 4 until it reaches its final state without, in this latter state, exhibiting folds, tears, etc. not desired. To this end, the original state is adapted to the final state to be obtained and to the shape of the internal face S; so that, simultaneously, deformation is possible and that no folds are made.

 The decorative element 3 is a sheet comprising at least one layer of paper towards its internal face, at least one metallization towards its external face.

 The support substrate of the decorative element is essentially of, or based on, paper, nonwoven or equivalent.

 According to a first preferred variant embodiment, the decorative element is substantially devoid of elongation capacity in its own plane.

 According to a second alternative embodiment usable in certain applications for certain aesthetic effects, the decorative element 3 has a certain capacity for elongation in its own plane and is stretched when applied to the internal face 5.

 Furthermore, according to a first variant, the decorative element 3 has a pattern or decorative appearance towards its external face.

 According to a second variant which can be combined with the previous one, the motif or decorative aspect of the element 3 is given by the fact that the element 3 is cut for this purpose.

 This latter variant, more particularly shown in FIG. 4, includes spindles, branches or the like 13 from a central zone 14. Not only does this structure make it possible to give a pattern or decorative appearance but also it ensures the possibility of deformation of the element 3 originally flat then finally curved.

 The external face of the decorative element 3 is understood to mean its visible face opposite to that applied to and included in the part 1 proper.

 According to different possible embodiments, the attachment means 11 are mechanical, magnetic, pneumatic.

 The corresponding fixing of the decorative element 3 to the male injection part 4 is then carried out, respectively, by suction, mechanical attachment, magnetic attraction.

 In the embodiment more particularly considered and shown in the figures, the attachment means 11 are mechanically operated and comprise at least one lug. Such a lug 11 can cooperate with a hole, a sheet, a local hollow deformation 15 of the decorative element 3. Such a hole, slot, deformation 15 can easily be produced in the case of a decorative element 3 cut according to the second variant described above. For example, it is the cutout 15 between the middle zone 14 and the spindles or branches 13.

 Where appropriate, several lugs 11 and several holes, slots, cut-out deformation 15 are provided.

 In the embodiment under consideration, the removable attachment part - male 4 - decorative element is produced in the immediate vicinity of an injection zone 10 and, in line with such a zone 10, the decorative element 3 has a part substantially full on which the injection flow 12 can interfere, which makes it possible to push and move the element 3 by and from this full part. This solid part is, in this case the middle zone 14. It should be noted that even in the case under consideration ot the decorative element 3 is cut out, it is applied to the internal face 5.

 The decorative element is substantially insensitive to injection temperatures.

 According to a first variant (case of FIG. 7), the decorative element 3 is originally substantially flat or planar. According to a second variant (not shown) it is originally pre-formed at the end of the injection.

 In the embodiment considered, the closing opening axis 7 is substantially horizontal and the decorative element 3 originally extends substantially vertically.

 Not only is it the middle zone 14 of the decorative element 3 which is fixed to the male part 4 but it is fixed to the middle zone 16 of this male part 4 which is protruding and distal. The attachment means 11 are located in the immediate vicinity (in particular around) of the injection zone and in the protruding middle zone 16.

 When the two male and female parts 4 and 6 are brought to the closed state, the decorative element 3 is entirely located in the cavity 9 and it is deformed by the internal face 5, although still hooked or associated with the male part 4 by means 11.

 Reference is made to the embodiment considered in which the means 11 comprise one or more lugs.

 Such a lug has an axial length substantially equal to the thickness of the decorative element 3 used.

In the closed state of the mold 2, the lug 11 is spaced from the internal face 5 of the female part 6. The lug 11 extends in a direction substantially parallel to the direction of the injection flow 12.

Claims (31)

 1. Method for decorating a part (1) based on plastic material produced by injection into a mold (2)  characterized by the fact that  a) with the mold (2) in the open state, locally and removably fixed & a male injection part (4) thereof, a thin decorative element (3), in sheet form, self bearing, deformable perpendicular to its plane, cut so as to be able to be deformed and applied & flat, without folds on the internal face (5) of a female part (6) of the mold (2)  b) then the male (4) and female (6) parts are made to cooperate to bring the mold (2) to the closed state  c) then, the mold (2) being in the closed state, gradually, the constituent material of the part (1) is injected into the mold (2), the mold (2) is filled, it is moved and the shape deformed. decorative element (3) with the flow (12) of injected material to detach it from the male part (4) and apply it flat generally on the internal face (5) of the female part (6)  d) then, once the part (1) has been produced, the mold (2) is brought to the open state and the part (1) is ejected from the mold (2);  so that the decorative element (3) is included on the part (1), the junction between them being smooth.  2. Method according to claim 1, characterized in that one uses as a decorative element (3) a sheet comprising at least one layer & base of paper.  3. Method according to claim 1, characterized in that one uses as a decorative element (3) a sheet comprising at least one metallization towards its outer face.  4. Method according to claim 1, characterized in that one uses as decorative element (3) a sheet essentially comprising paper forming a support substrate.  5. Method according to claim 1, characterized in that one uses a decorative element (3) having a thickness of the order of 1/10 & 5/10 of a millimeter, the part (1) having a thickness of the order of l to 5 millimeters.  6. Method according to claim 1, characterized in that one uses a decorative element (3) substantially devoid of elongation capacity in its own plane.  7. Method according to claim 1, characterized in that one uses a decorative element (3) having a certain elongation capacity in its own plane, the decorative element (3) being stretched when applied flat on the internal face (5) of the female part (6).  8. Method according to claim 1, characterized in that one uses a decorative element (3) having a pattern or decorative appearance towards its outer face.  9. Method according to claim 1, characterized in that one uses a decorative element (3) cut to form a pattern or give a decorative appearance on the part (1).  10. Method according to claim 1, characterized in that the decorative element (3) is fixed locally and removably to the male injection part (4) by suction, mechanical attachment, magnetic attraction.  11. Method according to claim 10, characterized in that the decorative element (3) is fixed to the male injection part (4) by mechanical attachment by means of at least one lug (11) cooperating with a hole, a slot, a local hollow deformation (25) of the decorative element (3).  12. Method according to claim 1, characterized in that the decorative element (3) is fixed locally and removably to the male injection part (4) in the immediate vicinity of an injection zone ( 10).  13. Method according to claim 1, characterized in that one uses a decorative element (3) having a substantially full part in line with an injection zone (10).  14. Method according to claim 1, characterized in that one uses a decorative element (3) which is substantially insensitive to injection temperatures.  15. The method of claim 1, characterized in that one uses a decorative element (3) originally substantially flat.  16. Method according to claim 1, characterized in that one uses a decorative element (3) originally pre-formed.  17. The method of claim 1, characterized in that one implements a mold (2) with an opening axis (7) substantially horizontal and a decorative element (3) extending originally substantially vertically.  18. Method according to claim 1, characterized in that the decorative element (3) is fixed by its central region (14) to a male part (4).  19. Method according to claim 1, characterized in that the decorative element (3) is fixed to the projecting middle zone (16) of the male part (4).  20. Method according to claim 1, characterized in that when the two male (4) and female (6) parts are brought to the closed state, the decorative element (3) is entirely located in the cavity (9 ) of the mold (2).  21. Method according to claim 20, characterized in that when the two male (4) and female (6) parts are brought to the closed state, the decorative element (3) is deformed by the internal face (5) of the mold cavity (9) (2).  22. Device for decorating a part (1) based on plastic material produced by injection into a mold (2)  including  - a mold (2) having a male part ((4) and a female part (6) movable between a closed state and an open state, by means of opening - closing means, the male part (4) being provided with 'at least one injection conduit (8) opening into the cavity (9) formed by the two male (4) and female (6) parts;  - and means for injecting the plastic material which can be associated with the injection pipe (8)  characterized in that the male part (4) comprises means for hooking (11) a decorative element (3), active when the mold (2) is in the open state and passive when the mold (2) is in the closed state and the injection means are implemented.  23. Device according to claim 22, characterized in that the attachment means (11) are located in the immediate vicinity of the injection zone (10).  24. Device according to any one of claims 22, 23, characterized in that the attachment means (11) are located in the protruding median zone (16) of the male part (4).  25. Device according to any one of claims 22 & 24, characterized in that the attachment means (11) are & mechanical, magnetic, pneumatic operation.  26. Device according to any one of claims 22 to 25, characterized in that the attachment means (11) are mechanically operated and comprise at least one lug.  27. Device according to claim 26, characterized in that the lug (11) has an axial length substantially equal to the thickness of the decorative element (3) used.  28. Device according to any one of claims 26, 27, characterized in that in the closed state of the mold (2), the lug (11) is spaced from the internal face (5) of the female part (6).  29. Device according to any one of claims 26 to 28, characterized in that the lug (11) extends in a direction substantially parallel to the direction of the injection flow (12).  30. Device according to any one of claims 22 to 29, characterized in that the mold (2) has an opening - closing axis (7) substantially horizontal.  31. Injected and decorated part based on plastic material characterized in that it is obtained by the method according to any one of claims 1 to 21.