JPH07290501A - Heating device, device and method for decorating simultaneously with injection molding - Google Patents

Abstract

PURPOSE:To provide a heating device for manufacturing a decorated molded piece without strains in characters, a device for decorating simultaneously with injection molding equipped with the heating device, and a method for decorating simultaneously with injection molding using the above-mentioned devices. CONSTITUTION:A heating device 4 capable of controlling temperature distribution of a heating platen face to a pattern corresponding to a shape of a molded piece and/or a design of a decorating sheet 2. Concretely, the heating platen face 41 of the heating device has heating control materials 5 and 5a of desired shapes stuck thereto as a heating face or the heating device is made of an aggregation of two or more of part heating bodies which can control the temperature of the heating face of the heating platen face independently, so as to heat the heating face in a state that it is not in contact with the decorating sheet. Decorating is performed by a device for decorating simultaneously with injection molding equipped with such a heating device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simultaneous injection molding and decoration method. More specifically, the present invention relates to a simultaneous injection molding decoration method for reducing the distortion of a pattern to be decorated, a heating device used therefor, and an injection molding simultaneous decoration device.

[0002]

2. Description of the Related Art Conventionally, injection molding simultaneous decorating methods in which a pattern or the like is formed on the outer surface of a molded article by laminating or transferring the sheet simultaneously with the molding of the molded article have been performed in various modes. In Japanese Examined Patent Publication No. 50-19132, a decorative sheet made of a thermoplastic resin is heated and softened by a heater using a female mold provided with a ventilation hole for vacuum forming, vacuum-molded, and then the mold is clamped. A method of injecting a molten resin into a mold to laminate and integrate a decorative sheet on the outer surface of a molded article is disclosed. As described above, the simultaneous injection molding and decoration method is a method in which vacuum molding and injection molding are combined, and a complicated curved surface shape can be patterned. Further, in Japanese Examined Patent Publication No. 63-6339 and Japanese Examined Patent Publication No. 4-42172, after heating and softening a decorative sheet using a flat plate-shaped heating plate, the decorative sheet is vacuum-formed by a female mold. Is disclosed. With such a configuration, it is possible to efficiently and uniformly heat and soften the decorative sheet prior to vacuum forming. Furthermore, JP-A-5
In Japanese Patent Laid-Open No. 96568/1994, in order to heat the decorative sheet with a temperature distribution corresponding to the uneven shape of the molded product, Japanese Patent Publication No.
No. 42172 gazette, a sheet having air permeability and different thermal conductivity from the heating plate is used as a heat insulating material on the heating surface of a contact heating type heating plate having ventilation holes on the surface, and a molded article shape is obtained. The invention of adhering in a pattern corresponding to is disclosed. By such a device, the heating temperature of the portion of the decorative sheet having a large amount of displacement during vacuum forming is relatively lower than that of the portion having a small amount of displacement, so that the displacement (strain) during vacuum forming of the decorative sheet can be reduced. It is said that it is possible to make it as uniform as possible within the range where the condition of molding into a mold shape is satisfied.

[0003]

However, in the conventional simultaneous injection-molding decoration methods such as those described above, the outer surface of the molded product to be decorated has a large unevenness, that is, the molded product with a deep drawing is decorated. Even if the sheet can be molded,
Depending on the pattern to be decorated, the distortion was too large and desired decoration could not be performed. In particular, the decorative sheet having characters and figures is likely to be distorted, and the decorative sheet for imparting conductivity or providing the metal vapor deposition layer has a reduced performance, or cracks in the metal vapor deposition layer are noticeable. The large elongation that the resin undergoes during molding causes a certain limit to the application of the simultaneous injection-molding decoration method. If such a problem is formed by lowering the heating temperature of the decorative sheet, elongation is suppressed and distortion and the like are reduced, but on the other hand, since the formability of the entire decorative sheet is reduced, the unevenness of the molded product is sufficiently reduced. There is a problem that the decorative sheet cannot be molded following the shape and the decorative sheet is broken. Therefore, the shape of the molded product that can be applied is extremely limited to the molded product having less unevenness, which is not practical.

By the way, in the case of forming a decorative sheet, the expansion in the deep part of the drawing is large and the expansion in the shallow part of the drawing is small, as in the ordinary vacuum forming method. However, as long as the entire decorative sheet is heated uniformly, the heating temperature is set based on the deep portion of the diaphragm, and the extension of the shallow portion of the diaphragm depends on the heating temperature. Even the shallow part of the diaphragm may be unintentionally stretched. That is, if an attempt is made to form a decorative sheet that has been softened to a uniform temperature over the entire surface into a female concave-convex shape, the amount of displacement that is greater than the amount originally required for forming is concentrated in the portion where the amount of sheet displacement is large. In particular, the part where you want to reduce the distortion of the decorative sheet with characters etc. is not necessarily the part where you want to deepen the diaphragm and increase the expansion,
There has been a long-felt need for a method capable of forming a portion to be stretched and a portion not to be stretched at different elongations for molding in order to obtain a more excellent decorative molded product. Also in the above invention,
Although it is possible to heat the decorative sheet to the desired temperature distribution that corresponds to the shape of the molded product, since the decorative sheet comes into direct contact with the heating surface, the boundary line between the areas with different temperatures on the heating surface becomes the decorative sheet. Also appears as discontinuous steps in temperature. further,
If there is a step in the thickness of the heat insulating material compared to the surroundings, the step becomes embossed as unevenness of the decorative sheet. As a result, there is a problem that traces of the heat insulating material portion remain on the vacuum-formed decorative sheet. Furthermore, since the decorative sheet comes into direct contact with the heat insulating material, if the releasability between the heat insulating material and the decorative sheet is not sufficient, the decorative sheet is partially pulled by the heating surface during vacuum forming, and There is also a problem that the decorative sheet is broken when it has a trace of the shape or is severe. Therefore, in the present invention, the above-mentioned problem is solved, and the heating of the decorative sheet is not uniformly performed over the entire surface, but it is unevenly corresponding to the shape or pattern of the molded product, that is, the desired heating temperature distribution is easily realized. It is an object of the present invention to provide a heating device capable of molding a decorative sheet, an injection-molding simultaneous decorating device including the heating device, and an injection-molding simultaneous decorating method using the heating device.

[0005]

Therefore, in the heating device of the present invention, a decorating sheet is placed between a pair of dies including a die A having a vent and a die B having an injection hole to decorate. After heating and softening with a heating device facing the sheet, the decorative sheet is made to adhere to the cavity surface of the mold A by air pressure by degassing from the ventilation hole, and then the mold is clamped to melt the molten resin into the mold. A heating device used in an injection-molding simultaneous decorating method of injecting into a product and decorating a molded article with a decorating sheet, wherein the heating plate surface of the heating device has a thermal conductivity and / or an emissivity as a heating plate surface. A different heating adjustment material is partially stuck, and the heating sheet is heated by arranging a heating device at a position where the heating plate surface and the heating surface formed by the heating adjustment material are not in contact with the decoration sheet. To determine the heating temperature distribution of the decorative sheet, Or it is an heating apparatus, wherein being configured to be controlled in accordance with the pattern of the decorative sheet. Alternatively, the heating plate of the heating device is composed of an assembly of at least two partial heating bodies capable of individually controlling the temperature, and by controlling the heating temperature of each partial heating body individually, the shape of the molded product can be obtained. And / or a heating device characterized by being configured so that the heating temperature distribution of the decorative sheet corresponding to the pattern of the decorative sheet can be controlled.

Further, the injection-molding simultaneous decorating device of the present invention is an injection-molding simultaneous decorating device characterized by including at least the above heating device. In addition, the injection-molding simultaneous decorating method of the present invention uses the injection-molding simultaneous decorating apparatus as described above to remove a pair of molds including a mold A having a vent hole and a mold B having an injection hole. The step of arranging the decorative sheet between them, the step of heating and softening the decorative sheet at the position where the heating surface of the heating device is not in contact with the decorative sheet, and the decorative sheet is applied to the cavity surface of the mold A by air pressure. It is a simultaneous injection-molding and decorating method, which comprises a step of closely adhering and molding, a step of mold clamping and injecting a molten resin into a mold, a step of mold opening to obtain a molded article decorated with a decorative sheet. By controlling the heating temperature of the decorative sheet by the heating device to be non-uniform, the low temperature heating is applied to the portion of which the elongation should be reduced corresponding to the shape of the molded product and / or the pattern of the decorative sheet. Characterized by controlling the heating temperature distribution of the sheet It is an injection-mold decorating method.

[0007]

According to the heating device of the present invention, a heating adjusting material having a thermal conductivity and / or an emissivity different from that of the heating surface is partially adhered to the heating surface of the heating plate, and the heating surface and the heating adjustment material are also attached. In order to heat the decorative sheet by arranging the heating device at a position where the heating surface formed by the non-contact with the decorative sheet, the decorative sheet is made non-uniform so as to have a desired heating temperature distribution. Can be heated. At that time, the decorative sheet is not in direct contact with the heating surface, but is heated by the infrared rays radiated from the heating surface and the heating atmosphere between the decorative sheet and the heating surface. The line is inconspicuous. Further, since the heating adjusting material and the heating plate are not in contact with each other, partial mold release from the heating surface during vacuum forming does not occur. Furthermore, since the heating adjustment material can be easily attached and peeled in a desired shape, the desired heating temperature distribution of the decorative sheet can be easily realized according to the shape of the molded product and / or the pattern of the decorative sheet. it can. Further, in the structure in which the heating device is composed of the assembly of the partial heating bodies whose temperature can be controlled independently, the desired heating temperature distribution can be realized only by controlling the temperature of each portion. An injection-molding simultaneous decorating device equipped with such a heating device or an injection-molding simultaneous decorating method using such a heating device is used to perform decorating with a pattern or the like that partially suppresses elongation and has less distortion. Be seen.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heating device, an injection-molding simultaneous decorating device, and an injection-molding simultaneous decorating method according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the simultaneous injection molding and decorating device of the present invention. The injection-molding simultaneous decorating device of the present invention is characterized by a heating device, and the other parts are not particularly different from the conventionally known injection-molding simultaneous decorating device. Referring to FIG. 1, a mold A1 having a vent hole.
1 and the decorative sheet 2 between the mold B12 having an injection hole
Are continuously supplied from the supply roll 31 via the feed roll 32, and the decorative sheet 2 after molding is wound up by the winding roll 33. The decorative sheet 2 is provided with positioning sensor marks (line segments, straight lines, crosshairs, etc.) (not shown) for positioning, and the positioning sheet 34 such as a photoelectric tube detects this sensor mark to detect the decorative sheet 2. It is arranged at a desired position with respect to the mold A11. Although not shown, the decorative sheet is aligned by the sensor mark and the positioning sensor not only in the direction parallel to the feeding direction but also in the direction perpendicular to the feeding direction. Of course, if it is not necessary to precisely align the decorative pattern of the decorative sheet with the concave-convex shape of the mold, the positioning sensor and the sensor mark are unnecessary.

In the figure, the mold A11 is generally called a female mold because it has a concave cavity surface, and the mold B12 is called a male mold because it has a convex cavity surface.
However, it is not always necessary to have a cavity surface in which the mold A is concave and the mold B is convex, and the reverse case is also possible. The point is that the mold A has at least a vent hole for forming the decorative sheet, and the mold B has at least an injection hole for introducing the molten resin into the mold.

The heating apparatus of the present invention equipped in the injection-molding simultaneous decorating apparatus has two kinds of modes. The first mode is to dispose the heating adjusting material partially between the heating plate surface and the decorating sheet. The configuration is as described above, and FIG. 1 corresponds to this. In the second mode, the hot platen surface itself is provided with means for realizing a desired temperature distribution, and the hot platen surface is composed of at least two or more small parts, and each of these parts can be independently temperature controlled. This is a configuration and will be described later.

In FIG. 1, the heating plate surface 41 facing the decorative sheet is shown.
The heating adjusting material 5 is attached to a part of the upper side to arrange the heating adjusting material 5 between the decorative sheet and the heating surface. In FIG. Material 5
A smaller heating adjustment material 5a is attached. With such a configuration, the heating surface of the heating device shown in FIG.
And the exposed surfaces of the heating control materials 5 and 5a. As a result, the heating temperature of the decorative sheet in the portion facing the heating adjusting material 5 and the heating adjusting material 5a is controlled to be lower than that in the other portion, and the portion where the heating adjusting materials 5 and 5a are laminated is controlled to be lower. To be done. However, when it is sufficient to pattern the temperature distribution of the heating surface in two steps, high and low, the heating adjusting material 5 of the same material may be used by stacking only one sheet.

In order to heat the decorative sheet by using the above heating device, the decorative sheet is clamped by the mold A.
The heating device is fixed to the heating device, and the heating device is arranged at a position where the heating surface of the heating device faces the decorating sheet and is not in contact with the decorating sheet. In order to arrange the heating device at a position where its heating surface is not in contact with the decorative sheet, the movable supporting member 42 supporting the heating device in FIG. 1 has sufficient rigidity in consideration of the weight of the heating device and the like. If so, it is possible to dispose the decorating sheet and the heating device at a position separated by a predetermined distance only by disposing the heating device at a predetermined facing position with respect to the decorating sheet by the movable support.

Thereafter, the cavity space of the mold A is degassed by a vent hole 13 provided in the mold A and connected to a vacuum source (not shown), and the decorative sheet 2 is formed by air pressure.
By making the mold adhere to the cavity surface of mold A,
The decorative sheet 2 is formed. At this time, if necessary,
Die A for decorative sheet by using compressed air blowing from the hot platen side
Molding may be performed.

After forming the decorative sheet, the mold is clamped and the molten resin is injected into the mold. The heating device 4 is a piston
When the mold is clamped by the movable supporting member 42 such as a cylinder, it moves upward in FIG. 1 and retracts from between the molds. Thus, a desired decorative molded product can be obtained by the method using the simultaneous injection-molding decorative device equipped with the heating device of the present invention.

In the heating device of the present invention, a heat source such as an electric heater is embedded in a flat plate-shaped heating plate, and a blowout hole 46 for compressed air is further provided on the heating surface 41 of the heating plate 45 as illustrated in FIG. It may be provided (even in the case of non-contact heating, compressed air may be used for later forming of the decorative sheet). In the heating device of FIG. 2, the heating adjustment material 5 is attached to a part of the heating platen surface 41 of the heating platen 45. The heating plate 45 has an electric heater 47 inside, and a heat insulating member 51 is provided on the back surface of the heating plate 45 to prevent wasteful heat dissipation to the back surface. An outlet 46 is provided on the surface of the heating plate, and the outlet 4
Reference numeral 6 is connected to an external compressed air source via a valve. The heating plate 45 is connected to a supporting member 49 by a solenoid 48, and the supporting member 49 is fixed to a movable supporting member 42 composed of a piston, a cylinder and the like.

In the heating device illustrated in FIG. 2, first, the heating device is moved by the support 42 to a position corresponding to the decorative sheet to be heated, and the solenoid 48 moves the heating plate to the decorative sheet side. , The decorative sheet is sandwiched between the peripheral wall 6 and the parting surface of the mold A11, and fixedly held,
The decorative sheet is heated while keeping the decorative sheet and the heating surface at a predetermined distance. At this time, the height of the peripheral wall 6 with respect to the surface of the heating plate functions to keep the distance between the surface of the heating plate and the decorative sheet constant. When the heating device is provided with the mechanism for fixing and holding the decorative sheet by the peripheral wall 6 as described above, the clamp 35 fixes and holds the decorative sheet to the mold as in the case of the heating device shown in FIG. The operation can be omitted.
Next, when the decorative sheet is softened by heating and vacuum-formed, the decorative sheet can be vacuum-pressure formed by both the vacuum on the mold A side and the pressure on the heating device side by the compressed air from the blowout holes. It was done. Of course, if only vacuum suction from the mold A is sufficient, compressed air from the heating device side may be omitted. In that case, the blow-out hole 46 is unnecessary.

In addition, a so-called planar heating element made of resin or metal may be used as the heating plate. Such a sheet heating element usually does not have a vent hole or the like. However, in the case of a planar heating element, it has the advantage of being thin and space-saving, and can be easily deformed and curved, so the heating surface is not necessarily a flat surface and may be used on a curved surface. In some cases, a heating adjusting material that follows the curved surface is used. Further, since it is lightweight, it is possible to hold only one end of the hot platen far from the portion supported by the movable support by only the movable support as shown in FIG. The heating surface of the heating device can be located at a predetermined distance.

As the heating adjusting material to be adhered to the surface of the heating plate as described above, a thin plate having a thermal conductivity K and / or an emissivity ε different from that of the surface material forming the heating surface of the heating plate is cut into a desired shape. Use the original one. For example, when the hot platen surface is iron (pure iron or ordinary carbon steel), ceramics, mica, steres steel, steatite, etc., or a resin plate containing fine powder of such a substance, or a flexible rubber-like sheet, etc. Can be used. When attaching to a curved surface,
A rubber-like sheet such as silicone rubber is suitable. Further, a resin sheet may be used as long as it has heat resistance that can withstand a heating temperature for a desired use time. In this case, if a resin foam having a network structure or a structure having internal voids such as nonwoven fabric is used, the internal air has a heat insulating effect. Alternatively, as a method of adjusting the emissivity, the surface roughness of the heating surface may be changed into a pattern, or white or black may be applied. Further, when the heating adjustment material is stuck, if the heating adjustment material 5a is laminated on the heating adjustment material 5 as shown in FIG. It can be controlled in a complicated way. By the way, according to the Stefan-Boltzmann radiation law regarding temperature radiation, if the absolute temperature of the heating surface is T, the Stefan-Boltzmann constant is σ, and the emissivity is ε, the unit surface area per unit surface area per unit time is Radiant energy E radiated
Is represented by E = εσT ⁴ . Therefore, in order to make the radiant energy E of the heating surface into a pattern, at least either the emissivity ε or the temperature T may be made into a pattern.
In order to pattern the temperature, the thermal conductivity K of the heating surface is patterned. The heating surface facing the portion where the decorative sheet should be relatively high in temperature has a higher emissivity (closer to 1) or a higher thermal conductivity.

To attach the heating adjusting material to the surface of the heating plate, it is fixed by using a tap hole or the like provided on the heating plate in advance,
It can be mechanically fixed by screwing or the like, or a heat resistant adhesive such as an epoxy / phenolic adhesive or an alkyd adhesive can be used. The heating conditioner is not permanently fixed to the heating surface, but the shape and the amount of heat insulation of the heating conditioner can be adjusted appropriately by changing the heating conditioner according to the shape of the molded product and the pattern to be decorated. It is preferable. For this reason, it is preferable that the heating adjustment material is attached to the heating plate with bolts or screws so that it can be peeled off from the heating surface.

When the heating adjusting material is attached to the heating platen of the heating device, if the heating platen and the heating surface formed by the heating adjusting member are closely adhered to the decorative sheet and heated, a step due to the heating adjusting member is generated. Although it remains on the decorative sheet, there is no such danger if the non-contact heating method by radiant heating is used with a certain distance from the decorative sheet as in the present invention. The temperature distribution of the decorative sheet in a form in which the contour of the pattern of the radiant energy E on the surface of the hot plate is blurred due to the spread due to the radiation of thermal radiation and the heating atmosphere in the enclosed space formed by the decorative sheet, the peripheral wall and the heating surface. Because it will be.

As a method of creating a temperature distribution on the surface of the decorative sheet while keeping the radiant energy E of the heating surface constant,
The heating adjustment material may be located between the decorative sheet and the hot platen surface of the heating device. Therefore, other than the method of directly adhering it to the hot platen surface, for example, it may be located between the decorative sheet and the hot platen surface. The heat adjusting member may be detachably fixed to a net or a blind made of a heat-resistant material, such as a metal, which is arranged at least larger than the hot platen surface, by fixing means such as bolts and nuts to form a heat ray shielding plate. . The heat-shielding plate is arranged so as not to contact at least the decorative sheet.

As described above, the amount of radiant heat from the heating surface of the heating device is partially blocked by the heat ray shielding material,
A desired heating temperature distribution of the decorative sheet can be realized depending on the shape, heat insulating property and thickness of the heat ray shielding material.

Next, a second mode of the heating device will be described. FIG. 4 is a sectional view of the embodiment, and FIG. 5 is a front view of the same. In this case, the heating device should be at least 2
It is provided with an assembly of one or more partial heating bodies 43. Each partial heating body 43 is composed of an electric heater or the like, and the heating temperature is independently controlled by a temperature control device (not shown). The partial heating bodies 43 are preferably arranged on the support base 44 so that the respective heating plate surfaces 41 are closely adjacent to each other. This is because, if they are separated, the heating temperature is likely to drop at the boundary. Similar to the first aspect, the surface of the partial heating body 43 is fixedly held by the peripheral wall 6 of the peripheral edge portion and is heated in a non-contact manner by separating the decoration sheet from the partial heating body 43 by a certain distance. It is possible to prevent the trace of the boundary line of the partial heating body 43 which occurs when the decorative sheet is closely heated. Although not shown, the support 44 has a wiring space such as an electric wiring to each partial heating body 43. Further, the support base 44 is connected to the movable support tool 42, and has a structure to be retracted from between the molds when the heating device 4 is not needed during mold clamping. In order to control the temperature of each partial heating body 43 to a desired temperature, a temperature sensor such as a thermocouple may be installed in the partial heating body 43 and feedback control may be performed using the sensor output. The output of the electric heater can be adjusted by on-off control by bimetal, transformer such as sliderac, S
It may be performed by a known electric heating output control means such as stepless control by a thyristor such as CR, triac, GTO. It is preferable that the partial heating body 43 be divided into 48 divisions of vertical 8 × horizontal 6 as shown in FIG. In the figure, "H" or "L" is applied to the partial heating element 43.
The "represented" means that the temperature is controlled to a high temperature and the temperature is controlled to a low temperature.

An injection molding simultaneous decorating device equipped with the above heating device of the present invention is, for example, as shown in FIG.
There is an injection-molding simultaneous decorating device provided with a heating means by the heating device of the present invention and a decorating sheet supplying means for supplying the decorating sheet with continuous alignment. In this case,
Although not shown in the figure, a control means according to a known method using a microcomputer or the like for controlling the linking operation of the heating means and the decorative sheet supply means is usually provided. Further, as a matter of course, the simultaneous injection-molding decoration also requires an injection-molding die or the like provided with a ventilation hole for molding the decorative sheet due to a difference in air pressure. However, the simultaneous injection-molding decorating device of the present invention is characterized by the heating device, and therefore the decorating sheet supply means as illustrated in FIG. 1 may be omitted. In such a case, the decorative sheet may be placed at a predetermined position by hand, for example, one by one in a single sheet, and even if the apparatus adopts such a method, the heating temperature distribution of the present invention is controlled. The advantages of doing so are not impaired. When the decorative sheet is supplied by hand, the decorative sheet may be arranged at a predetermined position and fixed by the clamp 35 or the peripheral wall 6, for example.
It is preferable that the clamp 35 and the decorative sheet fixing means for the peripheral wall 6 are provided as a device, but the purpose can be achieved even with a temporary fixing adhesive tape. It should be noted that productivity may not always be a problem, although there may be a difficulty in productivity when the decorative sheet is supplied by hand. For example, if the size of the decorative sheet is very large, and it is thick and flexible at room temperature, such a single-wafer supply is sufficiently meaningful in addition to the continuous supply in the roll form. . Of course, in such a case, it is needless to say that a means for mechanically intermittently supplying the sheet may be provided instead of the continuous feeding means in a roll shape as illustrated in FIG. As described above, the advantage of controlling the heating temperature distribution of the present invention is not impaired even if the supply means for the decorative sheet, the fixing means, and the like are not provided, and the injection-molding simultaneous decoration of the present invention is performed. It is not an essential part of the device. The simultaneous injection-molding decorating device of the present invention may be any device provided with a heating device capable of realizing at least the above heating temperature distribution, and other means may be selected from known means at any time depending on the application. It is a thing.

The heating temperature and the heating temperature distribution of the decorative sheet heated by the heating apparatus of the present invention and the simultaneous injection-molding decorative apparatus are determined by the material of the decorative sheet used, the uneven shape of the molded product, and It depends on the resin used in the injection molding and is appropriately selected. For example, when polyethylene terephthalate is used as the sheet base material of the decorative sheet, if the shape of the molded product is relatively flat and close to a flat surface, no heating device is required. However, if unevenness becomes large and the drawing becomes deeper in the shape of the molded product, it is difficult to mold without heating,
The decorative sheet is heated in the range of 80 to 180 ° C., for example, about 120 ° C. according to the unevenness. Furthermore, if the unevenness of the molded product is larger, the molding suitability of polyethylene terephthalate itself makes molding difficult even if the heating temperature is raised. As described above, when considering only the moldability, the heating condition of the decorative sheet is from the condition without heating,
It will be appropriately selected from the range up to the maximum heating temperature determined by the sheet base material used. When the method for suppressing the elongation of the decorative sheet intended in the present invention is applied to this, the portion where the elongation is to be suppressed is at a lower temperature than the other, and therefore, the temperature range that this part can take is only the moldability. Over the entire temperature range considering. In particular, in the case of the above-mentioned polyethylene terephthalate, if the degree of suppressing the elongation is large, preferable results can be obtained by controlling the temperature distribution so that the heating temperature at this portion is lower than 80 ° C. Needless to say, this heating temperature varies depending on the base sheet.

Next, the correspondence between the portion where the heating temperature should be lowered, the shape of the molded product, and the pattern of the decorative sheet will be described. First, in the case of controlling the heating temperature distribution of the decorative sheet in accordance with the pattern of the decorative sheet, only the character portion provided on the convex plane as shown in FIG. Then, the heating temperature is suppressed. In addition, in the figure, (a) is a perspective view of the molded product, and (b) is a longitudinal section obtained by cutting the molded product along the AA ′ plane. In the case of FIG. 6 as well, in the case of a molded product close to a flat plate, if the character portion is on the convex plane, the entire decorative sheet has a small elongation and is substantially uniform, and it is not necessary to suppress the heating temperature of the character portion. However, in practice, since the decorative sheet is a molded product having rising steps around it, the decorative sheet is particularly stretched at the four corners, so that the elongation becomes uneven. Therefore,
The shape corresponding to the character part suppresses the heating temperature and reduces the elongation to make it uniform. However, there is no pattern similar to the shape (pattern) of the part that suppresses the heating temperature in the molded product shape,
Correspondence with the shape of the molded product is rare. Therefore, the shape of the heating temperature distribution corresponds to the pattern of the decorative sheet and does not correspond to the shape of the molded product.

Next, as an example in which the heating temperature distribution corresponds to the shape of the molded product, there is a case where the molded product is provided with a uniform pattern from a decorative sheet having a uniform stone pattern such as granite. The elongation of each part of the decorative sheet corresponds to the shape of the molded product.
However, as it is, the uniform pattern of the decorative sheet becomes inhomogeneous corresponding to the elongation. Therefore, the portion with a large elongation is heated at a low temperature to homogenize the elongation as a whole. In this case, since the decorative sheet has a uniform pattern, even if the decorative sheet has a minute pattern, there is no pattern as a whole. Therefore, in order to reproduce a uniform pattern of the decorative sheet, the heating temperature distribution is related, but the heating temperature distribution does not essentially correspond to the pattern of the decorative sheet pattern. The heating temperature distribution corresponds to the shape of the molded product.

Next, as an example in which the heating temperature distribution corresponds to both the shape of the molded product and the pattern of the decorative sheet, for example,
Examples of the above combinations are given. It is a decorative sheet in which characters are provided on a uniform stone pattern as a base.
When decorating this on a molded product with large unevenness, the character part should be kept at a relatively low temperature, and the other parts should be flattened at a relatively low temperature in order to make the sheet deformation uniform over the entire surface. Bring the near part to a relatively high temperature. In any of the above cases, it is difficult to reproduce from a completely ideal decorative sheet, but in practice, by heating the decorative sheet with a heating device capable of controlling the heating temperature distribution of the present invention, a remarkable reproduction is possible. The improvement of sex is realized.

The decorative sheet that can be used in the simultaneous injection-molding and decorating method of the present invention can be any conventionally known one, and is not particularly limited. The decorative sheet can be roughly classified into a laminated type and a transfer type. The laminated type is a method in which a decorative sheet is laminated and integrated with a molded product, and the transfer type is a decorative sheet that is composed of at least a releasable sheet base material and a transfer layer having a pattern or a function. Only one is laminated on the molded product. Further, the term "decoration" in the present invention includes providing a hard coating or a functional layer such as conductivity in addition to simply providing a visible pattern such as a picture, a character, or a figure to a molded article. To do.

The present invention will be described in detail below with reference to specific examples by the simultaneous injection molding and decorating method.

<Examples> * Preparation of decorative sheet A biaxially stretched polyethylene terephthalate film having a thickness of 38 μm was used as a sheet substrate, and a transfer layer was formed on the biaxially oriented polyethylene terephthalate film.
Peeling layer coating amount 2 g / m ² (acrylic resin), picture layer - total coating amount 3 g / m ² in the 4-color (acrylic resin + vinyl chloride mixed system of vinyl acetate copolymer), adhesive layer (acrylonitrile -The styrene copolymer system was sequentially formed by gravure printing so that the coating amount was 2 g / m ^2, and a transfer type decorative sheet to be used was obtained. Printed.

* Molded product and heating device Seed heater embedded thermal conductivity K = 52 W / (m ·
K), an injection-molding simultaneous decorating device equipped with a heating device of the form shown in FIG. 2 in which a metal plate made of iron having an emissivity ε = 0.95 is used as a heating plate. The mold used was for molding parts around the gearbox of an automobile. FIG. 6 shows a perspective view of the shape of the molded product used in the examples. The characters are approximately 10 mm in size. On the other hand, on the hot platen surface of the heating device, the heat conductivity K = 0.5 W / (m · K) and emissivity ε = 0.
Seventy-five mica was adhered with an alkyd adhesive.
FIG. 3 is a view of the heating surface viewed from the front surface (= decorative sheet side).

* Simultaneous decoration by injection molding First, the sensor mark is read by the positioning sensor using the decorative sheet feeding device of the apparatus shown in FIG. 1, and the roll-shaped decorative sheet is fed between the feeding roll and the male / female mold. It was supplied at a predetermined pitch and stopped at a desired position. The decorative sheet is arranged so that the adhesive layer faces the male mold having the injection holes.
The temperature of the heating device was set to 260 ° C. on the surface of the hot platen where the heating adjusting material was not attached. In addition, the adhered portion of the heat adjusting material was in equilibrium at 190 ° C. The heating device under these conditions was pressed against the female mold (corresponding to the mold A), the decorative sheet was sandwiched between the female mold and the peripheral wall of the heating plate, and fixedly held, and the decorative sheet was separated from the heating surface of the heating plate by 10 mm. The decorative sheet was placed at a distance and heated without contact for 10 seconds. The decorative sheet is 70 ° C in the part corresponding to the heating adjustment material (part c in Fig. 9) and 100 around it.
C (part b in FIG. 9), 120 ° C. in other parts (part a in FIG. 9)
Department). Part b did not reach 70 ° C due to heat from the surroundings, but reached 100 ° C between 70 ° C and 120 ° C. It should be noted that although FIG. 9 shows typical temperatures, the boundaries of the respective temperatures continuously and smoothly change. Then, the decorative sheet was vacuum formed using a female mold. The decorative sheet was almost along the female cavity surface, but some corners could not be completely formed. After that, retract the heating device from between the molds, clamp the mold,
Injection-molding was performed, the sheet base material of the decorative sheet was peeled from the obtained molded product, and a decorative molded product having the transfer layer transferred was obtained.

In the decorative molded product, the corner portions are also sufficiently stretched by the heat and pressure of the injection resin, the character portion and the surrounding decorative sheet are not stretched so much, and the character is not distorted as shown in FIG. It was something.

Comparative Example 1 In Example 1, except that the heating adjusting material was not attached to the hot platen surface of the heating device, and the heating platen surface (heating surface) was heated uniformly to 260 ° C. A decorative molded product was manufactured in the same manner as in Example 1. At this time, the entire surface of the decorative sheet was heated to 120 ° C. In the obtained decorative molded product, the characters were also greatly stretched, and the characters were distorted as shown in FIG.

<Comparative Example 2> In Example 1, except that heating of the decorative sheet and vacuum formation by the female mold were omitted.
A decorated molded product was produced in the same manner as in Example 1. In the obtained decorative molded product, the decorative sheet was pressed and broken by the mold at the time of mold clamping, and a satisfactory result was not obtained.

[0037]

Since the heating device of the present invention is constructed as described above, the decorative sheet can be heated to a desired heating temperature distribution and molded. As a result, for example, if the decorative sheet has characters and figures, the heating temperature of the portion corresponding to them can be heated to a lower level. As a result, the decorative molded product obtained by the simultaneous injection-molding decorating device equipped with the heating device has a remarkable effect that characters and figures without distortion can be obtained. Further, even in the case of forming a functional layer in which the performance is not obtained when the layer is excessively stretched such as a conductive layer or a metal vapor deposition layer into a molded article by a decorative sheet, it is possible to suppress the elongation of a desired portion. Therefore, a molded product maintaining excellent functionality can be obtained. Alternatively, when decorating a pattern with less distortion on the entire surface of a molded product, by setting the heating temperature at the corners of the unevenness to a low temperature, the pattern is evenly stretched from the uneven part to the flat part. It is possible to decorate, and there is a remarkable effect that the strain is not locally increased due to the concentration of the elongation at the corners.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a heating device and a simultaneous injection-molding decorating device of the present invention.

FIG. 2 is a front view of an embodiment of the heating device of the present invention.

FIG. 3 is a front view of the heating device of FIG.

FIG. 4 is a sectional view of another embodiment of the heating device of the present invention.

5 is a front view of the heating device of FIG.

FIG. 6 An example of the shape of a decorative molded product

FIG. 7 is a view showing a decorative molded product by a conventional heating device.

FIG. 8 is a view showing a decorative molded product by the heating device of the present invention.

FIG. 9 is a diagram showing an example of a decorative sheet and a heating temperature distribution corresponding to the decorative sheet.

[Explanation of symbols]

 11 Mold A 12 Mold B 13 Vent hole 14 Injection hole 2 Decorative sheet 31 Supply roll 32 Feed roll 33 Winding roll 34 Positioning sensor 35 Clamp 4 Heating device 41 Heating plate surface 42 Movable support tool 43 Partial heating element 44 Support stand 45 Hot Plate 46 Blowing Hole 47 Electric Heater 48 Solenoid 49 Supporting Member 5,5a Heat Adjusting Material 51 Heat Insulating Member 6 Peripheral Wall

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29C 45/78 7365-4F 51/42 7421-4F

Claims (4)

[Claims] 1. A decorative sheet is arranged between a pair of molds including a mold A having ventilation holes and a mold B having injection holes,
After heating and softening with a heating device facing the decorative sheet, the decorative sheet is brought into close contact with the cavity surface of the mold A by air pressure due to deaeration from the ventilation hole, and then,
A heating device used in a simultaneous injection-molding decorating method in which a mold is clamped, a molten resin is injected into a mold, and a molded product is decorated with a decorating sheet. And / or a heating adjusting material having a different emissivity from the surface of the heating plate is partially adhered, and the heating device is arranged at a position where the heating surface formed by the surface of the heating plate and the heating adjustment material is not in contact with the decorative sheet. The heating device is configured so that the heating temperature distribution of the decorative sheet can be controlled according to the shape of the molded product and / or the pattern of the decorative sheet by heating the decorative sheet. . 2. A decorative sheet is arranged between a pair of molds consisting of a mold A having ventilation holes and a mold B having injection holes,
After heating and softening with a heating device facing the decorative sheet, the decorative sheet is brought into close contact with the cavity surface of the mold A by air pressure due to deaeration from the ventilation hole, and then,
A heating device used in a simultaneous injection-molding decorating method in which a mold is clamped, a molten resin is injected into a mold, and a molded product is decorated with a decorating sheet, and at least two heating plates are capable of individually controlling the temperature. It is composed of an assembly of the above partial heating elements, controls the heating temperature of each partial heating element individually, and arranges the heating device at a position where the heating surface of the heating plate is not in contact with the decorative sheet. The heating device is configured to control the heating temperature distribution of the decorative sheet by heating the decorative sheet according to the shape of the molded product and / or the pattern of the decorative sheet. 3. An injection-molding simultaneous decorating device, comprising at least the heating device according to claim 1 or 2. 4. A mold A having a vent hole and a mold B having an injection hole using the simultaneous injection-molding decoration device according to claim 3.
Arranging the decorative sheet between the pair of molds,
The step of heating and softening the decorative sheet at a position where the heating surface of the heating device is not in contact with the decorative sheet, the step of closely adhering the decorative sheet to the cavity surface of the mold A by air pressure, and the mold clamping. A step of performing injection of a molten resin into a mold, a step of opening a mold to obtain a molded article decorated with a decorative sheet, and a simultaneous injection molding decorative method comprising: By controlling the heating temperature non-uniformly, it is possible to control the heating temperature distribution of the decorative sheet where low temperature heating is applied to the portion where elongation should be reduced corresponding to the shape of the molded product and / or the pattern of the decorative sheet. A feature of simultaneous injection molding and decoration.