JPH1058486A - Method and apparatus for manufacture of skin integral molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of drape due to fur fallen flat by holding a temperature of a gigging layer of a skin material fusion bonded integrally with a core material resin layer in a rubber-like elastic temperature range of a glass transition point to a melting point after molding. SOLUTION: Two molds are opened. With a skin material base layer disposed at an inside the material is set, and both the molds are closed. The material is a two-layer sheet obtained by forming a gigging layer of synthetic resin on a resin sheet (base layer) surface of polypropylene. The base layer is obtained by forming a gigging layer on a molding, and fusion bonding to integrate it with a core material. A mold clamping state is held, and the material is injected in a cavity. Upon completion of the filling, it is dwelled, cooled to be solidified, the molds are opened, and a molding is removed. The molding is conveyed to a conveyor type heating holding unit 200. A heater 220 maintains a hold cover 220a at a set temperature set in a rubber-like elastic range of a melting point to a glass transition point of the skin material gigging layer. The gigging layer deformed during molding obtains an excellent molding having recovered drape (hand contact feeling).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin integral molded product obtained by fusing and integrating a decorative skin material having a raised layer on the surface of the core material simultaneously with shaping of the core material. More particularly, the present invention relates to a method and an apparatus for manufacturing a skin-integrated molded product that can provide a high-quality molded product at low cost without impairing the feel of the skin material.

[0002]

2. Description of the Related Art In recent years, resin molded parts used for automobiles, home appliances, building materials, and the like have increased added value such as cushioning property, decorativeness, touch feeling, and the like, or have reduced cost by reducing the number of molding steps. For this reason, two-layer molding has been practiced in which a decorative skin material such as a brushed skin material is integrally molded on the surface of a core layer resin as shown below. That is, when using an injection molding machine, a skin material is set between the opened molds, the mold is closed and the mold is closed, and then a mold cavity formed by the skin material and the mold is formed. The inside is injected and filled with a molten resin as a core material.
Then, the holding pressure is supplied by using the injection unit, the cooling is performed for a specified time, the mold is opened, and the product is taken out. From the mold clamping to the product removal in this method, the molding operation is performed by a normal injection molding method, and the mold is clamped with high pressure so that the resin does not leak during injection filling. A method using a press molding machine A skin material is set between both molds that have been opened, and while holding both molds at a predetermined mold opening amount, a space is formed between the skin material and the mold. Then, after injecting and filling the molten resin to be the core material, both molds are subjected to mold clamping press, and then cooled for a specified time,
Open the mold and take out the product.

[0003]

However, such a conventional method has the following problems. (1) When a high-temperature and high-pressure molten resin is applied to the skin material having a raised layer, the skin material is severely damaged such as hair falling, the texture is deteriorated, and the quality is reduced and the appearance is poor. That is, the texture (feeling of touch and sense of quality) is lost due to the fall of the hairs, resulting in poor appearance and lower quality. (2) For this reason, for example, a protective layer was attached to the skin material to reduce or prevent an external force load at the time of molding. However, there is a problem that the cost is increased, and the texture is completely restored. It was difficult to make it. (3) In particular, in order to meet the demand for reducing the weight of the product, in the case where the thickness is reduced, a higher external load must be applied, and the damage to the skin material is further increased.

[0004]

Means for Solving the Problems To solve the above problems, in the first invention, in the first invention, a raised layer is formed on the surface of the core material resin layer simultaneously with the shaping of the core material resin. In the method for producing a skin-integrated molded article in which a decorative skin material having a decorative material is fused and integrated, the temperature of the raised layer of the skin material which is fusion-integrated after molding is set within a rubber-like elastic temperature range from the glass transition point to the melting point. In addition to maintaining the temperature set in the above, this state was maintained for a preset time. According to a second aspect of the present invention, there is provided an apparatus for manufacturing a skin-integrated molded product according to the first aspect of the present invention, wherein the decorative skin has a raised layer on the surface of the core material resin layer simultaneously with the shaping of the core material resin. A structure comprising a skin integral molding device for fusing and integrating materials, a transport means for conveying the molded skin integral molded article, and a heating and holding means for heating and holding the raised layer of the skin integral molded article at a set temperature. And

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for producing a skin-integrated molded product in which a decorative skin material having a raised layer on the surface of a core material resin layer is fused and integrated simultaneously with shaping of a core material resin. The temperature of the raised layer of the skin material fused and integrated after molding is maintained at a temperature set within a rubber-like elastic temperature range from a glass transition point to a melting point and a melting point, and this state is maintained for a preset time. I made it. Also, the second
In the invention of the present invention, a skin integral molding device for forming a core integral resin and simultaneously fusing and integrating a decorative skin material having a raised layer on the surface of the core resin layer, A transport means for transporting the subsequent integrated skin product and a heating and holding means for heating and holding the raised layer of the integrated skin product at a set temperature were adopted. As a result, the following preferable molding is performed. After molding, the molded product is heated at the temperature set within the rubber-like elastic temperature range and held in that state for a predetermined time, so that the raised material deformed by external force during molding recovers elastically, And the stable supply of high quality molded products becomes possible. Further, it is not necessary to attach the protective layer to the skin material as conventionally performed, and the cost can be reduced. It is possible to cope with thinning for the purpose of weight reduction. At a relatively low temperature between the melting point Tm and the glass transition point Tg,
Since the heating and holding are performed, the heat treatment is simple, the apparatus is simple, and the initial cost can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 relate to an embodiment of the present invention,
1 is an overall configuration diagram of a skin integral molding apparatus used in the present invention, FIG. 2 is a flowchart of a skin integral molding step, FIG. 3 is a schematic longitudinal sectional view of a heating / holding means for a skin material in the skin integral molding step, FIG. Is a graph showing the correlation between the temperature of the skin material raised layer and the amount of deformation of the core material resin or the recovery time of the raised layer,
FIG. 5 is an explanatory view showing the state of elastic recovery of the skin raising layer.

As shown in FIG. 1, a skin integral molding apparatus 100 according to the present invention utilizes a general-purpose injection molding machine, and includes a mold apparatus 10, a mold clamping apparatus 20, an injection apparatus 30, a control apparatus 60, and the like. It consists of. The mold apparatus 10 includes a fixed mold 3 attached to the fixed board 1 and a movable mold 4 attached to the movable board 2, and includes the movable board 2 and the movable mold 4.
Is configured to be able to move forward and backward by the mold clamping cylinder 22 of the mold clamping device 20. The mold clamping device 20 includes a mold clamping cylinder 22 that operates to open and close the molds 3 and 4 of the mold device 10. The movable mold 4 is connected to the fixed mold 3 by a tie bar (not shown). You will be guided back and forth.

The injection device 30 is provided with a screw 34 having a screw blade 36 spirally mounted on the outer periphery of a barrel 32. The screw 34 is rotatably driven by a forward / reverse hydraulic motor 42 and an injection cylinder 40, and is capable of moving forward and backward. The molten resin is injected into the mold cavity 5 formed between the molds 3 and 4 via the nozzle 39 while heating and melting and kneading the resin pellets supplied to the hopper 38. That is, the injection device 30 heats and compresses the resin raw material in the hopper 38 in the supply zone and the compression zone in the barrel 32, melts and measures in the measurement zone, and passes through the injection zone into the mold cavity 5 through the nozzle 39. It is configured to fire. Hydraulic oil supplied from a hydraulic supply source 50 is supplied to the injection cylinder 40 and the forward / reverse rotation hydraulic motor 42 at a constant pressure set by a hydraulic control valve 52 that has received an operation command from an injection control unit 61, and is driven. You.

On the other hand, as shown in FIG. 1, the control device 60 includes a hydraulic control valve 69 on the mold clamping cylinder 22 of the mold clamping device 20.
, A timer 63 connected to the mold clamping control unit 62, and an injection control unit 61 connected to the mold clamping control unit 62. 70 is a hydraulic supply source. In this embodiment, an injection molding machine having a direct pressure type mold clamping device is used. However, an injection molding machine having a toggle mold clamping device, or an injection molding machine having a vertical injection molding machine or an electric type mold clamping device is used. A molding machine, or a stamping molding machine or a press molding machine or a blow molding machine may be used.

FIG. 2 shows an embodiment of the molding step of the method for integrally molding skin according to the present invention, and the operation is performed according to the step shown in FIG. (1) First, the molds 3 and 4 of the mold apparatus 10 are opened, and the skin material S is set with the skin material raised layer facing the mold parting surface and the skin material base layer inside, and the periphery is set. After holding the parts, both molds are closed. The skin material S is a two-layer sheet in which a raised layer of synthetic fibers is formed on the surface of a resin sheet (base layer) such as PP (polypropylene) or PE (polyethylene), and the base layer forms a raised layer on the surface of the molded product. And it is provided for the purpose of achieving fusion integration with the core material. If necessary, a cushion layer or the like may be provided on the back surface of the resin sheet. Also, a pre-molded product roughly preformed into a molded product shape may be used. In order to utilize the elastic recovery phenomenon, a material having a melting point Tm higher than the melting point T'm of the core material resin and a glass transition point Tg lower than the melting point T'm of the core material resin is used for the raised layer. As a specific example, for example, when PP (talc may be added) is used for the core material Q,
Since the core material melting point T′m is 170 to 180 ° C., PET (melting point Tm = 250 to 270 ° C., glass transition point Tg = 70 to 90 ° C.) is adopted for the raised layer.

(2) Next, while maintaining the mold clamping state, the core material Q is injected and filled into the mold cavity 5 by the usual injection insert molding procedure. At this time, by adopting the following molding control, it is possible to further shorten and completely recover the raised hair in the raised hair recovery processing step described later. Injection compression control is performed. That is, the core material is injected and filled in a low-pressure mold-clamped state that allows the mold to be opened by the injection-filled resin pressure. Therefore, during the filling, a small mold opening behavior is exhibited, and the holding pressure after the completion of the filling applies a compressing action from the mold clamping side. Performs injection press control. In this case, the mold is held in advance in the state where the minute mold is opened, and the core material resin processing machine laboratory is injected and filled, and after the filling is completed, the mold clamping pressure is applied to hold (press). In this way, by employing injection compression control and injection press control during injection insert molding, low pressure and short time filling can be achieved by mold open filling, and high adhesion without deformation and warpage due to mold clamping pressure. An integrated molded product is obtained. The lowering of the resin pressure during molding is
Reduces damage (hair fall) of the skin raising layer during molding, promotes short and complete recovery of the elasticity of the raising in the raising process, shortens processing time and lowers processing temperature. To achieve.

(3) When the injection filling of the core material Q is completed,
When the cooling and solidification is completed after a certain period of time in the pressure holding step, the mold is opened and the molded product is taken out. Next, the molded product is transported to the heating / holding device 200 shown in FIG. The heating / holding device 200 is provided with a heating / holding cover 220 having a heater 220a in the upper center of the belt conveyor 210, and heats the molded product placed on the belt 210a while moving, By adjusting the traveling speed, the holding time T is controlled by the residence time from when the heating / holding cover 220 reaches the outlet to the outlet. As described above, in the belt conveyor system of the heating and holding device 200, the holding control of the set time required for the elastic recovery of the raised layer can be easily performed by adjusting the belt speed. The heater 220a has a melting point T of the skin raising layer.
m to maintain the inside of the heating / holding cover 220 at the set temperature set in the rubbery elastic region between the glass transition point Tg, by using hot air or steam alone or in combination. Increase the heating efficiency and shorten the heating time of the raised layer.

The holding time T is a time required for the elasticity of the raised layer to recover, and varies depending on the set temperature. FIG. 4 is a graph showing the correlation between the temperature of the skin material raised layer and the deformation amount of the core material resin or the recovery time of the raised layer.
At high temperatures around m, the recovery time of the raised layer is short, but the core material is easily deformed at high temperatures. On the other hand, at Tg near the glass transition point, the recovery time of the raised layer is long, but the core material is not easily deformed at low temperatures. Therefore, the holding time T is determined and set based on the molding cycle, the degree of deformation of the core material, and the like. For example, at a temperature of the glass transition point Tg plus 10 to 50 ° C., the set time may be 30 seconds or less.

As shown in FIG. 5, the raised layer deformed during molding recovers elasticity to recover the texture (feeling of touch and high quality), and supplies a molded product having excellent surface properties stably. Is done. Since the elastic recovery of the raised layer is not forced by external force but occurs naturally, the original texture of the skin material S can be completely restored. Therefore, it is not necessary to attach the protective layer, which is conventionally performed, and the heating / holding device 200
Since only heat treatment by the above method is required, automation can be easily performed and cost can be reduced. Further, by performing the brush raising treatment immediately after the molding, the molded product has a certain temperature, so that the skin material can be shortened. Furthermore, the combined use of hot air, steam, and the like can shorten the elasticity recovery, prevent the molding cycle from being lengthened, and realize space saving of the processing apparatus.

The heat treatment after molding employed in the present invention is characterized in that the treatment temperature is the melting point Tm of the brushed layer and the glass transition point Tg.
(E.g., a glass transition temperature Tg plus 10).
About 50 ° C., that is, 100 to 100% if the raised layer is PET
(Approximately 140 ° C.), so that the apparatus can be simplified, leading to cost reduction. It is possible to perform a recovery process after a considerable time has passed after molding, but in this case, the heating is performed from a low temperature state close to room temperature, which leads to a longer molding cycle. In order to prevent deformation of the core material, for example, after molding, a molded product is set on a correction jig (only the core material side is held and the skin material side is opened) to perform a recovery process. Deformation can be alleviated by preventing deformation and removing residual stress during molding.

[0016]

As described above, according to the method of the present invention, the following excellent effects are achieved. (1) A skin-integrated molded product having extremely excellent appearance performance can be stably obtained at low cost without impairing the feel such as the feeling of touch and the feeling of luxury due to the falling of the decorative skin material having a raised layer. (2) Since the texture of the raised layer can be recovered only by heat treatment at a relatively low temperature, it is possible to simplify the incidental equipment, easily automate the molding control, and supply a product having excellent surface properties at low cost.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a step of forming the integral skin according to the embodiment of the present invention (first embodiment)
15 is a flowchart of Example).

FIG. 3 is a schematic longitudinal sectional view of a heating / holding means for a skin material in a skin integral molding step according to an embodiment of the present invention.

FIG. 4 is a graph showing a correlation between the temperature of the skin material raised layer and the deformation amount of the core material resin or the recovery time of the raised layer according to the example of the present invention.

FIG. 5 is an explanatory diagram showing an elastic recovery state of the skin raising layer according to the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed board 2 Movable board 3 Fixed mold 4 Movable mold 5 Mold cavity 10 Mold device 20 Mold clamping device 22 Mold clamping cylinder 30 Injection device 32 Barrel 34 Screw 36 Screw blade 38 Hopper 39 Nozzle 40 Injection cylinder 42 Hydraulic motor Reference Signs List 50 Hydraulic supply source 52 Hydraulic control valve 60 Control device 61 Injection control unit 62 Mold clamping control unit 63 Timer 69 Hydraulic control valve 70 Hydraulic supply source 100 Integrated skin molding device 200 Heating / holding device 210 Belt conveyor 210a Belt 220 Heating / protective cover 220a Heater A Brushed layer B Base layer C Core layer Q Core material (core material resin) S Skin material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 9:00

Claims (2)

[Claims] 1. A method for producing a skin-integrated molded article, wherein a decorative skin material having a raised layer on the surface of a core material resin layer is fused and integrated simultaneously with the shaping of the core material resin. The temperature of the raised layer of the skin material is maintained at a temperature set within a rubber-like elastic temperature range from a glass transition point to a melting point but not higher than a melting point, and this state is maintained for a preset time, wherein the skin is integrally molded. Product manufacturing method. 2. An integrated skin forming apparatus for fusing and integrating a decorative skin material having a raised layer on the surface of a core material resin layer simultaneously with shaping of the core material resin, and transporting the formed integrated skin material. An apparatus for manufacturing an integral skin product comprising a transport means and a heating and holding means for heating and maintaining the raised layer of the integral skin product at a set temperature.