JP4539208B2 - Method for producing thermoplastic resin molded article - Google Patents

Description

  The present invention relates to a method for producing a thermoplastic resin molded article.

Thermoplastic resin molded products are manufactured by various methods such as injection molding and compression molding. For example, Patent Document 1 describes a method of manufacturing a molded product by supplying a molten thermoplastic resin between a pair of male and female molds in an open state and closing the mold at a speed of 30 mm / second or less. . Patent Document 2 describes the application of this method to the production of multilayer molded articles.
According to the method of Patent Document 1, it is possible to obtain a molded article that is hardly deformed and has a good appearance, and according to the method of Patent Document 2, a multilayer having a good appearance without impairing the texture of the skin material. A molded product can be obtained.

JP-A-61-222917 JP-A-1-235613

  In general, in the process of manufacturing a thermoplastic resin molded product by compression molding or injection compression molding using a mold composed of a female mold and a male mold, the molten thermoplastic resin supplied between the male and female molds is forced to be forced between the male and female molds. The mold is pushed between the cavity surfaces of the male and female molds by approaching, that is, closing the mold, and then the clamping force is applied to the expanded thermoplastic resin by clamping the male and female molds, thereby The resin is spread to the point of time and the molten resin is solidified by cooling. In general, the scale of a molding apparatus used for manufacturing a thermoplastic resin molded product mainly depends on a clamping force required after the mold is closed. For this reason, the development of a molding method with the smallest possible clamping force after closing the mold is desired.

  An object of the present invention is a method for producing a thermoplastic resin molded article by compression molding or injection compression molding using a mold composed of a female mold and a male mold, and the mold clamping force required after closing the mold is conventionally The present invention is to provide a method that is smaller than the above method and that can contribute to downsizing of a required molding apparatus.

The present invention
Providing a pair of opposed female and male molds each having a cavity surface;
Supplying a predetermined amount of molten thermoplastic resin between both cavity surfaces;
The male and female molds are brought relatively close until a cavity of a predetermined dimension is formed by both cavity surfaces (however, the relative approach of the male and female molds starts during or after the thermoplastic resin is supplied, A thermoplastic resin comprising: pressurizing the thermoplastic resin in the cavity with the male and female molds and filling a predetermined region in the cavity with the thermoplastic resin. A method of manufacturing a molded article,
When approaching the male and female molds, the relative speed of both molds is accelerated until the maximum value Vmax is reached, and then the relative speed is reduced from Vmax to zero, where Vmax is 30 mm / second or more and 300 mm / second or less. In addition, the present invention provides a method characterized in that the deceleration during the period in which the relative speed is reduced from 50% of Vmax to 10% of Vmax is 100 mm / sec ² or more.
In one aspect of the present invention, the male and female molds are started to be separated at any timing before, simultaneously with, and after the start of the supply of the molten thermoplastic resin between both cavity surfaces.
In another aspect of the present invention, the maximum pressing surface pressure during pressing of the thermoplastic resin is 0.5 MPa or more and 5 MPa or less.
In one aspect of the present invention, the skin material is supplied between the cavity surfaces before the supply of the molten thermoplastic resin is started, and then the melt is performed with a part or all of one cavity surface covered with the skin material. Supply a thermoplastic resin.
In one aspect of the present invention, the cavity includes the predetermined region and the remaining region, and an additional amount of molten heat is applied to the remaining region during the pressurization of the thermoplastic resin in the predetermined region. Supply plastic resin.
In one embodiment of the present invention, the thermoplastic resin is a thermoplastic resin containing a foaming agent, and after the pressurization, the male and female molds are separated until the distance between both cavity surfaces reaches a predetermined value. And further foaming the inside of the thermoplastic resin in the cavity.

  According to the present invention, when the mold closing is performed under a specific condition, the pressure (clamping force) required after the mold closing is reduced as compared with the case where the mold clamping is performed under a conventionally employed condition. .

The method for producing the thermoplastic resin molded article of the present invention is as follows.
Providing a pair of opposed female and male molds each having a cavity surface;
Supplying a predetermined amount of molten thermoplastic resin between both cavity surfaces;
The male and female molds are brought relatively close until a cavity of a predetermined dimension is formed by both cavity surfaces (however, the relative approach of the male and female molds starts during or after the thermoplastic resin is supplied, And after pressurizing the thermoplastic resin in the cavity with the male and female molds to fill a predetermined area in the cavity with the thermoplastic resin. .
When the thermoplastic resin is pressurized by the male and female molds in the cavity, the temperature of the male and female molds is usually lower than the temperature of the thermoplastic resin in the cavity. Therefore, generally, the thermoplastic resin in the cavity is cooled in the process of pressurization.
In the following description, the expression “close the mold” means that the male and female molds are relatively approached, and the expression “open the mold” indicates that the male and female molds are relatively separated from each other. Means.

Hereinafter, although an example of the present invention is described in detail based on a drawing, the present invention is not limited to this example.
1 and 2 show an example of a thermoplastic resin molded article produced by the method of the present invention. In the thermoplastic resin molded article shown in FIG. 2, the skin material (2) is bonded and integrated to a part of the surface of the thermoplastic resin substrate (1). In this example, the skin material is bonded and integrated only on a part of the surface of the thermoplastic resin base material, but the surface material may be bonded and integrated on the entire surface of the base material. A plurality of skin materials may be bonded and integrated on part or the entire surface of the plastic resin substrate. Hereinafter, the case where a skin material is used as shown in FIG. 2 will be mainly described. However, the case where no skin material is used as shown in FIG.

  FIG. 3 shows a sectional view of an example of a mold used in the method of the present invention. This mold consists of a pair of opposed female molds (3) and male molds (4) each having a cavity surface. The male mold (4) is provided with a gate (5) for supplying molten thermoplastic resin, and from the gate (5) via a passage (6) provided in the male mold (4). Molten thermoplastic resin is supplied between the cavity surfaces. The position and number of gates to be installed are appropriately determined depending on the shape and size of the molded product to be manufactured. As shown in FIG. 2, when bonding a skin material, it is preferable to install a gate (5) in the site | part to which a skin material is bonded.

  In general, one of the pair of male and female molds has one mold fixed to a fixed plate of a press device (not shown) and the other mold fixed to a movable plate. The movable platen moves toward the fixed platen to close the mold. Examples of the drive device include a hydraulic drive device and an electric drive device, and an electric drive device is preferably used. It is preferable to use an electric drive device because it has excellent responsiveness, can accurately control the mold closing speed, and can easily increase the speed.

Next, a method for producing the thermoplastic resin molded article shown in FIG. 2 using this mold will be described.
FIG. 4 shows a state in which the skin material (2) is supplied between the cavity surfaces of the male and female molds. The skin material (2) is preferably placed so as to cover the gate (5). The skin material (2) supplied between the molds may be placed on the male mold (4), but the male (4) or female (3) main body and the skin material fixed around them are fixed. The frame may be fixed using pins or the like. Prior to the supply of the skin material between the male and female molds, the skin material may be preheated, or may be preshaped according to the desired product shape.

In the method of the present invention, a predetermined amount of molten thermoplastic resin is supplied between the cavity surfaces of the male and female molds. FIG. 5 is a view showing a state in which the molten thermoplastic resin (7) is supplied from the gate (5) via the passage (6) between the skin material (2) and the male mold (4). The cavity clearance of the male and female molds when supplying the molten thermoplastic resin, that is, the distance between both cavity surfaces in the mold closing direction, is appropriately determined according to the type of skin material used, the product shape to be manufactured, the size, etc. . If the cavity clearance at the start of mold closing is too small, a sufficient mold closing speed cannot be obtained. Therefore, the relationship between the cavity clearance at the start of mold closing (a: unit mm) and the product thickness (b: unit mm) is (B + 5) ≦ a is preferable, and (b + 7) ≦ a is more preferable.
When the skin material is not used, the cavity clearance at the start of mold closing is preferably (b + 20) or less from the viewpoint of the appearance of the obtained molded product. The cavity clearance at the start of mold closing is preferably (b + 5) or more.

In the method of the present invention, the male and female molds are relatively brought close to each other until a cavity having a predetermined dimension is formed by both cavity surfaces. This operation is a so-called “mold closing”. The relative approach of the male and female molds begins during or after the thermoplastic resin is supplied and ends after the thermoplastic resin is supplied.
FIG. 6 is a diagram illustrating a state where mold closing is completed. The molten thermoplastic resin supplied between the male and female molds flows between both cavity surfaces by mold closing and is shaped into a cavity shape defined by both cavity surfaces. The start of mold closing may be either during or after the supply of the molten thermoplastic resin. When the mold closing is started after the supply of the molten thermoplastic resin is completed, the mold closing is preferably started promptly (usually within 1 second) after the supply of the molten thermoplastic resin is completed.
In addition, before and after the start of the supply of molten thermoplastic resin between both cavity surfaces, the male and female molds begin to be separated at any timing after the start, during or after the supply of molten thermoplastic resin is completed It is a preferred embodiment to start approaching the male and female molds later. For example, the mold can be closed after the mold is opened until the cavity clearance reaches a predetermined value while supplying the molten thermoplastic resin between the male and female molds in the closed state. In this case, the supply of the molten thermoplastic resin may be started after the male and female molds are opened, or the male and female molds may be opened after the supply of the molten thermoplastic resin is started. Alternatively, the male and female molds may be opened simultaneously with the start of the supply of the molten thermoplastic resin. The closed state means a state in which a substantially closed cavity is formed by both cavity surfaces. The mold closing may be started during or after the supply of the molten thermoplastic resin. When the mold closing is started after the supply of the molten thermoplastic resin is completed, the mold closing is preferably started immediately (usually within one second) after the completion of the supply. The maximum value of the cavity clearance when the mold is opened while supplying the molten thermoplastic resin between the male and female molds in the closed state is preferably b + 50 (mm) or less when the skin material is bonded, When not bonding a skin material, it is preferable to set it as b + 20 (mm) or less. Here, b has the same meaning as described above.

  Before mold closing is completed, only a part of the thermoplastic resin required for forming the final product is supplied between the male and female molds, and the remaining molten thermoplastic during pressurization after mold closing is completed. You may supply resin to the unfilled space in a cavity. The amount of molten thermoplastic resin supplied before completion of mold closing and the amount of molten thermoplastic resin supplied after completion of mold closing are formed by the region formed by the resin supplied earlier and the resin supplied later in the final product. What is necessary is just to adjust according to the ratio of the area | region to perform. Further, the type of resin supplied earlier and the type of resin supplied later may be the same or different. A more beautiful appearance can be obtained by blocking the region formed by the resin supplied earlier and the region formed by the resin supplied later by a frame or the like.

In any case, as shown in FIG. 9, when the male and female molds are relatively approached, that is, when the mold is closed, the relative speed of both molds, that is, the mold closing speed is set to the maximum value Vmax. After that, the mold closing speed is reduced until the mold closing speed becomes zero from Vmax. Usually, acceleration and deceleration are performed continuously. The acceleration end time and the deceleration start time may be substantially the same, or the mold closing speed is maintained at Vmax for a predetermined period after the mold closing speed reaches Vmax, and then the mold closing speed is decreased. The control pattern is also allowed. When the mold closing speed is kept at Vmax for a predetermined period, the mold closing speed may slightly vary depending on the accuracy of the apparatus. However, unless the fluctuation has a special effect, such a variation in the mold closing speed may occur. Embodiments involving are also encompassed by the present invention. Vmax is 30 mm / second or more and 300 mm / second or less, and the deceleration during the period in which the mold closing speed is reduced from 50% of Vmax to 10% of Vmax is 100 mm / second ² or more. The maximum value of the mold closing speed is preferably 40 mm / second or more and 250 mm / second or less, and more preferably 50 mm / second or more and 200 mm / second or less. The deceleration is preferably 150 mm / second ² or more, and more preferably 200 mm / second ² or more.
If the maximum value of the mold closing speed is too small, the mold clamping force required to complete the shaping of the molten thermoplastic resin spread in the cavity by mold closing is too large, and a large mold clamping device is required. . Further, when the molten thermoplastic resin has foaming properties, if the maximum value of the mold closing speed is too small, the gas stored in the resin escapes during the mold closing, and a good appearance and desired A foamed molded article having an expansion ratio may not be obtained. If the maximum value of the mold closing speed is too large, the impact force acting on the mold when the mold is closed increases, and the apparatus and the mold may be damaged.

The deceleration in the deceleration region from the start of deceleration from the maximum value Vmax of the mold closing speed to the completion of mold closing can be changed, but the deceleration during the period of deceleration from 50% of Vmax to 10% of Vmax in the deceleration region is This greatly affects the flow efficiency of the resin due to mold closing, and the greater the deceleration during this period, the better the flow efficiency of the resin due to mold closing, and the shaping of the molten thermoplastic resin spread into the cavity by mold closing. The clamping force required for completion can be reduced. The upper limit of deceleration is not particularly limited, but is usually 1000 mm / second ² or less.
The deceleration D _50-10 (mm / sec ² ) during the period of deceleration from 50% of Vmax to 10% of Vmax is defined by the following equation.
D _50-10 = (V ₅₀ -V ₁₀ ) / (t ₁₀ -t ₅₀ )
In the formula, V ₅₀ represents a speed (mm / second) of 50% of the maximum value of the mold closing speed, V ₁₀ represents a speed (mm / second) of 10% of the maximum value of the mold closing speed, and t ₅₀ represents The time (second) when the mold closing speed reaches V ₅₀ and t ₁₀ indicate the time (second) when the mold closing speed reaches V ₁₀ , respectively.
3 to 6 show an example in which the mold is closed in the vertical direction, the mold closing direction may be the vertical direction or the horizontal direction.

  In order to suppress uneven glossiness between the part formed during the supply of the molten thermoplastic resin and the part formed between the end of the supply of the molten thermoplastic resin and the completion of the mold closing, supply of the molten thermoplastic resin The relationship between the average flow velocity V1 of the molten thermoplastic resin in the inside and the average flow velocity V2 of the molten thermoplastic resin from the completion of the supply of the molten thermoplastic resin to the completion of the mold closing is 0.5 <V2 / V1 <5 It is preferable that 1 <V2 / V1 <3.

  The average flow velocity V1 of the molten thermoplastic resin at the time of supplying the molten thermoplastic resin is the average flow distance of the molten thermoplastic resin from the time when the supply of the molten thermoplastic resin is completed to the time when the molten thermoplastic resin is completed. It is a value obtained from the supply time of the thermoplastic resin. The average flow distance of the molten thermoplastic resin is obtained from the cavity clearance at the end of the supply of the molten thermoplastic resin and the supply amount of the molten thermoplastic resin. The average flow velocity V1 is usually 10 mm / sec or more and 1000 mm / sec or less.

  The average flow velocity V2 of the molten thermoplastic resin at the mold cavity surface during pressurization from the end of the supply of the molten thermoplastic resin is the melted thermoplasticity from the end of the supply of the molten thermoplastic resin to the completion of mold clamping This is a value obtained from the average flow distance through which the resin has flowed and the time from the completion of the supply of the molten thermoplastic resin to the completion of mold clamping. The average flow velocity V2 is usually 10 mm / sec or more and 5000 mm / sec or less.

  The average flow distance of the molten thermoplastic resin used to determine V1 and V2 may vary depending on the flow direction depending on the product shape even if there is only one gate. The average value of the moving distance and the shortest moving distance is used.

  When there are a plurality of gates for supplying molten thermoplastic resin and the amount of resin supplied from each gate is substantially the same, the average flow rate of the molten thermoplastic resin supplied from any one of the gates You can ask for. When the amount of resin supplied from each gate is greatly different, the average flow rate required for the molten thermoplastic resin supplied from the gate having the largest amount of supplied resin may be within the above range.

After the mold is closed until a cavity of a predetermined size is formed, the thermoplastic resin in the cavity is pressurized by a male and female mold, thereby filling the thermoplastic resin in a predetermined area in the cavity. . The “predetermined region in the cavity” may be the entire cavity or a portion other than the entire cavity. In the latter case, as described above, the inside of the cavity is preferably divided by a frame or the like.
The maximum pressure applied to the thermoplastic resin in the cavity at the time of pressurization is preferably 0.5 MPa or more and 5 MPa or less, and more preferably 0.5 MPa or more and 3 MPa or less. When the maximum pressure contact pressure is too small, it may be difficult to shape the molten thermoplastic resin into a desired shape. In order to apply the maximum pressure contact pressure exceeding 5 MPa, a large mold clamping device is required. The pressing surface pressure is obtained by dividing the clamping force by the projected area of the cavity, and the maximum pressing surface pressure is the maximum value of the pressing surface pressure.

During the pressurization, the heat of the thermoplastic resin is taken away by the mold, and as a result, the thermoplastic resin in the cavity gradually solidifies from the surface.
When the thermoplastic resin used is a non-foaming thermoplastic resin, the male and female molds are opened as shown in FIG. 7 when the thermoplastic resin has solidified to such an extent that deformation does not occur even if the pressure is released. By taking out the molded product, a thermoplastic resin molded product in which the skin material as shown in FIG. 2 is partially bonded and integrated can be obtained.

When the thermoplastic resin used is a foamable thermoplastic resin containing a foaming agent, primary cooling is performed while suppressing foaming of the thermoplastic resin in the cavity by pressurization, and thereby the surface of the thermoplastic resin A skin layer that is not substantially foamed is formed in the vicinity. The primary cooling time varies depending on properties such as the mold temperature, the temperature of the molten thermoplastic resin, and the melt viscosity, but is usually about 0.1 to 5 seconds.
After the skin layer having a predetermined thickness is formed, the cavity is enlarged in the thickness direction of the molded body (FIG. 8). The gas encapsulated therein expands to form bubbles in the thermoplastic resin. Thereby, a thermoplastic resin foams and a foaming layer is formed inside a skin layer. When the cavity clearance reaches a predetermined product thickness, the expansion of the cavity is stopped. Furthermore, the cavity clearance is maintained and the thermoplastic resin in the cavity is cooled and solidified. When the thermoplastic resin has solidified to such an extent that deformation does not occur even if the pressure is released, the male and female molds are opened and the thermoplastic resin foam molded article is taken out.

As a foaming agent used for this invention, the well-known chemical foaming agent and physical foaming agent currently used when manufacturing the foam of a thermoplastic resin can be used.
Examples of the chemical foaming agent include inorganic foaming agents such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate, nitroso compounds such as N, N′-dinitrosopentamethylenetetramine, azodicarbonamide, azobisisobutyronitrile. Azo compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, sulfonyl hydrazides such as diphenylsulfone-3,3′-disulfonyl hydrazide, and p-toluenesulfonyl semicarbazide. These chemical foaming agents may contain foaming aids such as salicylic acid and urea.
Examples of the physical foaming agent include inert gases such as nitrogen and carbon dioxide, and volatile organic compounds other than chlorofluorocarbon organic compounds such as butane and pentane.

The type of the foaming agent is appropriately selected in consideration of the melting temperature of the thermoplastic resin to be used, the target expansion ratio, and the like. The addition amount of the foaming agent is appropriately selected in consideration of the strength, density and the like of the target molded product, but is usually 0.1 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin.
When a physical foaming agent is used, a method of press-fitting a liquid or gaseous foaming agent into a molten thermoplastic resin can be used.

In the present invention, a thermoplastic resin usually used for compression molding, injection molding, extrusion molding or the like can be used. In the present invention, the thermoplastic resin refers to a thermoplastic resin, a thermoplastic elastomer, a mixture thereof, a polymer alloy using these, and the like.
Examples of the thermoplastic resin include general polyamides such as nylon, polypropylene, polyethylene, acrylonitrile-styrene-butadiene block copolymer, polystyrene, polyvinyl chloride, polycarbonate, acrylic resin, and styrene-butadiene block copolymer. Examples thereof include thermoplastic resins, thermoplastic elastomers, mixtures thereof, and polymer alloys using these.

  Further, the thermoplastic resin may contain various additives such as glass fiber, inorganic filler, organic filler, pigment, lubricant, antistatic agent and stabilizer.

  Examples of the skin material used in the present invention include woven fabrics and knitted fabrics such as moquettes and tricots, nonwoven fabrics such as needle punch carpets, metal foils, sheets and films of thermoplastic resins and thermoplastic elastomers, and the like.

Examples of the fibers constituting the nonwoven fabric include natural fibers such as cotton, wool, silk, and hemp, and synthetic fibers such as polyamide, polyester, and nylon. The nonwoven fabric may be composed of a single type of fiber or may be composed of two or more types of fibers. Moreover, you may be comprised with the mixture of a natural fiber and a synthetic fiber. Nonwoven fabrics are classified into needle punch, thermal bond, spunbond, meltblown, and spunlace types, and any nonwoven fabric can be applied to the present invention.
Synthetic resin sheets and films include, for example, thermoplastic resins such as polypropylene and polyethylene, and polyolefin thermoplastic elastomer sheets and films. Good fusion with thermoplastic resins used as base resins. Are preferably used.

These skin materials may be multilayer skin materials having a foam layer or a backing layer.
Examples of the foam layer include polyolefin foams such as polypropylene and polyethylene, polyvinyl chloride foams, soft or semi-rigid polyurethane foams, and the like.
Moreover, as a backing layer, a nonwoven fabric, a synthetic resin sheet, a film, etc. are mentioned, for example.

  These multi-layer skin materials have good heat-fusibility with a thermoplastic resin from the viewpoint of adhesion to a base material portion made of a thermoplastic resin, or a molten thermoplastic resin is impregnated on the back surface of the skin material. Thus, those capable of bonding to the base resin are preferably used.

  The present invention will be further described below with reference to examples, but the present invention is not limited to the examples.

Example 1
As the thermoplastic resin, polypropylene (trade name: Sumitomo Nobrene AZ664E4, manufactured by Sumitomo Chemical Co., Ltd., MFR (measured at 210 ° C., 2.16 kgf) 30 g / 10 min), with a projected area of 0.5 m ² and a thickness of 2 A molded product of 0.0 mm was formed. The mold used was a vertical clamping mold composed of a movable upper female mold and a fixed lower male mold, and the clamping force of the clamping apparatus was 980 kN. With the cavity clearance maintained at 30 mm, molten thermoplastic resin was fed between the male and female molds. The mold was closed after completing the supply of the thermoplastic resin, and after completion of the mold closing, the molded article was obtained by pressurizing with a pressurized surface pressure of 2 MPa. The maximum value Vmax of the mold closing speed was 70 mm / second, and the deceleration during the period during which the mold closing speed was reduced from 50% (V ₅₀ ) of Vmax to 10% (V ₁₀ ) of Vmax was 330 mm / second ² . The shape of the obtained molded product corresponded exactly to the shape of the cavity of the mold used.

Comparative Example 1
Example 1 except that Vmax is 25 mm / second, and the mold closing speed is 120 mm / second ² during the period in which the mold closing speed is reduced from 50% of Vmax (V ₅₀ ) to 10% of Vmax (V ₁₀ ). Molded to obtain a molded product. The shape of the obtained molded product was a shape in which a part of the shape of the cavity of the used mold was missing.

Comparative Example 2
Vmax and 30 mm / sec, the mold closing speed of 50% of the Vmax (V ₅₀₎ from the deceleration period to slow to 10% of Vmax (V ₁₀₎ in the same manner as in Example 1 except that a 60 mm / sec ² Molded to obtain a molded product. The shape of the obtained molded product was a shape in which many portions of the shape of the cavity of the mold used were missing.

An example of the thermoplastic resin molded product manufactured by the method of this invention is shown with the perspective view. The other example of the thermoplastic resin molded product manufactured by the method of this invention is shown with the perspective view. An example of the metal mold | die used for the method of this invention is shown with sectional drawing. In the implementation of the method of the present invention, the skin material is supplied between the male and female molds. In the implementation of the method of the present invention, the molten thermoplastic resin is supplied between the male and female molds. In this figure, in particular, a molten thermoplastic resin is supplied between the skin material and the male mold. In the implementation of the method of the present invention, the state where mold closing is completed is shown. In the implementation of the method of the present invention, the mold is opened and the product is taken out. In the implementation of the method of the present invention, the foamable thermoplastic resin is foamed in the cavity. It is a schematic diagram which shows an example of the change of the mold closing speed in the process of mold closing.

Explanation of symbols

1: Thermoplastic resin molded product 2: Skin material 3: Female mold 4: Male mold 5: Gate 6: Passage 7: Molten thermoplastic resin 8: Foamed molten thermoplastic resin

Claims (6)

Providing a pair of opposed female and male molds each having a cavity surface;
Supplying a predetermined amount of molten thermoplastic resin between both cavity surfaces;
The male and female molds are brought relatively close until a cavity of a predetermined dimension is formed by both cavity surfaces (however, the relative approach of the male and female molds starts during or after the thermoplastic resin is supplied, A thermoplastic resin comprising: pressurizing the thermoplastic resin in the cavity with the male and female molds and filling a predetermined region in the cavity with the thermoplastic resin. A method of manufacturing a molded article,
When the male and female molds are moved relatively close to each other, the relative speed of both molds is accelerated until the maximum value Vmax is reached, and then the relative speed is reduced until Vmax becomes zero, and Vmax is 30 mm / second or more and 300 mm. And the deceleration during the period in which the relative speed is reduced from 50% of Vmax to 10% of Vmax is 100 mm / sec ² or more. The method according to claim 1, further comprising starting to separate the male and female molds at any timing before, simultaneously with, and after the start of supplying the molten thermoplastic resin between both cavity surfaces.   The method according to claim 1 or 2, wherein the maximum pressing surface pressure during pressing of the thermoplastic resin is 0.5 MPa or more and 5 MPa or less.   Supply a skin material between the cavity surfaces before starting the supply of the molten thermoplastic resin, and then supply the molten thermoplastic resin with a part or all of one cavity surface covered with the skin material. The method according to claim 1, wherein:   The cavity is composed of the predetermined region and the remaining region, and an additional amount of molten thermoplastic resin is supplied to the remaining region during the pressurization of the thermoplastic resin in the predetermined region. The method according to any one of claims 1 to 4. The thermoplastic resin is a thermoplastic resin containing a foaming agent. After the pressurization, the male and female molds are separated until the distance between both cavity surfaces reaches a predetermined value, and the thermoplastic resin in the cavity is separated. The method according to claim 1, further comprising foaming the inside.

Images