JP2016055622A - Method for producing synthetic resin molding and synthetic resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a method for producing a synthetic resin molding capable of producing a synthetic resin molding having an accurate shape; and a synthetic resin molding produced by the production method.SOLUTION: There is provided a method for producing a synthetic resin molding by insert-molding a synthetic resin molding (lid) having a three-dimensional shape using a synthetic resin-made surface sheet material 7 for forming a product surface, the method comprising: a sheet material formation step of forming a surface sheet material from a synthetic resin sheet substrate 11 as a base of a surface sheet material; a sheet material bending step of bending the surface sheet material into a predetermined shape; and a formation step of placing the bent surface sheet material in a molding die, followed by performing insert-molding, where in the sheet material formation step, cuts 7d penetrating through the synthetic resin sheet substrate and a substrate surface layer removed portion (bend line 7c) after removing only a portion on the substrate surface side of the synthetic resin sheet substrate are formed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a synthetic resin molded product in which a three-dimensional synthetic resin molded product is insert-molded using a synthetic resin sheet material, and a synthetic resin molded product manufactured by the manufacturing method.

  Conventionally, as disclosed in, for example, Patent Document 1, after introducing a three-dimensional processing flat film having an insert molding use region and a non-use region into an injection mold, at least the three-dimensional processing flat film is used. Insert molding in which the insert molding area is brought into close contact with the cavity forming surface of the injection mold and processed into a three-dimensional shape. After the mold is closed, the molding resin is injected into the injection mold to produce a resin molded product. A method for manufacturing a product is known.

  The flat film for three-dimensional processing is formed so that the laminate that becomes a part of the resin molded product can be peeled on the cover film, and the laminate has a cover film at the boundary between the insert molding use area and the non-use area. A cut is provided so as not to penetrate. Then, by injecting the molding resin into the mold for injection molding, simultaneously with the molding of the resin molded product, the laminate in the insert molding use area and the molding resin are integrated and bonded, and then the cover film is peeled off and the resin is peeled off. Manufacture molded products.

Japanese Patent No. 3262750

  In the method of manufacturing an insert molded product as described above, a three-dimensional processing planar film in which a laminate and a cover film are integrated is placed in an injection mold. That is, the mold is closed in a state where the non-use area of the three-dimensional processing planar film protrudes outside the cavity of the injection mold. For this reason, it is difficult to accurately process a planar film for three-dimensional processing into a shape along the cavity forming surface of an injection mold, and the three-dimensional processing planar film and the cavity forming surface are used when closing the mold. Therefore, there is a problem that it is difficult to manufacture a resin molded product having an accurate shape.

  The present invention was devised in view of the above-described conventional problems, and is a method for producing a synthetic resin molded product capable of producing a synthetic resin molded product having an accurate shape, and a synthetic resin produced by the production method. The object is to provide a molded product.

  A synthetic resin molded product manufacturing method according to the present invention is a synthetic resin molded product manufacturing method in which a three-dimensional synthetic resin molded product is insert-molded using a synthetic resin surface sheet material that forms a product surface, A sheet material forming step of forming the surface sheet material from a synthetic resin sheet base material that is a base of the surface sheet material, a sheet material folding step of bending the surface sheet material into a predetermined shape, and the folded surface sheet material A molding step that is placed in a mold and insert-molded. In the sheet material forming step, only the cuts that penetrate the synthetic resin sheet base material and the portion on the base material surface side of the synthetic resin sheet base material are included. A removed base material surface layer removal portion is formed.

  Of the substrate surface layer removal part, the removal depth of the substrate surface layer removal part located near the gate for pouring and filling the synthetic resin into the mold is shallow, and the substrate surface layer located far from the gate The removal depth of the removal portion is characterized by being deep.

  The surface sheet material is separated from the synthetic resin sheet material by forming the cut line connected to the synthetic resin sheet base material along the contour of the surface sheet material.

  The base material layer on one side of the two base material surface layers of the synthetic resin sheet base material constitutes a surface coat layer to be the product surface, and the base material surface layer on the other side has an adhesive. The adhesive layer provided is comprised, The said base-material surface removal part is formed in the said adhesive layer side, It is characterized by the above-mentioned.

  In the sheet material folding step, the surface sheet material is valley-folded or mountain-folded along the base material surface layer removal portion formed in a linear manner.

  Each surface of the surface sheet material that is bent is arranged along the inner surface of the recess provided in the molding die, and does not protrude from the recess.

  Of the respective surfaces of the folded surface sheet material, the surface located near the gate where the synthetic resin is poured into the mold to be filled is set to have a long protruding dimension from the base material surface layer removal portion. The surface located far from the gate is characterized in that the protruding dimension from the base material surface removal portion is set short.

  Of the respective surfaces of the folded surface sheet material, the surface located near the gate where the synthetic resin is poured into the mold and filled is set to have a short protruding dimension from the substrate surface layer removal portion. The surface located far from the gate is characterized in that the protruding dimension from the substrate surface layer removal portion is set long.

  The synthetic resin sheet base material is formed with air venting pores penetrating through the synthetic resin sheet base material, and the air venting pores reach the synthetic resin filled in the molding die with the latest delay in the molding step. It is arranged near the resin filling terminal part.

  The air vent pores are provided in the substrate surface layer removal portion.

  In the sheet material forming step, the base material surface layer removing portion is sandwiched between the edges of any one of adjacent surfaces among the surfaces of the folded surface sheet material. In the form, a tongue piece is formed by projecting to overlap the other surface, and the protruding direction of the tongue piece from the end edge is a synthetic resin from a gate that is filled with a synthetic resin poured into the mold The tongue piece on the one surface is pressed against the other surface by the heat and flow pressure of the synthetic resin.

  The surface sheet material is foldable and is positioned at the cut that forms the side portion, and the tongue pieces sandwiched between the side portion and the synthetic resin after the molding step are separated by a pair of adjacent the cut pieces. Of the side surface portions, the tongue is connected to one of the side surface portions, and when the side surface portion is bent and the surface sheet material is inserted into the mold and subjected to insert molding, The cuts in the other side surface where the pieces are not continuously provided are arranged along the corners of the synthetic resin molded product and are exposed on the surface of the synthetic resin molded product.

  The tongue piece is disposed so as not to be exposed on the surface of the synthetic resin molded product with respect to the side surface portion located farther from the gate position where the synthetic resin is poured into the mold and filled. To do.

  The synthetic resin molded product according to the present invention is manufactured by the method for manufacturing a synthetic resin molded product.

  In the synthetic resin molded product manufacturing method and the synthetic resin molded product according to the present invention, an accurate-shaped synthetic resin molded product can be manufactured, and the manufactured synthetic-resin molded product can have an accurate shape. .

It is a perspective view which shows the lid | cover which is an example of the synthetic resin molded product which shows suitable embodiment of the manufacturing method of the synthetic resin molded product which concerns on this invention, and a synthetic resin molded product. It is a longitudinal cross-sectional view of the lid | cover shown in FIG. It is a longitudinal cross-sectional view which shows the shaping | molding die for manufacturing the lid | cover shown in FIG. It is a perspective view which shows the surface sheet material for manufacturing the lid | cover shown in FIG. It is a perspective view which shows the sheet material formation process which forms the surface sheet material shown in FIG. 4 from a synthetic resin sheet base material. It is a perspective view which shows the bending die of the press working machine used at a sheet material folding process. It is a top view which shows the state by which the surface sheet material shown in FIG. 4 is bent by the bending die shown in FIG. FIG. 8 is a cross-sectional view taken along line AA in FIG. It is explanatory drawing explaining the shaping | molding process of a synthetic resin molded product. It is explanatory drawing explaining the modification of the shape of the surface sheet material shown in FIG. It is explanatory drawing explaining the modification regarding the surface sheet material shown in FIG. It is explanatory drawing explaining the other modification regarding the surface sheet material shown in FIG. It is explanatory drawing explaining the further another modification regarding the surface sheet material shown in FIG. It is explanatory drawing explaining the example of a form of the tongue piece of the surface sheet material shown in FIG. It is explanatory drawing explaining the crimping | compression-bonding state of the tongue piece of the surface sheet material shown in FIG. It is explanatory drawing explaining the other example of the tongue piece position in the surface sheet material shown in FIG. It is explanatory drawing explaining the other example of the protrusion direction of the tongue piece in the surface sheet material shown in FIG.

  Hereinafter, a preferred embodiment of a method for producing a synthetic resin molded article and a synthetic resin molded article according to the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, for example, a manufacturing method for manufacturing a compact container made of a synthetic resin by injection molding will be described as an example, and as a manufactured synthetic resin molded product, for example, a lid of a compact container will be described as an example. Therefore, the present invention can be applied to a container body of a compact container. FIG. 1 is a perspective view showing a lid. FIG. 2 is a longitudinal sectional view showing the lid.

  As shown in FIGS. 1 and 2, the lid 1 of the compact container of the present embodiment includes an upper surface portion (top surface portion) 2 having a rectangular shape in plan view, and a side surface portion 3 that is suspended from four sides of the upper surface portion 2. The lower surface side has a rectangular recess 4 that is surrounded by the side surface portion 3 and is recessed upward. The container body is the same, and is formed into a three-dimensional shape having a lower surface portion (bottom surface portion) having a rectangular shape in plan view and side portions erected from the four sides of the lower surface portion. And has a rectangular recess recessed downward. The lid 1 has a hinge that is rotatably supported with respect to a container body (not shown) by a side surface portion 3 that is suspended from one of a pair of long side portions that define a rectangular upper surface portion. An engagement piece 6 that is engaged with the container main body and maintains the closed state of the lid 1 is provided on the side surface portion 3 provided from the other side. The side surface portion 3 is provided with a draft angle for removing the molded lid 1 from the mold.

  In the lid 1 of the compact container, the top surface 2a of the upper surface portion 2 and the side surface 3a of the side surface portion 3 are product surface portions. The surface sheet material 7 made of synthetic resin that forms the product surface is applied to these portions, and the lid 1 is insert-molded.

  FIG. 3 is a longitudinal sectional view showing a mold 8 for manufacturing the lid 1. As shown in FIG. 3, the mold 8 used for manufacturing the lid 1 has an upper injection mold 9 and a lower injection mold 10 that are divided in the vertical direction. On the lower surface side of the upper injection mold 9, an upper mold recess 9 a that is recessed upward corresponding to the outer dimensions of the upper surface portion 2 and the side surface portion 3 of the lid 1 is provided. A lower mold protrusion 10a that protrudes upward corresponding to the inner dimension of the provided recess 4 and lower mold recesses 10b and 10c that are recessed downward corresponding to the outer dimensions of the hinge part 5 and the engagement piece 6 are provided. .

  In a state where the upper injection mold 9 and the lower injection mold 10 are overlapped, a molding space that forms the shape of the lid 1 is formed inside, and the molding is formed in the lower mold recess 10b that forms the hinge portion 5 in the lower injection mold 10. A gate 10e of a sprue 10d communicating with the space is connected. Then, the parting positions of the upper injection mold 9 and the lower injection mold 10 are set so that the upper surface 10 f excluding the lower mold protrusion 10 a of the lower injection mold 10 forms the lower surface of the side surface portion 3. In the present embodiment, a slide mold or the like arranged for forming the undercut portion is omitted.

  FIG. 4 is a perspective view showing the top sheet material 7. The surface sheet material 7 is an insert molding resin sheet in which an adhesive layer provided with an adhesive is formed on one surface, and a surface coat layer serving as a product surface is formed on the other surface. As shown in FIG. 4, a portion 7 a that forms the top surface 2 a of the lid 1 and a portion 7 b that forms each side surface 3 a are arranged in a developed view on the product surface of the lid 1. And the surface sheet material 7 is arrange | positioned so that it may be bend | folded in a predetermined position corresponding to the shape of the product surface of the lid | cover 1, and it closely_contact | adheres to the inner surface of the upper mold | type recessed part 9a. At this time, the folding line 7c for folding the surface sheet material 7 into the shape of the product surface is a folding position of the surface sheet material 7 so that the folded surface sheet material 7 is more easily adhered to the inner surface of the upper mold recess 9a. Is provided. The folding line 7c is formed, for example, by linearly connecting the base material surface removal portions from which the base material surface side portion of the synthetic resin sheet base material 11 (see FIG. 5), which is the basis of the surface sheet material 7, is removed. Has been. That is, in the present embodiment, the fold line 7c corresponds to the base material surface layer removal portion.

  FIG. 5 is a perspective view showing a sheet material forming step of forming the surface sheet material 7 from the synthetic resin sheet base material 11. As shown in FIG. 5, the surface sheet material 7 is formed from a synthetic resin sheet base material 11 wound in a roll shape. The synthetic resin sheet base material 11 is not limited to a form wound in a roll shape, but may be a sheet-like flat form. When the surface sheet material 7 is formed, the synthetic resin sheet base material 11 is pulled out on a support base (not shown) so that the synthetic resin sheet base material 11 becomes flat, and the surface sheet is formed by, for example, a laser marker machine 12. The material 7 is separated from the synthetic resin sheet base material 11 and a fold line 7c is formed for folding the material 7 into the shape of the product surface of the lid 1.

  The laser marker machine 12 has a control unit 12b that can control the output of the laser 13 irradiated from the laser irradiation unit 12a. For this reason, the base-material surface removal part (folding line 7c) which removed the site | part by the side of the base-material layer of the synthetic resin sheet base material 11 is formed by controlling the output of the laser 13 irradiated to the synthetic resin sheet base material 11 For example, only the adhesive layer is removed, and a cut 7d penetrating the synthetic resin sheet substrate 11 can be formed.

  The method of forming the surface sheet material 7 is to arrange the synthetic resin sheet base material 11 on the support base so that the adhesive layer side faces upward, and the laser irradiation unit 12a disposed above the synthetic resin sheet base material 11. The surface sheet material 7 is formed by irradiating the laser 13 toward the adhesive layer of the synthetic resin sheet base material 11 (sheet material forming step).

  In the sheet material forming step, the laser irradiation unit 12a and the support base are moved relative to each other to irradiate the laser 13 and continuously penetrate the synthetic resin sheet base material 11 along the contour of the outer shape of the surface sheet material 7. By forming the cut 7d, the top sheet material 7 is separated from the synthetic resin sheet substrate 11. Further, the top surface 2a and each side surface 3a of the lid 1 are formed by removing the adhesive layer of the synthetic resin sheet base material 11 along the boundary between the portions forming the top surface 2a and the side surfaces 3a of the lid 1. A fold line 7c is formed at the boundary of the part to be performed.

  FIG. 6 is a perspective view showing the bending dies 14 and 15 of the press machine used in the sheet material folding step. FIG. 7 is a plan view showing a state in which the top sheet material 7 is bent by the bending dies 14 and 15. 8 is a cross-sectional view taken along line AA in FIG.

  After the surface sheet material 7 formed in the sheet material forming step is placed on the lower bending die 14 of the press machine, it is pressed against the upper bending die 15 from above, thereby forming a valley along the folding line 7c. Folded (sheet material folding step). Of course, you may fold the mountain.

  The lower bending die 14 is formed in the same shape as the contour shape of the surface sheet material 7 on the horizontal upper surface, and is recessed by a slight step, and the contour step portion 14a on which the surface sheet material 7 is placed, and the contour step Inside the portion 14a, a bent concave portion 14b formed on the surface of the product to be formed is formed to be depressed downward. A plurality of small-diameter through-holes 14c communicating with the space below the lower bending die 14 are provided on the bottom surface of the bending die recess 14b.

  The upper bending die 15 has a pressing portion 15a that is inserted into the bending die concave portion 14b of the lower bending die 14 and forms a gap corresponding to the thickness of the surface sheet material 7 between the upper bending die 15 and the inner surface of the bending die concave portion 14b. The upper bending die 15 is moved in the vertical direction with respect to the lower bending die 14, and the pressing portion 15a is provided in the bending die concave portion 14b so as to appear and retract. Then, after the surface sheet material 7 is arranged on the contour step 14a so as to cover the bending die recess 14b with the adhesive layer facing upward, the upper bending die 15 is lowered, and the pressing portion 15a becomes the bending die recess 14b. Is inserted into the front sheet material 7, the surface sheet material 7 is bent along the fold line 7 c. The surface of the folded surface sheet material 7 on the surface coat layer side is formed in the shape of the product surface.

  FIG. 9 is a diagram showing a molding process. When insert-molding the lid | cover 1 provided with the surface sheet material 7, first, as shown to Fig.9 (a), the upper injection mold 9 and the lower injection mold 10 are isolate | separated up and down. Next, as shown in FIG. 9B, the top sheet material 7 that has already been bent as described above is placed in the upper mold recess 9 a of the upper injection mold 9. At this time, since the surface sheet material 7 is bent into the shape of the product surface, the surface sheet material 7 is more closely attached to the inner surface of the upper mold recess 9a when arranged along the inner surface of the upper mold recess 9a. In order to hold the top sheet material 7 appropriately in the upper mold recess 9a, for example, it is desirable to adsorb the top sheet material 7 in the upper mold recess 9a. At this time, the top sheet material 7 is completely accommodated in the upper mold recess 9a so as not to protrude downward from the upper mold recess 9a.

  Next, as shown in FIG. 9C, the upper injection mold 9 and the lower injection mold 10 are overlapped. Thereafter, as shown in FIG. 9D, a molding resin (synthetic resin) is injected from the gate 10e into the molding space, and the surface sheet material 7 and the injected molding resin are integrated (molding process).

  The upper injection mold 9 is a so-called female mold, and the lower injection mold 10 is a male mold. In the illustrated example, a case where a molding resin (synthetic resin) is injected and molded from the lower injection mold 10 toward the upper injection mold 9 is shown. When the upper injection mold 9 is a female mold, each side surface 3a of the folded surface sheet material 7 is disposed along the inner surface of the upper mold recess 9a included in the mold 8 and protrudes from the upper mold recess 9a. Not to be. However, it goes without saying that the molding resin may be injected and molded from the upper injection mold 9 which is a female mold toward the lower injection mold 10 which is a male mold.

  Furthermore, each side surface 3a of the folded surface sheet material 7 may be arranged along the outer surface of the convex portion provided in the mold 8, that is, along the outer surface of the lower mold protrusion 10a of the lower injection mold 10. In this case, the surface sheet material 7 is disposed on the inner surface side of the product, and such a configuration may be adopted.

  The surface sheet material 7 (synthetic resin sheet base material 11) is previously penetrated before the molding step, and air in the molding die 8 is discharged according to the flow of the molding resin into the molding die 8. For this purpose, air vent holes 16 are formed. In particular, the air vent hole 16 is disposed in the vicinity of the resin filling end portion where the molding resin filled in the molding die 8 arrives most late in the molding process. Since the position of the resin filling terminal portion varies depending on the position of the gate 10e and the shape of the molding die 8, the position of the air vent 16 is set according to the actual condition.

  In this embodiment, the air vent 16 is provided in the fold line 7c (base material surface removal portion) (see FIG. 4). In the drawing, the air vent pores 16 are shown so as to be easy to see and protrude from the fold line 7c. It is formed. In the present embodiment, the case where the air vent pores 16 are provided in the fold line 7c has been described. Needless to say, the air vent hole 16a is also referred to in FIG. By forming the air vent pores 16 in the surface sheet material 7, good resin filling can be ensured.

  Next, as shown in FIG. 9E, after the injected molding resin is cured, the upper injection mold 9 and the lower injection mold 10 are separated into upper and lower parts, and the molded lid 1 is removed from the mold. Finally, a useless resin portion connected by the gate 10e is cut off to complete the lid 1 as a synthetic resin molded product.

  According to the method for manufacturing the lid 1 as the synthetic resin molded product according to the present embodiment, the top sheet material 7 that forms the product surface of the lid 1 is bent into the shape of the product surface, and then the upper injection mold for injection molding. 9 is disposed in the upper mold recess 9a, the product surface of the top sheet material 7 can be easily along the inner surface of the upper mold recess 9a. Further, the front sheet material 7 is formed from the synthetic resin sheet base material 11 by forming a cut 7d connected along the contour of the surface sheet material 7 in the synthetic resin sheet base material 11 before being bent into the shape of the product surface. Since they are separated, the ease of handling the top sheet material 7 can be improved. At this time, since the laser 13 was used to form the surface sheet material 7 from the synthetic resin sheet base material 11, the control was easy, the adhesion of the cut powder was small, and the fine adjustment according to the product and molding conditions was easy. Can be done.

  In other words, in the present embodiment, the synthetic resin sheet substrate 11 is arranged so that the surface sheet material 7 easily and reliably follows the shape of the mold 8 when the surface sheet material 7 is inserted into the mold 8. The base material surface layer removal portion (fold line 7c) is provided using the laser 13. The synthetic resin sheet base material 11 has variations in thickness and hardness between lots. However, if the laser 13 is used, the shape and depth of the cut can be immediately and accurately changed and adjusted. Sheet material 7 can be created. Further, when the top sheet material 7 is inserted into the molding die 8, it can be inserted after being folded at the fold line 7c and prepared in a three-dimensional shape. Therefore, in the lid 1 (synthetic resin molded product) having the gate 10e on the outer surface , Can decorate the inner surface.

  Then, by separating the surface sheet material 7 into the developed view shape of the product surface of the lid 1, the surface sheet material 7 provided on the upper surface of the lower bending die 14 has a contour step portion having a step having the same shape as the contour shape. Since it became possible to arrange | position to 14a, when pressing the surface sheet material 7 with the upper bending die 15, it can prevent that the position of the surface sheet material 7 shifts | deviates.

  Further, the front sheet material 7 before being folded is formed with a folding line 7c along the boundary between the portion 7a for forming the top surface 2a of the lid 1 and the portion 7b for forming each side surface 3a. Thus, the surface sheet material 7 can be easily and accurately folded along the fold line 7c. For this reason, the surface sheet material 7 can be bent so that the shape of the product surface can be obtained more accurately than when the surface sheet material 7 is bent simply by being sandwiched between the upper bending die 15 and the lower bending die 14. At this time, since the fold line 7c is formed on the adhesive layer side, it can be folded into an accurate product shape by performing valley fold or mountain fold on the formed fold line 7c without damaging the product surface. it can. Thus, since the surface sheet material 7 is bent so as to form a product surface having a more accurate shape, the surface sheet material 7 is brought into close contact with the inner surface of the upper mold recess 9a of the upper injection mold 9. Can do.

  Further, since the folded surface sheet material 7 is arranged so as not to protrude from the upper mold recess 9a when it is arranged along the inner surface of the upper mold recess 9a, the upper injection mold 9 and the lower injection mold Even when 10 and 10 are overlapped, the position of the top sheet material 7 does not move. For this reason, it is possible to inject the molding resin while maintaining the state in which the surface sheet material 7 is disposed at an accurate position in the upper mold recess 9a. For this reason, the shape transferability of the molding uneven part can be improved, and not only the productivity can be improved, but also the lid 1 having a more accurate shape and an excellent product surface can be manufactured.

  In the said embodiment, although the example which forms the fold line 7c only by removing the contact bonding layer of the synthetic resin sheet base material 11 was penetrated, the synthetic resin sheet base material 11 penetrates a part of the fold line 7c. A cut 7d may be formed. When the cut line 7d is provided in the middle of the fold line 7c, air between the top sheet material 7 and the mold is easily released, so that defects such as air accumulation can be avoided.

  FIG. 10 is a view showing a modification of the shape of the top sheet material 7. As shown in FIG. 10 (a), at least a part of the pattern 7e applied to the product surface is formed so as to penetrate the synthetic resin sheet substrate 11, and as shown in the figure, straddles the folding line 7c. Even if formed in this manner, it is possible to avoid air accumulation defects. Further, as shown in FIGS. 10B and 10C, a recess 7 f that avoids a portion disposed in the vicinity of the gate 10 e may be formed in the surface sheet material 7.

  FIG. 11 shows a modification of the surface sheet material 7 (synthetic resin sheet substrate 11). In this modification, the removal depth D1 at the fold line 7c located near the gate 10e (near the depression 7f) that fills the mold 8 by pouring the molding resin into the mold 8 among the fold line 7c (base material surface removal part). Is formed so that the removal depth D2 at the folding line 7c located far from the gate 10e is deep (D1 <D2).

  According to the flow analysis of the molding resin, when the molding resin is poured into the molding die 8 from the gate 10e (indicated by arrows Y and y in the figure), distortion such as wrinkles may occur in the surface sheet material 7 depending on the fluidity. understood.

  Therefore, the removal depth D1 that forms the fold line 7c located near the gate 10e having a high fluid pressure is made shallow, so that the shape stability is maintained, and on the other hand, it is located far from the gate 10e where the fluid pressure becomes low. The removal depth D2 for forming the folding line 7c is made deep so that the deformation of the surface sheet material 7 is flexible.

  Accordingly, the synthetic resin molded product (lid 1) can be formed so that the thin surface sheet material 7 is stretched without distortion in accordance with the flow property of the molded resin to be poured. Even when the gate 10e is the top sheet material 7 and is disposed in the portion 7a that forms the top surface, it may be set similarly.

  FIG. 12 shows another modification of the surface sheet material 7 (synthetic resin sheet base material 11). This modification also considers the result of flow analysis of the molded resin.

  A gate 10e (recessed portion) that fills the molding die 8 by pouring molding resin into the molding die 8 among the surfaces of the bent surface sheet material 7 that form the side surfaces 7b (indicated by arrows Y and y in the figure). 7 (near 7f), the side surface (for example, the side surface on the side where the hinge portion 5 is formed) is set to have a longer protruding dimension (side surface width dimension) H1 from the fold line 7c (base material surface layer removing portion). The side surface (for example, the side surface on the side where the engagement piece 6 is formed) located far from the gate 10e is set to have a short protruding dimension (side surface width dimension) H2 from the fold line 7c (H1> H2). ).

  That is, in order to prevent distortion such as wrinkles that may occur in the surface sheet material 7 described above, in this modification, the width dimension H1 of the side surface located near the gate 10e where the fluid pressure is high is firmly secured by the molding die 8. The width dimension H2 of the side surface located far from the gate 10e where the flow stability is lowered is set so as to be held long, and on the other hand, the flow pressure is low, so that the holding action by the mold 8 is weakened. Specifically, when the surface sheet material 7 is stretched by a flowable molding resin, the elongation due to the stretching is reduced to the side of the short side (H2 As a result, it is configured so that the surface sheet material 7 can be provided on the synthetic resin molded product (the lid 1) with the dimensions according to the setting and with good appearance.

  Thus, in the same manner as described in the modification of FIG. 11, the synthetic resin molded product (lid 1) is formed so that the thin surface sheet material 7 is stretched without distortion in accordance with the fluidity of the molding resin to be poured. ) Can be formed. Even when the gate 10e is the top sheet material 7 and is disposed in the portion 7a that forms the top surface, it may be set similarly.

  Instead of the illustrated example, filling of the folded surface sheet material 7 by pouring a molding resin into the molding die 8 among the surfaces that form the side portions 7b (indicated by arrows Y and y in the figure) The side surface (for example, the side surface on the side where the hinge portion 5 is formed) located near the gate 10e (in the vicinity of the recessed portion 7f) is projected from the fold line 7c (base material surface layer removing portion) (side width dimension). ) H1 is set short, and the side surface (for example, the side surface on which the engagement piece 6 is formed) located far from the gate 10e is set to have a large protruding dimension (side surface width dimension) H2 from the fold line 7c. Of course, it may be made (H1 <H2).

  Needless to say, the setting of the removal depth described in FIGS. 11 and 12 and the setting of the width dimension of the side surface may be used in combination.

  13 to 17 show still another modification of the surface sheet material 7 (synthetic resin sheet base material 11). This modification also considers the result of flow analysis of the molded resin.

  Among the surfaces of the folded surface sheet material 7, at the edge of one of the adjacent surfaces so that a gap is created when arranged in the recesses 9a, 10b, 10c of the mold 8 In the sheet material forming step, a tongue piece is formed by projecting in order to close the gap and overlap the other surface with the base material surface removal portion sandwiched between the edges.

  Then, the protruding direction of the tongue piece from the end edge is aligned with the flow direction y of the molding resin from the gate 10e for pouring and filling the molding resin into the molding die 8. Thereby, the tongue piece of one surface is crimped | bonded to the other surface with the heat | fever and flow pressure of molding resin. Therefore, it is preferable to employ a heat-sealable material as the synthetic resin sheet substrate 11.

  As shown in FIG. 13 and FIG. 14, the adjacent surface is disposed so as to surround the portion 7 a forming the top surface so that a gap is generated when the molding die 8 is disposed in the upper mold recess 9 a. In addition, it refers to a surface that becomes a portion 7b that forms a side surface when bent.

  When each surface forming these parts 7b is arranged in the upper mold recess 9a provided in the mold 8 to form a synthetic resin molded product (lid 1), in the direction along the part 7a forming the top surface, Adjacent to each other in a state where a gap may occur. In this modification, a tongue piece 17 is provided for the purpose of closing the gap.

  The tongue piece 17 is formed so as to protrude from an edge 7g in a direction along the periphery of the portion 7a forming the top surface on any one of a pair of adjacent surfaces forming the side surface 7b. The tongue piece 17 is formed by sandwiching an additional base material surface layer removing portion, that is, an additional fold line 7h, with respect to the end edge 7g from which the tongue piece 17 is protruded. By the additional folding line 7h, the tongue piece 17 is formed so as to be bendable with respect to the surface to be the portion 7b forming the side surface.

  This tongue piece 17 is included in the outline that is the outer shape of the surface sheet material 7 in the sheet material forming step, and is cut off from the synthetic resin sheet base material 11 as a part of the surface sheet material 7 by forming the cut 7d. Further, the additional fold line 7h located between the tongue piece 17 and the edge 7g is folded at the boundary between the surface 7a that forms the top surface and each surface 7b that forms the side surface. When the line 7c is formed, it is formed together.

  The tongue piece 17 protruding from the edge 7g is bent at an additional fold line 7h when the surface sheet material 7 is placed in the upper mold recess 9a and bent to form a pair of adjacent side surfaces. Overlaid on the other side of the surface to be the portion 7b to close the gap. The tongue piece 17 is formed in such a size that it does not protrude when folded and overlapped.

  FIG. 14 shows a form example of the tongue piece 17. FIG. 14A shows a case where the tongue piece 17 is formed in a fan shape having a central angle slightly smaller than 90 degrees, and is overlapped as shown by a two-dot chain line.

  In FIG. 14B, a curved cut line 7i is formed on the fan-shaped central angle side so as to be continuous with a fold line 7c that folds a surface that becomes a portion 7b that forms a pair of side surfaces adjacent to each other. In this case, the tongue piece 17 has a central angle of about 60 degrees. Compared with the case of FIG. 14 (A), the tongue piece 17 can be smoothly folded by the curved cut 7i.

  In FIG. 14C, a curved fold line 7j is formed on the fan-shaped central angle side so as to be continuous with a fold line 7c that folds a surface that becomes a portion 7b that forms a pair of side surfaces adjacent to each other. This is the case of the tongue piece 17 in which a curved cut 7k is formed outside the folding line 7j so as to follow the curved folding line 7j. Compared with the case of FIG. 14B, the curved fold line 7j and the curved cut line 7k further smooth the folding of the tongue piece 17 and almost completely eliminate the crease. The gap can be closed.

  The protruding direction of the tongue piece 17 from the end edge 7g is along the flow direction 7 of the molding resin from the gate 10e. Molding resin filled in the mold 8 from the gate 10e is filled and filled in the upper mold recess 9a of the mold 8 from the side close to the gate 10e and gradually fills away from the gate 10e.・ Charge progresses.

  That is, the molding resin flows radially into the upper mold recess 9a of the mold 8 around the gate 10e and reaches a position where the upper mold recess 9a is dammed, and thereafter, the form of the upper mold recess 9a is formed. And further flows away from the gate 10e, and fills the upper mold recess 9a.

  When the upper mold recess 9a is rectangular and the gate 10e is formed on the side edge thereof, as shown in FIG. 13, the position of the gate 10e is offset even if the position of the side edge is the center position in the length direction. Even if it is the position, the molding resin is a surface (R) that forms the side surface 7b that forms the side surface on the other side from the surface (P) that forms the side surface 7b that faces the side edge on both sides of the gate 10e. )

  Based on this, the tongue piece 17 is formed on the surface (P) which becomes the portion 7b forming the side surface close to the gate 10e, and protrudes toward the other surface (Q) adjacent to the surface (P). The surface (Q) is formed so as to project toward another surface (R) adjacent to the surface (Q). Then, as shown in FIG. 15, the tongue piece 17 is pressure-bonded to the other surface where the tongue pieces 17 overlap with each other so as not to generate a gap and to be flat by heat and flow pressure of the molding resin.

  In other words, the structure shown in FIGS. 13 to 15 is positioned at the cut 7d that forms the side surface portion 3 so that the top sheet material 7 can be folded, and is sandwiched between the side surface portion 3 and the synthetic resin after the molding step. The piece 17 is connected to one side surface portion 3 among a pair of adjacent side surface portions 3 and 3 divided by the cut line 7d, and the side surface portions 3 and 3 are bent to place the surface sheet material 7 in the molding die 8. When inserted and insert-molded, the cut 7d of the other side surface portion 3 of the pair of side surface portions 3 and 3 where the tongue piece 17 is not connected is formed at the corner portion of the lid 1 (side surface portions 3 and 3). It is arranged along the ridge line formed in (1) and is exposed on the surface of the lid 1.

  When the distance from the gate 10e position where the synthetic resin is poured into the mold 8 and the respective side portions 3 is not uniform, the tongue piece 17 is located with respect to the side portion 3 located farther from the gate 10e position. , And arranged so as not to be exposed on the surface of the lid 1.

  According to the above structure, the continuous pattern 7e can be decorated without a gap without recognizing the trace which piled up the surface sheet material 7 on the whole surface of the lid | cover (synthetic resin molded product) 1. FIG. Specifically, the side surface portion 3 of the top sheet material 7 that covers the peripheral side surface of the lid 1 can be bent independently from each other via the cut line 7d, starting from a fold line 7c formed by the base material surface layer removing portion. is there. Of the pair of side surface parts 3 and 3 adjacent to each other through the cut line 7d, the cut line 7d of the other side surface part 3 is formed at the corner of the lid 1 when the top sheet material 7 is fixed to the surface of the lid 1. And is positioned so as to be exposed on the surface of the lid 1. By doing so, it becomes difficult to recognize the cut 7d exposed on the surface of the lid 1, that is, the ridge line between the side surface portions 3 and 3, and the traces overlapping the side surface portion 3 including the tongue piece 17 can be almost erased. it can.

  At the time of injection molding, the surface sheet material 7 is stretched in the flow direction of the synthetic resin in a molten state, though slightly, by heat and pressure. The degree of stretching increases as the direction of flow of the synthetic resin is increased, and as the flow pressure decreases less. Taking the upper surface 2 of the lid 1 as an example, when the gate 10e is provided at the center of the rectangles having greatly different vertical and horizontal lengths, the side surface 3 connected in the short direction of the upper surface 2 However, the degree of extension is larger than that of the side surface portion 3 connected in the longitudinal direction of the upper surface portion 2. For this reason, if the side piece 3 connected to the short side direction of the upper surface part 2 is provided with the tongue piece 17, the tongue piece 17 moves and its position changes, and there is a gap between the adjacent side parts 3 and 3. Occurs and the synthetic resin is exposed. In order to solve such a situation, the tongue piece 17 is provided on the side surface portion 3 connected in the longitudinal direction of the upper surface portion 2, and the pair of adjacent side surface portions 3 and 3 are located farther from the gate 10e. The tongue piece 17 is disposed on the side surface portion 3 so as to be folded, and the cut 7d of the side surface portion 3 connected in the short direction of the upper surface portion 2 is overlapped thereon.

  In FIG. 13, the case where the four tongue pieces 17 are provided correspondingly to the respective gaps that may be generated at the four corners of the portion 7a forming the top surface having a rectangular shape in plan view has been described, but as shown in FIG. Of course, the formation of any of the tongue pieces 17 may be omitted.

  FIG. 17 shows a case where the gate 10e is formed with reference to the center in the front-rear and left-right directions. In this case, even if the gate 10e is not exactly at the center position but at a position shifted in the front-rear direction or the left-right direction, the molding resin is close to the gate 10e from the surface (P) that forms the side surface 7b. It flows toward the surface (R) that is a portion 7b that forms a side surface that is far from the gate 10e.

  Based on this, the tongue piece 17 is formed to project toward the other surface adjacent to the surface which becomes the portion 7b forming the side surface close to the gate 10e. Then, as shown in FIG. 15, the tongue piece 17 is pressure-bonded to the surface where the tongue pieces 17 overlap with each other in a flat state so that no gap is generated by the heat and flow pressure of the molding resin.

  By providing such a configuration, when there is a portion where a gap may occur, the gap can be formed by the tongue piece 17 that is formed to protrude by the cut line 7d and the fold line 7h, which can be additionally formed in the sheet material forming step. Can be blocked.

  Since the protruding direction of the tongue piece 17 is aligned with the flow direction y of the molded resin, the flow of the molded resin is used to automatically and rationally, without any special procedure, in other words, according to the process. The overlapping of the pieces 17 can be ensured.

  And since the tongue piece 17 was crimped | bonded by the heat | fever and flow pressure of the molding resin, like the superposition, the tongue piece 17 can be rationally automatically, in other words, according to the process, without requiring a special procedure. Can be secured. As described above, by forming the tongue piece 17, a synthetic resin molded product having high form stability and improved strength can be manufactured from the synthetic resin sheet substrate 11.

  Moreover, in the said embodiment, when forming the fold line 7c, although the example which removes only the contact bonding layer of the synthetic resin sheet base material 11 was demonstrated, if it does not penetrate the synthetic resin sheet base material 11, a surface coat layer May be partially removed. Further, when forming the folding line 7c, the adhesive layer may be removed to leave only the surface coat layer, or a part of the adhesive layer may be left.

  Moreover, in the said embodiment, when forming the surface sheet material 7 from the synthetic resin sheet base material 11, the example using the laser 13 was demonstrated, but of course, a Thomson blade etc. may be used.

  Furthermore, although the said embodiment demonstrated and demonstrated the thing of the type opened up and down as the shaping | molding die 8, of course, the shaping | molding die of the type opened to right and left may be sufficient.

DESCRIPTION OF SYMBOLS 1 Lid 2 Upper surface part 2a Top surface 3 Side surface part 3a Side surface 4 Recessed part 5 Hinge part 6 Engagement piece 7 Surface sheet material 7a The part which forms a top surface 7b The part which forms a side surface 7c Folding line 7d Cut 7e Pattern 7f Depression part 7g Edge 7h Additional fold line 7i Curved cut 7j Curved fold line 7k Curved cut 8 Mold 9 Upper injection mold 9a Upper mold recess 10 Lower injection mold 10a Lower mold projection 10b Lower mold recess 10c Lower mold Recess 10d Sprue 10e Gate 10f Lower injection mold top surface 11 Synthetic resin sheet substrate 12 Laser marker machine 12a Irradiation unit 12b Control unit 13 Laser 14 Lower bending die 14a Contour step 14b Bending die recess 14c Through hole 15 Upper bending die 15a Press Part 16 Air vent pore 16a Air vent pore 17 Tongue piece D1, D2 Removal depth H1, H2 Projection dimension Y Flow of y-molded resin

Claims (14)

A synthetic resin molded product manufacturing method comprising insert molding a three-dimensional synthetic resin molded product using a synthetic resin surface sheet material forming a product surface,
A sheet material forming step of forming the surface sheet material from a synthetic resin sheet base material that is the basis of the surface sheet material;
A sheet material folding step of folding the surface sheet material into a predetermined shape;
A molding process in which the folded surface sheet material is placed in a mold and insert molded;
In the sheet material forming step,
Production of a synthetic resin molded article, characterized in that a cut line penetrating the synthetic resin sheet substrate and a substrate surface layer removal portion from which only a portion on the substrate surface layer side of the synthetic resin sheet substrate is removed are formed. Method.   Of the substrate surface layer removal part, the removal depth of the substrate surface layer removal part located near the gate for pouring and filling the synthetic resin into the mold is shallow, and the substrate surface layer located far from the gate The method for producing a synthetic resin molded product according to claim 1, wherein the removal depth of the removal portion is deep.   The surface sheet material is separated from the synthetic resin sheet material by forming the cut line connected to the synthetic resin sheet base material along the contour of the surface sheet material. The manufacturing method of the synthetic resin molded product as described in 2. The base material layer on one side of the two base material surface layers of the synthetic resin sheet base material constitutes a surface coat layer to be the product surface, and the base material surface layer on the other side has an adhesive. Constituting the adhesive layer provided,
The said base-material surface layer removal part is formed in the said contact bonding layer side, The manufacturing method of the synthetic resin molded product in any one of Claims 1-3 characterized by the above-mentioned.   The said sheet | seat material folding process WHEREIN: The said surface sheet material is a valley fold or a mountain fold along the said base-material surface layer removal part formed in a linear form, The one of Claims 1-4 characterized by the above-mentioned. The method for producing a synthetic resin molded article according to item.   The composition according to any one of claims 1 to 5, wherein each surface of the folded top sheet material is disposed along an inner surface of a recess provided in the mold and does not protrude from the recess. Manufacturing method of resin molded product.   Of the respective surfaces of the folded surface sheet material, the surface located near the gate where the synthetic resin is poured into the mold to be filled is set to have a long protruding dimension from the base material surface layer removal portion. The method for producing a synthetic resin molded product according to claim 6, wherein the surface located far from the gate is set to have a short protruding dimension from the base material surface removal portion.   Of the respective surfaces of the folded surface sheet material, the surface located near the gate where the synthetic resin is poured into the mold and filled is set to have a short protruding dimension from the substrate surface layer removal portion. The method for producing a synthetic resin molded article according to claim 6, wherein the surface located far from the gate is set to have a longer protruding dimension from the base material surface removal portion.   The synthetic resin sheet base material is formed with air venting pores penetrating through the synthetic resin sheet base material, and the air venting pores reach the synthetic resin filled in the molding die with the latest delay in the molding step. The method for producing a synthetic resin molded article according to any one of claims 1 to 8, wherein the synthetic resin molded article is disposed near a resin filling terminal portion.   The method for producing a synthetic resin molded product according to claim 9, wherein the air vent pores are provided in the base material surface layer removal portion.   In the sheet material forming step, the base material surface layer removing portion is sandwiched between the edges of any one of adjacent surfaces among the surfaces of the folded surface sheet material. In the form, a tongue piece is formed by projecting to overlap the other surface, and the protruding direction of the tongue piece from the end edge is a synthetic resin from a gate that is filled with a synthetic resin poured into the mold The said tongue piece of the said one surface is crimped | bonded to the said other surface with the heat | fever and flow pressure of a synthetic resin along the flow direction of the above-mentioned. Manufacturing method of synthetic resin molded product. The surface sheet material is foldable and is positioned at the cut that forms the side portion, and the tongue pieces sandwiched between the side portion and the synthetic resin after the molding step are separated by a pair of adjacent the cut pieces. Of the side portions, one of the side portions is connected,
When the side surface portion is bent and the surface sheet material is inserted into the mold and subjected to insert molding, of the pair of side surface portions, the cut of the other side surface portion where the tongue piece is not continuously provided The synthetic resin molded article according to any one of claims 1 to 10, wherein the synthetic resin molded article is disposed along a corner of the synthetic resin molded article and exposed on a surface of the synthetic resin molded article. Manufacturing method.   The tongue piece is disposed so as not to be exposed on the surface of the synthetic resin molded product with respect to the side surface portion located farther from the gate position where the synthetic resin is poured into the mold and filled. The method for producing a synthetic resin molded product according to claim 12.   A synthetic resin product manufactured by the method for manufacturing a synthetic resin molded product according to any one of claims 1 to 13.

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