JP3781161B2 - Blow molded product manufacturing method and blow molded product - Google Patents

Description

【００４７】
【表２】

【００４８】
【表３】

【００４９】
【表４】

【００５０】
【発明の効果】
以上説明したことからも明らかなように、本発明では、パリソンに設けた凹凸により、シートとパリソン間のエアーはブロー成形の賦形時にパリソンの凹凸部から排出され、シートとパリソンが密着し密着強度が向上する。更にエンボス加工したシートを用いることにより一層エアーの抜けが良好となるとともに、アンカー効果でシート材とパリソン材密着が強固となる。またシートの肉厚を０．３ｍｍから３ｍｍとすることにより、ブロー成形時のシートのシワの発生を抑えられ、従来にない外観の良好なブロー成形体が供給可能となる。
【図面の簡単な説明】
【図１】本発明のシート成形の工程の一例を示す説明図である。
【図２】本発明のシート成形の工程の一例を示す説明図である。
【図３】本発明における成形機の構成を示す斜視説明図である。
【図４】本発明におけるブロー成形工程を示す説明図である。
【図５】本発明におけるブロー外径ダイの内壁凹凸部の拡大図である。
【符号の説明】
１ シート成形用押出機
２ 逆Ｌ字ロールユニット
３ シート
４ 艶付きロールユニット
５ ブロー成形用押出機
６ アキュームレーター
７ ブローダイ
８ ブロー金型
９ 樹脂シート
１０ パリソン
１１ 凹凸付きブロー外径ダイ
１２ 溝
１３ 凸条
１４ エアーシリンダー
１５ ブローピン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bonded blow molding method for forming a molded product in which a resin sheet is bonded to a parison surface, and in particular, a blow molded product capable of obtaining a high-quality resin sheet bonded molded product with excellent appearance. The present invention relates to a manufacturing method and a blow molded product.
[0002]
[Prior art]
As a method for obtaining a resin molded product, there are an injection molding method and a blow molding method. The injection molding method is a method in which molten resin is injected into a sealed mold at a high pressure (200 to 1000 kg / cm ² ), and the molding surface of the mold is transferred to the resin. Since the resin pressure is high and the molding surface is accurately transferred, it is suitable for obtaining a molded product having a mirror surface or a grain surface. However, because of the high speed and high pressure, it is difficult to improve the design by forming a film, sheet, or fabric layer on which the design is printed on the surface of the molded product. In addition, because a mold that can withstand high pressure is required, the structure of the mold becomes complicated and expensive, and it is not suitable for high-mix low-volume production. There is also a problem that the production process becomes complicated.
[0003]
In the blow molding method, a parison (melted / softened hollow cylindrical resin) is supplied between molds and then clamped, and a fluid is pumped into the hollow portion to make the outer surface of the parison the molding surface of the mold. This is a method of transferring the image by pressing on the surface. Since it is pressed by the pressure of the fluid, the pressure is relatively low (4 to 10 kg / cm ² ). For this reason, the molding surface is not accurately transferred, which is unsuitable for obtaining a molded product having a mirror surface or a grain surface. However, since it is suitable for mass production of hollow products, it is widely used, and there is a demand for producing a hollow resin molded product having a mirror surface and a grain surface by blow molding in a simple process.
[0004]
On the other hand, the major problems with blow molding are the use of recycled burr and die cleaning when changing materials. Although blow molding differs depending on the molding method and the size of the product, burrs of about 5% to 70% of the product weight are generated. Therefore, in order to reduce the cost of the product, it is indispensable to recycle this burr, but at the same time, it causes external appearance defects such as foreign matter contamination and burnt lines. Cleaning at the time of material change is based on blow die disassembly and cleaning. However, blow dies such as large molding machines and multilayer blow dies that are difficult to disassemble are mainly cleaned by resin purging, with several hours of cleaning time and several hundred kg. This requires more cleaning resin, leading to increased costs and industrial waste.
[0005]
In order to solve such blow molding problems, a blow molded product in which a resin sheet is interposed between the discharged parison and the mold cavity, the mold is clamped, and the resin sheet is bonded to the surface is formed. Production has traditionally been practiced.
[0006]
However, such a conventional bonded blow-molded product has a problem that the resin sheet is torn during blow molding, or the surface of the molded product is wrinkled and the formation of a smooth flat surface is impaired. There is an inconvenience that air intervenes between them to remain as bubbles on the surface of the molded product and the resin sheet and the parison surface do not adhere to the entire surface.
[0007]
In order to solve these problems, for example, in Japanese Patent Application Laid-Open No. Sho 62-255115, a fine hole is provided in a blow mold, and air is actively sucked from the inner surface of the mold to thereby remove the resin sheet from the mold surface. And a method for preventing the generation of wrinkles. However, in this method, air is not sufficiently removed between the parison and the sheet, and depending on the shape of the product, an air pool is generated, which causes a poor appearance.
[0008]
JP-A-8-323847 discloses a method in which a plurality of fine through holes are formed in advance in a resin sheet to be bonded to a parison, and air is actively sucked from the inner surface of the mold after the mold is clamped. In addition, a method is described in which air interposed between the resin sheet and the parison surface is discharged to achieve close contact between the two. However, when a sheet having fine holes is used, there is a problem in that fine hole marks are formed on the product surface and the commercial value is lowered.
[0009]
[Problems to be solved by the invention]
The present invention solves the problems that could not be solved by the above-described prior art, and it is possible to obtain a high-quality bonded blow-molded product that increases the adhesion between the resin sheet and the parison surface and is excellent in surface transferability. The present invention relates to a method for producing a blow-molded product and a blow-molded product.
[0010]
[Means for Solving the Problems]
That is, the present invention relates to a method of manufacturing a blow molded product in which a thermoplastic resin sheet is disposed between a cavity surface of a mold and a parison, and the mold is clamped and pressure is applied from the inside of the parison to form a blow molded article. A method for producing a blow-molded product, characterized by forming irregularities on the mold.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, in the method for producing a blow molded product, a thermoplastic resin sheet is disposed between a cavity surface of a mold and a parison, and the mold is clamped and pressure is applied from the inside of the parison. It is formed and molded. The unevenness of the parison surface is intended to improve the air escape between the parison and the sheet, and to prevent the sheet from adhering and the sheet from swelling.
[0012]
The irregularities on the parison surface are grooves or ridges continuous in the vertical or horizontal direction, and the depth or height is preferably 10 μm to 1 mm. By making the unevenness of the parison surface into continuous grooves or ridges, it is possible to continuously vent the air from when the parison starts to contact the sheet until the shaping is completed.
[0013]
Moreover, the height (depth) of the unevenness is preferably 10 μm or more. By setting it to 10 μm or more, when the parison is pre-blowed, the unevenness does not become too small, and sufficient air bleeding can be performed. On the other hand, when the thickness is 1 mm or more, there is a possibility that uniform shaping may not be possible at the time of shaping, and there may be uneven marks on the product surface. Moreover, as for the width | variety of a groove | channel or a protruding item | line, 10 micrometers-1 mm are preferable.
[0014]
The thermoplastic resin for parison used in the present invention can be used as long as it can be blow-molded. However, when comparing a crystalline resin and an amorphous resin, the amorphous resin is generally a sheet material. Therefore, an amorphous thermoplastic resin is preferable. Examples of the amorphous thermoplastic resin include polycarbonate resin, PPO resin, AS resin, PS resin, HIPS resin, ABS resin, AES resin, ACS resin, acrylonitrile-hydrogenated diene rubber-styrene and / or methyl methacrylate. Graft copolymer comprising, acrylonitrile-silicone rubber-graft copolymer comprising styrene and / or methyl methacrylate, maleimide-styrene and / or acrylonitrile and / or α-methylstyrene graft copolymer, rubber polymer -A graft copolymer consisting of maleimide-styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene and a composite thereof, and a plasticizer, a heat stabilizer, a light stabilizer, a colorant, Add flame retardant and inorganic filler Resin. The melt viscosity of the resin by the capillary method is preferably 10000 poise or more (10 sec ⁻¹ ) at 280 ° C. for polycarbonate resin and PPO resin, and 10000 poise or more at 240 ° C. for other resins. If the melt viscosity is less than 10,000 poise, drawdown is likely to occur during molding, which is not preferable. Examples of the crystalline resin include nylon 6, nylon 66, nylon 46, nylon 610, nylon 11, nylon 12, PBT resin, PET resin, PPS resin, PP resin, PE resin, and composites thereof, and plastics thereof. And a resin to which an agent, a heat stabilizer, a light stabilizer, a colorant, a flame retardant, and an inorganic filler are added. The melt viscosity of the crystalline resin by the capillary wrinkle method is preferably 10,000 poise or more (10 sec ⁻¹ ) at the melting point + 30 ° C.
[0015]
In this invention, it is preferable that the thickness of a thermoplastic resin sheet is 0.3 mm-3 mm. If the thickness of the sheet is less than 0.3 mm, when the parison partially contacts the sheet, it is likely to wrinkle due to heat shrinkage or rigidity difference from the non-contact part, and the preblowed parison is wrapped because the sheet rigidity is low Depending on the shape of the product, it may be difficult to remove air. On the other hand, if it exceeds 3 mm, there may be a problem in the weight balance of the product due to the formability and the difference in thickness between the sheet laminated portion and the non-laminated portion. A more preferable thickness range of the sheet is 0.7 mm to 2.0 mm from the balance of sheet rigidity and weight reduction.
[0016]
In this invention, it is preferable that the embossing is given to the single side | surface or both surfaces of the arrange | positioned thermoplastic resin sheet. In the sheet pasting blow molding of the present invention, the air release between the parison and the sheet is carried out with the unevenness of the parison surface, but it can be carried out more efficiently by embossing the sheet surface, and further the adhesiveness due to the anchor effect. Expected to be up. Further, when embossing is performed on both sides of the sheet, air venting between the mold and the sheet is further improved, and a more preferable molded product is obtained.
[0017]
In this invention, it is preferable that the arrange | positioned thermoplastic resin sheet consists of at least 1 or more types of thermoplastic resins chosen from the styrene resin, the acrylic resin, and the polycarbonate resin.
[0018]
The styrene resin used in the sheet is, for example, an AS resin, PS resin, HIPS resin, ABS resin, AES resin, ACS resin, acrylonitrile-hydrogenated diene rubber-graft copolymer composed of styrene and / or methyl methacrylate, acrylonitrile. -Graft copolymer consisting of silicone rubber-styrene and / or methyl methacrylate, maleimide-styrene and / or acrylonitrile and / or graft copolymer consisting of α-methylstyrene, rubber polymer-maleimide-styrene and / or acrylonitrile And / or a graft copolymer composed of methyl methacrylate and / or α-methylstyrene and a composite thereof, and a resin obtained by adding a plasticizer, a heat stabilizer, a light stabilizer, a colorant, and a flame retardant to these. It is done.
[0019]
The sheet used in the present invention may be a single layer, but by using a multilayer sheet, a highly functional product can be obtained at a low cost with a simple process. For example, by using a thermoplastic resin with a light stabilizer added to the resin layer on the surface side of the product and a resin without a light stabilizer added to the parison side layer, an inexpensive and good light-resistant molded product can be obtained. can get. Further, by using a resin having a high surface hardness for the layer on the surface side of the product and an impact-resistant resin for the back layer, a product that is hardly damaged and has a high impact strength can be obtained.
[0020]
The sheet used in the present invention can be produced by any known method. For example, a thermoplastic resin is introduced into a hopper of an extruder, melted and kneaded in the extruder, and the sheet-like flow is performed in a T-shaped die. And discharged in the horizontal direction, and the thickness is adjusted by a roll unit.
[0021]
At this time, if the roll of the roll unit is a glossy unit, a sheet having a glossy surface is obtained, and if an embossed roll is used, a wrinkled sheet is obtained. Furthermore, if two extruders and a T die having a two-layer structure are used, a sheet having a two-layer structure can be obtained.
[0022]
The production method of the present invention is preferably used for large blow molded products having a blow molded product weight of 1 kg or more. In the sheet bonding blow, heat for softening the sheet and welding with the parison material is supplied from the parison. Therefore, the parison needs to be thick to some extent, and it is desirable for achieving the object of the present invention that the parison can obtain a product of 1 kg or more.
[0023]
Examples of the molded article suitably molded according to the present invention include a housing, a sports product, a playground equipment, a vehicle product, a furniture product, a sanitary product, a building material product, and a kitchen product. Specific examples of these molded products include, for example, a cooler box, a TV, an audio device, a printer, a FAX, a copying machine, a game machine, a washing machine, an air conditioner, a refrigerator, a vacuum cleaner, an attache case, a musical instrument case, and a tool. There are boxes, containers, camera cases, etc. Examples of sports products include swimming boards, surfboards, windsurfing, skiing, snowboarding, skateboarding, ice hockey sticks, curling balls, gateball rackets, canoes, and boats. Examples of play equipment include bats, blocks, blocks, fishing tackle cases, and pachinko frame frames. Vehicle products include air spoilers, doors, bumpers, fenders, bonnets, sunroofs, rear gates, wheel caps, instrument panels, glove boxes, console boxes, armrests, headrests, fuel tanks, driver seat covers, trunk tool boxes, etc. is there. Furniture products include, for example, drawers, desk tops, bed tops / bottoms, head frame frames, box boxes / front doors, chair backs / bottoms, trays, trays, umbrella stands, vases, medicine boxes, hangers, There are decorative boxes, storage box plates, trash cans, book stands, office desk top plates, OA desk top plates, OA racks, and the like. Examples of sanitary products include shower heads, toilet seats, toilet plates, drain pans, water tank lids, vanity doors, bathroom doors, and the like. Examples of building material products include ceiling boards, floor boards, wall boards, window frames, doors, benches, and the like. Examples of kitchen products include cutting boards and kitchen doors. In addition, these are illustrations, and molded articles other than these can also be suitably molded.
[0024]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
The formability and appearance of the sheet-bonded blow described in the examples and comparative examples described below were measured by the following methods.
[0025]
The blow molding machine uses Φ90mm made by Placo, blow molding using ABS resin “Toyolac” TH10 manufactured by Toray Industries, Ltd., and thermoplastic resin sheet using the resin material and thick sheet shown in Table 1. did. As the mold, a square bottle having a height of 700 mm and a size of 400 mm × 200 mm was used.
The weight of the blow molded product is about 2.8 kg.
[0026]
[Formability]
After blow molding by the above method, the product was taken out from the mold and the shaping state was visually determined according to the following criteria.
◎: No deformation of the molded body ○: Almost no mold deformation of the molded body △: There is a slight deformation of the molded body due to insufficient elongation of the sheet ×: There is a deformation of the molded body due to insufficient elongation of the sheet [0027]
[Appearance]
After blow molding by the above method, the product was taken out from the mold and the shaping state was visually determined according to the following criteria.
◎: Air accumulation, no wrinkles ○: Air accumulation, some wrinkles △: Air accumulation, wrinkles ×: Air accumulation, wrinkles, swollen 【0028】
Comparative Example 1
Sheet forming: ABS resin “Toyolac” 100 manufactured by Toray Industries, Inc. is placed in the hopper of a Φ50 mm extruder (1) as shown in FIG. 1, melted and kneaded in a cylinder set at 220 ° C., and then sheeted with a T-die. The sheet (3) having a thickness shown in Table 1 was obtained by extruding in a vertical direction as a flow of the material and rolling with an inverted L-shaped calendar roll (2) adjusted to 100 ° C.
[0029]
Blow molding: As shown in FIG. 3, after a resin sheet (9) having a predetermined size is attached to the parting surface so as to cover the cavity surface of the mold, a φ90 mm extruder (5) manufactured by Plako Toray Co., Ltd. ABS resin “Toyolac” TH10 is put into the hopper of this product, melt-kneaded in a cylinder set at 225 ° C., fed to the accumulator (6), and then annularly formed in a die (7) set at 230 ° C. Was extruded outside the die to form a parison (10) having a diameter of about 360 mm, a length of about 1000 mm, and a wall thickness of 5 mm.
[0030]
Next, as shown in FIG. 4a, the top and bottom of the parison were pre-pinch with an air cylinder (14). Furthermore, as shown in FIGS. 4b to 4c, air was blown through a blow pin (15) and mold clamping was started to form a square bottle. The product was removed after the product had cooled sufficiently in the mold.
[0031]
In Comparative Example 1, there was no problem in formability, but air omission between the sheet and the parison was bad, and air accumulation, swelling of the molded product due to the air accumulation, and generation of wrinkles of the sheet were observed.
[0032]
Example 1
Sheet molding was carried out in the same manner as in Comparative Example 1 to obtain thick sheets as shown in Table 1.
Blow molding: An uneven blow die with 100 Φ90 mm extruders (5) manufactured by Plako Corp. and 100 grooves (12) having a depth of 1 mm and a width of 1 mm on the lip portion of the outer diameter die as shown in FIG. (11) was attached. The obtained resin sheet was attached to the parting surface so as to cover the cavity surface of the mold. The Toray Co., Ltd. ABS resin “Toyolac” TH10 is put into the hopper, melted and kneaded in a cylinder set at 225 ° C., supplied to the accumulator, and then extruded out of the die as an annular flow in the die set at 230 ° C. A parison with a convex strip having a diameter of about 360 mm, a length of about 1000 mm, and a wall thickness of 5 mm was formed. The height of the convex portion at this time was about 0.8 mm. Next, the bottom of the parison was pre-pinch, air blown, and mold clamping started to form a square bottle. The product was removed after the product had cooled sufficiently in the mold.
[0033]
In Example 1, the occurrence of slight wrinkles was observed, but other problems did not occur, and it can be seen that the projections of the parison are very effective for venting air.
[0034]
Comparative Examples 2-3
Sheet forming: As shown in FIG. 2, ABS resin “Toyolac” 100 manufactured by Toray Industries, Inc. was put into the hopper of a Φ50 mm extruder (1), melted and kneaded in a cylinder set at 220 ° C., and then sheeted with a T die. Extruded in a horizontal direction. The extruded molten resin was taken up by a glossy roll unit (4) whose temperature was controlled at 80 ° C. to obtain a resin sheet (3) having a width of 700 mm, a length of 1000 mm, and a thickness shown in Table 1. Blow molding was the same as in Comparative Example 1.
[0035]
In Comparative Example 2, no problem was found in the moldability, but as in Comparative Example 1, air accumulation was confirmed. In Comparative Example 3, the thickness of the sheet was sometimes too thick, the shaping was insufficient, and only a molded body that was out of shape was obtained.
[0036]
Examples 2-4
Sheet molding was carried out in the same manner as in Comparative Example 2, and the thick sheets shown in Table 1 were obtained. Blow molding was the same as in Example 1. In Examples 2 to 4, there was no problem in moldability and appearance, and very good molded articles were obtained. It can be seen from Examples 1 to 4 that the preferred sheet thickness of the present invention is 0.3 to 3 mm.
[0037]
Examples 5 to 7 and Comparative Example 4
Sheet molding was performed in the same manner as in Example 3, and blow molding was performed in the same manner as in Example 3 except that the groove depth of the blow die was changed and the convex height generated in the parison was changed to Table 2.
[0038]
In Examples 5 and 6, air removal was good and no air pool was found, but in Example 7, a slight air pool was observed. In Comparative Example 4, the air venting was good, but the trace of the convex part of the parison was generated on the surface of the molded body, and a preferable one was not obtained.
[0039]
From the results of Examples 3 and 5 to 7, it can be seen that the height of the convex portion of the parison surface, which is favorable for air bleeding of the sheet and the parison, is 10 μm to 1 mm.
Example 8 and Comparative Example 5
[0040]
In sheet forming, the same procedure as in Example 7 and Comparative Example 2 was performed except that the second roll of the roll unit was an embossed roll having an average roughness (Rt) of 4.5 microns. By embossing the sheet surface on the side in contact with the parison, the air escape is improved, but it can be seen that the air pool cannot be completely eliminated if the parison has no irregularities.
[0041]
Example 9
In sheet molding, the same procedure as in Example 7 was performed except that the second and third rolls of the roll unit were embossed rolls having an average roughness (Rt) of 4.5 microns. When both surfaces of the sheet are embossed as in this embodiment, not only air accumulation between the sheet and the parison but also air accumulation between the sheet and the mold can be prevented, and a more preferable molded body can be obtained.
[0042]
Example 10
The same procedure as in Example 3 was conducted except that the sheet material was polycarbonate resin “Panlite” L1250Y manufactured by Teijin Chemicals Limited. It can be seen that even if the sheet material is polycarbonate, a good molded body can be obtained in the same manner as the ABS resin. .
[0043]
Example 11
The same procedure as in Example 3 was performed except that the acrylic resin “Acrypet” V manufactured by Mitsubishi Rayon Co., Ltd. was used as the sheet material. When an acrylic sheet was used, the elongation of the resin was small compared to the ABS resin, and a slight shaping failure occurred at the corner (the portion with the highest blow ratio) of the molded body.
[0044]
Example 12
Sheet molding: Acrylic resin “Acrypet” V manufactured by Mitsubishi Rayon Co., Ltd. is placed in one of the hoppers of two Φ50 mm extruders, and ABS resin “Toyolac” 100 manufactured by Toray Industries, Inc. is introduced into the hopper of the other extruder. The same procedure as in Example 1 was performed except that the mixture was melt-kneaded in a cylinder set at 220 ° C. to form a two-layer plate-like flow in a multilayer T-die. The thickness of the sheet was set to a total of 1.5 mm including an acrylic resin layer of 0.5 mm and an ABS resin layer of 1.0 mm. Blow molding was the same as in Example 3.
Since the 1.5 mm acrylic sheet is inferior in resin elongation at the time of softening compared to the ABS sheet, it is liable to cause poor shaping to form a deep-drawn molded article or to tear the sheet. Therefore, by using a two-layer sheet in which the acrylic resin layer is thinly laminated on the ABS resin layer as in Example 10, a molded body having both the moldability of the ABS resin, the surface hardness and gloss of the acrylic resin can be obtained.
[0045]
Example 13
Sheet molding was the same as in Example 3. As shown in FIG. 5c, the blow molding was performed except that a blow die having 100 ridges (13) having a height of 0.5 mm and a width of 1 mm was attached to the lip portion of the outer die at intervals of about 5 mm. Same as 3. Formability and appearance are good, and no particular problem is seen. Therefore, it can be seen that the air between the parison and the sheet can be removed by either unevenness of the parison surface.
[0046]
[Table 1]

[0047]
[Table 2]

[0048]
[Table 3]

[0049]
[Table 4]

[0050]
【The invention's effect】
As is clear from the above explanation, in the present invention, due to the unevenness provided in the parison, the air between the sheet and the parison is discharged from the uneven portion of the parison when forming the blow molding, and the sheet and the parison are in close contact with each other. Strength is improved. Further, by using the embossed sheet, air escape is further improved, and the adhesion between the sheet material and the parison material is strengthened by the anchor effect. Further, by setting the thickness of the sheet from 0.3 mm to 3 mm, the occurrence of wrinkling of the sheet at the time of blow molding can be suppressed, and a blow molded body having an unprecedented appearance can be supplied.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of a sheet forming process of the present invention.
FIG. 2 is an explanatory diagram showing an example of a sheet forming process of the present invention.
FIG. 3 is a perspective explanatory view showing a configuration of a molding machine according to the present invention.
FIG. 4 is an explanatory view showing a blow molding process in the present invention.
FIG. 5 is an enlarged view of an inner wall uneven portion of a blow outer diameter die in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sheet forming extruder 2 Inverted L-shaped roll unit 3 Sheet 4 Glossy roll unit 5 Blow molding extruder 6 Accumulator 7 Blow die 8 Blow mold 9 Resin sheet 10 Parison 11 Contoured blow outer diameter die 12 Groove 13 Convex Article 14 Air cylinder 15 Blow pin

Claims (6)

In the method of manufacturing a blow molded product in which a thermoplastic resin sheet is placed between a cavity surface of a mold and a parison, the mold is clamped and pressure is applied from the inside of the parison, unevenness is formed on the surface of the parison. A method for producing a blow-molded product, comprising molding. The method for producing a blow-molded product according to claim 1, wherein the irregularities on the parison surface are continuous grooves or ridges in the vertical or horizontal direction, and the depth or height thereof is 10 µm to 1 mm. The blow molded product manufacturing method according to claim 1 or 2, wherein the thickness of the arranged thermoplastic resin sheet is 0.3 mm to 3 mm. The method for producing a blow-molded product according to any one of claims 1 to 3, wherein embossing is performed on one side or both sides of the arranged thermoplastic resin sheet. The arranged thermoplastic resin sheet is composed of two or more layers, and each layer is composed of at least one thermoplastic resin selected from styrene resin, acrylic resin, and polycarbonate resin. 4. A method for producing a blow molded product according to any one of 4 above. A blow molded product having a product weight of 1 kg or more produced by the production method according to claim 1.

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