JP2837380B2 - Low-foaming ethylene polymer resin deep drawn product and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a moderate flexibility,
The present invention relates to a deep-drawn molded article and a method for producing the same.

[0002]

2. Description of the Related Art Various molded articles such as containers, inner cases (guess), trays and underlays manufactured by thermoforming methods such as vacuum molding, air pressure molding, vacuum / pressure molding, and embossing of thermoplastic resin sheets are known. It is widely used because it is relatively inexpensive. However, some of these compacts are rigid,
There were problems that the rigidity was too large to be used, that it was easy to get injured when cracked, and that it wanted to improve the feel when touched.

[0003] More specifically, in the case of a sheet in which a concave portion conforming to the shape of an article is formed, for example, an IC storage case or a metal can storage case is too rigid to easily damage a product to be stored. In case of glass products such as cosmetics and liquor, it is easy to drop glass products etc. because it is slippery, or it is too hard to use with pads etc. that are in contact with the human body, or face or fingers in broken parts for toys etc. There were problems such as easy injury. Therefore, in the case of the above specific example, at present, a paper sheet laminated with a velvet cloth, a cloth product containing cotton, or a highly foamed resin sheet is used.

[0004] However, there is a problem that it is difficult to give a high-quality feeling to paper, and that the production process becomes complicated and costs increase for cloth products. In a highly foamed resin sheet, for example,
In the case of expanded polystyrene, there is a problem that the material is too hard to recover when deformed, it is difficult to maintain the initial shape, and it is not suitable for sheet thermoforming. In the case of foamed polyurethane, there is a problem that the thermoforming of uniform and good deep drawn sheets cannot be performed except for the material being too hard. There is a problem that it can not fit properly.

[0005]

Therefore, foamed polyethylene can be considered as a highly foamed resin sheet material.
When performing thermoforming, the foam cells are easily broken, and when deep-drawing or forming at an acute angle in order to sharply shape the drawn shape, the foam cells are broken when the foam is locally strongly stretched. There is a problem that a deep drawn compact having a clear shape or a complicated drawn shape cannot be formed, and a good compact cannot be obtained. Therefore, the present invention provides a low-foamed ethylene polymer resin deep-drawn molded article having moderate flexibility and capable of performing deep-drawn molding with a sharp drawn shape while maintaining a good foamed state, and a method for producing the same. The purpose is to provide.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have used a low-foaming ethylene polymer resin sheet having a specific property and thermoformed it. Based on the finding that the above object can be achieved, the present invention has been completed. That is, the deep drawn molded article of the present invention has a melt flow rate of 0.1 to 10 g / 10 minutes and a melt tension of 2 to 20 g.
g of an ethylene polymer resin having an expansion ratio of 1.01
３3 times. Further, the method for producing a deep drawn molded article according to another invention of the present invention is characterized in that the melt flow rate containing a foaming agent is 0.1 to 10 g / 1.
0 minutes, the melt tension is extruded from 2 to 20 g of ethylene polymer resin to form a foam sheet having an expansion ratio of 1.01 to 3 times, and the foam sheet is laminated with another base material layer,
Alternatively, it is characterized by being thermoformed without lamination.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION [I] Raw Materials (1) Ethylene Polymer Resin (a) Kind As the ethylene polymer resin constituting the deep drawn molded article of the present invention, a homopolymer of ethylene or ethylene is mainly used. And a copolymer of this with another α-olefin and / or another unsaturated monomer. Examples of the α-olefin include about 3 to 12 carbon atoms, such as propylene, butene-1, 3-methylpentene-1, 4-methylpentene-1, hexene-1, and octene-1, and preferably 3 to 8 carbon atoms. Α-olefins. Examples of the other unsaturated monomers include, for example, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, and maleic anhydride, and derivatives thereof; vinyl acetate, vinyl butyrate, and the like. Esters; unsaturated aromatic monomers such as styrene, methylstyrene and divinylbenzene; and vinylsilanes such as vinyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

Among these, ethylene polymer resins which are preferable in terms of foam moldability and vacuum moldability include a low-density ethylene homopolymer produced by a high-pressure method, ethylene and vinyl acetate containing mainly ethylene, acrylic acid, and acrylate. , A copolymer of methacrylic acid, methacrylate, etc .; a high-density ethylene homopolymer produced by a medium-low pressure method, ethylene and propylene containing ethylene as a main component, and butene-
And linear copolymers with other α-olefins such as 1, hexene-1, and octene-1. These copolymers are not limited to binary copolymers, but may be terpolymers or more. Among these, particularly preferred ethylene polymer resins are low-density ethylene homopolymer (LDPE) produced by a high-pressure method, ethylene-vinyl acetate copolymer (EVA), and high-density ethylene homopolymer produced by a medium-low pressure method. It is a polymer (HDPE), a linear copolymer of ethylene and another α-olefin (L-LDPE). The content of the α-olefin and / or other unsaturated monomer in the ethylene polymer resin in the ethylene polymer resin may be in a range in which ethylene is the largest component as long as the effects of the present invention are not significantly impaired. However, it is generally preferably 30% by weight or less, particularly preferably 15% by weight or less.

(B) Physical properties The physical properties of the ethylene polymer resin are as follows: MFR (melt flow rate) is 0.1 to 10 g / 10 min, preferably 0.1 to 10 g / 10 min.
2 to 8 g / 10 min, particularly preferably 0.3 to 6 g / 10
In minutes, the MT (melt tension) is 2 to 20 g, preferably 3 to 16 g, particularly preferably 4 to 12 g. Further, the ethylene polymer resin generally has a Q value (molecular weight distribution) of 2 to 9, and Preferably it is 3 to 8, particularly preferably 4 to 7. If the value of the MFR is too low, the surface gloss of the foam becomes poor, while if it is too high, the mechanical strength becomes poor. When the MT value is too low, it is difficult to obtain a high-magnification foam, while when it is too high, the foam cells become rough. If the value of the Q value is too low, vacuum formability tends to decrease, while if it is too high, the impact strength of the foam tends to deteriorate.

(2) Foaming agent As the foaming agent, various ones can be used as long as they are used for low foaming. For example, chemical foaming agents such as azodicarbonamide, sodium bicarbonate / citric acid, sodium bicarbonate and the like can be used. Although a physical foaming agent such as butane, pentane, hexane, and butanol may be used, the use of the above-mentioned chemical foaming agent is preferable in that an appropriate amount of gas can be generated for low foaming. These foaming agents can be used in combination. Among these blowing agents, it is particularly preferable to use azodicarbonamide. The amount of the foaming agent used is generally 0.01 to 0.2% by weight, preferably 0.0 to 0.2% by weight.
2 to 0.1% by weight, particularly preferably 0.02 to 0.07%
It is blended in a ratio of weight%.

(3) Other compounding agents (optional components) In the ethylene polymer resin constituting the deep drawn product of the present invention, other than the above-mentioned foaming agent, other than the above-mentioned foaming agent, as long as the effects of the present invention are not significantly impaired. Optional components can be blended.
As this optional component, for example, for the purpose of adjusting physical properties and appearance, etc., an elastomer component or another resin component, or
Antioxidants, heat stabilizers, light stabilizers, coloring agents, antistatic agents, antibacterial agents, fungicides, rust inhibitors, foam regulators (foaming accelerators), foaming agent decomposition temperature regulators, neutralizers, Conductivity imparting agent, dispersant, molecular weight modifier (radical generator, etc.), crosslinking agent, crosslinking aid, nucleating agent, filler, lubricant, flame retardant, flame retardant aid, processing aid, heavy metal deactivator And various additive components such as a plasticizer, a fluorescent brightener, a release agent, a softener, and a gloss-imparting agent.

[II] Production of Deep-Drawn Article The various methods can be used to produce the deep-drawn article of the present invention. Generally, the above-mentioned blowing agent is mixed with the above-mentioned ethylene polymer resin. The mixture is melt-kneaded and extruded to produce a low-expanded ethylene polymer resin sheet (foamed sheet), which is then subjected to thermoforming such as vacuum forming, pressure forming, vacuum / pressure forming, and stamping. It is preferable to produce deep drawn articles of various shapes.

(1) Production of low foamed ethylene polymer resin sheet (foam sheet) (a) Molding conditions The above foaming agent is blended with ethylene polymer resin, and these are mixed with a usual kneading extruder, for example, a single screw extruder. In a twin screw extruder or the like, the resin temperature is generally 170 to 240 ° C., preferably 1 to 240 ° C.
The mixture is melt-kneaded under a temperature condition of 80 to 230 ° C. and extruded from a slit of a die to obtain an expansion ratio of 1.01 to 3.
Times, preferably 1.1 to 2 times, particularly preferably 1.3 to 2 times.
Foamed 1.8 times, the thickness is generally 0.1-5mm,
Preferably, a low foamed ethylene polymer resin sheet (foamed sheet) of 0.2 to 3 mm can be produced. This sheet is obtained as a non-crosslinked low foam sheet. If the foaming ratio is too low, inferior flexibility can be obtained,
In the next thermoforming step, beautiful shaping may not be possible. On the other hand, if the expansion ratio is too high, molding will be defective in the next thermoforming step. The foam sheet obtained here is
Also in the later-described thermoforming, since the foaming state can be formed without pulling while maintaining a good foamed state, the drawn shape can be clearly formed, which is preferable. By the above molding, a large number of foam cells are generated in the foam sheet,
In the foam sheet of the present invention, the foam cells are fine, they are uniform, and the average size of the foam cells is generally 0.0
What is in the range of 5 to 0.5 mm, preferably 0.1 to 0.4 mm, particularly preferably 0.15 to 0.3 mm, the foam cells are hardly broken even when thermoformed later,
This is preferable because the drawn shape can be clearly obtained while the foaming state is maintained well. The average size of such a foam cell can be adjusted by appropriately selecting the type and amount of the foaming agent, and the conditions at the time of compounding.

(B) Lamination The low-expanded ethylene polymer resin sheet (foamed sheet) can be subjected to thermoforming by itself, but it can be laminated with another material sheet (base layer). It can also be subjected to thermoforming as a laminated body. By laminating with such another material sheet (substrate layer), it is possible to obtain a more beautiful one with improved shape and rigidity, a molded body with excellent feel, and the like. In particular, by laminating with a woven or nonwoven fabric, there is also an advantage that a drawdown at the time of vacuum forming described later can be prevented.

Examples of the laminated base material sheet (base layer) include, for example, an unfoamed resin (ethylene polymer, propylene polymer, styrene polymer, etc.) sheet, another foamed resin sheet, and an elastomer ( Ethylene / propylene copolymer rubber, ethylene / butene copolymer rubber, styrene / butadiene copolymer rubber, styrene / butadiene / styrene block copolymer hydrogenated product, styrene / isoprene / styrene block copolymer hydrogenated product, Butadiene rubber etc.) sheet,
Alternatively, a woven or non-woven fabric of polyester fiber, nylon fiber, polypropylene fiber, or the like can be used.
Among these other base material layers, it is preferable to use a polyethylene foamed sheet, a woven or non-woven fabric of polyester resin or nylon resin, or the like. In addition, various functional agents described in the above optional components, for example, an antistatic agent, an antibacterial agent, an antifungal agent, a rust inhibitor, a conductivity imparting agent, a flame retardant, a coloring agent, and the like may be added to an ethylene polymer resin foam sheet and / or Alternatively, a thermoformed article having the respective functions can be obtained by containing it in a base material layer laminated therewith.

(2) Thermoforming The above low foamed ethylene polymer resin sheet (foamed sheet)
In the state of being heated and softened by various thermoforming methods such as vacuum forming method, pressure forming method, vacuum / press forming method, and embossing method shown below, external force is applied thereto by means such as vacuum or pressure. After adding and deforming the mixture to form them into various shapes and then cooling, the deep drawn molded article of the present invention can be obtained. (A) Vacuum forming method In the vacuum forming method, only one of a female mold and a male mold is used, and after heating and softening a foamed sheet, the foamed sheet is placed on a mold and a gap between the sheet and the mold is formed. Is applied to the surface of a mold by applying a vacuum, and the sheet is cooled and molded.
Specifically, straight molding, drape molding, plug assist molding, plug assist reverse draw molding, air slip molding, snapback molding, reverse draw molding, plug assist air slip molding, free molding, match molding, plug ring Various known molding methods such as molding, slip molding, and contact heating molding can be employed. (B) Pressure forming method The pressure forming is a method in which a sheet heated and softened with compressed air is pressure-bonded to a mold instead of using the atmospheric pressure in the vacuum forming. (C) Vacuum / pressure forming method The vacuum / pressure forming method is a method of forming by combining the vacuum forming and the pressure forming. (D) Embossing Method As the embossing method, a method in which a heat-softened foam sheet is inserted between upper and lower base plates and pressed by a mold to form the foam sheet, or a foam sheet is heated as it is This is a method of molding by pressing. The thermoforming is carried out by a usual thermoforming device according to a conventional method.

[0017] deep drawing in general thermoforming of the foam sheet, as the shape aperture while maintaining good foaming state out clearly, it is difficult to perform deep drawing narrow to more than a depth of typically 30 mm, the In the present invention, surprisingly, deep drawing can be performed to a depth of 30 mm or more, preferably 40 mm or more, particularly preferably 50 mm or more. In the deep drawing, since the sheet surface and the deep drawn wall surface can be bent and formed to an angle of about a right angle, extremely to an inverse taper, the drawn shape can be formed clearly. . At this time, advanced deep drawing can be performed because the foamed cells are fine and their dimensions are uniform, so that the foamed cells are not broken even during thermoforming, and a good foamed state is maintained. It is presumed that this is because deep drawing can be performed uniformly without bias in one direction. It was surprising that the deep drawing as described above was achieved by using the low foamed ethylene polymer resin sheet (foamed sheet) as a thermoforming material as in the present invention.

(3) Cutting The deep drawn molded article thermoformed into the above-mentioned various shapes is cut so as to conform to various uses, and cut off from the foamed sheet on the thermoforming machine. It is carried out by a method of punching. At this time, in the ethylene polymer resin raw material, it is preferable to previously add a small amount of a material which is usually used as a polyolefin antiblocking agent, since the blade separation at the time of cutting is good and the punching property becomes good. .

[III] Deep-Drawn Molded Article (1) Shape The deep-drawn molded article of the present invention thus obtained has an ethylene polymer resin having an expansion ratio of 1.01 to 3 times (preferably having a thickness of 0 to 0). .1 to 5 mm) on which a concave portion 2a and a convex portion 2b are formed (preferably formed by deep drawing to a depth of 30 mm or more on at least a part of the molded body). An ampoule case 1 in which a concave portion 2a conforming to the shape of an ampoule is formed in a low-foaming ethylene polymer resin sheet 2 as shown in FIG. 1 or a low-foaming ethylene polymer resin sheet layer as shown in FIG. Highly foamed polyethylene resin sheet on back side of 2 (expansion ratio 30 times)
4 is laminated on a laminated sheet 5 in which a concave portion 2a conforming to the shape of the can is formed. Alternatively, as shown in FIG. This is a molded product such as an inner case (guess) 10 or the like in which a concave portion 2a conforming to the shape of a wine bottle 9 or the like is formed in a laminated sheet 8 on which a woven fabric layer 7 is laminated.

[IV] Applications Since the low-foaming ethylene polymer resin sheet of the present invention can be subjected to deep drawing at a large depth, it can be applied to various deep drawn products applied to various applications. Can be molded. Examples of the use of the deep drawn product include:
For example, an ampoule case as shown in FIG. 1, an inner case for can storage as shown in FIG. 2, an antistatic storage case such as an IC,
Inner case for glasses, distribution tray, instant food container,
The inner case (guess) of liquor or the like in which a woven fabric is laminated on the surface as shown in FIG. 3, or the inner case (guess) of cosmetics, drinks, etc., and a metal for storing a gloss agent such as wax or oil Also used as a buffer holder (holder for preventing damage to contact with metal cans, etc.) fitted to the surface of containers such as cans, insoles, pads for bras, padding for hats, masks for toys, binders for documents, etc. can do.

[0021]

The present invention will be described more specifically with reference to the following experimental examples. [I] Raw materials (a) Ethylene polymer LD / PE (high-pressure low-density ethylene homopolymer): MFR 4 g / 10 min,: MT 5 g: Q value 6.2 LD / PE (high-pressure low-density ethylene homopolymer): MFR 0.3 g / 10 min,: MT 12 g: Q value 6.0 EVA (ethylene / vinyl acetate copolymer): MFR 0.5 g / 10 min,: MT 11 g: Q value 5.5 HD / PE (high-density ethylene) Homopolymer): MFR 0.6 g / 10 min,: MT 9 g: Q value 5.6 L-LD / PE (copolymer of ethylene and 7 wt% butene-1): MFR 0.8 g / 10 min, : MT 5g: Q value 7.0

(B) Blowing agent AA: azodicarbonamide CS: 1: 1 mixture of sodium bicarbonate and citric acid

(C) Laminated material Polyester woven fabric: 0.40 m thick, manufactured by Toray Industries, Inc.
m was used. Polyethylene resin sheet: JSP 0.20 thickness
mm was used.

[II] Evaluation method (1) Resin physical properties The MFR melt flow rate (MFR) was measured according to JIS K7210.
Is a value measured at a temperature of 190 ° C. and a load of 2.16 kgf. M T melt tension (MT) is used Capillograph manufactured by Toyo Seiki Co., melting drop speed 10 mm / min, a value measured extrusion, by haul-off speed 4m / min at a temperature 190 ° C.. Q value The Q value (molecular weight distribution) is a value measured by gel permeation chromatography (GPC).

(2) Evaluation Expansion Ratio The expansion ratio is a value obtained by measuring the densities before and after foaming using a pycnometer and dividing the density before foaming by the density after foaming. Foam Cell Size The average size of the foam cell is a value obtained by magnifying and seeing through a surface sliced in the thickness direction and the parallel direction of the foam using a microscope and measuring the average size of the cells. The drawing depth (mm) of the formed body was measured using a vacuum forming machine (ASANO
This is a value obtained by measuring the maximum drawable depth that can be formed using a cylindrical mold having an opening of 150 mm ^φ using the above method.

[III] Experimental Examples Examples 1 to 5 and Comparative Examples 1 and 2 (1) Molding of Low Foamed Ethylene Polymer Resin Sheet A 90 mm diameter twin-screw extruder manufactured by Masculo Co., Ltd. was compounded according to the compounding composition shown in Table 1. And it extruded at the forming temperature of 180 degreeC using the die, and formed the low foaming ethylene polymer resin sheet of thickness 1mm. Next, the expansion ratio and the dimensions of the expanded cells of the low-expanded ethylene polymer resin sheet were measured, and the results are shown in Table 1. (2) Vacuum forming Next, this low foamed ethylene polymer resin sheet is
Using a vacuum forming machine (Model M330) manufactured by O Corporation, the mold heater temperature was set to 260 ° C., and vacuum forming was performed to perform deep drawing. The maximum depth at which good deep drawing could be performed without breaking the foam cells or making holes in the low foam ethylene polymer resin sheet was measured. (3) Results Table 1 shows the above results. In addition, as for the obtained vacuum-formed body, what was manufactured in the Example all had a pearl-like appearance.

Example 6 A low foamed ethylene polymer resin sheet was produced in the same manner as in Example 1 except that the thickness of the low foamed ethylene polymer resin sheet was changed to 0.3 mm. A polyester woven fabric (0.40 mm thick) is laminated on the ethylene polymer resin sheet, and the mold heater temperature is set to 2
Vacuum forming is performed at a temperature of 60 ° C. and a drawing depth of about 52
mm inner case for Western sake was thermoformed and cut. The foamed state of this molded product was clearly drawn while maintaining a good foaming state, and the appearance was satisfactory with a pearl-like appearance.

Example 7 A low-foaming ethylene polymer resin sheet was produced in the same manner as in Example 1, except that the thickness of the low-foaming ethylene polymer resin sheet was changed to 0.2 mm. Foaming ratio 8 times, thickness 0.2 on ethylene polymer resin sheet
mm high-expanded polyethylene polymer resin sheets were stacked, vacuum-molded at a mold heater temperature of 260 ° C., and an inner case for can storage with a drawing depth of about 50 mm was thermoformed and cut. The foamed state of this molded article is clearly drawn while maintaining good condition, and,
The appearance was also pearly and satisfactory.

[0029]

[Table 1]

[0030]

The deep-drawn molded article of the present invention is a low-foamed article having moderate flexibility, and the foamed cells are fine and uniform in size. Since deep drawing can be performed uniformly without biasing in one direction without breaking and maintaining a good foaming state, advanced deep drawing can be performed.

In the deep drawing, since the sheet surface and the deep drawn wall surface can be bent and formed to an angle of about a right angle, and extremely to an inverse taper, the drawn shape is formed clearly. be able to.

In the deep drawn molded article of the present invention, since the foam cells are fine and their dimensions are uniform and constant,
Pearl-like appearance can be obtained without adding pigments such as mica and titanium powder.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ethylene polymer resin deep drawn product vacuum-formed into the shape of an ampule case for the present invention.

FIG. 2 is a perspective view of an inner case for can storage in which a concave portion conforming to the shape of a can is formed in a laminated sheet in which a high-expanded polyethylene resin sheet is laminated on the back side of a low-expanded ethylene polymer resin sheet layer. It is.

FIG. 3 is an inner case (guess) in which a concave portion conforming to the shape of a liquor bottle is formed in a laminated sheet in which a polyester woven fabric layer is laminated on the surface side of a low-foaming ethylene polymer resin sheet layer.
It is a perspective view of.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deep drawing molded object 2 Sheet 2a Depression 2b Convex part 3 Ampoule case 4 High foam polyethylene resin sheet 5 Laminated sheet 6 Inner case for can storage 7 Polyester woven fabric layer 8 Laminated sheet 9 Liquor bottle 10 Inner case (guess)

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI B29L 9:00 (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 51/00-51/16 B29C 44/00 B29C 67/20 C08J 9/04-9/14 B29K 23:00 B29K 105: 04 B29L 9:00

Claims (12)

(57) [Claims] 1. A melt flow rate of 0.1 to 10 g / 1.
A deep drawn molded article obtained by thermoforming a foamed sheet made of an ethylene polymer resin having a melt tension of 2 to 20 g and having an expansion ratio of 1.01 to 3 times for 0 minutes. 2. The deep drawn product according to claim 1, wherein the ethylene polymer resin has physical properties of a Q value of 2 to 9. 3. An ethylene polymer resin comprising: a low-density ethylene homopolymer, an ethylene / vinyl acetate copolymer produced by a high-pressure method, and a high-density ethylene homopolymer produced by a medium-low pressure method; The deep drawn molded article according to claim 1, wherein the molded article is at least one selected from linear copolymers with another α-olefin. 4. The foam cell has an average size of 0.05 to 0.5 m.
2. The deep drawn molded article according to claim 1, wherein m is m. 5. A molded product having a depth of at least 30 mm
The deep drawn product according to claim 1, wherein the deep drawing is performed. 6. The deep drawn molded article according to claim 1, wherein the molded article is a laminate of a low foamed ethylene polymer resin layer and another base material layer. 7. A melt flow rate containing a foaming agent is 0.1 to 10 g / 10 minutes, and a melt tension is 2 to 20.
g of the ethylene polymer resin, and the expansion ratio is 1.
A method for producing a deep drawn product, comprising forming a foamed sheet having a size of 01 to 3 times, laminating the foamed sheet with another base material layer, or thermoforming without laminating the foamed sheet. 8. The method according to claim 7, wherein the ethylene polymer resin has a physical property of a Q value of 2 to 9. 9. An ethylene polymer resin comprising a low-density ethylene homopolymer and an ethylene / vinyl acetate copolymer produced by a high-pressure method, and a high-density ethylene homopolymer produced by a medium-low pressure method and ethylene. The method for producing a deep-drawn molded article according to claim 7, which is at least one selected from linear copolymers with another α-olefin. 10. The method according to claim 7, wherein the foamed sheet has a thickness of 0.1 to 5 mm. 11. The foam cell has an average size of 0.05 to 0.5.
The method for producing a deep-drawn molded product according to claim 7, which is in mm. 12. The thermoforming is a process in which at least a part of a foamed sheet is subjected to deep drawing at a depth of 30 mm or more.
A method for producing a deep drawn product according to claim 7.