JP2005103549A - Insertion film for stainless steel strip, and manufacturing method for stainless steel strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of defects on the surface of a stainless steel strip, such as transcription of surface pattern of a spacing paper, which is generated in using a conventional technique of inserting a kraft paper as the spacing paper into a stainless steel strip, when winding the strip into a coil. <P>SOLUTION: When winding the steel strip into a coil at the outlet side of at least one of an annealing and pickling process, a temper rolling process, a finish polishing process, and an inspection process, a resin film is inserted. The material of the resin film is, for example, selected from polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polyethylene terephthalate, and their composite material. The thickness of the resin film is 0.01-0.5 mm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a stainless steel strip insertion film capable of preventing contact between coils and preventing formation patterns that cannot be avoided with kraft paper in the production of a stainless steel strip, and The present invention relates to a method for producing a stainless steel strip used.

  Since stainless steel strips are usually used without painting, they are often rolled to have a surface gloss by mirror finish. Therefore, in each process after the annealing and pickling process after the final rolling, when winding into a coil shape for the transition to the next process, usually neutral kraft paper is inserted between the coils and wound together As a result, the occurrence of wrinkles and uneven gloss due to friction between the coils is prevented. This insertion paper is generally called interleaving paper, but kraft paper has been generally used as interleaving paper inserted into a stainless steel strip because it is strong and inexpensive.

As an interleaving paper to be inserted into a stainless steel strip, Japanese Patent Application Laid-Open No. 7-216794 discloses that the surface of the kraft paper used for the interleaving paper is coated with polyvinyl alcohol on the surface of the dry paper weight in order to increase the heat resistance and surface strength. It is proposed that the coating is performed by two roll size presses so as to be 0.13 to 0.57 g / m ² .

  In JP-A-9-3792, kraft paper is provided with at least one lubricant selected from calcium stearate, resin wax and the like so that the coefficient of dynamic friction is 0.20 to 0.40, thereby imparting lubricity. Neutral slip sheets for stainless steel strips have been proposed. This interleaf is shown to have an effect of imparting excellent elongation to the steel strip and improving its rollability when rolling the stainless steel strip.

In JP-A-6-154804, in order to prevent the surface damage of the metal plate in the cold rolling line, the surface of the paper made by adjusting the pulp slurry with a beating degree of CSF 200-600 ml to pH 5-9, Specific sheet metal sheet with electrostatic properties with a specific resistance value of 1.0 × 10 ¹⁰ Ω or less, a volume resistivity value of 1.0 × 10 ¹¹ Ω · cm or less, a charged voltage of 150 V or less, and a decay time of 7.O sec or less. Proposed. Such electrostatic characteristics can be obtained by internally adding an antistatic agent at the time of paper making or by applying an antistatic agent to the paper made. When this slip sheet is used, it is possible to prevent dirt and dust from adhering to the slip sheet during skin pass rolling, which causes surface flaws.
JP-A-7-216794 JP 9-3792 A JP-A-6-154804

  As described above, various attempts have been proposed to improve the properties of slip sheets for insertion into stainless steel strips. However, since the interleaf paper is made of fibers called pulp, the thickness is not completely uniform microscopically. That is, since it is inevitable that the pulp fibers are entangled in a non-uniform manner, there is a minute thickness distribution per unit area called a formation in any interleaving paper.

  When a slip sheet with the thickness distribution is inserted between the stainless steel strips, the difference in the thickness of the slip sheet causes a difference in surface pressure against the coil surface, so the texture is transferred to the coil surface. Small irregularities may be generated, and the surface quality of the stainless steel strip may be significantly impaired. In addition, when a minute slip occurs between the coils in which the slip sheets are inserted, the slip sheets of the slip sheets may adhere to the stainless steel strip, resulting in the worst situation as slip sheets.

  It is an object of the present invention to provide a sheet material for inserting a stainless steel strip, which can achieve complete prevention of defects on the surface of the stainless steel strip, which cannot be achieved with a slip paper such as kraft paper made from pulp. And

  As a result of searching for a sheet material for inserting a stainless steel belt instead of a conventional kraft paper, the present inventors have found that a resin film used for filling, packaging, and packing foods and beverages is optimal. Then, by using this instead of the slip sheet, it was found that the occurrence of surface defects in the stainless steel strip that could not be resolved when using the slip sheet with the ground was completed, and the present invention was completed. .

  Here, the present invention is a stainless steel strip insertion sheet material made of a resin film having a thickness of 0.01 to 0.5 mm. The resin film particularly suitable for use as a sheet material for inserting a stainless steel strip in the present invention was selected from polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polyethylene terephthalate, and composite materials thereof. It is a film of material.

  According to the present invention, when the steel strip is wound around the coil at the exit side of at least one of the annealing / pickling step, the temper rolling step, the finish polishing step, and the inspection step in the production of the stainless steel strip, A method for producing a stainless steel strip is also provided, wherein the steel strip is wound around a coil while the resin film is inserted.

  While inserting the resin film according to the present invention, by winding the coil in the process after the annealing of the stainless steel strip, it is possible to reliably prevent defects such as wrinkles that occur when using interleaf made of kraft paper. Product yield is improved.

  In the present invention, a resin film is used as a sheet material for inserting a stainless steel strip having no texture. Since the resin film does not essentially have a texture that is a problem with craft interleaving paper and does not generate foreign matter such as pulp pieces, various problems that have occurred with interleaving paper can be avoided. .

  The material of the resin film is preferably polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polyethylene terephthalate, or a composite material thereof. All of these are used for filling and packaging foods and beverages, and do not cause any problems in terms of safety. It also has sufficient heat resistance to be used in the steps after annealing.

  In the present invention, the composite film includes both a film made of a copolymer or blend of two or more resins and a laminate film obtained by laminating two or more resin films.

  In order to prevent dirt and dust from adhering to the resin film, an antistatic treatment may be applied according to a conventional method. There are two types of antistatic treatments: coating type treatments that are applied by spraying a solution of an antistatic agent (generally a surfactant) and internal treatments that contain an antistatic agent in the resin. Any processing method may be used. The type of antistatic agent to be used and the amount of the antistatic agent can be appropriately selected according to the resin type.

  The thickness of the film should be at least 0.01 mm to ensure the strength required to insert between the coils when winding the stainless steel strip coil. If the film thickness exceeds 0.5 mm, the flexibility of the film is impaired, so the upper limit of the thickness is 0.5 mm. As the inserted film thickness increases, the diameter of the coil wound up increases. In that sense, a smaller film thickness is advantageous. A preferred film thickness is 0.02 to 0.15 mm.

  The resin film of the present invention is used for winding in the production process of a stainless steel strip by the same method as conventional slip sheets (for example, unrolled from a roll as shown in FIG. 1 of Patent Document 2). be able to.

  When the resin film is a film of a material selected from polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polyethylene terephthalate, or a composite material thereof, which is described above as a preferable material, after cold rolling It can be used in the annealing / pickling process and the subsequent processes, that is, the temper rolling process, the finish polishing process, and the inspection process. That is, when the steel strip is wound around the coil on the exit side of at least one of these steps, the steel strip can be wound around the coil while the resin film is inserted. In such a process, since the steel strip temperature is usually 60 ° C. or lower, the use of the resin film does not cause a heat resistance problem.

  If a heat-resistant resin film such as polyimide is used, the resin film can be inserted into the winding in the cold rolling process in which the steel strip temperature is about 100 to 200 ° C. Therefore, the material of the resin film to be used can be selected according to the steel strip temperature at the time of coil winding in the process.

  When the wound coil is unwound for processing in the next step, the resin film is separated from the coil as shown in FIG. The resin film thus peeled may be reused for gardening or agriculture, for example. Alternatively, it can be incinerated as auxiliary fuel in a blast furnace or the like.

  The type of the stainless steel strip into which the resin film of the present invention is inserted is not particularly limited, and the present invention can be applied to both austenitic and ferritic stainless steel strips. Further, the present invention can be applied not only to a cold-rolled stainless steel strip but also to a hot-rolled stainless steel strip.

  Various resin films with the materials and thicknesses shown in Table 1 are used in the annealing and pickling process (steel strip temperature of about 50 ° C) or temper rolling (steel strip temperature of about 40 ° C) in the production of cold-rolled stainless steel strips. Inserted when winding the coil on the side. When the coil is rewound and the next step shown in Table 1 is performed, the surface of the stainless steel strip after separation of the resin film is visually observed before processing, and a defect such as a texture pattern on the surface of the stainless steel strip is generated. The presence or absence of was determined. The results are also shown in Table 1. The “polyethylene / polypropylene” used in Example 5 is a laminate film of polyethylene and polypropylene.

  As shown in Table 1, in Comparative Examples 1 to 3 in which a slip sheet was inserted and the coil was wound up as in the prior art, defects due to transfer of the texture of the formation occurred. On the other hand, according to the present invention, in each example in which a resin film having a thickness of 0.01 to 0.5 mm was inserted, there was no such defect. However, in Comparative Example 4 in which the thickness of the resin film was less than 0.01 mm, the film strength was weak, the film was broken at the time of winding the coil, and rubbing due to contact between the stainless steel strips occurred.

Claims (3)

  A sheet material for inserting a stainless steel strip, comprising a resin film having a thickness of 0.01 to 0.5 mm.   The sheet for inserting a stainless steel strip according to claim 1, wherein the resin film is a film of a material selected from polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polyethylene terephthalate, and composite materials thereof. material.   3. When winding a steel strip around a coil on the outlet side of at least one of an annealing / pickling process, a temper rolling process, a finish polishing process, and an inspection process in the production of a stainless steel strip, according to claim 1 or 2. A method for producing a stainless steel strip, comprising winding a steel strip around a coil while inserting the resin film.