JPS5945142A - Manufacture of spirallywound pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing spiral winding.

The simplest type of Sumi 4 Air winding pipe is the toilet pipe.
i'? - Known as the core of rolls and household wrap films, these are manufactured by laminating several paper strips together with an adhesive.

In addition, in recent years, there has been a demand for high-quality, high-performance products that have airtightness, water resistance, chemical resistance, flattening strength against crushing, etc. In order to satisfy these requirements, (1) an inner base material pre-laminated with synthetic resin or metal foil was used; and (2) after the tube was finished, treatments such as laminating a synthetic resin film on the inner surface of the tube were carried out. .

However, in the former method, when the inner surface material is spirally wound, the sealing of the joint where adjacent materials overlap is not sufficient, and water leakage cannot be prevented unless the edges of the material are treated. Furthermore, the latter method of laminating a synthetic resin film on the inner surface has the problem that it is difficult to incorporate extrusion into the equipment.

Furthermore, in order to seal the seam of the inner surface material to be wound, a hot melt adhesive is mainly supplied through a nozzle for bonding. Due to the necessity of manufacturing tubes by winding the band-shaped base material around a mandrel and transporting it,
Usually, low-molecular-weight wax or the like is added to reduce the viscosity. Therefore, when the tube is filled with petroleum-based liquid, the adhesive may melt, and the adhesive may not be stored in the refrigerator. Products that are expected to be used in low-temperature conditions, such as sterilization, may crack, and high-temperature treatments such as sterilization may cause peeling, so their uses are limited. There wasn't.

As a result of intensive research to solve these problems, the present inventors have succeeded in achieving airtightness, water resistance, and The present invention has been fully completed, allowing the manufacture of an improved spiral wound tube with improved chemical properties and flattened strength against crushing.

The gist of the present invention is to provide a method for manufacturing a spiral-wound tube in which a tube is manufactured by winding a plurality of band-shaped base materials around a mandrel in a square shape, including: The inner base material is wound on the mandrel so that the lateral ends of the adjacent base materials partially overlap each other in a spiral winding tube to form a joint, and prior to overlapping the joint, the inner base material is wound around the mandrel. Manufacturing a spiral-wound tube characterized in that at least a portion of the outer peripheral surface corresponding to the seam overlap υ is coated with a thermoplastic resin melt-extruded through a T-die or a hot-melt adhesive mainly composed of the thermoplastic resin. It's in the method.

The above-mentioned base materials may include paper, aluminum foil, tin-based metal foil, copper foil, etc., polyethylene, polynolopyrene, polyvinyl chloride, polyvinylidene chloride, nylon,
Synthetic resin films or sheets such as polyvinyl alcohol and polyester can be selected as appropriate, and composite base materials made by laminating these materials are also acceptable, but in particular, as the inner base material, materials with water resistance, chemical resistance, etc. Preferably, metal foil, synthetic resin film or sheet, or a laminated composite thereof. Note that in order to improve the adhesiveness of the thermoplastic resin, the surface of these base materials may be subjected to a surface treatment such as anchor coating or corona discharge.

In addition, thermoplastic resins used in the present invention include polyethylene, ethylene-vinyl acetate copolymer, polypropylene, bori ester, ionic copolymer, etc., as well as hot melt adhesive compositions containing these thermoplastic resins as main components. In addition, a thermoplastic resin containing all commonly used additives such as stabilizers and processability improvers may also be used. In addition to using such a thermoplastic resin, the present invention also has the feature of using a T-die as a method for extruding the resin. This is because it is impossible to use the thermoplastic resin used in the present invention with the conventional nozzle type due to the melt viscosity.The T-die makes it possible to use the thermoplastic resin and at the same time There is no problem with OT dies, which are commonly used and which are capable of fully demonstrating various functions such as controlling the thickness of the coating film (5).

The melt extrusion processing temperature of the thermoplastic resin is appropriately selected depending on the resin selected; for example, polyethylene 200
~350°C, ethylene-vinyl acetate copolymer 200~2
60° C. hot melt adhesive composition 140 to 180° C. When a hot melt adhesive composition is also used, the viscosity thereof must be 1.0×10 cP or more. 1.0
This is because if it is less than X10cP, it cannot be used in T-die and at the same time, sufficient effects such as chemical resistance and crack resistance at low temperatures cannot be obtained.

By using the above-mentioned adhesive mainly composed of thermoplastic resin, S! Iral winding tubes had excellent sealing properties, water resistance, and waterproofing properties, as well as chemical resistance, cold resistance, and crack resistance, and were extremely effective in improving the performance of the winding tubes and expanding their uses.

In addition, in an embodiment of the present invention, in addition to bonding only the overlapping ends of the inner base material with melt-extruded thermoplastic resin, by changing the width of the T-die, the overlapping ends of the inner base material can be bonded together. It is also possible to bond (6) the inner surface base material to the resin and to adhere the inner surface base material and the outer surface base material to be wound later.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an example of the implementation of the method for manufacturing a spiral wound tube according to the present invention.

In the figure, ■ is a mandrel as a fixed shaft, and the inner surface base material 2 is wound around this mandrel 1 in a spiral shape and moves while rotating. Reference numeral 3 denotes a backside base material, which is wound around the outer periphery of the inner surface base material 2 that has already been wound around the mandrel 1. 4 is a T-die, and in this embodiment, when the inner base material 2 is wound around the mandrel 1, a strip of a constant width is formed on the outer peripheral surface of the overlapping portion of the adjacent lateral ends. The thermoplastic resin 5 selected as appropriate is melt-extruded and coated.

Reference numeral 6 denotes a winding belt, which is used to rotate and move the winding tube.

FIG. 2 is an enlarged cross-sectional view of a part of the spiral-wound tube according to the present embodiment, in which the overlapping lateral ends of the inner surface base material 2 are adhered via a thermoplastic resin 5, and the inner surface base material 2 and the outer substrate 3 are shown bonded together by another adhesive layer 7. Note that the means for forming the entire adhesive layer 7 for adhering the inner surface base material 2 and the outer surface base material 3 and the type of adhesive are as follows, except in the case of another embodiment of the present invention described later. Since the layer 7 is a part that does not come into direct contact with the liquid contained in the tube, a conventionally known hot melt adhesive composition, for example, can be used. The illustration of the means for applying is omitted.

In implementation, the inner surface material 2 is spirally wound around the mandrel 1, and before both ends of the inner surface material 2 are overlapped, a T-die 4 placed on the mandrel 1 is used to heat the polythermoplastic material. The resin 5 is melt-extruded and coated on the outer peripheral surface of the inner base material 2. The T-die 4 is usually installed as a single extruder, and the T-die 4 is
The falling position of the thermoplastic resin 5 melt-extruded from the die 4 can be appropriately selected as long as it is a pre-position where both ends of the inner base material 2 are overlapped. The direction of the T-die 4 is preferably perpendicular to the flow direction (traveling direction) of the inner surface base material 2. The inner base material 2 coated with the thermoplastic resin 5 moves as it rotates, and both ends thereof are overlapped and bonded. This can prevent peeling of the overlapping lateral ends of the inner surface base material 2 and water leakage from these ends. Further, the outer base material 3 coated with the adhesive 7 is wound around the inner base material 2 and the two base materials are bonded together, thereby integrating the spiral and spiral tubes.

FIGS. 3 and 4 show another embodiment of the present invention, in which the thermoplastic resin 5 is coated over the entire outer circumferential surface of the inner base material 2, so that the overlapped ends of the inner base material 2 can be covered with the thermoplastic resin 5. Figure 3 shows an outline of the structure of the main parts, and Figure 4 is a partially cutaway cross-sectional view of the finished spiral-wound tube. .

When the entire outer peripheral surface of the inner base material 2 is coated with the thermoplastic resin 2 as in this embodiment, after the both ends of the inner base material 2 are overlapped and bonded, the outer surface base material 2 is coated with the thermoplastic resin 2 before the resin 5 hardens. 3 can be wound around the inner surface base material 2 to integrate both base materials.

(9) As described above, according to the present invention, a thermoplastic resin can be used as an adhesive without modifying the conventional Spicil winding tube manufacturing apparatus, and in conjunction with this, a means for completely melting and extruding this thermoplastic resin can be used. By using the inexpensive and simple equipment and method of simply installing a T-die on a mandrel, we can improve not only the sealing, water resistance, and water resistance of the inner surface of the winding tube, but also crack resistance, cold resistance, chemical resistance, etc. In addition, it is possible to manufacture a spiral-wound tube with high flat strength and no peeling of the inner base material, which has extremely beneficial effects.

Although the present invention has been explained using a double-wound tube in the above embodiments, the present invention is not limited thereto, and can also be implemented with a multi-wound tube in which a base material is further wound around the outer surface base material. Needless to say.

Therefore, the spiral wound tube provided by the manufacturing method of the present invention can be used for liquid foods such as soft drinks, juices, and alcoholic beverages, as well as oils such as motor oil, machine oil, and cooking oil, which conventional wound tubes could not withstand sufficiently. (10) It can be used as a filling container for powders, printing inks, paints, shavings, adhesive compositions, sealants, chemicals, etc., and its usefulness is extremely large.

[Brief explanation of the drawing]

FIG. 1 shows an example of the method for manufacturing a spiral-wound tube according to the present invention in which the overlapping ends of the inner surface base material are bonded together, and FIG. 2 shows a part of the spiral-wound tube produced by the method of FIG. It is a broken enlarged cross-sectional schematic diagram. FIG. 3 shows the overlapping ends of the inner base material in the present invention,
An example of a method for manufacturing a spiral-wound tube in which the inner surface base material and the outer surface base material are also bonded is shown, and FIG. 4 is a schematic cross-sectional view of the spiral-wound tube produced by the method shown in FIG. 3. 1... Mandrel 2... Inner surface base material 3... Outer surface base material 4... T die 5... Thermoplastic resin
6...Tightening belt 7...Adhesive Figure 1

Claims (1)

[Claims] In a method for manufacturing a winding tube in which a winding tube is manufactured by winding a plurality of strip base materials around a mandrel in a spiral shape, the inner surface materials wound around the mandrel are adjacent to each other in spiral winding. The base material is wound so as to form a seam where the lateral ends partially overlap, and prior to overlapping the joint, at least one of the outer peripheral surfaces of the inner base material wound around the mandrel is wound. 1. A method for producing a spiral wound tube, which comprises coating a joint or a corresponding portion with a thermoplastic resin melt-extruded from a T-die or a hot-melt adhesive mainly composed of the thermoplastic resin.