A paper sleeve for a metal coil to prevent roll collapse

Abstract

The utility model discloses a kind of paper sleeves for preventing metal coiled material from collapsing, comprising: main body cylinder, by multiple layers high-strength kraft paper adhesion;Radial reinforcement structure, is set to one end of the main body cylinder End, and it is distributed along circumference direction;Axial stiffener, along the axial extension of the main body cylinder, and it is set to the wall of the main body cylinder;Waterproof barrier layer, is set to the outer surface of the main body cylinder;Buffer layer, is set to the inner wall of the main body cylinder, the utility model relates to paper sleeve technical field.The paper sleeve for preventing metal coiled material from collapsing, radial compression strength is greatly promoted, can effectively resist the weight and external impact of heavy coiled material, the waterproof barrier layer of outer surface makes paper sleeve have waterproof capacity, effectively prevent inner circle indentation, scratch and other surface defects, improve the finished product quality of coiled material, embedded reinforcing ring or annular protruding portion is integrated with main body cylinder, stress is uniform, there is no risk of loosening and falling off.

Description

Technical Field

[0001] This utility model relates to the field of paper sleeve technology, specifically a paper sleeve for preventing collapse of metal rolls. Background Technology

[0002] In the metal processing and distribution process, strip metal materials (such as cold-rolled steel plates, hot-rolled steel plates, stainless steel strips, aluminum strips, copper strips, etc.) are usually produced and delivered in the form of coils. These metal coils (hereinafter referred to as "coils") have a standard inner hole at their center. To protect this inner hole and facilitate lifting and uncoiling using equipment such as overhead cranes and coil lifting devices, the industry commonly uses paper sleeves inserted into the center hole of the coil as an internal support structure.

[0003] Traditional paper sleeves for metal coils are mainly made of multiple layers of high-strength kraft paper, formed by spiral winding or flat winding, and then bonded and cured with adhesives. They have a simple structure, low cost, and certain radial and axial strength. However, with the increase in the width of metal coils, the weight of a single roll (up to tens of tons), and the extension of transportation distances and the complexity of storage environments (such as open-air stacking, rain and snow, multi-layer stacking, etc.), the performance defects of traditional paper sleeves have become increasingly prominent. Under the action of the coil's own weight, lifting impact, or external compression (such as forklift collisions, stacking pressure), the ends or the entire traditional paper sleeve are prone to radial compression deformation, causing the inner ring of the coil to collapse inward, forming a "collapsed roll." Collapse not only causes wrinkling at the edges of the coil, interlayer misalignment, and inner diameter deformation, seriously affecting the flatness and continuity of subsequent unwinding, but may even lead to the scrapping of the entire roll, causing huge economic losses. In humid environments or rainy and snowy weather, moisture will quickly penetrate the paper sleeve, causing its fiber structure to soften, the adhesive to fail, and the overall strength (especially compressive strength) to drop sharply. Traditional paper sleeves typically have a rigid, smooth paper surface on their inner wall, which is in direct contact with the inner ring of the metal roll. Under winding tension or transport vibration, stress concentration can easily occur at the contact point, leading to surface defects such as indentations and scratches on the inner ring of the roll.

[0004] While existing technologies have attempted to improve the strength of paper sleeves by increasing wall thickness, using higher basis weight paper, or improving winding processes, the effects have been limited and costs have increased significantly. Some solutions have introduced plastic or metal liners, but these suffer from high costs, heavy weight, and difficulty in recycling. Therefore, developing a structurally innovative, high-performance, cost-effective, and environmentally friendly anti-collapse paper sleeve has become an urgent need in the metal coil packaging industry. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a paper sleeve for preventing collapse of metal rolls, which solves the problem that traditional paper sleeves are prone to radial compression deformation at the ends or as a whole, causing the inner ring of the roll to collapse inward and the overall strength (especially compressive strength) to drop sharply.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a paper sleeve for preventing collapse of metal rolls, comprising: The main body is made of multiple layers of high-strength kraft paper bonded together. A radial reinforcement structure is provided at one end of the main cylinder and distributed circumferentially; Axial reinforcing ribs extend along the axial direction of the main body and are disposed within the wall of the main body; A waterproof barrier layer is provided on the outer surface of the main body cylinder; A buffer layer is provided on the inner wall of the main cylinder.

[0007] Preferably, the radial reinforcement structure is an annular protrusion, which is formed by increasing the number of winding layers at the end of the main cylinder and performing hot or cold pressing.

[0008] Preferably, the cross-section of the annular protrusion is trapezoidal or semi-circular.

[0009] Preferably, the radial reinforcement structure is an embedded reinforcing ring, which is made of metal or high-strength engineering plastic and is pre-embedded in the wall thickness at the end of the main body cylinder.

[0010] Preferably, the number of axial reinforcing ribs is 8-10, which are evenly distributed on the circumference of the main body cylinder, and their material is glass fiber strips, carbon fiber strips or high-strength plastic strips.

[0011] Preferably, the waterproof barrier layer is a polyethylene coating, a polypropylene coating, or an aluminum-plastic composite film.

[0012] Preferably, the buffer layer is made of foamed polyethylene, foamed polypropylene, or rubber.

[0013] Preferably, the wall thickness of the main cylinder is 10-30mm, and the height of the annular protrusion is 5-15mm, and the width is 10-25mm.

[0014] Beneficial effects This invention provides a paper sleeve for preventing collapse of metal rolls. It has the following beneficial effects: 1. Through the composite reinforcement design of "radial reinforcement structure + axial stiffener", the radial compressive strength of this paper sleeve is greatly improved, which can effectively resist the self-weight of heavy rolls and external impacts, and solve the problem of roll collapse.

[0015] 2. The waterproof barrier layer on the outer surface gives the paper sleeve waterproof capability, and its strength does not decrease even after long-term use in rain, snow and high humidity environments, thus extending its service life and scope of application.

[0016] 3. The inner buffer layer avoids direct contact between the metal coil and the rigid material, effectively preventing surface defects such as inner ring indentations and scratches, and improving the finished quality of the coil.

[0017] 4. The embedded reinforcing ring or annular protrusion is integrated with the main body of the cylinder, ensuring uniform stress distribution and eliminating the risk of loosening or falling off. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of the annular protrusion of this utility model; Figure 3 This is a schematic diagram of the embedded reinforcing ring of this utility model.

[0019] In the diagram: 1. Main cylinder; 2. Annular protrusion; 3. Axial reinforcing rib; 4. Waterproof barrier layer; 5. Buffer layer; 6. Embedded reinforcing ring. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-3 This utility model provides a technical solution: a paper sleeve for preventing collapse of metal rolls, comprising: The main body 1 is made of multiple layers of high-strength kraft paper bonded together. As the basic load-bearing structure of the paper sleeve, it is formed by spiral winding or flat rolling of multiple layers of high-strength kraft paper and then bonded and cured layer by layer using an environmentally friendly water-based adhesive. The main body 1 constitutes the main cylinder of the paper sleeve, and its wall thickness, number of layers, and paper basis weight are optimized according to the weight and size of the roll material to provide basic radial and axial support.

[0022] Radial reinforcement structures are preferably located at both ends of the main body 1 to improve the radial compressive strength of the paper sleeve ends and resist pressure from the end face of the roll material. This structure can take various forms: The annular protrusion 2 is formed by locally increasing the number of winding layers at the end of the main body cylinder 1 and hot-pressing or cold-pressing during the molding process to create a continuous annular protrusion along the circumference. The cross-section of this protrusion can be designed as trapezoidal, semi-circular, or rectangular to ensure that stress can be effectively dispersed under pressure and to avoid local yielding caused by stress concentration.

[0023] During the winding of the main body cylinder 1, the embedded reinforcing ring 6 is pre-embedded at predetermined positions at both ends. It is made of metal such as stainless steel, aluminum alloy, or high-strength engineering plastics such as nylon or polycarbonate. The reinforcing ring 6 is tightly integrated with the main body cylinder 1 to form a rigid support, which greatly improves the compressive and impact resistance of the ends.

[0024] Axial reinforcing ribs 3 extend axially along the main body cylinder 1 and are disposed within the wall of the main body cylinder 1; they extend axially along the main body cylinder 1 and are disposed on the inner or outer wall of the main body cylinder 1 or partially embedded in the wall. There are 8-10 axial reinforcing ribs 3, evenly distributed on the circumference of the main body cylinder 1, and their material is glass fiber strips, carbon fiber strips, or high-strength plastic strips. These materials have the characteristics of high modulus and low density, which can significantly enhance the axial stiffness and bending resistance of the paper sleeve, preventing bending deformation during hoisting, and also contributing to radial strength.

[0025] A waterproof barrier layer 4 is coated, sprayed, or thermally laminated onto the entire outer surface of the main body 1. The primary function of this layer is to isolate moisture and humidity, protecting the internal paper structure. Preferred materials include polyethylene coating, polypropylene coating, polyvinyl chloride coating, or aluminum-plastic composite film. The coating thickness is typically between 0.05-0.2 mm, providing excellent waterproof and moisture-proof performance without affecting the overall dimensions and recyclability of the paper sleeve.

[0026] A buffer layer 5 is disposed on the entire inner wall surface of the main body cylinder 1. This layer forms a flexible contact interface between the metal roll and the rigid paper tube, serving to cushion, absorb shock, and prevent scratches. Preferred materials include foamed polyethylene, foamed polypropylene, rubber sponge, or silicone. Its thickness is typically 1-5 mm, selectable according to the surface quality requirements of the roll.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A paper sleeve for preventing collapse of metal rolls, characterized in that, include: The main body (1) is made of multiple layers of high-strength kraft paper bonded together; A radial reinforcement structure is provided at one end of the main body cylinder (1); Axial reinforcing ribs (3) extend along the axial direction of the main body cylinder (1) and are disposed within the wall of the main body cylinder (1); A waterproof barrier layer (4) is provided on the outer surface of the main body cylinder (1); A buffer layer (5) is disposed on the inner wall of the main body cylinder (1).

2. A paper sleeve for preventing collapse of metal rolls according to claim 1, characterized in that, The radial reinforcement structure is an annular protrusion (2), which is formed by increasing the number of winding layers at the end of the main body cylinder (1) and hot pressing or cold pressing.

3. A paper sleeve for preventing collapse of metal rolls according to claim 2, characterized in that, The cross-section of the annular protrusion (2) is trapezoidal or semi-circular.

4. A paper sleeve for preventing collapse of metal rolls according to claim 1, characterized in that, The radial reinforcement structure is an embedded reinforcing ring (6), which is made of metal or high-strength engineering plastic and is embedded in the wall thickness at the end of the main body cylinder (1).

5. A paper sleeve for preventing collapse of metal rolls according to claim 1, characterized in that, The number of axial reinforcing ribs (3) is 8-10, which are evenly distributed on the circumference of the main body (1), and their material is glass fiber strips, carbon fiber strips or high-strength plastic strips.

6. A paper sleeve for preventing collapse of metal rolls according to claim 1, characterized in that, The waterproof barrier layer (4) is a polyethylene coating, a polypropylene coating, or an aluminum-plastic composite film.

7. A paper sleeve for preventing collapse of metal rolls according to claim 1, characterized in that, The buffer layer (5) is made of foamed polyethylene, foamed polypropylene or rubber.

8. A paper sleeve for preventing collapse of metal rolls according to claim 2, characterized in that, The wall thickness of the main cylinder (1) is 10-30mm, and the height of the annular protrusion (2) is 5-15mm and the width is 10-25mm.

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