A bamboo sheet endo-cutting and pasting full-green anti-folding process

Abstract

The present application relates to bamboo processing technical field, and disclose a kind of bamboo inner cut fitting full green anti-bending process, including providing two pieces of bamboo for fitting to form the big edge bone of fan, and the thickness of the inner surface of each bamboo piece is modified, so that the thickness of the fitting area of two bamboo pieces is matched;Form inner cut fitting surface at the inboard of the shoulder opening of each bamboo piece, the inner cut fitting surface is relative to the inside convergent form of bamboo outer green surface;At least one of the inner cut fitting surface is coated with adhesive, and the inner cut fitting surface of two bamboo pieces is fitted relatively.The present application forms inner cut fitting surface by processing inboard and keeps outside green surface complete and continuous, completely avoids the damage of traditional outer cut process to bamboo natural fiber structure, so that there is no stress concentration notch at the shoulder opening of the big edge bone of fan, thereby significantly improving overall bending strength and impact resistance, effectively prevent cracking or breaking phenomenon in use.

Description

Technical Field

[0001] This invention relates to the field of bamboo processing technology, and in particular to a process for in-lined and bonded bamboo strips to prevent bending. Background Technology

[0002] The main rib of a folding fan is its most important supporting component, and its mechanical properties and appearance directly affect the fan's lifespan and artistic value. Currently, the traditional processing method for the main rib often involves cutting and bonding two bamboo strips together at the shoulder (the area where the main rib connects to the fan head). This external cutting and bonding process involves cutting off the outer edges of the two bamboo strips at a certain angle and then bonding them together to form the desired shoulder shape. While this process is simple and convenient, it has significant drawbacks: the external cutting directly severs the outer green surface (the dense outer layer of bamboo), disrupting the bamboo's natural continuous fiber structure and causing the shoulder to become a stress concentration area. During use, this area is highly susceptible to cracking or breaking along the cut direction, severely reducing the fan's overall sturdiness and lifespan.

[0003] Several technical solutions have been proposed to improve the strength of the large side ribs of a fan. For example, CN109366648A discloses a processing technology for the large side ribs of a fan, which improves structural strength by setting ebony edging around bamboo strips and using a concave-convex fit connection. While this solution enhances the deformation resistance of the side ribs to some extent, it introduces additional dissimilar materials, increasing processing complexity and cost, and the long-term bonding reliability between ebony and bamboo still needs to be verified. Another disclosure, CN113693354A, discloses a fan side rib with an external bamboo yellow strip, which uses the bamboo yellow strip to adhere to the outer side of the green surface of the side rib to strengthen the structure. Although this solution achieves an all-green appearance, the bamboo yellow strip is attached to the outside and does not change the problem of green surface breakage caused by outward cutting at the shoulder, and there is a risk of easy separation when it falls. Summary of the Invention

[0004] This invention provides a bamboo strip inward-cut and bonded all-green anti-folding process to solve existing technical problems. It solves the problem that the traditional processing of the large side ribs of fans, which uses two bamboo strips to be outwardly cut and bonded at the shoulder, seriously reduces the overall sturdiness and service life of the fan.

[0005] To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a process for in-lined and bonded bamboo strips to prevent bending, comprising the following steps: S1. Provide two bamboo strips for bonding to form the large edge of the fan, and adjust the thickness of the inner surface of each bamboo strip so that the thickness of the bonding area of ​​the two bamboo strips matches. S2. An inner-cut fitting surface is formed on the inner side of the shoulder of each bamboo strip, and the inner-cut fitting surface is inwardly shaped relative to the outer green surface of the bamboo strip. S3. Apply adhesive to at least one of the inner tangential bonding surfaces and bond the inner tangential bonding surfaces of the two bamboo strips together. S4. Provide a shaping insert that matches the inner curvature of the bamboo strip after bonding. Insert the shaping insert between the inner sides of the two bonded bamboo strips along the length of the bamboo strip and press it down to make the two bamboo strips fit together tightly. At the same time, a fan-shaped lower plate space is formed inside the bonded body. S5. Keep pressing down until the adhesive cures to obtain a fan-shaped large side bone with a continuous blue surface on the outside and no external cutting marks at the shoulder. S6. Polish the outer surface of the fan's large side frame after curing, and flush the ends to make the inner and outer surfaces of the shoulder joint smooth.

[0006] Furthermore, the thickness adjustment of the inner surface of the bamboo strip in step S1 specifically involves: Using the outer green surface of the bamboo strip as a reference, the yellow part of the bamboo strip on the inner surface is planed or polished to make the bamboo strip have a gradually changing thickness distribution along the width direction, which is thinner in the middle and thicker at both ends.

[0007] Furthermore, in step S2, the inner tangent mating surface is an arc-shaped concave surface or a plane extending along the length of the bamboo strip, and the shapes of the inner tangent mating surfaces on the two bamboo strips match each other.

[0008] Furthermore, the adhesive used in step S3 is an environmentally friendly adhesive, including white glue or glutinous rice glue; Before applying the adhesive, the process includes machining multiple microholes or microgrooves on the inscribed mating surfaces to increase the bonding strength.

[0009] Furthermore, in step S4, the cross-sectional shape of the shaping insert matches the shape of the space enclosed by the inner sides of the two bamboo strips after they are attached, and the width of the shaping insert gradually changes from one end to the other end to form a fan-shaped lower plate space with a gradually changing width.

[0010] Furthermore, the pressure applied in step S4 is segmented pressure, including an initial pressure stage and a holding pressure stage. The pressure in the initial pressure stage is greater than the pressure in the holding pressure stage, and the shaping insert maintains line or surface contact with the inner side of the bamboo strip during the pressing process.

[0011] Furthermore, in step S2, the thickness of the incisional bonding surface at the shoulder opening is 1 / 5 to 1 / 3 of the total thickness of the bamboo strip, and the depth of the incisional bonding surface gradually decreases from the shoulder opening towards the middle of the bamboo strip.

[0012] Furthermore, the fan ribs made using the inward-cutting and bonding process of bamboo strips have no cuts or gaps extending to the outer green surface at the shoulder, and their overall bending strength is at least 20 times higher than that of fan ribs made using the outward-cutting and bonding process.

[0013] This invention provides a bamboo strip in-line bonding and anti-folding process. Compared with existing technologies, this method achieves the following advantages: 1. This invention completely avoids the damage to the natural fiber structure of bamboo strips caused by the traditional external cutting process by processing the inner cutting and bonding surface on the inner side while keeping the outer green surface intact and continuous. This eliminates the stress concentration cut at the shoulder of the large side rib of the fan, thereby significantly improving the overall bending strength and impact resistance, and effectively preventing cracking or breakage during use.

[0014] 2. The present invention adopts an arc-shaped inward-cut bonding surface design that gradually becomes shallower from the shoulder to the middle, combined with the gradual thickness adjustment of the inner surface of the bamboo strip with "thin in the middle and thick at both ends", so that the composite structure after gluing can smoothly transfer and disperse stress to the thick end area when subjected to force, which not only ensures the overall flexibility of the large side bone, but also strengthens the structural stability of the key load-bearing parts.

[0015] 3. This invention processes micropores and microgrooves on the inner bonding surface, and forms a dual chemical and mechanical connection with environmentally friendly adhesive, which greatly enhances the peel resistance of the bonding interface; at the same time, it adopts variable cross-section shaping inserts and segmented pressure control to simultaneously shape the fan-shaped lower plate space with a gradually changing width during the pressing process, realizing the coordinated completion of pressing and forming, and avoiding potential damage to the blue surface by secondary processing.

[0016] 4. The fan with large side ribs produced by this invention has a complete and continuous all-green surface on the outside, without the need for any external wrapping or reinforcement with different materials. It not only retains the natural texture and luster of bamboo, but also ensures dimensional accuracy and interface bonding quality through constant temperature and humidity with insert curing. The final product maintains the traditional aesthetic appearance, while its durability and reliability far exceed those of similar products using external cutting and bonding processes. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention; Figure 2 This is a comparison chart for verifying the performance of the finished product of this invention. Detailed Implementation

[0018] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, according to one aspect of the present invention, a process for in-line bonding of bamboo strips to prevent bending is provided, comprising the following steps: I. Material Preparation and Pretreatment Select Anji bamboo that has grown for 4-6 years and has a diameter at breast height of about 10-12mm. After removing the waxy layer on the surface of the bamboo, cut it longitudinally along the bamboo tube to obtain bamboo strip blanks with a width of 18-22mm, a length of 320mm, and a thickness of 3-4mm. Each fan requires two identical bamboo strips, which are used to glue together to form the left and right large side ribs, respectively.

[0020] Thickness adjusted to: Using the outer green surface of the bamboo strip as a reference surface, a CNC planer is used to trim the thickness of the inner surface (yellow surface) of each bamboo strip. The trimming goal is to reduce the thickness of the middle area to 2.0-2.2 mm along the width of the bamboo strip, while maintaining the thickness of the two side edges (near the shoulder) at 2.8-3.0 mm, forming a gradually changing cross-section that is thinner in the middle and thicker at both ends. A laser thickness gauge is used to control the planing depth in real time, ensuring uniform thickness variation along the entire length of the bamboo strip. After trimming, the thickness deviation of the mating area between two bamboo strips should not exceed ±0.05 mm.

[0021] This step uses the outer green surface of the bamboo strip as a reference, and performs a gradual thickness adjustment on the inner surface, making it thinner in the middle and thicker at both ends, breaking through the traditional mindset of processing with uniform thickness. Its innovation lies in providing structural redundancy for subsequent internal cutting and bonding by retaining more bamboo thickness in the shoulder area, while avoiding any damage to the green surface.

[0022] Using closed-loop control of CNC planing and a laser thickness gauge, the yellow part of the bamboo is precisely removed, with the green surface as the absolute reference. The gradient cross-section design allows stress to be naturally dispersed to the thicker ends of the bamboo strips under load, avoiding stress concentration in the shoulder area. This principle is similar to the mechanical optimization of variable cross-section beams, ensuring overall flexibility while strengthening key load-bearing areas.

[0023] II. Inner Surface Forming The trimmed bamboo strips are fixed on the worktable of a five-axis CNC machining center, with the outer green side facing down and the inner surface facing up. A ball end mill (6mm diameter) is used to machine the inner tangential mating surface at the shoulder of each bamboo strip. Here, "shoulder" refers to the area extending 30-50mm backward from the front end of the bamboo strip (i.e., the top of the fan).

[0024] An arc-shaped concave surface extending along the length of the bamboo strip is machined, with a radius of curvature of R80-R100mm and an arc length of 35mm. The lowest point of this arc-shaped concave surface is located at the shoulder end, and its depth (relative to the unprocessed inner surface of the bamboo strip) is 0.8-1.0mm, meaning that the remaining thickness after incision at the shoulder is approximately 1 / 4 to 1 / 3 of the total thickness of the bamboo strip (corresponding to claim 8). From the shoulder towards the middle of the bamboo strip, the depth of the arc-shaped concave surface gradually decreases, transitioning to zero depth at a distance of 40mm from the shoulder, smoothly connecting with the unprocessed inner surface of the bamboo strip.

[0025] The inner tangential surfaces of the two bamboo strips are identical in shape and fit together perfectly, ensuring a seamless fit during bonding. After processing, a coordinate measuring machine is used to verify that the contour error is ≤0.02mm.

[0026] For the first time, an arc-shaped concave surface was machined on the inner side of the bamboo strip's shoulder as a bonding surface, achieving "inner cutting without outer cutting," completely avoiding the damage to the continuous fibers of the bamboo surface caused by traditional outer cutting processes. This inner cut surface gradually becomes shallower along its length, eventually smoothly connecting with the unprocessed inner surface to form a stepless transition.

[0027] A concave arc with a consistent radius of curvature is formed through five-axis CNC machining, and the inner tangential shapes of the two bamboo strips are mirror images of each other. When the two strips are bonded together, a continuous adhesive interface is formed between the concave surfaces, while the outer green surface remains intact. The arc design increases the adhesive area and puts the adhesive layer in a compressive-shear composite state under stress, significantly improving its peel resistance. The depth-gradient structure ensures that stress is smoothly transferred from the shoulder to the center of the bamboo strip.

[0028] III. Processing of Adhesive-Reinforced Structures On the finished inner bonding surface, a laser marking machine (wavelength 1064nm) is used to create an array of micropores. The micropores are 0.2mm in diameter, 0.3mm deep, and 2mm apart, arranged in a diamond pattern. Simultaneously, a microgroove 0.5mm wide and 0.3mm deep is machined along the lowest point of the concave surface to guide adhesive flow and store excess adhesive. This step increases the bonding area and improves bond strength.

[0029] Introducing a micropore array and microgroove structure on the inner bonding surface is a biomimetic adhesive reinforcement design. The micropores increase mechanical interlocking anchor points, while the microgrooves guide the flow of adhesive and store excess adhesive, preventing insufficient or uneven adhesive overflow.

[0030] The micropores formed by laser processing create a "glue nail" effect after the adhesive cures, significantly improving shear strength. The microgrooves act as a buffer zone for the adhesive, ensuring consistent adhesive layer thickness during segmented pressing. This design transforms the bonding interface from a simple chemical bond to a "chemical + mechanical" composite connection, increasing peel strength by more than three times.

[0031] IV. Glue Application and Assembly Food-grade glutinous rice glue was selected as the adhesive and mixed with purified water at a mass ratio of 1:2.5. The mixture was stirred in a 60℃ water bath for 20 minutes until a uniform, viscous consistency was achieved. The prepared glutinous rice glue was then evenly applied to the inner tangential surface of one of the bamboo strips, with the amount of glue applied controlled at 80-100g / m². 2 Use a toothed scraper to scrape out parallel stripes to ensure a consistent adhesive layer thickness. Then, press the two bamboo strips together with their inner tangent surfaces facing each other, gently pressing to remove large air bubbles and ensuring that the ends of the two bamboo strips are aligned with a deviation of no more than 0.2mm.

[0032] Food-grade glutinous rice glue is used in conjunction with a toothed scraper to form a parallel striped glue layer, which is both environmentally friendly and controllable. Compared to traditional white glue, glutinous rice glue has a longer open time and better toughness, making it suitable for multi-stage pressure holding processes.

[0033] After activation in a 60℃ water bath, the glutinous rice glue's molecular chains fully extend. During coating, a toothed scraper forms directional stripes, increasing the contact area between the glue and the bamboo surface. These parallel stripes spread laterally under pressure, automatically expelling air bubbles and forming a defect-free thin film. This principle ensures that the glue layer thickness uniformity is controlled within ±0.02mm, providing a stable foundation for subsequent setting.

[0034] V. Shaping and pressing down, and the formation of space between the lower plate of the fan-shaped surface. 1. Preparation of shaping inserts: The shaping insert is made of 304 stainless steel, with a length identical to that of the bamboo strip (320mm) and a variable cross-sectional arc shape. Specifically, the cross-sectional profile of the shaping insert matches the shape of the space enclosed by the inner sides of the two bamboo strips after they are glued together: at the shoulder end (first 20mm), the thickness of the shaping insert is 1.2mm and the width is 4mm; extending from the shoulder to the tail, the thickness gradually increases to 2.5mm and the width gradually increases to 8mm, forming a gradually expanding space. The upper and lower surfaces of the insert are both smooth arc surfaces with a surface roughness Ra≤0.4μm.

[0035] 2. Pressing down: Place the assembled bamboo strips onto the worktable of the pneumatic pressing machine, with the outer green sides facing up and down respectively. Insert the shaping insert along the length of the bamboo strips from the tail end (the rivet hole end of the large side rib of the fan) into the assembled body until the front end of the insert reaches the inner cut surface area of ​​the shoulder. Start the pressing machine, using segmented pressure control: The pressure is 0.6 MPa, and the holding time is 30 seconds. The purpose is to quickly bond the two bamboo strips together and force excess glue out of the micropores and microgrooves on the inner cut surface.

[0036] The pressure is reduced to 0.3 MPa and maintained for 5 minutes. During this time, the shaping insert maintains continuous surface contact with the inner side of the bamboo strip under pressure, expanding and shaping the inner side of the bamboo strip to form a permanent space under the fan surface (i.e., the gap for installing fan paper or thin sheets). During the pressure holding process, as the shaping insert gradually thickens from the shoulder to the tail, the space under the fan surface also exhibits a gradual change in shape, narrower at the front and wider at the back, conforming to the natural curvature of the large side ribs when the fan is closed.

[0037] Throughout the pressing process, a dial indicator was used to monitor the parallelism of the outer green surfaces of the two bamboo strips, ensuring that the deviation was ≤0.03mm.

[0038] For the first time, a variable cross-section arc-shaped shaping insert is used, combined with segmented pressure control (initial pressure > holding pressure). The shaping insert not only plays a pressing role, but also permanently shapes the fan-shaped lower plate space with a gradually changing width, realizing "one-time pressing, dual function".

[0039] The high pressure (0.6 MPa) during the initial pressing stage causes excess adhesive to quickly overflow from the micropores, forming an initial tight contact. The low pressure (0.3 MPa) during the holding pressure stage, combined with the gradually changing cross-sectional shape of the insert, allows the inner side of the bamboo strip to slowly expand and solidify under constant pressure. The insert gradually thickens from the shoulder to the tail, forming a fan-shaped lower plate space that is narrower at the front and wider at the back, perfectly matching the natural curvature of the fan when closed. A dial indicator monitors the process in real time to ensure that the parallelism of the two bamboo strips is ≤0.03 mm, preventing twisting and deformation.

[0040] VI. Curing and Post-treatment The bamboo strip assembly with the shaping insert is placed in a constant temperature and humidity curing chamber at a temperature of 35±2℃ and a relative humidity of 55%±5% for 24 hours. After curing, the assembly is removed, and the shaping insert is gently rotated and pulled out. At this point, the two bamboo strips are firmly bonded together by the cured glutinous rice adhesive strip, with the outer green surface intact and continuous, without any cuts or glue lines.

[0041] finishing: The outer surface of the fan's large ribs was sanded and polished using 1000-grit wet sandpaper to remove minor machining marks. Then, a wool wheel and bamboo wax were used for polishing until a mirror finish was achieved. A diamond end mill was used to flush the ends, ensuring a smooth transition between the inner and outer surfaces at the shoulder, and removing any remaining adhesive residue. Finally, 1.8mm diameter rivet holes were drilled at the tail for subsequent assembly with fan rivets.

[0042] The entire process, including the insert, is cured under constant temperature and humidity conditions, avoiding dimensional mismatches caused by curing first and then slotting in traditional processes. After curing, the insert can be removed to obtain a precisely shaped space for the fan-shaped lower plate, eliminating the need for secondary processing.

[0043] A constant temperature (35℃) accelerates the cross-linking reaction of the glutinous rice adhesive, while a constant humidity (55% RH) prevents the bamboo strips from absorbing moisture and expanding or losing moisture and shrinking. The shaping insert remains open throughout the curing process, and the inner shape of the bamboo strip is "locked in" after the adhesive layer cures. After the insert is removed, the gap between the two bamboo strips becomes the permanent space for the lower fan-shaped panel, and its width gradient is entirely determined by the geometry of the insert. This method eliminates the risk of secondary damage to the bamboo surface caused by the traditional process of "adhering first and then grooving."

[0044] VII. Product Performance Verification like Figure 2As shown, the fan ribs manufactured according to the above process, when observed with a 10x magnifying glass at the shoulder, show no cuts or gaps extending to the outer blue surface. A three-point bending strength test (span 150mm, loading speed 5mm / min) was conducted according to GB / T 17657-2013 standard, yielding an average bending strength of 168MPa. In contrast, the average bending strength of the comparative sample manufactured using the traditional external cutting and bonding process (i.e., cutting directly on the outer side of the shoulder and then bonding) was only 7.5MPa. Calculations show that the bending strength of the fan ribs manufactured using this process is increased by approximately 22.4 times, meeting the requirement of "at least 20 times". In actual use testing, the fan was dropped freely from a height of 1.2m onto a hardwood floor 20 times. The fan ribs of this embodiment showed no cracking or delamination, while the traditional external cutting and bonding sample fractured along the cut at the shoulder within 3 drops.

[0045] Comparative tests have verified that the bending strength of the large side ribs of the fan produced by this process reaches 168MPa, which is 22.4 times higher than that of the traditional external cutting process (7.5MPa), and there are no cuts or gaps penetrating the blue surface at the shoulder.

[0046] The outer, intact bamboo surface retains the natural fiber continuity and high elastic modulus (approximately 15-20 GPa) of the bamboo, while the inner, glued surface transforms the two bamboo strips into a composite structure. Under bending loads, the outer bamboo surface bears tensile stress, while the inner glued interface bears shear stress. The stress is smoothly transmitted through a gradually thickening region, avoiding the stress singularity at the cut root in traditional external cutting processes. Drop tests further demonstrate that this structure possesses excellent impact and fatigue resistance.

[0047] VIII. Supplementary Explanation of Process Optimization In actual production, to further improve the consistency of bonding, a layer of polytetrafluoroethylene release agent can be coated on the surface of the shaped insert, and the bamboo strip assembly can be preheated (50°C, 5 minutes) before pressing to increase the fluidity of the glutinous rice glue. The specific values ​​of the segmented pressure can be finely adjusted according to the thickness and hardness of the bamboo strips: for thicker bamboo strips (>3.2mm), the initial pressure can be increased to 0.8MPa; for softer bamboo species (such as bitter bamboo), the holding pressure is reduced to 0.2MPa. These adjustments all fall within the protection scope of this invention.

[0048] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A process for inlaying and bonding inner bamboo strips to prevent bending, characterized in that, Includes the following steps: S1. Provide two bamboo strips for bonding to form the large edge of the fan, and adjust the thickness of the inner surface of each bamboo strip so that the thickness of the bonding area of ​​the two bamboo strips matches. S2. An inner-cut fitting surface is formed on the inner side of the shoulder of each bamboo strip, and the inner-cut fitting surface is inwardly shaped relative to the outer green surface of the bamboo strip. S3. Apply adhesive to at least one of the inner tangential bonding surfaces and bond the inner tangential bonding surfaces of the two bamboo strips together. S4. Provide a shaping insert that matches the inner curvature of the bamboo strip after bonding. Insert the shaping insert between the inner sides of the two bonded bamboo strips along the length of the bamboo strip and press it down to make the two bamboo strips fit together tightly. At the same time, a fan-shaped lower plate space is formed inside the bonded body. S5. Keep pressing down until the adhesive cures to obtain a fan-shaped large side bone with a continuous blue surface on the outside and no external cutting marks at the shoulder. S6. Polish the outer surface of the fan's large side frame after curing, and flush the ends to make the inner and outer surfaces of the shoulder joint smooth.

2. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: The specific steps for adjusting the thickness of the inner surface of the bamboo strips in step S1 are as follows: Using the outer green surface of the bamboo strip as a reference, the yellow part of the bamboo strip on the inner surface is planed or polished to make the bamboo strip have a gradually changing thickness distribution along the width direction, which is thinner in the middle and thicker at both ends.

3. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: In step S2, the inner tangent mating surface is an arc-shaped concave surface or a plane extending along the length of the bamboo strip, and the shapes of the inner tangent mating surfaces on the two bamboo strips match each other.

4. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: The adhesive used in step S3 is an environmentally friendly adhesive, including white glue or glutinous rice glue; Before applying the adhesive, the process includes machining multiple microholes or microgrooves on the inscribed mating surfaces to increase the bonding strength.

5. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: In step S4, the cross-sectional shape of the shaping insert matches the shape of the space enclosed by the inner sides of the two bamboo strips after they are attached, and the width of the shaping insert gradually changes from one end to the other end to form a fan-shaped lower plate space with a gradually changing width.

6. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: The pressure applied in step S4 is segmented, including an initial pressure stage and a holding pressure stage. The pressure in the initial pressure stage is greater than the pressure in the holding pressure stage, and the shaping insert maintains line or surface contact with the inner side of the bamboo strip during the pressing process.

7. The bamboo strip inward-cutting and bonding anti-folding process according to claim 1, characterized in that: In step S2, the thickness of the incisional bonding surface at the shoulder opening is 1 / 5 to 1 / 3 of the total thickness of the bamboo strip, and the depth of the incisional bonding surface gradually decreases from the shoulder opening towards the middle of the bamboo strip.

8. The bamboo strip in-line bonding and anti-folding process according to any one of claims 1 to 7, characterized in that: The fan ribs made using the inward-cutting and bonding process of bamboo strips have no cuts or gaps extending to the outer green surface at the shoulder, and their overall bending strength is at least 20 times higher than that of fan ribs made using the outward-cutting and bonding process.

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