Production equipment of wide frequency high efficiency damping wrapping belt based on non-vulcanized butyl rubber

Abstract

The application discloses a production device of a wide-frequency high-efficiency damping wrapping belt based on non-vulcanized butyl rubber, and belongs to the technical field of bridge engineering damping. The wrapping belt comprises a damping function layer and a backing reinforcing layer combined on one side of the damping function layer. The damping function layer comprises, by weight, butyl rubber 100 parts, hydrogenated petroleum resin 20-50 parts, hindered phenol A0-80 10-30 parts, mica powder 15-40 parts, polysiloxane boride 10-25 parts, carbon black N330 5-20 parts and rubber additives. The high internal friction of butyl rubber, the reversible hydrogen bond toughening of hindered phenol, the interfacial friction of mica powder and the self-adaptive shear thickening effect of polysiloxane boride are utilized to realize excellent damping performance with a loss factor tan delta of 1.5 or more in a wide-frequency range of 0.1-20 Hz. The wrapping belt is spirally wound on the surface of a cable, and can simultaneously and efficiently suppress low-frequency large-amplitude vibration caused by crosswind and medium-high-frequency vibration caused by vehicle passing. The application has the advantages of simple process, no vulcanization, convenient construction, recyclability and suitability for passive high-efficiency damping of bridge cables.

Description

[0001] This application is a divisional application of application number CN202610772449.2, filed on June 1, 2026, entitled "Broadband High-Efficiency Damping Wrapping Tape Based on Non-Vulcanized Butyl Rubber and Its Preparation Method". Technical Field

[0002] This invention belongs to the field of vibration reduction and noise reduction technology in bridge engineering, specifically relating to a damping wrapping tape of non-vulcanized butyl rubber for the synergistic suppression of crosswind excitation and vehicle frequency excitation of bridge cables and its preparation method. Background Technology

[0003] Cable-stayed bridges are widely used in the construction of long-span bridges due to their advantages such as strong span capacity, aesthetic appeal, and cost-effectiveness. As the core load-bearing component of a cable-stayed bridge, the cables are characterized by their low weight, high flexibility, and low inherent damping, making them highly susceptible to large-amplitude vibrations under environmental excitation. Long-term vibration can lead to problems such as cable fatigue damage, loosening of the anchoring system, sheath wear, and cable tension reduction, seriously threatening the operational safety of the bridge.

[0004] The vibration excitation faced by bridge cables can be mainly divided into two categories:

[0005] The first type is crosswind excitation (frequency range 0.1~5Hz, large amplitude). Long-span cable stays are prone to various forms of wind-induced vibration under wind loads, such as vortex-induced resonance and wind-rain excitation. Actual measurement data shows that under continuous crosswinds, the amplitude of the cables on some cross-sea bridges can reach more than 1 meter. Such large-amplitude vibrations cause serious fatigue damage to the cable anchorage ends and the cable body itself.

[0006] The second type is vehicle-frequency excitation (frequency range 5~20Hz, small amplitude but strong persistence). The bridge deck vibration generated by vehicle traffic is transmitted to the cables through the anchoring ends. When the vehicle excitation frequency is close to the natural frequency of the cables, parametric resonance will occur. Actual measurements show that when there is a dense flow of traffic (≥2000 vehicles / hour), the peak acceleration of the cables can reach more than 0.35g. Long-term effects will accelerate fatigue damage to the cables and seriously affect the service life of the bridge.

[0007] Existing cable vibration reduction technologies mainly have the following problems:

[0008] (1) Limitations of mechanical dampers: Mechanical damping devices such as viscous dampers and inertial mass dampers have insufficient damping energy dissipation efficiency under low-frequency strong wind excitation, while they are prone to clamping effect under medium- and high-frequency vehicle excitation—the excessive viscosity coefficient leads to increased local deformation of the cable and reduced damper stroke, which in turn reduces energy dissipation efficiency. In addition, mechanical dampers need to be specially installed at the anchoring end, which is complex in structure, costly, and difficult to maintain.

[0009] (2) Frequency domain defects of vulcanized rubber damping materials: Currently, there are various vulcanized rubber-based damping materials (such as vulcanized butyl rubber, vulcanized nitrile rubber, and vulcanized hydrogenated nitrile rubber), which form a three-dimensional network through vulcanization crosslinking. However, vulcanization crosslinking significantly restricts the mobility of molecular chains, resulting in a significant decrease in the damping performance of the material in the high-frequency region (>5Hz), and it is unable to maintain high damping in the wide frequency range of 0.1~20Hz.

[0010] (3) Inadequate performance of existing damping wrapping tape products: Although there are cable damping wrapping tape products on the market, most of them use vulcanized rubber or ordinary viscoelastic materials, which still have poor broadband damping performance and cannot take into account both low-frequency crosswind vibration and mid-to-high-frequency vehicle vibration. Moreover, most existing products are single damping layer structures and lack frequency self-adaptation capability.

[0011] Therefore, developing a damping wrapping tape based on non-vulcanized butyl rubber, suitable for cable surface wrapping construction, and capable of providing stable high damping over a wide frequency range, has significant engineering value and innovative significance for solving the vibration problem of bridge cables. Summary of the Invention

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0013] A broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, including a backing reinforcement layer and a damping functional layer;

[0014] The backing reinforcement layer is distributed on one side of the damping functional layer;

[0015] The damping functional layer comprises the following components by weight: 100 parts butyl rubber, 20-50 parts hydrogenated petroleum resin, 10-30 parts hindered phenol AO-80, 15-40 parts mica powder, 10-25 parts polyborosiloxane, 5-20 parts carbon black N330, 1-3 parts stearic acid, 1-2 parts antioxidant 4010NA, and 5-15 parts paraffin oil.

[0016] In the aforementioned broadband high-efficiency damping wrapping tape based on unvulcanized butyl rubber, the butyl rubber has an unsaturation degree of 1.0% to 2.5% and a Mooney viscosity of ML. (1+4) 125℃ corresponds to 40~70.

[0017] In the broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, the softening point of the hydrogenated petroleum resin is 90-120°C.

[0018] In the broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, the mica powder has a particle size of 200-800 mesh and an aspect ratio of ≥30.

[0019] In the broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, the boron content of the polyborosiloxane is 2% to 5%, and the number average molecular weight is 5000 to 15000.

[0020] In the aforementioned broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, the backing reinforcement layer is polyester fiber cloth, glass fiber cloth, nylon mesh cloth or metal wire mesh, with a thickness of 0.2 to 2.0 mm.

[0021] The preparation method of broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber includes the following steps:

[0022] (1) Butyl rubber kneading and plasticizing:

[0023] Add butyl rubber into a kneader and knead and plasticize it at 40-60°C for 5-10 minutes to fully soften the butyl rubber, reduce the Mooney viscosity, and achieve a uniform and plastic state.

[0024] (2) Filler premixing:

[0025] Stearic acid, antioxidant 4010NA, carbon black N330 and mica powder are added sequentially to the kneader and kneaded for 8 to 15 minutes at 50 to 70°C to make the powder filler and butyl rubber initially and evenly mixed.

[0026] (3) Blending of resin with hindered phenol:

[0027] Add hydrogenated petroleum resin and hindered phenol AO-80 in 2 to 4 batches. After each addition, knead for 5 to 8 minutes at 60 to 80°C to utilize the melting characteristics of the resin to promote the uniform dispersion of hindered phenol in the rubber matrix and form a preliminary blend.

[0028] (4) Final blending of functional components:

[0029] Add polyborosiloxane and paraffin oil, and continue kneading at 70-90°C for 10-20 minutes until all components are mixed evenly to form a homogeneous non-vulcanized butyl rubber composite material.

[0030] (5) Discharge and filtration:

[0031] The uniformly kneaded rubber compound is discharged from the kneader and filtered.

[0032] (6) Coating preheating:

[0033] The cooled rubber compound is preheated to 95-115°C using a single-screw extruder or melt pump to achieve a molten and fluid state.

[0034] (7) Coating and molding:

[0035] The preheated molten adhesive is evenly applied to the surface of the backing reinforcement layer through a coating head (slit coating head, roller coating head or doctor blade coating head) to form a damping functional layer with a thickness of 1 to 4 mm.

[0036] (8) Cooling and shaping:

[0037] After coating, the composite strip is cooled to below 40°C by cooling rollers or cooling boxes to solidify and shape the damping functional layer. Release paper or release film is then covered on the surface of the damping functional layer, and the strip is wound into a coil.

[0038] A production apparatus for a broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, and used to implement the above-described preparation method of the broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, comprising:

[0039] The kneading assembly includes a kneader and a pressure plate mounted on the outlet flange of the kneader, with a filter screen clamped between the pressure plate and the outlet flange.

[0040] The coating assembly applies a damping functional layer to the surface of the path backing reinforcement layer.

[0041] Backing delivery assembly for actively releasing the backing reinforcement layer;

[0042] Release film delivery assembly for actively releasing the release film;

[0043] The composite component is arranged between the coating component and the release film conveying component for roll bonding of the release film and the backing reinforcement layer coated with the damping functional layer.

[0044] The transition roll assembly is located in the area between the composite assembly and the winding assembly. The transition roll assembly includes a transition roll and a compensating roll. There are two sets of transition rolls. The compensating roll is located between the two sets of transition rolls and its height relative to the transition roll is adjustable. The compensating roll and the backing reinforcement layer are in contact.

[0045] The take-up assembly includes a rotary disk, a drive unit 1, a movable frame, a side top component, a flying cutter, and a guide component. Two sets of rotary disks are symmetrically distributed, each set equipped with a take-up shaft 1 and a take-up shaft 2. The take-up shafts 1 and 2 on each set of rotary disks are symmetrically distributed. Drive unit 1 is independently located on one side of the rotary disk to drive its rotation. The movable frame is independently located on one side of the rotary disk, and drive unit 3 and drive unit 2 are installed on it. Drive unit 3 is used to move the movable frame closer to or away from the rotary disk, and drive unit 2 is used to drive the corresponding take-up shaft to rotate. Two sets of side top components are independently installed on the opposite side of the rotary disk to constrain the corresponding take-up shaft. The flying cutter is installed in the middle of the two sets of rotary disks. The guide component includes a telescopic guide frame independently installed on one side below the area between the two sets of rotary disks. An arc-shaped guide frame and a telescopic cylinder are rotatably mounted on the top of the telescopic guide frame. The piston rod end of the telescopic cylinder is rotatably connected to the arc-shaped guide frame, and a suction cup is installed on the arc-shaped guide frame.

[0046] In the production equipment for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, both the first winding shaft and the second winding shaft include a rotating sleeve rotatably mounted on a rotary disk. A return spring and an insert shaft axially slidably mounted and passing through the inner side of the return spring are installed inside the rotating sleeve. Multiple expansion grooves are distributed circumferentially on the outer side of the insert shaft. An expansion body is rotatably mounted in each expansion groove. A drive shaft is movably mounted on the inner side of the insert shaft. Multiple recessed grooves are distributed circumferentially on the outer side of the insert shaft. An arc-shaped constraint body is rotatably mounted in the recessed groove, and a torsion spring is installed at the rotation node.

[0047] The inner wall of the rotating sleeve is provided with an axial guide groove, one end of the arc-shaped constraint body is slidably engaged with the axial guide groove, and the root of the axial guide groove is provided with an inner groove 9, which is adapted to the arc-shaped constraint body.

[0048] The end of the drive shaft facing the outer expansion body is tapered. The end of the drive shaft away from the outer expansion body is provided with a countersunk hole. An elastic top pin is installed on the side of the countersunk hole. The inner wall of the plug shaft is provided with a spiral groove and an arc-shaped groove located at the root of the spiral groove and distributed circumferentially. The depth of the spiral groove gradually decreases along the direction close to the arc-shaped groove, and the depth of the spiral groove near the arc-shaped groove is less than the inlet depth of the arc-shaped groove. The depth of the arc-shaped groove gradually increases along the direction away from the spiral groove. The end of the elastic top pin is adapted to the spiral groove and the arc-shaped groove. A T-shaped hole is provided on the side of the plug shaft. The T-shaped hole is used to connect the arc-shaped groove and the countersunk groove. An outer top member is movably installed in the T-shaped hole. The elastic top pin extends the free end of the arc-shaped constraint body outward through the outer top member.

[0049] The end of the outer expansion groove away from the countersunk hole is provided with a notch, and a sealing plate is installed at the notch;

[0050] A sealing ring plate is installed at the opening of the plug shaft.

[0051] In the production equipment for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, the side top component includes a lateral cylinder and a side push component installed at the output end of the lateral cylinder. A limit ring is provided on the outer side of the side push component. A constraint plate is installed at the end of the side push component away from the output end of the lateral cylinder. A flat push sleeve and a spring component are fitted on the outer side of the side push component. The spring component and the flat push sleeve are located between the constraint plate and the limit ring, and the spring component is distributed between the limit ring and the flat push sleeve. A rotating block is provided on the constraint plate. A rotating groove adapted to the rotating block and a retraction groove arranged linearly along the inner wall of the countersunk hole of the drive shaft are provided on the inner wall of the drive shaft.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. The butyl rubber molecules of this invention have densely distributed methyl side groups on their main chain, which hinders the movement of molecular chain segments, resulting in extremely high internal friction and loss. In the uncured state, there are no chemical cross-linking points between molecular chains, allowing for greater freedom of chain segment movement, but also higher intermolecular friction, resulting in a very high loss factor (tanδ can reach over 1.5). The uncured state avoids the restriction on chain segment movement imposed by vulcanization cross-linking, thus maintaining high damping performance over a wide frequency range.

[0054] 2. The hydrogenated petroleum resin of the present invention, as a tackifying resin, has good compatibility with butyl rubber, forming physical entanglement points and micro-phase separation structures in the material, increasing the frictional energy dissipation between molecular chains. At the same time, the hindered phenol A0-80 contains multiple phenolic hydroxyl groups, which can form reversible hydrogen bonds with the butyl rubber molecular chains. Under vibrational excitation, the hydrogen bonds break and absorb energy. After the excitation is removed, the hydrogen bonds reform, giving the material self-recovery properties. The synergistic effect of the two broadens the damping temperature range to -20~80℃ and provides a stable high loss factor in the range of 0.1~20Hz.

[0055] 3. The mica powder of this invention has a high aspect ratio sheet-like structure that aligns along the rubber matrix during mixing and calendering. During vibration energy transmission, relative slippage occurs between the sheets, generating significant interfacial friction energy dissipation. Simultaneously, the sheet-like structure extends the propagation path of stress waves, further enhancing energy dissipation. The presence of the sheet-like mica powder also improves the rigidity of the material, preventing excessive flow and deformation of the material in the non-vulcanized state.

[0056] 4. The B-O dynamic coordination bond in the polyborosiloxane of the present invention has unique frequency sensitivity. At low frequencies (0.1~5Hz, crosswind excitation), the B-O bond has sufficient time to undergo reversible breakage and recombination, mainly manifested as viscous dissipation, contributing additional damping. At medium and high frequencies (5~20Hz, vehicle frequency excitation), the B-O bond does not have enough time to relax, manifested as shear thickening effect, and the damping force increases with the increase of strain rate, thereby providing targeted damping enhancement in the high frequency range, so that the material can maintain efficient energy dissipation under vibration excitation of two different frequencies.

[0057] 5. Compared with existing vulcanized rubber damping materials, the non-vulcanization process of this invention has the following advantages: no vulcanization equipment is required, simplifying the production process and reducing energy consumption by about 50%; and avoiding the negative impact of vulcanizing agents on damping performance.

[0058] 6. The damping wrapping tape of this invention forms a multi-layer composite structure through spiral overlapping and winding. The relative slippage between the layers generates additional frictional energy dissipation, which can contribute 12-15% of the additional damping effect in actual tests. The backing reinforcement layer provides structural support, prevents construction tensile deformation, constrains the lateral creep of the damping functional layer, and improves dimensional stability. The self-adhesive design allows for easy tearing and pasting, resulting in high on-site construction efficiency. It does not require disassembly of the cable anchoring structure and is suitable for both new bridges and the reinforcement of old bridges.

[0059] In summary, by employing multiple mechanisms of synergy among various components in the damping functional layer, a wideband and efficient synergistic suppression of low-frequency, large-amplitude crosswind vibrations and mid-to-high-frequency vehicle vibrations can be achieved.

[0060] 7. In the processing of this broadband high-efficiency damping wrapping tape, since there are various powder raw materials in each component, metal particles are often mixed in the raw materials during the production process. Once they enter the coating process, they will cause problems such as damage to the coating head or uneven coating. Therefore, a filter component is added at the outlet of the kneader to solve this problem.

[0061] 8. In processing this wide-band high-efficiency damping wrapping tape, the present invention adds a transition roller assembly as a compensation mechanism during take-up shaft switching. By adjusting the up and down position of the compensation roller when the take-up shaft is switched, and in conjunction with the take-up assembly, the wrapping tape can be kept smooth and within the set tension range without stacking without stopping the equipment. After the take-up shaft is switched, the compensation roller acts on the backing reinforcement layer and will not cause wrapping tape quality problems.

[0062] 9. In processing this wideband high-efficiency damping wrapping tape, the present invention addresses the limitation of automated drum loading and unloading in existing winding processes. By using an axially adjustable side-top component on the outside of the rotary disc in conjunction with the winding shaft, the side-top component moves the insertion shaft outward relative to the rotating sleeve during a single feed, inserting it into the inside of the drum. Subsequently, it drives the drive shaft to move inward relative to the insertion shaft and rotate until the outer expansion body extends outward and the insertion shaft position is locked, thus installing the drum. When removal is required, the side-top component feeds again (greater than the previous feed stroke), rotating the drive shaft in the opposite direction relative to the insertion shaft by a certain angle, unlocking the insertion shaft and subsequently retracting the outer expansion body inward. During retraction, the retracted insertion shaft is separated from the inside of the drum's end, allowing the drum to be unloaded. When used with a robot, this invention effectively improves production efficiency and operational safety. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the structure of the broadband high-efficiency damping wrapping tape of the present invention.

[0064] Figure 2 This is a structural diagram of the broadband high-efficiency damping wrapping tape production equipment of the present invention.

[0065] Figure 3 This is a schematic diagram of the kneading component.

[0066] Figure 4 This is a schematic diagram of the outlet location of the kneading component.

[0067] Figure 5 This is a cross-sectional view of the broadband high-efficiency damping wrapping tape production equipment of the present invention.

[0068] Figure 6 This is a structural diagram of the transition roller assembly.

[0069] Figure 7 This is a cross-sectional view of the winding assembly.

[0070] Figure 8 This is a cross-sectional view of the cut part.

[0071] Figure 9 This is a schematic diagram of the winding shaft (outer expansion state).

[0072] Figure 10 This is a schematic diagram of the winding shaft (outer expansion, inner contraction state).

[0073] Figure 11 This is a schematic diagram of the rotating sleeve.

[0074] Figure 12 , 13 This is a schematic diagram of the plug-in shaft.

[0075] Figure 14 This is a cross-sectional view of the rotation node of the outer expansion body.

[0076] Figure 15 This is a cross-sectional view of the arc-shaped constraint.

[0077] Figure 16 This is a structural diagram of the side top component.

[0078] Figure 17 This is a structural diagram of the guide component.

[0079] In the diagram: 101, backing reinforcement layer; 102, damping functional layer;

[0080] 100. Coating assembly; 200. Backing conveyor assembly; 300. Release film conveyor assembly; 400. Composite assembly; 500. Transition roller assembly; 600. Rewinding assembly; 700. Kneading assembly;

[0081] 510. Transition roller; 520. Compensating roller; 521. Servo motor; 522. Lead screw; 523. Slide; 610. Rotary disk; 620. Drive component one; 630. Drive component two; 640. Moving frame; 650. Flying cutter; 651. Central tube; 652. Moving groove; 653. Transmission screw; 654. Moving seat; 655. Flying knife; 660. Guide component; 661. Telescopic guide frame; 662. Arc-shaped guide frame; 663. Telescopic cylinder; 664. Suction cup component; 670. Drive component three; 680. Side top component; 681. Lateral cylinder; 682. Side push component; 683. Limiting ring; 684. Constraint disk; 685. Flat push sleeve; 686. Rotating lever; 710. Pressure plate; 720. Kneader;

[0082] 10. Rewinding shaft one; 11. Rotating sleeve; 1101. Sealing ring plate one; 12. Insertion shaft; 121. Outer top piece; 13. Outer expansion groove; 131. Sealing plate; 14. Outer expansion body; 15. Drive shaft; 151. Countersunk hole; 152. Elastic top pin; 153. Spiral groove; 154. Arc groove; 155. Sealing ring plate two; 156. Rotating groove; 157. Retraction groove; 16. Countersunk groove; 17. Arc-shaped constraint body; 18. Axial guide groove; 20. Rewinding shaft two. Detailed Implementation

[0083] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0084] Example 1

[0085] like Figure 1 As shown, this embodiment provides a broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber. Its structure includes a polyester fiber cloth backing reinforcement layer 101 with a thickness of 0.5 mm, and a damping functional layer 102 coated thereon. Of course, the backing reinforcement layer 101 can also be glass fiber cloth or nylon mesh cloth.

[0086] The damping functional layer 102 is composed of, by weight, butyl rubber (unsaturated 1.8%, Mooney viscosity ML). (1+4) 100 parts of 125℃ (55), 35 parts of hydrogenated petroleum resin (softening point 105℃), 20 parts of hindered phenol AO-80, 28 parts of mica powder (500 mesh, aspect ratio 35), 18 parts of polyborosiloxane (boron content 3.5%, number average molecular weight 10000), 12 parts of carbon black N330, 2 parts of stearic acid, 1.5 parts of antioxidant 4010NA, and 10 parts of paraffin oil.

[0087] The preparation method is as follows:

[0088] (1) Plasticizing: Put butyl rubber into a kneader and knead and plasticize it at 50°C for 8 minutes to soften the butyl rubber and reduce the Mooney viscosity, so as to achieve a uniform plastic state.

[0089] (2) Filler premixing: Stearic acid, antioxidant 4010NA, carbon black N330 and mica powder are added to the kneader in sequence and kneaded at 60°C for 12 minutes to make the powder filler and butyl rubber initially mixed evenly.

[0090] (3) Blending of resin with hindered phenol: Hydrogenated petroleum resin and hindered phenol AO-80 are added in 3 batches. After each addition, the mixture is kneaded at 70°C for 6 minutes to promote the uniform dispersion of hindered phenol AO-80 in the rubber matrix by utilizing the melting characteristics of the resin to form a preliminary blend.

[0091] (4) Final mixing of functional components: Add polyborosiloxane and paraffin oil, knead at 80°C for 15 minutes until all components are mixed evenly to form a uniform non-vulcanized butyl rubber composite material.

[0092] (5) Discharge and filtration: Discharge the uniformly kneaded rubber compound from the kneader and filter it;

[0093] (6) Coating preheating: The rubber compound is preheated to 95-115°C through a single screw extruder to make it reach a melt flow state;

[0094] (7) Coating and molding: The molten adhesive is uniformly coated onto the surface of the polyester fiber cloth using a slit coating head. The thickness of the damping functional layer 102 is 2.5 mm.

[0095] (8) Cooling and shaping: The damping functional layer 102 is cooled to below 40°C by cooling rollers, and then covered with release film and rolled into a disc.

[0096] Example 2

[0097] The difference between this embodiment and Embodiment 1 lies in the different component ratios of the damping functional layer 102. Specifically, it consists of: 100 parts butyl rubber, 25 parts hydrogenated petroleum resin, 15 parts hindered phenol AO-80, 20 parts mica powder, 12 parts polyborosiloxane, 8 parts carbon black N330, 1.5 parts stearic acid, 1 part antioxidant 4010NA, and 8 parts paraffin oil. The preparation process is the same as in Embodiment 1.

[0098] Example 3

[0099] The difference between this embodiment and Embodiment 1 lies in the different component ratios of the damping functional layer 102. Specifically, it consists of: 100 parts butyl rubber, 45 parts hydrogenated petroleum resin, 28 parts hindered phenol AO-80, 35 parts mica powder, 22 parts polyborosiloxane, 18 parts carbon black N330, 2.5 parts stearic acid, 2 parts antioxidant 4010NA, and 13 parts paraffin oil. The preparation process is the same as in Embodiment 1.

[0100] Comparative Example 1

[0101] The difference between this comparative example and Example 1 is that hindered phenol AO-80 is not added, the hydrogenated petroleum resin is adjusted to 55 parts to maintain the thickening effect, and the remaining components and preparation process are the same as in Example 1.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 1 is that: no polyborosiloxane is added, the paraffin oil is adjusted to 28 parts to maintain processing fluidity, and the remaining components and preparation process are the same as in Example 1.

[0104] Comparative Example 3

[0105] The difference between this comparative example and the embodiment is that mica powder is not added, and the carbon black N330 is adjusted to 40 parts to maintain the reinforcing effect. The remaining components and preparation process are the same as in Example 1.

[0106] Comparative Example 4

[0107] This comparative example uses the exact same damping functional layer 102 composition as Example 1, but undergoes a vulcanization process to compare the effects of non-vulcanization and vulcanization processes on damping performance.

[0108] The specific vulcanization process is as follows: The rubber compound, after final mixing according to the formula in Example 1, is added to a two-roll mill along with the vulcanization system: 1.5 parts sulfur, 1.0 part accelerator DM, 0.5 parts accelerator TMTD, and 5 parts zinc oxide. After uniform mixing, the rubber compound is coated onto the surface of a polyester fiber cloth to form a 2.5 mm thick damping layer. Vulcanization is then carried out on a flat vulcanizing machine under the following conditions: temperature 150°C, pressure 10 MPa, and time 30 minutes. After vulcanization, the mixture is cooled to room temperature, covered with a release film, and wound into a reel.

[0109] Performance testing and verification of beneficial effects: The damping wrapping tapes prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to dynamic mechanical performance tests (DMA, tensile mode, frequency range 0.1~20 Hz, temperature 25℃), and vibration attenuation tests were conducted simulating cable winding construction. The results are shown in Table 1.

[0110]

[0111] As shown in the table above, compared with Comparative Example 4, Example 1 showed a significant decrease in loss factor from 1.62 to 1.08 at 0.1 Hz (a reduction of 33.3%), from 1.57 to 0.76 at 10 Hz (a reduction of 51.6%), and from 1.55 to 0.68 at 20 Hz (a reduction of 56.1%). The simulated cable vibration attenuation rate decreased from 87.5% to 52.3% (a reduction of 40.2%). This indicates that the three-dimensional network formed by vulcanization significantly restricts the movement of butyl rubber molecular chains, while also disrupting the hydrogen bond network of hydrogenated petroleum resin / hindered phenol A0-80 and the dynamic response characteristics of polyborosiloxane B-O bonds, leading to a comprehensive deterioration of broadband damping performance. This invention employs a non-vulcanization process, avoiding this defect, which is key to maintaining a high loss factor in the 0.1–20 Hz broadband range.

[0112] Comparative Example 1 maintained a loss factor of 1.35 at 0.1 Hz, but tanδ decreased continuously with increasing frequency: to 1.15 at 10 Hz and to 1.08 at 20 Hz, a decrease of 20.0% from 0.1 Hz to 20 Hz. In contrast, Example 1 remained stable within the same frequency range (1.62→1.57→1.55), with a decrease of only 4.3%. This indicates that the reversible hydrogen bonds formed between the phenolic hydroxyl groups of hindered phenol AO-80 and the butyl rubber molecular chain contribute to viscous dissipation at low frequencies through breakage and recombination. After the excitation is removed, the hydrogen bonds reform, endowing the material with self-healing properties, which is an important mechanism for maintaining broadband damping stability.

[0113] The tanδ values ​​of Comparative Example 2 at 5 Hz, 10 Hz, and 20 Hz were 1.31, 1.23, and 1.15, respectively, significantly lower than those of Example 1 (1.58, 1.57, and 1.55). Particularly noteworthy is that the loss factor of Comparative Example 2 decreased from 1.45 at 0.1 Hz to 1.15 at 20 Hz, a decrease of 20.7%, and the rate of decrease accelerated with increasing frequency (0.08 decrease from 5 to 10 Hz, 0.08 decrease from 10 to 20 Hz). In contrast, Example 1 only decreased by 4.3% from 0.1 Hz to 20 Hz, with a relatively slow rate of decrease. This verifies the frequency sensitivity of the BO dynamic coordination bonds in polyborosiloxane. Under mid-to-high frequency vibration excitation, the BO bonds do not have enough time to fully relax, resulting in a shear thickening effect, which specifically compensates for high-frequency damping, allowing the material to maintain efficient energy dissipation even under high-frequency excitation.

[0114] Comparative Example 3 showed tanδ values ​​of 1.38, 1.32, 1.28, and 1.25 at 0.1 Hz, 5 Hz, 10 Hz, and 20 Hz, respectively, all significantly lower than those of Example 1. In terms of frequency response, the tanδ of Comparative Example 3 decreased by 9.4% from 0.1 Hz to 20 Hz, which, while better than Comparative Examples 1 and 2, was still far worse than the 4.3% decrease in Example 1. More notably, the simulated cable vibration attenuation rate decreased dramatically from 87.5% (Example 1) to 68.5% (Comparative Example 3), a reduction of 19.0 percentage points, representing the most significant decrease in vibration attenuation rate among all single-component missing comparative examples. This indicates that the sheet-like structure of the high aspect ratio mica powder not only dissipates energy through interfacial friction via relative slippage between layers during vibration, but also contributes crucial interfacial slippage additional damping in the spiral winding structure of the wrapping tape, making a unique contribution to the overall vibration reduction effect.

[0115] Comparative Example 4 showed the most severe damage to damping performance, with a 56.1% decrease in tanδ at 20 Hz, far exceeding the impact of the absence of any single component. This indicates that the non-sulfurization process chosen in this invention is not a simple process replacement, but rather a core technical feature that works synergistically with the various functional components.

[0116] At the same time, such as Figures 2 to 17 As shown, the following improvements are also made to the existing production equipment:

[0117] A production apparatus for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, used to implement the above-described preparation method of broadband high-efficiency damping wrapping tape, including:

[0118] The kneading assembly 700 includes a kneader 720 and a pressure plate 710 installed on the outlet flange of the kneader 720. A filter screen is clamped between the pressure plate 710 and the outlet flange. The filter screen is made of 100-mesh stainless steel mesh. During the production of composite materials, the main powder raw materials often encounter metal particles (such as iron nails) as impurities. Once these impurities enter the coating process, they will cause problems such as clogging and damage to the coating head, affecting the production of wrapping tape.

[0119] The coating assembly 100 coats a damping functional layer 102 onto the surface of the path backing reinforcement layer 101.

[0120] Backing delivery assembly 200 for actively releasing backing reinforcement layer 101;

[0121] Release film delivery assembly 300 is used for actively releasing the release film;

[0122] Composite component 400 is arranged between coating component 100 and release film conveying component 300 for roll bonding of release film and backing reinforcement layer 101 coated with damping functional layer 102.

[0123] The transition roll assembly 500 is located in the area between the composite assembly 400 and the take-up assembly 600. The transition roll assembly 500 includes a transition roll 510 and a compensating roll 520. Two sets of transition rolls 510 are provided. The compensating roll 520 is positioned between the two sets of transition rolls 510 and its height relative to the transition rolls 510 is adjustable. The compensating roll 520 maintains contact with the lower surface of the backing reinforcement layer 101 it passes through. The compensating roll 520 requires two separately configured adjustable adjustment structures, with the two adjustment structures distributed between the two sets of adjustment structures. At both ends of the roller 520, each set of adjustment structures includes a servo motor 521, a lead screw 522, and a slide block 523. The output end of the servo motor 521 is connected to the lead screw 522. The lead screw 522 is vertically distributed and matched with the slide block 523. The two sets of slide blocks 523 are equipped with tension adjusters for connection with the compensation roller 520. The servo motor 521 drives the lead screw 522 to rotate and adjusts the vertical position of the slide block 523 and the connected compensation roller 520, which can ensure that the wrapping tape is always within the set tension range.

[0124] The take-up assembly 600 includes a rotary disk 610, a drive unit 620, a moving frame 640, a side top component 680, a cutting component 650, and a guide component 660. Two sets of rotary disks 610 are symmetrically distributed, each set mounted on a corresponding frame. Each set of rotary disks 610 is equipped with a take-up shaft 10 and a take-up shaft 20. The take-up shafts 10 and 20 on each set of rotary disks 610 are symmetrically distributed around the center of the rotary disk 610. The drive unit 620 is independently arranged on the rotary disk. A frame on one side of the rotary disk 610 is used to drive the rotary disk 610 to rotate. A movable frame 640 is independently distributed on the frame on one side of the rotary disk 610. A third drive component 670 and a second drive component 630 are mounted on the movable frame 640. The third drive component 670 is used to move the movable frame 640 closer to or further away from the rotary disk 610, and the second drive component 630 is used to drive the corresponding take-up shaft to rotate. The first drive component 620 and the second drive component 630 are both servo motors, and the third drive component 670 is a telescopic cylinder mounted on the frame. Two sets of side-top components 680 are independently mounted on the frame on the opposite side of the rotary disk 610, used to constrain and release the corresponding take-up shaft. The flying cutter 650 is installed in the middle of the two sets of rotating disks 610. The flying cutter 650 includes a central tube 651 connecting the middle of the two sets of rotating disks 610 and a motor independently located on the outside of the frame. The central tube 651 has symmetrically distributed moving slots 652 on its side. A transmission screw 653 is installed inside the central tube 651. One end of the transmission screw 653 is connected to the output end of the motor. A moving seat 654 is installed on the transmission screw 653. Two sets of flying cutters 655 are installed on the moving seat 654. The flying cutters 655 extend to the outside of the moving slots 652 for cutting wrapping tape.

[0125] The guide 660 includes a telescopic guide frame 661 independently installed on one side below the area between the two sets of rotating disks 610. An arc-shaped guide frame 662 and a telescopic cylinder 663 are rotatably mounted on the top of the telescopic guide frame 661. The piston rod end of the telescopic cylinder 663 is rotatably connected to the arc-shaped guide frame 662. A suction cup 664 is installed on the arc-shaped guide frame 662.

[0126] Driven by drive component 620, the rotary disk 610 rotates, enabling the position switching between take-up shaft 10 and take-up shaft 20, achieving online roll changing operations without stopping the machine. Taking take-up shaft 20 winding to a set length as an example, drive component 670 starts, moving the moving frame 640 away from the rotary disk 610, forcing drive component 630 and take-up shaft 20 to separate; then drive component 620 starts, driving the rotary disk 610 to rotate, rotating take-up shaft 10 to the position of take-up shaft 20, i.e., the two positions are switched. The telescopic guide frame 661 extends outward to attract the suction cup component 664 to the backing reinforcement layer 101 between take-up shaft 10 and take-up shaft 20. Drive component 670 starts, moving the moving frame 640 closer to the rotary disk 610. The output end of drive component 2 630 is connected to take-up shaft 10, and the flying cutter 650 cuts the attracted wrapping tape. After the air cylinder 663 and the telescopic guide frame 661 drive the arc-shaped guide frame 662 to attach the adsorbed end of the wrapping tape to the pre-installed drum (with double-sided adhesive on the surface) on the take-up shaft 10, the suction cup 664 separates from the wrapping tape. The second drive unit 630 starts to drive the take-up shaft 10. During the switching between the positions of the take-up shaft 10 and the second take-up shaft 20, when the take-up shaft 10 is running at the set winding speed, the system will use the tension regulator to control the servo motor 521 to adaptively adjust the position of the compensation roller 520 so that the wrapping tape is always within the set tension range. The robot arm fixes the end of the wrapping tape on the second take-up shaft 20 and removes the second take-up shaft 20 to replace the new drum.

[0127] To achieve a one-time locking of the position of the inserted winding drum and the tightening drum, the following design is adopted: Both the first winding shaft 10 and the second winding shaft 20 include a rotating sleeve 11 rotatably mounted on the rotary disk 610 via a one-way bearing, ensuring that no unwinding occurs when the positions of the first winding shaft 10 and the second winding shaft 20 are switched. A return spring and an insert shaft 12, which is axially slidably mounted and passes through the inner side of the return spring, are installed inside the rotating sleeve 11. The insert shaft 12 has a T-shaped structure with a large end and a small end. The large end slides axially within the rotating sleeve 11, and the small end can pass through the rotating sleeve 11. Multiple outward expansion grooves 13 are distributed circumferentially on the outer side (small end) of the plug shaft 12. An outward expansion body 14 is rotatably installed in each outward expansion groove 13 away from the large end. A drive shaft 15 is movably installed on the inner side of the plug shaft 12. Multiple recessed grooves 16 are distributed circumferentially on the outer side (large end) of the plug shaft 12 located on the inner side of the rotating sleeve 11. An arc-shaped constraint body 17 is rotatably installed in the recessed groove 16, and a torsion spring is installed at the rotation node.

[0128] The inner wall of the rotating sleeve 11 is provided with an axial guide groove 18. The free end of the arc-shaped constraint body 17 is slidably engaged with the axial guide groove 18. The root of the axial guide groove 18 is provided with an inner groove 19. The inner groove 19 is adapted to the arc-shaped constraint body 17 (when the arc-shaped constraint body 17 extends outward, it can engage with the inner groove 19 to prevent the insertion shaft 12 from retracting). The end of the rotating sleeve 11 is provided with a sealing ring plate 1101 to seal the end of the rotating sleeve 11 and prevent the insertion shaft 12 from detaching from the inside.

[0129] The end of the drive shaft 15 facing the outer expander 14 is tapered, and a slope is provided on the side where the outer expander 14 and the drive shaft 15 contact, facilitating the compression of the outer expander 14 for tightening inside the drum. A countersunk hole 151 is provided at the end of the drive shaft 15 away from the outer expander 14, and an elastic top pin 152 is installed on the side of the countersunk hole 151. A spiral groove 153 and circumferentially distributed arc-shaped grooves 154 located at the root of the spiral groove 153 are provided on the inner wall of the insertion shaft 12. The depth of the spiral groove 153 gradually decreases towards the arc-shaped groove 154, and the depth of the spiral groove 153 near the arc-shaped groove 154 is less than the inlet depth of the arc-shaped groove 154. The depth of the arc groove 154 gradually increases in the direction away from the spiral groove 153. The end of the elastic top pin 152 is adapted to the spiral groove 153 and the arc groove 154. A T-shaped hole is provided on the side of the plug shaft 12. The T-shaped hole is used to connect the arc groove 154 and the countersink 16. An outer top member 121 is movably installed in the T-shaped hole. The elastic top pin 152 extends the free end of the arc restraint body 17 through the outer top member 121. A slope is provided on the side where the outer top member 121 and the elastic top pin 152 are in contact. The outer top member 121 moves outward to extend the arc restraint body 17 and adapt it to the inner groove 19, thereby axially constraining and fixing the plug shaft 12, and thus constraining the drum.

[0130] The outer expansion groove 13 is provided with a notch at one end away from the countersunk hole 151. The notch is provided with a recessed part at one end away from the large end of the insertion shaft 12 for the installation of the rotating shaft of the outer expansion body 14, which facilitates the installation of the outer expansion body 14. A sealing plate 131 is installed at the notch to prevent the outer expansion body 14 from detaching.

[0131] A sealing ring plate 155 is installed at one end of the insertion shaft 12 located inside the rotating sleeve 11 to prevent the drive shaft 15 from disengaging from the inside.

[0132] The side-top component 680 includes a lateral cylinder 681 and a side-push component 682 installed at the output end of the lateral cylinder 681. A limit ring 683 is provided on the outer side of the side-push component 682. A constraint plate 684 is installed at the end of the side-push component 682 away from the output end of the lateral cylinder 681. A flat push sleeve 685 and a spring are fitted on the outer side of the side-push component 682. The spring and the flat push sleeve 685 are located between the constraint plate 684 and the limit ring 683, and the spring is distributed between the limit ring 683 and the flat push sleeve 685. A rotating block 686 is provided on the constraint plate 684. A rotating groove 156 adapted to the rotating block 686 is provided on the inner wall of the countersunk hole 151 of the drive shaft 15.

[0133] During drum installation, a robotic arm places the drum between two rotating sleeves 11. Lateral cylinders 681 on both sides drive the side pushers 682 closer to the rotating disk 610. The flat pusher 685 pushes the drive shaft 15 and the insertion shaft 12 closer to the drum, compressing the return spring. The arc-shaped constraint 17 moves along the axial guide groove 18, moving outward from the rotating sleeve 11 and inserting into the drum until the arc-shaped constraint 17 aligns with the inner groove 19. Then, the flat pusher 685 gradually compresses the spring, while the drive shaft 15 moves inward into the insertion shaft 12, compressing the elastic top pin 152. As the pin 152 moves along the spiral groove 153, it gradually compresses the length of the elastic top pin 152. At the junction of the spiral groove 153 and the arc groove 154, it enters the arc groove 154 under the action of inertia and enters the root along the arc groove 154. Finally, it squeezes the outer top piece 121 to move outward, and rotates the free end of the arc constraint body 17 into the inner groove 19, thereby locking the position of the plug shaft 12 inside the roll. Then, the lateral cylinder 681 will drive the side push piece 682 to reset. After locking is completed, the rotating block 686 on the constraint plate 684 and the rotating groove 156 are in a non-contact state.

[0134] When the drum needs to be unloaded, the lateral cylinders 681 on both sides drive the lateral pusher 682 to approach the rotating disk 610 again. The stroke of the rotating sleeve 11 is greater than the stroke required to tighten the drum. The rotating block 686 will enter the rotating groove 156. Since the constraint disk 684 moves linearly, it will drive the drive shaft 15 to rotate in the opposite direction, causing the elastic top pin 152 to move in the opposite direction to the junction of the spiral groove 153 and the arc groove 154. At the same time, the rotating block 686 will enter the return groove 157. Since the spring is in a compressed state at this time, the insertion shaft 12 is in its original position. Then, the lateral pusher 682 will gradually reset under the drive of the lateral cylinder 681. The rotating block 686 will disengage linearly relative to the drive shaft 15 along the return groove 157. The flat pusher 685 will fit against the end face of the drive shaft 15. As the spring gradually recovers its length and the elastic top pin 152 gradually resets, the axial constraint of the insertion shaft 12 is released. Then, the insertion shaft 12 is fully reset under the action of the reset spring.

[0135] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A production equipment for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber, characterized in that, include: The kneading assembly (700) includes a kneader (720) and a pressure plate (710) mounted on the outlet flange of the kneader (720), with a filter screen clamped between the pressure plate (710) and the outlet flange; The coating assembly (100) applies a damping functional layer (102) to the surface of the path backing reinforcement layer (101). Backing delivery assembly (200) for actively releasing backing reinforcement layer (101). Release film delivery assembly (300) for actively releasing the release film; A composite component (400) is disposed between a coating component (100) and a release film delivery component (300) for roll bonding of a release film and a backing reinforcement layer (101) coated with a damping functional layer (102); The transition roll assembly (500) is located in the area between the composite assembly (400) and the winding assembly (600). The transition roll assembly (500) includes a transition roll (510) and a compensation roll (520). There are two sets of transition rolls (510). The compensation roll (520) is located between the two sets of transition rolls (510) and its height relative to the transition rolls (510) is adjustable. The compensation roll (520) and the backing reinforcement layer (101) are in contact. The take-up assembly (600) includes a rotary disk (610), a drive unit (620), a moving frame (640), a side top component (680), a cutting component (650), and a guide component (660). Two sets of rotary disks (610) are symmetrically distributed. Each set of rotary disks (610) is equipped with a take-up shaft (10) and a take-up shaft (20). The take-up shafts (10) and (20) on each set of rotary disks (610) are symmetrically distributed. The drive unit (620) is independently located on one side of the rotary disk (610) to drive the rotary disk (610) to rotate. The moving frame (640) is independently located on one side of the rotary disk (610). The moving frame (640) is equipped with a drive unit (670) and a drive unit (630). The drive unit (670)... The first part (640) is used to move the moving frame (640) closer to or away from the rotating disk (610). The second drive part (630) is used to drive the corresponding take-up shaft to rotate. The side top part (680) is provided with two sets of independently installed on the opposite side of the rotating disk (610) to constrain the corresponding take-up shaft. The flying cutter (650) is installed in the middle of the two sets of rotating disks (610). The guide part (660) includes a telescopic guide frame (661) independently installed on one side below the area between the two sets of rotating disks (610). The top of the telescopic guide frame (661) is rotatably mounted with an arc-shaped guide frame (662) and a telescopic cylinder (663). The piston rod end of the telescopic cylinder (663) is rotatably connected to the arc-shaped guide frame (662). The arc-shaped guide frame (662) is mounted with a suction cup part (664).

2. The production equipment for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber according to claim 1, wherein the first winding shaft (10) and the second winding shaft (20) both include a rotating sleeve (11) rotatably mounted on a rotating disk (610), a return spring and an insert shaft (12) axially slidably mounted and passing through the inner side of the return spring are installed in the rotating sleeve (11), a plurality of outer expansion grooves (13) are distributed circumferentially on the outer side of the insert shaft (12), an outer expansion body (14) is rotatably mounted in each outer expansion groove (13), a drive shaft (15) is movably mounted on the inner side of the insert shaft (12), a plurality of sink grooves (16) are distributed circumferentially on the outer side of the insert shaft (12), an arc-shaped constraint body (17) is rotatably mounted in the sink groove (16) and a torsion spring is installed at the rotation node; A axial guide groove (18) is provided on the inner wall of the rotating sleeve (11). One end of the arc-shaped constraint body (17) is slidably engaged with the axial guide groove (18). An inner groove (19) is provided at the root of the axial guide groove (18). The inner groove (19) is adapted to the arc-shaped constraint body (17). The end of the drive shaft (15) facing the outer expansion body (14) is tapered. The end of the drive shaft (15) away from the outer expansion body (14) is provided with a countersunk hole (151). An elastic top pin (152) is installed on the side of the countersunk hole (151). The inner wall of the plug shaft (12) is provided with a spiral groove (153) and an arc-shaped groove (154) located at the root of the spiral groove (153) and distributed circumferentially. The depth of the spiral groove (153) gradually decreases along the direction close to the arc-shaped groove (154) and the spiral groove (153) is close to the arc-shaped groove (154). The depth of one end is less than the inlet depth of the arc groove (154). The depth of the arc groove (154) gradually increases in the direction away from the spiral groove (153). The end of the elastic top pin (152) is adapted to the spiral groove (153) and the arc groove (154). A T-shaped hole is provided on the side of the plug shaft (12). The T-shaped hole is used to connect the arc groove (154) and the countersink (16). An outer top piece (121) is movably installed in the T-shaped hole. The elastic top pin (152) extends the free end of the arc constraint body (17) outward through the outer top piece (121). The outer expansion groove (13) is provided with a notch at one end away from the countersunk hole (151), and a sealing plate (131) is installed at the notch. A sealing ring plate (155) is installed at the opening of the plug shaft (12).

3. The production equipment for broadband high-efficiency damping wrapping tape based on non-vulcanized butyl rubber according to claim 2, wherein the side top member (680) includes a side cylinder (681) and a side push member (682) installed at the output end of the side cylinder (681), a limit ring (683) is provided on the outer side of the side push member (682), a constraint plate (684) is installed at the end of the side push member (682) away from the output end of the side cylinder (681), and the outer side of the side push member (682) is sleeved with a limit ring (683). The device is equipped with a push sleeve (685) and a spring component. The spring component and the push sleeve (685) are located between the constraint plate (684) and the limit ring (683), and the spring component is distributed between the limit ring (683) and the push sleeve (685). The constraint plate (684) is provided with a rotating block (686). The inner wall of the countersunk hole (151) of the drive shaft (15) is provided with a rotating groove (156) that matches the rotating block (686) and a return groove (157) that is straight along the inner wall.

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