Environment-friendly walking bead pen and assembling method thereof
By using biodegradable materials and a minimalist ink supply system, the environmental pollution and resource waste problems of disposable writing instruments are solved. The stable supply and biodegradability of environmentally friendly water-based ink are achieved, ensuring the smoothness and biodegradability of the writing instrument.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI AGRICULTURAL UNIV.
- Filing Date
- 2026-06-26
- Publication Date
- 2026-07-31
AI Technical Summary
Existing writing instruments pose problems of resource waste and environmental pollution in single-use scenarios, especially since plastic pen barrels and traditional ink supply systems are difficult to degrade, and it is common for them to be discarded before the ink is used up.
The pen barrel, cap, and stopper are made of fully biodegradable natural wood or bamboo materials. Combined with a minimalist ink supply architecture, it uses environmentally friendly water-based ink and a capillary gradient-designed ink core and pre-saturated ink reservoir to ensure writing stability and biodegradability.
It achieves complete degradation of writing instruments, reduces environmental pollution, lowers production costs, ensures smooth writing and a stable ink supply, and avoids ink leakage and ink shortage problems.
Smart Images
Figure CN122481384A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of writing instrument technology, and in particular to an environmentally friendly rollerball pen and its assembly method. Background Technology
[0002] Ballpoint pens (including rollerball pens, gel pens, and ballpoint pens) are the most widely used writing instruments in China, with students, enterprises, institutions, and government agencies being the core user groups, consuming billions of pens annually. Writing instruments used in scenarios such as meetings, business promotions, and temporary office work are often discarded before the ink is completely used up, causing not only serious resource waste but also environmental pollution.
[0003] The barrels and refills of existing writing instruments are mostly made of polystyrene or modified polystyrene. These materials are resistant to aging and corrosion, but they are almost impossible to degrade on their own in the natural environment. At the same time, the ink in the refills contains volatile harmful substances, and careless disposal will cause secondary pollution to soil and water bodies. Discarded writing instruments have become another major environmental hazard after plastic waste and used batteries.
[0004] To address the aforementioned issues, existing technologies mainly focus on two areas of improvement: one is to add ink filling holes, negative pressure ink filling mechanisms, and other structures to enable repeated ink filling of writing instruments. While this approach extends the product's lifespan, it suffers from complex structures, high manufacturing costs, and still primarily uses plastic pen barrels, failing to fundamentally solve the plastic pollution problem. The other approach involves using biodegradable materials such as polylactic acid (PLA) to make the pen barrel. This approach only improves the pen barrel material; the pen tip and ink supply system still utilize traditional plastic / metal structures, resulting in limited overall biodegradability and high production costs, making it difficult to promote on a large scale as a disposable product.
[0005] In addition, existing writing instruments employ complex multi-stage capillary ink supply structures and air pressure balance systems to ensure long-term storage and writing stability. However, in single-use scenarios, such complex structures not only waste materials and manufacturing costs, but also easily lead to situations where the entire pen is discarded due to problems such as the pen tip being damaged, drying out, or running out of ink before the ink is used up, resulting in extremely low resource utilization. Summary of the Invention
[0006] One objective of this invention is to provide an environmentally friendly rollerball pen that is optimized for single-use scenarios. It adopts a minimalist ink supply structure, fully biodegradable materials, and environmentally friendly water-based ink. While ensuring smooth and stable writing without the risk of ink leakage, it achieves structural simplification, cost reduction, and biodegradability, thus solving the environmental pollution and resource waste problems of disposable writing tools.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] An environmentally friendly rollerball pen includes a pen barrel assembly, a writing assembly, an ink supply assembly, and a sealing component. The pen barrel assembly includes a pen barrel and a pen cap, the pen cap being detachably fastened to the front end of the pen barrel. The writing assembly includes a needle-type pen tip and a ball bearing. The sealing component is fixedly installed at the rear end of the pen barrel. The needle-type pen tip is integrally formed from front to back with a ball-and-socket section, a pen tip writing section, a transition truncated cone section, and an embedded fixing section. The ball-and-socket section has an inwardly converging inner hole forming a ball socket. The ball bearing is rotatably embedded in the ball socket of the needle-type pen tip. An inner hole penetrating the pen tip is opened from the center of the embedded fixing section. The needle-type pen tip is connected to the front end of the pen barrel.
[0009] The ink supply assembly includes an ink guide core and a pre-saturated ink reservoir core. The pen barrel is a one-piece hollow tubular structure with both ends open. The pre-saturated ink reservoir core fills the hollow inner cavity of the pen barrel. The front end of the ink guide core is inserted into the inner hole of the needle-shaped pen tip, and the rear end of the ink guide core is inserted into the interior of the pre-saturated ink reservoir core. The fiber density of the ink guide core is greater than that of the pre-saturated ink reservoir core, making the capillary adsorption force of the ink guide core greater than that of the pre-saturated ink reservoir core, thus forming a unidirectional ink supply capillary force gradient.
[0010] The pen barrel, pen cap, and sealing component are all made of natural wood or bamboo, which are fully biodegradable materials.
[0011] Preferably, the pen barrel includes a pen tip mounting inner hole section, a sealing frustum section, a transition cylindrical section, a pen body main section, and a rear end mounting inner hole section. The pen body main section is an integral hollow structure with an outer hexagonal inner circle. The outer wall of the embedded fixing section is inserted into the pen tip mounting inner hole section and interference-fitted. The rear end face of the transition frustum section is fitted and sealed with the front end face of the sealing frustum section. The inner cavity of the pen body main section is used to accommodate the pre-saturated ink reservoir core. The rear end mounting inner hole section is used to fix the sealing component.
[0012] Preferably, the pre-saturated ink reservoir includes an ink reservoir sleeve and a cotton core. The ink reservoir sleeve is a thin-walled tubular structure that wraps around the outer periphery of the cotton core to shape it. The outer wall of the ink reservoir sleeve is in clearance fit with the inner wall of the pen barrel.
[0013] Preferably, the ink storage core sleeve is made of biodegradable paper / fiber material or thin-walled wood material, and the cotton core and ink guide core are both made of biodegradable fiber / paper material.
[0014] Preferably, the cotton core is made of loose and porous cotton fiber material, and the ink guide core is made of densely pressed cotton fiber material for absorbing and storing water-based ink. The outer diameter of the ink guide core is interference-fitted with the inner diameter of the needle-type pen tip, and the rear end of the ink guide core is inserted into the cotton core to a depth of not less than 1 / 5 of the total length of the cotton core.
[0015] Preferably, the outer diameter and length of the pre-saturated ink reservoir are adjusted according to the target writing length.
[0016] Preferably, the outer contour of the pen cap is an external hexagon that matches the outer contour of the main body of the pen barrel. The pen cap is integrally formed and has an opening at one end. The inner wall of the pen cap extends from a cylindrical inner surface to a frustum-shaped inner surface and matches the transition cylindrical section and sealing frustum-shaped section of the pen barrel. An annular groove is provided on the inner wall of the pen cap near the opening end. The annular groove engages and limits the front end of the pen barrel. The inner wall of the pen cap also has a pen tip receiving section for accommodating the pen tip.
[0017] Preferably, the sealing component is an integrally formed back cover, the back cover includes an exposed section and a sealing section, the outer wall of the sealing section is interference-fitted into the inner hole section at the rear end of the pen barrel to seal the hollow inner cavity of the pen barrel, and the outer contour of the exposed section is flush with the outer contour of the pen barrel.
[0018] Preferably, the inner walls of the pen barrel, pen cap, and sealing component are all treated with oil immersion to prevent leakage, forming a dense leak-proof coating.
[0019] In the above technical solution, the main structure of the rollerball pen, including the barrel, cap, and back cover, is made of natural wood or bamboo, which are fully biodegradable materials. The ink reservoir sleeve, cotton core, and ink guide core are all made of biodegradable materials, with an overall biodegradability rate exceeding 95%, effectively solving the environmental pollution problem of disposable writing instruments. The pre-saturated ink reservoir is used to store water-based ink, which is an environmentally friendly ink. The front end of the ink guide core is inserted into the inner hole of the needle-type pen tip, and the rear end of the ink guide core is inserted into the interior of the pre-saturated ink reservoir, forming an ink supply channel connecting the ink reservoir and the pen tip. The design of the pre-saturated ink reservoir locks the ink in the cotton fibers, eliminating the free-flowing liquid ink in the pen barrel and avoiding ink leakage. At the same time, through the capillary gradient design of the ink guide core and the ink reservoir, a unidirectional and stable ink supply channel is formed, ensuring that the ink is continuously delivered from the ink reservoir to the pen tip. There is no ink interruption or skipping during the writing process, and it can write continuously and stably until the ink is completely used up. The writing length meets the needs of disposable use. In addition, the design is optimized for single-use scenarios, and the ink capacity can be precisely matched according to the usage scenario, avoiding the waste of traditional long-life pens that are discarded before the ink is used up during single use.
[0020] Another objective of this invention is to provide an assembly method for an environmentally friendly rollerball pen, which assembles the rollerball pen used to complete the assembly of the above-mentioned technical solution.
[0021] To achieve the above objectives, the present invention adopts the following technical solution:
[0022] An assembly method for an environmentally friendly rollerball pen, the specific assembly method of which includes the following steps:
[0023] Step S1: Pre-saturate the ink reservoir core by fully immersing the cotton core in water-based ink to achieve saturated adsorption, then inserting it into the ink reservoir core sleeve for shaping and setting aside.
[0024] Step S2: Press the ball into the ball socket of the needle-type pen tip to complete the closing and limiting, and press the front end of the ink guide core into the inner hole of the needle-type pen tip to complete the pre-assembly of the writing component and the ink guide core.
[0025] Step S3: Press the pre-assembled needle-type pen tip into the pen tip mounting inner hole section at the front end of the pen barrel, so that the transition cone section and the sealing cone section are completely fitted and sealed.
[0026] Step S4: Insert the pre-saturated ink reservoir into the inner cavity at the rear end of the pen barrel until the front end of the pre-saturated ink reservoir is in contact with the rear end of the needle-type pen tip, while ensuring that the rear end of the ink guide core is fully inserted into the cotton core.
[0027] Step S5: Press the back cover into the inner hole section at the rear end of the pen barrel to complete the sealing of the rear end of the pen barrel;
[0028] Step S6: Attach the pen cap to the front end of the pen barrel and lock it in place using the annular slot to complete the pen assembly.
[0029] In the above technical solution, a pre-saturated ink reservoir core is first fabricated. The cotton core is pre-soaked in water-based ink to achieve a saturated adsorption state, eliminating free-flowing liquid ink inside the pen. The ink reservoir core sleeve is a thin-walled tubular structure that wraps around the outer periphery of the cotton core to shape it, prevent it from loosening and shedding, and facilitate assembly. The three-element ink supply architecture of "pre-saturated ink reservoir core + ink guide core + pen tip" significantly reduces the number of parts and simplifies the assembly process, fully meeting the cost requirements of single-use scenarios and enabling large-scale application. The minimalist structural design of this rollerball pen reduces material consumption and maximizes resource utilization. Assembly is convenient, and it is highly versatile. All components adopt standardized designs, and the pen tip, ball bearing, pen cap, and back cover are all standardized and interchangeable. Product specifications can be adjusted simply by changing the size of the ink reservoir core to meet different writing length requirements, resulting in extremely high production adaptability. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of the assembly structure of the present invention;
[0031] Figure 2 This is a schematic diagram of the exploded structure in this invention;
[0032] Figure 3 This is a cross-sectional structural diagram of the pen cap in this invention;
[0033] Figure 4 This is a schematic cross-sectional view of the needle-type pen tip in this invention.
[0034] Figure 5 This is a schematic cross-sectional view of the pen barrel in this invention;
[0035] Figure 6 This is a schematic diagram of the pre-saturated ink reservoir core in this invention;
[0036] Figure 7 This is a schematic diagram of the structure of the back cover in this invention.
[0037] In the diagram, 1. Pen cap; 1-1 Hexagonal outer surface; 1-2 Cylindrical inner surface; 1-3 Annular groove; 1-4 Frustum-shaped inner surface; 1-5 Pen tip receiving section; 2. Ball bearing; 3. Needle-type pen tip; 3-1 Ball socket; 3-2 Pen tip writing section; 3-3 Transition frustum-shaped section; 3-4 Embedded fixing section; 3-5 Inner hole; 4. Ink guide core; 5. Pen barrel; 5-1 Pen tip mounting inner hole section; 5-2 Sealing frustum-shaped section; 5-3 Transition cylindrical section; 5-4 Pen body main body section; 5-5 Rear end mounting inner hole section; 6. Pre-saturated ink reservoir core; 6-1 Ink reservoir core sleeve; 6-2 Cotton core; 7. Rear cover; 7-1 Exposed section; 7-2 Sealing section. Detailed Implementation
[0038] The invention will be further described below with reference to the accompanying drawings:
[0039] like Figures 1 to 7 As shown, this environmentally friendly rollerball pen mainly consists of four modules: a pen barrel assembly, a writing assembly, an ink supply assembly, and a sealing component. The pen barrel assembly includes a pen barrel 5 and a pen cap 1. The pen barrel 5 is a one-piece hollow tubular structure with both ends open. The pen cap 1 is detachable and snaps onto the front end of the pen barrel 5 to protect the writing assembly, which includes a needle-type pen tip 3 and a ball bearing 2. The ink supply assembly includes an ink guide core 4 and a pre-saturated ink reservoir core 6. The pre-saturated ink reservoir core 6 is used to store water-based ink, which is environmentally friendly. The sealing component is fixedly installed at the rear end of the pen barrel 5. The pen barrel 5, pen cap 1, and sealing component are all made of natural wood or bamboo, fully biodegradable materials, and are optimized for single-use scenarios. The inner walls of the pen barrel 5, pen cap 1, and sealing component are all treated with oil immersion to prevent leakage, forming a dense leak-proof coating to prevent ink leakage. The oil immersion treatment uses an oil that does not affect degradation.
[0040] This environmentally friendly rollerball pen features a needle-type tip 3 that, from front to back, is integrally composed of a ball-and-socket section, a writing section 3-2, a transition cone section 3-3, and an embedded fixing section 3-4. The inward-convex inner hole of the ball-and-socket section forms a ball-and-socket 3-1, within which the ball 2 is rotatably fitted. The opening end of the ball-and-socket 3-1 is tapered to confine the ball 2 within it, ensuring free rotation and preventing it from falling out. An inner hole 3-5, penetrating the tip, is located at the center of the embedded fixing section 3-4. The needle-type tip 3 connects to the front end of the pen barrel 5. As the core carrier of the writing component, the needle-type tip 3 confines the ball 2 and provides mounting and positioning for the ink guide 4, evenly distributing the ink from the ink guide 4 to the ball 2 for stable writing. The transition cone section 3-3 and the embedded fixing section 3-4 achieve a double seal and secure fixation with the pen barrel 5, preventing ink leakage and tip loosening. The ball bearing 2 is a writing actuator made of stainless steel. It is rotatably embedded in the ball socket 3-1 of the needle-type pen tip 3. During writing, the ball bearing 2 rolls to evenly spread the ink on the writing medium, ensuring smooth writing.
[0041] The pre-saturated ink reservoir 6 includes an ink reservoir sleeve 6-1 and a cotton core 6-2. The ink reservoir sleeve 6-1 is a thin-walled tubular structure that wraps around the outer periphery of the cotton core 6-2. It is used to shape the cotton core 6-2, preventing it from loosening and shedding, and also to facilitate assembly. The outer wall of the ink reservoir sleeve 6-1 is fitted with the inner wall of the pen barrel 5 with a clearance. The ink reservoir sleeve 6-1 is made of biodegradable paper / fiber or thin-walled wood material, while the cotton core 6-2 and the ink guide core 4 are both made of biodegradable fiber / paper material. Specifically, the cotton core 6-2 is made of loose and porous cotton fiber, which has a strong ink adsorption and retention capacity. The ink guide core 4 is made of densely pressed cotton fiber, which is used to adsorb and store water-based ink. The outer diameter of the ink guide core 4 is interference-fitted with the inner diameter of the needle-type pen tip 3 to ensure that the ink supply channel is sealed and connected. The rear end of the ink guide core 4 is inserted into the cotton core 6-2 to a depth of not less than 1 / 5 of the total length of the cotton core, forming an ink supply channel connecting the ink storage core and the pen tip, ensuring a continuous and stable ink supply. The pre-saturated ink reservoir 6 is filled in the hollow cavity of the pen barrel 5. The front end of the ink guide 4 is inserted into the inner hole 3-5 of the needle-type pen tip 3, and the rear end of the ink guide 4 is inserted into the interior of the pre-saturated ink reservoir 6. Both the ink guide 4 and the pre-saturated ink reservoir 6 are made of cotton fiber material, which is used to absorb and store water-based ink. The fiber density of the ink guide 4 is greater than that of the pre-saturated ink reservoir 6, so that the capillary adsorption force of the ink guide 4 is greater than that of the pre-saturated ink reservoir 6, forming a unidirectional ink supply capillary force gradient from the ink reservoir to the ink guide and then to the pen tip.
[0042] The ink guide core 4, as the core component of the ink supply channel, is made of dense fiber material. Utilizing its own capillary adhesion, it continuously draws ink from the pre-saturated ink reservoir 6 to the pen tip. Through a capillary gradient design with the ink reservoir core, it achieves stable unidirectional ink delivery, preventing ink interruptions and backflow, ensuring smooth writing until the ink is completely used up. The pre-saturated ink reservoir 6, as the sole ink storage and supply carrier, is made of loose, porous cotton fiber material. Pre-saturated with ink, it locks in all the ink needed for writing, eliminating free-flowing liquid ink within the pen barrel and structurally preventing the risk of leakage. Simultaneously, it provides a stable ink supply to the ink guide core 4, ensuring the writing length meets the requirements for single-use.
[0043] Furthermore, the pen barrel 5 has a tip mounting inner hole section 5-1, a sealing frustum section 5-2, a transition cylindrical section 5-3, a main body section 5-4, and a rear mounting inner hole section 5-5. The main body section 5-4 is an integral hollow structure with an outer hexagonal shape and an inner circle, and the entire pen barrel 5 is internally continuous. The outer wall of the needle-type pen tip 3's embedded fixing section 3-4 is inserted into the tip mounting inner hole section 5-1 and press-fitted to achieve a firm fixation between the pen tip and the pen barrel. The rear end face of the transition frustum section 3-3 fits and seals with the front end face of the sealing frustum section 5-2, so that the rear end of the needle-type pen tip 3 is fixedly inserted into the front end inner hole of the pen barrel 5, forming the writing execution end. The inner cavity of the main body section 5-4 is used to accommodate the pre-saturated ink reservoir 6, and the rear mounting inner hole section 5-5 is used to fix and install the sealing component.
[0044] The outer contour of the pen cap 1 is an external hexagon that matches the outer contour of the main body section 5-4 of the pen barrel. The pen cap 1 is integrally formed and has an opening at one end. The outer wall is a hexagonal outer surface 1-1. The inner wall of the pen cap 1 extends from a cylindrical inner surface 1-2 to a frustum-shaped inner surface 1-4. The cylindrical inner surface 1-2 and the frustum-shaped inner surface 1-4 match the transition cylindrical section 5-3 and the sealing frustum-shaped section 5-2 of the pen barrel. An annular groove 1-3 is provided on the inner wall of the pen cap 1 near the opening end. The pen cap 1 is locked and limited to the front end of the pen barrel 5 by the annular groove 1-3, so that the pen cap 1 can be detachably locked to the front end of the pen barrel 5. The inner wall of the pen cap 1 also has a pen tip receiving section 1-5 for accommodating the pen tip. After locking, the inner wall of the pen cap 1 and the front end of the needle-type pen tip 3 form a sealed space to protect the ball bearing 2 and the needle-type pen tip 3 and prevent ink evaporation. The hexagonal outer contour of the pen cap 1 matches the outer contour of the pen barrel 5, preventing the product from rolling and slipping when placed, while ensuring the overall appearance consistency of the product. The pen cap 1 protects the needle-type pen tip 3 and the ball bearing 2, preventing the pen tip from being damaged or the ball bearing from falling out, and also preventing the ink on the pen tip from evaporating and drying out; it achieves a stable engagement with the pen barrel through the annular grooves 1-3, and the outer hexagonal structure makes it easy to grip and remove, while also preventing the product from rolling and slipping.
[0045] The sealing component is a one-piece molded back cover 7, which includes an exposed section 7-1 and a sealing section 7-2. The outer wall of the sealing section 7-2 is interference-fitted into the inner hole section 5-5 at the rear end of the pen barrel 5. The diameter of the inner hole section 5-5 at the rear end matches the outer diameter of the sealing section 7-2 of the back cover 7, which is used to fix the back cover and seal the hollow inner cavity of the pen barrel 5, achieving a complete seal at the rear end of the pen barrel 5. At the same time, it isolates air, prevents the pre-saturated ink reservoir 6 from falling off the rear end of the pen barrel 5, avoids ink evaporation and drying, and ensures the product's shelf life. The outer contour of the exposed section 7-1 is hexagonal, and the outer contour of the exposed section 7-1 is completely flush with the outer contour of the pen barrel 5, ensuring a smooth grip on the pen barrel without any protrusions or jamming.
[0046] In this embodiment, the pen barrel 5, pen cap 1, and back cover 7 are all integrally machined from natural bamboo and wood. The inner walls are treated with food-grade wood wax oil to prevent leakage, forming a dense, leak-proof coating to prevent ink leakage. The ball bearing 2 is made of stainless steel, a standard industry component, and the needle-type pen tip 3 is integrally stamped from stainless steel. The ink guide core 4 is made of densely pressed polyester cotton fiber, the cotton core 6-2 of the pre-saturated ink reservoir 6 is made of loose, porous cotton fiber, and the ink reservoir sleeve 6-1 is made of biodegradable kraft paper. The overall biodegradability exceeds 95%, effectively solving the environmental pollution problem of disposable writing instruments.
[0047] Furthermore, the embedded fixing section 3-4 of the needle-type pen tip 3 is inserted into the pen tip mounting inner hole section 5-1 at the front end of the pen barrel 5. The two are interference fit with an interference amount of 0.02-0.05mm, which realizes the firm fixation of the pen tip and the pen barrel. The rear end face of the transition cone section 3-3 is completely fitted with the front end face of the sealing cone section 5-2 at the front end of the pen barrel 5, forming an end face seal, which completely prevents ink from leaking from the joint between the pen tip and the pen barrel.
[0048] The cotton wick 6-2 is pre-saturated with water-based writing ink until it reaches a saturated state, ensuring the ink is completely locked within the fiber pores of the cotton wick, with no free-flowing liquid ink. The ink reservoir sleeve 6-1 tightly wraps around the outer periphery of the cotton wick 6-2, shaping the cotton wick into a cylindrical form that matches the inner cavity of the pen barrel, preventing the cotton wick from loosening and shedding, and facilitating quick assembly. The pre-saturated ink reservoir 6 is inserted entirely into the inner cavity of the main body section 5-4 of the pen barrel 5. The outer wall of the ink reservoir sleeve 6-1 has a clearance fit with the inner wall of the pen barrel, facilitating quick and smooth assembly without any jamming.
[0049] The ink guide core 4 is a cylindrical dense fiber rod. Its front end is inserted into the inner hole 3-5 of the needle-type pen tip 3. The two are interference fit to ensure that the ink guide core and the inner hole of the pen tip are completely fitted without ink supply gap. The rear end of the ink guide core 4 is inserted into the cotton core 6-2 of the pre-saturated ink storage core 6. The insertion depth is 1 / 4 of the total length of the cotton core to ensure that the ink guide core and the cotton core are in full contact and achieve stable ink transfer.
[0050] Furthermore, the fiber density of the ink guide core 4 is much greater than that of the cotton core 6-2, resulting in a greater capillary adhesion force of the ink guide core 4 than that of the cotton core 6-2. This creates a unidirectional capillary force gradient for ink supply from the cotton core to the ink guide core and then to the pen tip. During writing, the ink guide core 4 continuously draws ink from the cotton core 6-2 to the pen tip through capillary force, ensuring stable unidirectional ink delivery and preventing ink backflow or ink interruption, until the ink in the cotton core is completely used up.
[0051] The pen barrel 5 has a tip mounting inner hole section 5-1, a sealing frustum section 5-2, a transition cylindrical section 5-3, a main body section 5-4, and a rear mounting inner hole section 5-5. The main body section 5-4 is an integral hollow structure with an outer hexagon and an inner circle, and the entire pen barrel 5 is open. The diameter of the tip mounting inner hole section 5-1 matches the outer diameter of the embedded fixing section 3-4 of the needle-type pen tip 3, and is used to fix the pen tip. The taper of the sealing frustum section 5-2 is completely consistent with the taper of the transition frustum section 3-3 of the needle-type pen tip 3, so as to achieve a close fit and seal. The inner cavity diameter of the main body section 5-4 matches the outer diameter of the pre-saturated ink reservoir 6, and is used to accommodate the ink reservoir. The pen barrel 5 serves as the main supporting structure of the product and also provides space for the pre-saturated ink reservoir 6. It replaces the traditional plastic pen barrel and uses biodegradable wood / bamboo materials to achieve environmental protection and biodegradability. The outer hexagonal structure conforms to ergonomics, ensuring stable grip and writing, while the inner hollow structure facilitates the assembly and positioning of various components.
[0052] The back cover 7 is a one-piece molded bamboo and wood component, featuring an exposed section 7-1 and a sealing section 7-2. The sealing section 7-2 is inserted into the rear mounting inner hole section 5-5 of the pen barrel 5. The diameter of the rear mounting inner hole section 5-5 matches the outer diameter of the sealing section 7-2 of the back cover 7, forming an interference fit. This fit secures the back cover 7, achieving a complete seal at the rear of the pen barrel and preventing the ink reservoir from falling out and ink from evaporating. The outer contour of the exposed section 7-1 is hexagonal, and its outer contour is completely flush with the outer contour of the pen barrel 5, ensuring a smooth grip without any protrusions or jamming.
[0053] The assembly method for this environmentally friendly rollerball pen is as follows:
[0054] Step S1: Pre-saturate the ink reservoir core 6 by completely immersing the cotton core 6-2 in water-based ink to achieve saturation, then inserting it into the ink reservoir core sleeve 6-1 for shaping and setting aside.
[0055] Step S2: Press the ball bearing 2 into the ball socket 3-1 of the needle-type pen tip 3 to complete the closing and limiting. Press the front end of the ink guide core 4 into the inner hole 3-5 of the needle-type pen tip 3 to complete the pre-assembly of the writing component and the ink guide core.
[0056] Step S3: Press the pre-assembled needle-type pen tip 3 into the pen tip mounting inner hole section 5-1 at the front end of the pen barrel 5, so that the transition cone section 3-3 and the sealing cone section 5-2 are completely fitted and sealed.
[0057] Step S4: Insert the pre-saturated ink reservoir 6 into the inner cavity of the rear end of the pen barrel 5 until the front end of the pre-saturated ink reservoir is in contact with the rear end of the needle-type pen tip 3, while making the rear end of the ink guide core 4 completely inserted into the cotton core 6-2.
[0058] Step S5: Press the back cover 7 into the inner hole section 5-5 at the rear end of the pen barrel 5 to complete the sealing of the rear end of the pen barrel 5.
[0059] Step S6: Attach the pen cap 1 to the front end of the pen barrel 5 and lock it in place using the annular slot to complete the pen assembly.
[0060] After assembly, the outer contours of the pen cap 1, pen barrel 5, and back cover 7 are flush.
[0061] The specific working process of this environmentally friendly rollerball pen is as follows:
[0062] When in use, simply remove the pen cap 1 from the front end of the pen barrel 5 to begin writing. During writing, the ball bearing 2 rolls on the writing medium, causing the ink in the pen tip to flow out. At this time, the ink guide 4 continuously draws ink from the cotton wick 6-2 of the pre-saturated ink reservoir 6 through its stronger capillary adhesion, replenishing the pen tip and forming a continuous and stable ink supply. Due to the existence of the capillary gradient, the ink can only flow unidirectionally from the ink reservoir to the ink guide wick and the pen tip, and there will be no ink backflow or ink interruption. Continuous and stable writing is possible until the ink in the cotton wick 6-2 is completely used up.
[0063] After use, reattach the pen cap 1 to the front end of the pen barrel 5 to protect the pen tip and ball bearing, and prevent the ink from evaporating and drying out for later use. Once the ink is used up, the pen can be discarded directly. The main body of the bamboo and wood material can be completely degraded in the natural environment without causing environmental pollution.
[0064] Furthermore, the outer diameter and length of the pre-saturated ink reservoir 6 can be adjusted according to the target writing length, thereby adjusting the ink loading capacity to match different writing length requirements. For example, the short-cycle version used in meeting scenarios can be designed with a writing length of 200-500 meters, while the daily temporary office version can be designed with a writing length of 500-1000 meters, fully covering various disposable use scenarios.
[0065] This embodiment is merely an illustration of the concept and implementation of the present invention and is not intended to limit it. Under the concept of the present invention, technical solutions without substantial changes are still within the scope of protection.
Claims
1. An environmentally friendly rollerball pen, comprising a pen barrel assembly, a writing assembly, an ink supply assembly, and a sealing component, characterized in that: The pen assembly includes a pen barrel and a pen cap. The pen cap is detachably fastened to the front end of the pen barrel. The writing assembly includes a needle-shaped pen tip and a ball bearing. The sealing component is fixedly installed at the rear end of the pen barrel. The needle-shaped pen tip is integrally provided from front to back with a ball-and-socket section, a pen tip writing section, a transition truncated cone section, and an embedded fixing section. The ball-and-socket section has an inwardly converging inner hole forming a ball-and-socket. The ball bearing is rotatably embedded in the ball-and-socket of the needle-shaped pen tip. An inner hole penetrating the pen tip is opened from the center of the embedded fixing section. The needle-shaped pen tip is connected to the front end of the pen barrel. The ink supply assembly includes an ink guide core and a pre-saturated ink reservoir core. The pen barrel is a one-piece hollow tubular structure with both ends open. The pre-saturated ink reservoir core fills the hollow inner cavity of the pen barrel. The front end of the ink guide core is inserted into the inner hole of the needle-shaped pen tip, and the rear end of the ink guide core is inserted into the interior of the pre-saturated ink reservoir core. The fiber density of the ink guide core is greater than that of the pre-saturated ink reservoir core, making the capillary adsorption force of the ink guide core greater than that of the pre-saturated ink reservoir core, thus forming a unidirectional ink supply capillary force gradient. The pen barrel, pen cap, and sealing component are all made of natural wood or bamboo, which are fully biodegradable materials.
2. The environmentally friendly bead pen according to claim 1, wherein: The pen barrel includes a tip mounting inner hole section, a sealing frustum section, a transition cylindrical section, a pen body main section, and a rear mounting inner hole section. The pen body main section is an integral hollow structure with an outer hexagonal inner circle. The outer wall of the embedded fixing section is inserted into the tip mounting inner hole section and interference-fitted. The rear end face of the transition frustum section is fitted and sealed with the front end face of the sealing frustum section. The inner cavity of the pen body main section is used to accommodate the pre-saturated ink reservoir core. The rear mounting inner hole section is used to fix the sealing component.
3. The environmentally friendly rollerball pen as described in claim 2, characterized in that: The pre-saturated ink reservoir core includes an ink reservoir core sleeve and a cotton core. The ink reservoir core sleeve is a thin-walled tubular structure that wraps around the outer periphery of the cotton core and is used to shape the cotton core. The outer wall of the ink reservoir core sleeve is in clearance fit with the inner wall of the pen barrel.
4. The environmentally friendly rollerball pen as described in claim 3, characterized in that: The ink storage core sleeve is made of biodegradable paper / fiber material or thin-walled wood material, and the cotton core and ink guide core are both made of biodegradable fiber / paper material.
5. The environmentally friendly rollerball pen as described in claim 4, characterized in that: The cotton core is made of loose and porous cotton fiber, while the ink guide core is made of densely pressed cotton fiber. It is used to absorb and store water-based ink. The outer diameter of the ink guide core is interference-fitted with the inner diameter of the needle-type pen tip. The rear end of the ink guide core is inserted into the cotton core to a depth of not less than 1 / 5 of the total length of the cotton core.
6. The environmentally friendly rollerball pen as described in claim 5, characterized in that: The outer diameter and length of the pre-saturated ink reservoir are adjusted according to the target writing length.
7. The environmentally friendly rollerball pen as described in claim 1, characterized in that: The outer contour of the pen cap is an external hexagon that matches the outer contour of the main body of the pen barrel. The pen cap is integrally formed and has an opening at one end. The inner wall of the pen cap extends from a cylindrical inner surface to a frustum-shaped inner surface and matches the transition cylindrical section and sealing frustum section of the pen barrel. An annular groove is provided on the inner wall of the pen cap near the opening end. The annular groove engages and limits the front end of the pen barrel. The inner wall of the pen cap also has a pen tip receiving section for accommodating the pen tip.
8. The environmentally friendly rollerball pen as described in claim 1, characterized in that: The sealing component is an integrally formed back cover, which includes an exposed section and a sealing section. The outer wall of the sealing section is interference-fitted into the inner hole section at the rear end of the pen barrel to seal the hollow inner cavity of the pen barrel. The outer contour of the exposed section is flush with the outer contour of the pen barrel.
9. The environmentally friendly rollerball pen as described in claim 1, characterized in that: The inner walls of the pen barrel, pen cap, and sealing component are all treated with oil immersion to prevent leakage, forming a dense leak-proof coating.
10. An assembly method for an environmentally friendly rollerball pen, characterized in that: The assembly method of the environmentally friendly rollerball pen according to any one of claims 1 to 9 includes the following steps: Step S1: Pre-saturate the ink reservoir core by fully immersing the cotton core in water-based ink to achieve saturated adsorption, then inserting it into the ink reservoir core sleeve for shaping and setting aside. Step S2: Press the ball into the ball socket of the needle-type pen tip to complete the closing and limiting, and press the front end of the ink guide core into the inner hole of the needle-type pen tip to complete the pre-assembly of the writing component and the ink guide core. Step S3: Press the pre-assembled needle-type pen tip into the pen tip mounting inner hole section at the front end of the pen barrel, so that the transition cone section and the sealing cone section are completely fitted and sealed. Step S4: Insert the pre-saturated ink reservoir into the inner cavity at the rear end of the pen barrel until the front end of the pre-saturated ink reservoir is in contact with the rear end of the needle-type pen tip, while ensuring that the rear end of the ink guide core is fully inserted into the cotton core. Step S5: Press the back cover into the inner hole section at the rear end of the pen barrel to complete the sealing of the rear end of the pen barrel; Step S6: Attach the pen cap to the front end of the pen barrel and lock it in place using the annular slot to complete the pen assembly.