Leather ironing machine

Abstract

A leather ironing machine comprising a fixed ironing plate (201) and at least three pneumatically movable ironing plates, a pneumatic actuation system (202) controlled by solenoid valves, a PLC-based control module (203) and an HMI interface (204) enabling programmable temperature, pressure and time settings for automated leather ironing.

Description

AREA OF INVENTION:

[0001] The present invention relates to the field of automated mechanical systems for material finishing, in particular to a leather ironing machine suitable as a cost-effective miniature model for small businesses, workshops, training environments, and decentralized leather production facilities. The invention integrates pneumatic actuation, controlled heating, a human-machine interface (HMI), and programmable logic controller (PLC)-based automation to enable efficient, uniform, and user-configurable leather ironing. It also addresses the need for cost-effective yet reliable alternatives to expensive hydraulic-based finishing systems used in the leather processing sector. BACKGROUND OF THE INVENTION:

[0002] The global leather industry, which focuses on footwear, apparel, automotive upholstery, fashion accessories, and luxury goods, demands consistent processing quality to meet rising consumer expectations. After tanning, dyeing, and drying, leather often retains creases, surface irregularities, moisture content, and inconsistent grain patterns, negatively impacting its aesthetics, texture, and mechanical properties. Ironing or pressing is therefore considered an essential manufacturing step to stabilize the leather structure, increase softness, and prepare the material for subsequent cutting and sewing operations.

[0003] Conventional leather ironing practices in small and rural sectors rely heavily on manual tools or semi-automatic pressing systems. Manual ironing lacks consistency, is labor-intensive, and depends significantly on the worker's skill. Variations in pressure, temperature, exposure time, and operating speed often result in over-ironing, burning, surface clouding, or damage to delicate leathers. Industrial hydraulic ironing machines overcome these limitations but are prohibitively expensive, energy-intensive, unsafe for inexperienced users, and unsuitable for artisans operating in decentralized production models.

[0004] The lack of an affordable, automated, and user-friendly leather ironing machine that offers programmable control over key parameters—pressure, temperature, cycle time, and plate movement—creates a significant technological gap. Many existing systems also fail to incorporate energy-efficient heating techniques, sequential processing of multiple plates, or remote control capabilities for easy configuration. Furthermore, large-scale machines cannot be effectively deployed in centers of excellence, small workshops, or community-based leather clusters, where budget constraints limit access to advanced equipment.

[0005] A solution is therefore required that combines reliability, reduced costs, automated operation, and multi-stage ironing capacity in a compact format without compromising safety and process accuracy. The present invention addresses these unmet needs by developing a compact yet feature-rich leather ironing system based on pneumatic actuation, HMI-PLC coordination, configurable ladder logic routines, and controlled hot air flow, thus offering high repeatability, consistent processing, and optimized productivity for small-scale users. SUMMARY OF THE INVENTION:

[0006] The present invention provides a miniature, yet fully functional leather ironing machine that utilizes a pneumatic system, solenoid-controlled plate movement, controlled hot air supply, and programmable electronic control via a PLC integrated into an HMI. The machine consists of four ironing plates, including one fixed plate and three pneumatically movable plates operated by pneumatic cylinders controlled by relays and solenoid valves.

[0007] The system introduces a novel combination of multi-plate sequential ironing with programmable delays, enabling the continuous processing of multiple leather sheets. Hot air is blown between the plates to remove moisture, smooth grain irregularities, and improve overall smoothness. The PLC control unit manages solenoid valves, pressure levels, motion cycles, and time delays using sophisticated ladder logic adapted for different leather types. Connected via IoT-enabled interfaces, the HMI allows the user to adjust temperature, pressure, operating mode, ironing duration, and speed using simple touch commands.

[0008] Unlike traditional hydraulic systems, this invention reduces costs, power consumption, installation requirements, and mechanical complexity. It also prevents overheating through integrated timing logic and offers emergency stops for safety. By enabling consistent, repeatable, and automated ironing, the invention significantly increases productivity and provides an accessible solution for artisans, small businesses, and leather training institutions. BRIEF DESCRIPTION OF THE DRAWING: Fig. shows a block diagram of the system according to the invention. DETAILED DESCRIPTION OF THE INVENTION:

[0009] The invention comprises a carefully constructed miniature leather ironing machine that integrates pneumatic actuation mechanisms, programmable control circuits, a touch-based user interface, and a supporting mechanical frame, designed to emulate full-fledged industrial systems at a significantly reduced cost. The main objective is to enable users to iron small to medium-sized leather upholstery with constant temperature and pressure settings, while minimizing human intervention and operational variations.

[0010] At the heart of the system is a rigid mechanical frame housing four ironing plates. These plates are arranged in a vertically stacked formation, with the top plate stationary and serving as a reference surface for ironing, while the remaining three plates—Plate 1, Plate 2, and Plate 3—are movable. Each movable plate is actuated by a dedicated pneumatic cylinder, which responds to solenoid valves connected via electrical relays to a PLC module. This modular actuation system ensures that each piece of leather undergoes a controlled and consistent pressing cycle, individually adjustable through programmed time delays.

[0011] During operation, the user switches on the machine via the main control panel and interacts with the HMI—configured by IoT-compatible libraries—to select the desired ironing profile. Leather types vary greatly in their grain, oil composition, elasticity, finishing chemicals, and thermal tolerance; therefore, the HMI offers customizable settings for temperature, pressure, platen speed, and dwell time. Once the user enters the leather data, the PLC interprets these values ​​using pre-programmed ladder logic and initializes the ironing cycle.

[0012] The pneumatic system is powered by a compact air compressor capable of delivering compressed air in the range of 0.15 to 0.8 MPa. This pressure is essential to generate sufficient force within the pneumatic cylinders to lift the ironing plates and press the leather against the fixed plate. Strategically placed solenoid valves along the air lines act as digital actuators, controlling the airflow direction and intensity based on electrical signals from relay modules. Each relay—R1, R2, and R3—is assigned to a solenoid valve connected to a pneumatic cylinder, allowing the PLC to independently control the movement of each ironing plate.

[0013] When the system starts the brushing sequence, the PLC activates relay 1, which opens solenoid valve 1 and allows air to enter pneumatic cylinder 1 (PC 1). This inflates the cylinder by pushing plate 1 upwards towards the fixed plate, generating a firm but controlled pressure. Simultaneously, heated air from an external source is injected through vents created between the plates. This warm airflow plays a vital role in removing residual moisture from the leather, ensuring that the surface becomes smooth, even, and uniform.

[0014] Using a hot air system instead of direct-contact heating elements significantly reduces the risk of scorching, especially with soft, chemically treated, or thin leathers. Furthermore, the air temperature can be adjusted to the type of leather, making the system highly adaptable. This innovation also minimizes energy consumption, as it eliminates the need to embed heavy resistance heating elements in the panels.

[0015] Once Plate-1 has completed its cycle based on the programmed timer, the PLC deactivates Relay-1, causing Solenoid Valve-1 to close. The cylinder empties, and Plate-1 returns to its rest position, ready for the next batch. This repeated cycle mimics the function of large industrial calenders, but at a fraction of the cost.

[0016] A unique aspect of the invention is the sequential multi-plate milling mechanism. After plate 1 has completed its cycle, a preset time delay allows leather to be placed on plate 2. The PLC then activates relay 2 and solenoid valve 2, causing PC 2 to lift plate 2 and press it against plate 1. This sequential, cascading movement continues with plate 3 after the respective programmed delays. This arrangement allows three pieces of leather to be processed within a short time, significantly increasing throughput for small workshops.

[0017] The HMI acts as a communication bridge between the user and the hardware. It enables real-time parameter changes, error code warnings, emergency shutdowns, and operational monitoring. IoT-based programming allows remote access, diagnostics, and firmware updates, which is particularly useful for training institutions and decentralized craft networks where technical support may not be immediately available.

[0018] The PLC acts as the brain of the system, executing ladder logic routines to manage solenoid valve switching, pneumatic control, and heating regulation. Ladder logic offers exceptional reliability and is widely used in industrial automation, making the system robust and suitable for demanding environments.

[0019] Safety is built into every part of the invention. An emergency stop button immediately deactivates all relays, stops the movement of the plates, and interrupts the air supply. This function protects both the operator and the material in the event of air leaks, overheating, unexpected pressure build-ups, or operational errors. The system also includes a stop button that gently ends the ironing process after the current pressing cycle is complete.

[0020] The overall cost-effectiveness of the invention results from replacing hydraulic actuation with pneumatic systems. Hydraulic machines, although powerful, require expensive pumps, valves, oil tanks, maintenance, and safety checks to prevent leaks and overheating. Pneumatic systems, on the other hand, are lightweight, inexpensive, and safer for training and small-scale use. The entire miniature model is estimated to cost approximately 35,000,000, a figure significantly lower than industrial alternatives, thus ensuring broad accessibility.

[0021] Essentially, this invention transforms the leather finishing process by creating a compact, programmable, and affordable ironing system that delivers high-quality results comparable to industrial equipment. The system can be used in shoe manufacturing plants, tailoring clusters, leather craft centers, rural self-help programs, and educational laboratories for practical demonstrations of PLC pneumatic integration. ADVANTAGES OF THE INVENTION:

[0022] The present invention offers numerous advantages over conventional leather hanger systems, particularly those relying on manual processes or costly hydraulic machinery. The integration of pneumatic actuation, PLC-based automation, heated airflow, and a user-friendly HMI provides a combination of efficiency, affordability, safety, and performance that is highly advantageous for small leatherworking environments. One of the most significant benefits is the substantial cost reduction achieved by replacing hydraulic components with pneumatic cylinders, solenoid valves, and compact relays. This lowers the overall capital investment and maintenance costs, making the system accessible to leather craftspeople, training institutions, and small manufacturing units.The miniature design also ensures that the system can be installed in confined spaces without requiring industrial-scale infrastructure.

[0023] The automated operation, enabled by ladder logic programming, ensures uniformity and repeatability, resulting in consistent, high-quality surfaces across various leather types. The system eliminates the variability associated with manual ironing, thereby minimizing defects such as burn marks, uneven grain, and surface distortion. By allowing users to select specific ironing parameters like temperature, pressure, and time, the invention adapts the process to a wide range of leather types, including soft, semi-soft, hardened, and chemically treated varieties. This flexibility improves material compatibility and reduces waste.

[0024] The use of hot air for moisture removal and surface finishing offers a further advantage by preventing direct thermal contact, which is often responsible for overheating in traditional systems. This method ensures even heating, prevents thermal shock, and preserves the natural grain and texture of delicate leathers. The sequential multi-plate arrangement with programmable time delays increases productivity by allowing multiple leather discs to be ironed in rapid succession, thus supporting higher throughput without increasing machine footprint or energy consumption.

[0025] The system's HMI interface significantly simplifies user interaction, making it suitable even for operators with limited technical training. IoT-enabled features enhance remote monitoring, troubleshooting, and machine diagnostics, thereby increasing operational reliability. Integrated safety functions, including emergency stop controls, protect both the operator and the equipment by immediately halting pneumatic movement and airflow in the event of a malfunction. Low energy consumption, easy maintenance, and minimized mechanical wear through reduced friction further contribute to the system's long-term durability.

[0026] Overall, the invention offers an optimal combination of cost efficiency, automation, safety, portability and quality improvement, addressing long-standing challenges in the leather finishing industry while enabling sustainable and scalable implementation in decentralized leather production networks. Reference symbol list: 200 System 201 ironing board 202 Pneumatic Actuation System 203 PLC-based control module 204 HMI interface

Claims

[1] A leather ironing machine comprising a fixed ironing plate (201) and at least three pneumatically movable ironing plates, a pneumatic actuation system (202) controlled by solenoid valves, a PLC-based control module (203) and an HMI interface (204) enabling programmable temperature, pressure and time settings for automated leather ironing. [2] Machine according to claim 1, wherein each movable plate is operated by an independent pneumatic cylinder connected to corresponding solenoid valves and relay modules controlled by ladder logic programmed in the PLC. [3] Machine according to claim 1, wherein heated air is supplied between the ironing plates during operation to remove moisture and improve the surface finish without direct heating elements. [4] Machine according to claim 1, wherein the sequential ironing of several pieces of leather is achieved by PLC-controlled time delays that control the actuation of each movable plate. [5] Machine according to claim 1, wherein the HMI provides real-time configuration and monitoring of pressure, temperature, dwell time and ironing modes and is optionally IoT-enabled for remote access. [6] Machine according to claim 1, wherein safety mechanisms including stop and emergency stop switches are provided to immediately stop the pneumatic actuation and airflow. [7] Machine according to claim 1, wherein the PLC stores multiple ironing profiles based on different types of leather adapted according to grain, thickness, moisture content and surface treatment type.

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