The preparation of cut footwear materials is a foundational step in shoe manufacturing, directly influencing product quality, durability, and appearance. In Kenya’s footwear industry, skilled material preparation ensures that shoes not only meet the demands of fashion but also withstand local environmental conditions and consumer expectations. Mastery of splitting and skiving techniques, combined with effective use of specialized machines and resources, is essential for professionals aiming to produce footwear that competes in both domestic and export markets. This chapter explores the technical operations and resource management required for precise cutting, splitting, and skiving of footwear materials.

4.19 Splitting Operations

Splitting is a critical process in footwear production, used to adjust the thickness of leather and other materials to suit specific shoe components. In Kenyan workshops, splitting is essential for maximizing material utilization and achieving the correct balance between strength and flexibility in finished shoes. Modern splitting machines enable operators to process a variety of hides, including cow, goat, and buff, ensuring that each piece meets the exact requirements for shoe uppers, linings, and soles.

4.19.1 Purpose of Splitting in Footwear Production

The splitting operation serves multiple purposes in the manufacturing of shoes, especially when working with natural leathers that vary in thickness and texture.

Key Purposes of Splitting

• Thickness Adjustment: Splitting allows for precise reduction of leather thickness, making materials suitable for different shoe sections such as uppers, linings, and soles.
• Material Uniformity: By splitting, manufacturers ensure consistent thickness across all pieces, which is crucial for assembly and durability.
• Improved Flexibility: Thinner, split materials are more flexible, enhancing wearer comfort, especially in shoe uppers and linings.
• Enhanced Appearance: Uniform thickness contributes to a smoother, more attractive finish, reducing visible imperfections in the final product.
• Efficient Material Usage: Splitting enables optimal use of expensive leather by producing multiple layers from a single hide, reducing waste and production costs.

In Nairobi’s footwear workshops, splitting machines are routinely used to prepare cowhide for both export-quality shoes and locally sold sandals, ensuring that every component meets design and functional specifications.

4.19.2 Types of Materials Suitable for Splitting

Not all footwear materials respond equally to splitting. The choice depends on the material’s physical properties and intended shoe application.

Materials Commonly Split in Footwear Production

• Cowhide Leather: Widely used for shoe uppers and soles due to its durability and strength; splitting helps achieve desired thickness for various shoe styles.
• Goat Skin: Preferred for softer uppers and linings; splitting ensures flexibility and comfort.
• Buff Leather: Often used for soles and heavy-duty footwear; splitting prepares it for easier processing and reduces weight.
• Synthetic Materials: Some synthetics, such as polyurethane-coated fabrics, can be split to mimic leather properties.
• Suede and Nubuck: These specialty leathers are split to enhance texture and achieve uniformity for fashion-oriented footwear.

Workshops in Eldoret frequently split buff leather to prepare rugged soles for agricultural boots, while urban shops in Mombasa may split goat skin for lightweight, fashionable sandals.

4.19.3 Splitting Machines: Specifications, Operation, and Maintenance

Splitting machines are specialized equipment designed to process leather and other materials with precision. Understanding their specifications and maintenance is vital for consistent quality.

Usage and Maintenance

• Routine Blade Sharpening: Use oil stones to maintain blade sharpness, ensuring clean and precise splits.
• Feed Roller Adjustment: Regularly check and adjust feed rollers for smooth material movement and consistent thickness.
• Cleaning: Remove leather dust and debris from the machine after each shift to prevent build-up and mechanical faults.
• Safety Checks: Inspect electrical connections and moving parts for wear; replace damaged components immediately.
• Calibration: Periodically calibrate thickness gauges for accuracy, especially when switching between different materials.

4.19.4 Steps in the Splitting Operation

The splitting process requires careful planning and execution to avoid waste and ensure optimal results.

1. Material Selection: Choose the hide or material to be split based on shoe design requirements.
2. Preparation: Clean the material and inspect for defects; cut to manageable size for the machine.
3. Machine Setup: Adjust blade width and thickness gauge according to specifications for the shoe component.
4. Positioning: Place the material on the feed rollers, ensuring proper alignment to avoid uneven splitting.
5. Splitting: Activate the machine and guide the material through, monitoring for uniform thickness.
6. Inspection: Check the split material for consistency, flexibility, and absence of damage.
7. Post-Splitting Handling: Stack and label split materials for further processing, such as skiving or cutting.

In Kisumu’s footwear factories, operators follow these steps to prepare leather for both school shoes and casual wear, adapting the process based on the end product’s requirements.

Quality Check

• Monitor for uneven thickness, which can cause assembly problems and affect shoe comfort.
• Ensure that split materials retain sufficient strength for their intended use.

Chapter Summary

This chapter has covered the essential processes and resources involved in cutting footwear materials, focusing first on splitting operations, which adjust the thickness of leather and other materials to ensure uniformity and optimal performance in shoe construction. It then explored the skiving operation, a technique used to thin the edges of material components for seamless joining and professional finishing. The discussion highlighted the importance of general resources and supplies, such as manilla paper, drawing paper, adhesives, and assorted leathers, all of which are foundational for accurate pattern making and assembly. Key machines and equipment were detailed, including clicking presses, splitting machines, and skiving machines, each playing a specific role in the preparation of footwear parts. The chapter also addressed the use of essential hand tools like clicking knives, pattern knives, scissors, rulers, and tailor's tape, which support precise measurement and cutting. Additional items such as oil stones, Indian pattern knives, silver pens, crayons, and cutting rubber mats were recognized for their roles in maintaining tools and marking materials. Throughout, the integration of these operations, machines, and resources was emphasized as critical for efficient workflow and high-quality footwear production.