Panel Cutting is a core manufacturing process that involves precisely cutting individual fabric pieces (Panels) that constitute products with three-dimensional structures, such as hats, bags, apparel, and footwear, according to a designed pattern. Particularly in the hat manufacturing industry, the primary method adopted involves using a Hydraulic Clicker Press and Steel Rule Dies to form the crown and brim of a 6-panel structure.
In terms of physical mechanisms, panel cutting utilizes the principle of "Compressive Shearing." Unlike scissors, where two blades engage to cut, this method involves a sharp single edge penetrating vertically into the fabric under a heavy hydraulic load to separate it. This method boasts overwhelming production speeds compared to CNC knife cutting or laser cutting. While laser cutting has the advantage of melting the edges of synthetic fibers to prevent fraying, it has the critical disadvantage of leaving burn marks on white or light-colored fabrics. In contrast, panel cutting uses only physical pressure, ensuring no fabric discoloration and allowing dozens of layers of fabric to be processed simultaneously in a single stroke, making it the preferred method in mass-production factories. In modern high-end bag and hat manufacturing, panel cutting is considered the task of setting the "Zero Point" (reference point) of the product; an error of 0.5mm here can amplify into a distortion of over 5mm during the final sewing stage, requiring extreme precision.
¶ 2. Definition and Technical Background
Panel cutting is performed to ensure efficiency and uniformity in a mass-production environment. After the Spreading process, where fabric is stacked in multiple layers, sharp steel rule dies made in the shape of the product are placed on the fabric, and strong hydraulic pressure is applied to stamp them out.
- Die Cutting Method: The most common method in hat manufacturing, capable of cutting dozens of fabric layers at once depending on the height and strength of the die. The hydraulic system applies Pascal's Principle to transmit loads of dozens of tons to the cutting head (Swing Arm or Traveling Head) with minimal force. The correlation between the die's blade angle (usually 19 to 42 degrees) and the fabric density is crucial.
- Precision Control: The technical core is aligning the Warp and Weft directions of the fabric with the Grain Line of the pattern. If the grain line is misaligned, the hat will twist after sewing. Particularly for knit or spandex-blend fabrics with elasticity, if the tension is not completely removed during spreading, a "Rebound" phenomenon occurs where the panels shrink after cutting, becoming smaller than the design dimensions.
Historical Background and Regional Practice Differences
Panel cutting technology originated from leather cutting in the footwear industry in the mid-19th century and spread to the mass-production apparel industry in the early 20th century. In Korean factories (especially during the peak of the 70s–90s), this was referred to as "Gata (型)" work and treated as a precision process relying on the artisan's intuition. Currently, Vietnamese factories tend to computerize the management of die serial numbers and history (such as regrinding frequency), known as "Khuôn." Chinese factories are introducing large Traveling Head Cutting Machines equipped with automatic nesting software to maximize fabric yield in response to rising labor costs. While Korean technicians still emphasize fine pressure adjustment through "feel," large overseas factories prioritize management based on standardized numerical values (Pressure Gauges).
| Item |
Detailed Specification |
Remarks |
| Process Classification |
Cutting Process |
Initial manufacturing stage |
| Stitch Classification |
N/A |
Process outside ISO 4915 standards |
| Main Equipment |
Hydraulic Swing Arm Clicker |
Commonly known as 'Clicker' |
| Equipment Models |
Atom S120, Sysco SE 25, Gerson GR-25, ATOM SE Series |
Industry standard models |
| Cutting Pressure |
20 Tons ~ 27 Tons (30+ Tons for leather/heavy canvas) |
Adjusted based on material resistance |
| Stroke |
5mm ~ 100mm (Adjustable range) |
Proportional to die height |
| Cutting Tools |
Steel Rule Die / Forged Die / 19mm~32mm Blade |
Custom-made per pattern |
| Suitable Materials |
Cotton Twill, Polyester, Mesh, Canvas, Leather, PE Board (Brim insert) |
Compatible with all items |
| Consumables |
PP/Nylon Cutting Board, Die Wax, Spreading Paper |
Consumable parts |
| Cutting Board Hardness |
Shore D 60 ~ 75 |
Selected based on material |
| Die Blade Hardness |
HRC 52 ~ 56 (High carbon steel base) |
Unverified (Varies by manufacturer) |
| Hydraulic Oil Spec |
ISO VG 46 or 68 |
Follow equipment manual |
¶ 4. Applications and Material Characteristics
Panel cutting is applied to all sewing industries where structural rigidity and aesthetic silhouette are important.
- Headwear:
- Crown: Front, side, and back panels of a 6-panel baseball cap. Since the curvature of each panel must form a sphere after sewing, an error within ±0.5mm is essential.
- Brim/Visor: Internal PE board (stiffener) and the upper/lower fabric panels covering it. Since the brim includes a thick stiffener, the use of Forged Dies is recommended.
- Sweatband: Long strip-shaped panels that contact the forehead.
- Apparel:
- Shirts: Small, precise parts such as collars, cuffs, pocket flaps, and epaulets.
- Suits/Coats: Internal reinforcement interlining and shoulder pad components.
- Sportswear: Side mesh panels and ergonomic panels for knees/elbows.
- Bags & Accessories:
- Backpacks: Main body panels, bottom panels, and the outer shell and internal EVA foam reinforcements for shoulder straps.
- Wallets/Pouches: Card slots and leather pieces for zipper pullers.
- Industrial Components: Complex leather panels for automotive seat covers, special fabric panels for airbag deployment areas, and multi-layered structures for shoe uppers.
Correlation with Industry SPI and Thread Types
In the sewing process following panel cutting, the condition of the panel's edge affects the SPI (Stitches Per Inch) settings. For example, if the edge of a canvas bag panel is rough, thick thread (such as 20/3 Core thread) with 8–10 SPI and a generous seam allowance must be used. Conversely, precise shirt collar panels require very clean edges for high-density sewing at 16–20 SPI.
-
Flaring / Undercutting
- Symptom: The sizes of the top and bottom panels in a stack differ slightly (bottom becomes larger).
- Cause: Fabric stacking height is too high, or the die blade bends instead of entering vertically.
- Solution: Reduce the number of fabric layers (recommended maximum 60% of blade height) and reset hydraulic pressure according to material density. Also, check if the die's "pitch" is leaning inward.
-
Material Fusing
- Symptom: Edges of synthetic fibers like polyester melt and stick together during cutting.
- Cause: Frictional heat from the blade or excessive pressure due to a dull blade.
- Solution: Sharpen the blade or apply silicone oil/die wax. If necessary, reduce the number of layers to shorten friction time. In the field, tissue paper is sometimes inserted between fabric layers to prevent fusing.
-
Grain Line Deviation
- Symptom: The finished hat is asymmetrical or leans to one side.
- Cause: The warp direction of the fabric does not align with the center line of the pattern during cutting.
- Solution: Strictly follow the warp direction during marker placement and adjust tension during spreading to prevent fabric stretching. Panels requiring bias cutting must maintain accurate angles using a protractor.
-
Uncut / Ragged Edges
- Symptom: Fabric threads are not completely severed or the edge is rough.
- Cause: Specific areas of the cutting board are deeply pitted, or the die blade is nicked.
- Solution: Plane the cutting board surface or rotate its position. A field proverb says, "If the sound is dull and thudding, it's time to change the board." Damaged dies should be replaced or repaired immediately.
-
Shading / Color Variation
- Symptom: Color differences occur between panels within the same hat.
- Cause: Panels cut from different fabric rolls are mixed.
- Solution: Separate fabric lots before cutting and perform bundling and numbering immediately after cutting. Using a "Shade Marking" pen to write the roll number on the back of the panel is the most reliable method.
¶ 6. QC Standards
- Dimensional Precision: Tolerance within ±0.5mm compared to the master pattern (for hat crowns). For leather, manage within ±0.3mm considering elongation.
- Notch Accuracy: Ensure the position and depth (usually within 3mm) of notches, which serve as sewing guides, are accurate. If a notch is too deep, a hole may be visible after sewing.
- Edge Condition: Check for material fusing in synthetic fibers and the degree of fraying in natural fibers.
- Quantity Matching: Conduct a 100% inspection to ensure left/right symmetrical panels and all components are included in one set (Bundle) without omission.
- Contamination Inspection: Check if hydraulic oil or rust from the die has stained the fabric. White fabrics, in particular, require the die to be wiped clean before cutting.
¶ 7. Factory Slang and Regional Terms
| Language |
Term |
Field Pronunciation/Notation |
Meaning & Remarks |
| Korean |
도마 |
Doma |
Refers to the Cutting Board. More common than the Japanese 'Ita'. |
| Korean |
철형 |
Cheol-hyeong |
Means Steel Rule Die. The most widely used term in the field. |
| Korean |
아다리 |
Adari |
Refers to the fit or precision between panels (derived from Japanese). |
| Japanese |
누키 |
抜き (Nuki) |
Means 'stamping out,' i.e., the panel cutting process itself. |
| Japanese |
가타 |
型 (Kata) |
Means die or pattern (mold). Used as in "The kata doesn't fit well." |
| Vietnamese |
Khuôn |
Khuôn |
Means the cutting die. |
| Vietnamese |
Máy dập |
마이 잡 |
Means the Hydraulic Clicker Press. |
| Chinese |
刀模 |
Dao Mu |
Means the knife mold (Steel Rule Die). |
| Chinese |
裁断 |
Cai Duan |
Refers to the overall cutting process. |
¶ 8. Equipment Setting and Precision Maintenance Guide
- Pressure Calibration: When loading a new die, start at the lowest pressure and gradually increase it until the fabric is cut cleanly. Excessive pressure shortens the life of the blade and cutting board. (Usually start between 120bar and 150bar for a 20-ton machine).
- Stroke Adjustment: Finely adjust the head's downward limit so it penetrates the cutting board surface by only about 0.2–0.3mm. Penetrating too deeply consumes the board quickly, while too shallow results in uncut fabric.
- Cutting Board Management: At the end of each workday, rotate the cutting board 180 degrees or shift it left/right to prevent uneven wear. If the surface becomes too deeply pitted, perform flattening using a dedicated planing machine.
- Die Storage: Store unused dies on dedicated racks to protect the blades. Apply anti-rust oil for long-term storage to prevent corrosion. If blades become dull, sharpen them using a die sharpener.
- Hydraulic Oil Management: If the viscosity of the hydraulic oil drops or it becomes contaminated, cutting pressure becomes inconsistent. Oil replacement is generally recommended after 2,000 hours of operation.
graph TD
A[Fabric Receipt and Inspection] --> B[Spreading: Layering Fabric]
B --> C[Relaxation: 12-24 Hours]
C --> D[Marker Placement & Die Arrangement]
D --> E{Hydraulic Panel Cutting}
E --> F[Panel Inspection: Dimensions & Contamination]
F --> G[Numbering & Bundling: Lot Management]
G --> H[Input to Sewing Process]
E -- Defect Occurs --> I[Die Sharpening & Pressure Reset]
I --> E
F -- Dimensional Defect --> J[Rework or Scrap]
¶ 10. Technical Depth: Types of Dies and Selection Criteria
Dies used in panel cutting are selected based on material and required precision.
* Steel Rule Die (Band Die): Made by bending thin steel rules and embedding them in a die board or welding them. They are lightweight and inexpensive, mainly used for apparel panel cutting. Blade thicknesses of 0.71mm (2pt) or 1.05mm (3pt) are commonly used.
* Forged Die: Made by machining or forging solid steel. They have extremely high durability and are used for materials requiring high pressure, such as leather, thick canvas, and PE boards. Forged dies must be used for cutting hat brims to prevent deformation.
* Blade Bevel Types:
* Center Bevel: Both sides of the blade are ground symmetrically. Used for general fabric cutting.
* Side Bevel: Only one side is ground. Used when the edge of the cut panel must remain perfectly vertical (e.g., thick leather).
- Two-Hand Operation: Ensure the machine is set so the head only descends when both hand buttons are pressed simultaneously to prevent hand-crushing accidents.
- Safety Distance Maintenance: Establish safety lines to ensure others do not approach within the head's rotation radius.
- Die Handling Caution: Always wear protective gloves when moving dies and ensure the blades do not face the body.
- Spreading: The preliminary process of stacking fabric layers for cutting.
- Steel Rule Die: The knife mold that determines the panel shape.
- Marker: The layout design of panels to maximize fabric yield.
- Numbering: The task of stamping sequential numbers to prevent cut pieces from being mixed.
- AQL (Acceptable Quality Level): Statistical sampling standards applied during cutting quality inspection.
- Nesting: Technology for optimally arranging panels to minimize fabric consumption.