Пома (polyoxymethylene), also known as acetal resin, is a top choice for sample models in industries like automotive, Электроника, and consumer goods—praised for its excellent механическая прочность, низкое трение, and superior износостойкость. Однако, POM’s unique traits—such as high hardness (сравнимо с некоторыми металлами) and sensitivity to high temperatures—make it tricky to process; overly aggressive cutting or improper cooling can lead to surface burns, трещины, or dimensional errors. Swiss CNC machines (особенно Швейцарский тип), с их Прецизионная инженерия and multi-functional capabilities, are perfectly suited to tackle POM’s challenges. They deliver POM sample models with tight tolerances, плавные поверхности, and consistent performance—critical for validating designs before mass production. This guide breaks down the complete Swiss CNC processing process for POM samples, from machine setup to quality control.
1. Swiss CNC Machine Basics: Key Features for POM Processing
Swiss CNC machines’ specialized design sets them apart from conventional equipment, making them ideal for POM. Their focus on stability, точность, and controlled motion addresses POM’s machining pain points—like the need to avoid heat buildup and maintain tight dimensional accuracy.
Core Components of Swiss CNC Machines & POM Processing Benefits
| Компонент | Описание | Advantage for POM Processing |
| Swiss CNC lathe | Sliding headstock + fixed guide bushing; compact, rigid frame | Minimizes vibration (POM’s hard surface shows vibration marks easily) for smooth finishes. |
| Machine structure | Heavy-duty cast iron base; reinforced linear guideways | Absorbs cutting forces (POM requires moderate force for material removal) to prevent tool chatter. |
| Axis movement | 4–5 axis linkage; positioning accuracy ±0.001 mm | Handles complex POM sample geometries (НАПРИМЕР., Изогнутые края, multi-sided features) in one setup. |
| Tool turret | 8–12 station turret; quick tool changes (0.3–0.8 seconds) | Enables “done-in-one” processing (поворот, фрезерование, бурение) without repositioning POM—reduces heat accumulation from repeated clamping. |
| Скорость шпинделя | Adjustable range: 2,000–8,000 rpm; low runout (≤0,001 мм) | Controlled rotation prevents POM from melting (high speeds >6,000 rpm cause heat buildup) or chipping (low speeds lead to uneven cuts). |
| Machine programming | CNC system (НАПРИМЕР., Fanuc, Siemens) with G-code support; CAM software compatibility (Мастеркам, Слияние 360) | Ensures repeatable precision (critical for batch POM samples) and optimizes toolpaths to avoid heat-prone areas. |
Analogy: Think of a Swiss CNC machine as a “precision chef” for POM. Just like a chef uses sharp tools and controlled heat to cook delicate ingredients without burning them, a Swiss CNC machine uses optimized Параметры резки and stable motion to machine hard, heat-sensitive POM without defects.
2. POM Material Properties: Know Its “Do’s and Don’ts”
POM’s properties directly influence every step of the processing process. Ignoring its unique characteristics—like high твердость and low thermal conductivity—can lead to ruined samples (НАПРИМЕР., burned surfaces from excessive heat or dull tools from abrasion).
Critical POM Properties & Machining Implications
| Свойство | Спецификация | Machining Precaution |
| Mechanical strength | Предел прочности: 60–70 МПа; воздействие сила: 5–10 kJ/m² (unnotched) | Moderate impact strength means POM can handle standard cutting forces but avoid sudden tool plunges (causes cracking). |
| Твердость | Rockwell M (RM) 80–90; Shore D 78–85 | Abrasive to tools—use wear-resistant cutting materials (НАПРИМЕР., карбид) to avoid frequent tool changes. |
| Износостойкость | Coefficient of friction: 0.15–0,3 (сухой); better than most plastics | Low friction means POM chips slide easily—use chip conveyors to prevent buildup (buildup causes surface scratches). |
| Химическая устойчивость | Сопротивляется маслам, растворители, and weak acids; attacked by strong alkalis and phenols | Use water-soluble coolant (avoid oil-based coolants that leave residues on POM’s surface). |
| Thermal properties | Точка плавления: 165–175°C; теплопроводность: 0.23–0.3 W/(м · к) (низкий) | Heat dissipates slowly—keep cutting temperature <150° C. (use high coolant flow) to avoid melting or crystallization. |
| Механизм | Хороший (low chip adhesion); produces continuous, stringy chips | Use tools with chip breakers to avoid long chip tangles (tangles scratch POM’s surface). |
Вопрос: Why do my POM samples have a burned, brownish surface?
Отвечать: Burn marks come from excessive heat (POM’s low thermal conductivity traps heat at the cutting zone). Fix it by: 1) Reducing spindle speed by 1,000 об/мин; 2) Increasing coolant flow rate to 25–30 L/min; 3) Using a tool with a larger rake angle (уменьшает трение).
3. Sample Model Design: Optimize for Swiss CNC Processing
A well-designed POM sample model minimizes processing challenges. Focus on simplicity, производство, and alignment with Swiss CNC machine capabilities—avoid features that force the machine to make risky cuts (НАПРИМЕР., глубокий, narrow slots that trap heat).
Design Guidelines for POM Samples
| Дизайн аспект | Recommendations | Почему это важно |
| CAD Software | Use SolidWorks, Слияние 360, or AutoCAD for 3D Моделирование. Include clear design specifications (НАПРИМЕР., Диаметр отверстия: 6± 0,02 мм). | Enables accurate машинное программирование—the CNC system “knows” exactly what to cut, уменьшение ошибок. |
| Точность размеров | Set target accuracy based on use: ±0.02–±0.05 mm (functional samples); ±0.01–±0.02 mm (critical features like mounting holes). | Overly tight accuracy (± 0,005 мм) increases processing time by 30%+ without adding value for most POM applications. |
| Допуски | Следуйте за ISO 286-1: Use H7/g6 for sliding fits (common in POM gears) and H8/f7 for loose fits (НАПРИМЕР., housing components). | Ensures the sample fits with other parts (НАПРИМЕР., a POM gear that meshes with a metal shaft) во время тестирования. |
| Feature complexity | Avoid deep features (глубина >3x width) or sharp internal corners (radius <0.5 мм). Используйте постепенные переходы (конус) Для изменений толщины. | Deep features trap heat; sharp corners cause stress concentrations (POM cracks easily at stress points). |
| Model geometry | Для цилиндрических частей (НАПРИМЕР., POM shafts), keep length-to-diameter ratio <10:1 (prevents deflection). Для плоских частей, add ribs (width 0.5x thickness) for rigidity. | POM’s low flexural strength means long, thin parts bend during machining—ribs add support without increasing weight. |
Тематическое исследование: A client designed a POM valve core with a 2 мм шириной, 8 mm deep slot (Соотношение сторон 4:1). Первый 10 samples had burned surfaces and cracks. By widening the slot to 3 мм (Соотношение сторон 2.7:1) and adding 0.8 mm radii at the corners, all subsequent samples were defect-free—proving how design tweaks solve processing issues.
4. Методы обработки: Step-by-Step POM Machining
Swiss CNC processing for POM follows a “precision-first” workflow—prioritizing sharp tools, controlled speeds, and efficient heat management. Below is the step-by-step process, with key techniques for each operation to avoid common defects.
Step-by-Step Processing Workflow
- Материал подготовка:
- Cut POM bar stock to length (add 5–10% machining allowance: НАПРИМЕР., 100 mm final length → 105–110 mm bar).
- Store POM in a dry environment (влажность <60%)—POM absorbs minimal moisture, but dampness causes surface blemishes.
- Настройка машины:
- Install режущие инструменты: Carbide turning inserts (grade K10-K20) для поворота; TiAlN-coated carbide end mills (2–3 flute) for milling; карбид упражнений (135° point angle) for drilling.
- Calibrate axes via машинное программирование: Input tool lengths, радиусы, and sample dimensions into the CNC system. Запустить сухой тест (no cutting) to verify toolpaths.
- Turning Operations:
- Rough turning: Remove excess material (Скорость шпинделя: 3,000–4,000 rpm; скорость корма: 0.015–0.025 mm/rev; глубина разрезания: 0.5–1,0 мм). Используйте охлаждающую жидкость под высоким давлением. (25–30 L/min) to dissipate heat.
- Finish turning: Достичь окончательных измерений (Скорость шпинделя: 4,000–5,000 rpm; скорость корма: 0.005–0.015 mm/rev; глубина разрезания: 0.1–0,3 мм). Use a sharp tool with a positive rake angle (10–15°) Для гладких поверхностей.
- Milling/Drilling (При необходимости):
- Фрезерование: For slots or flats (Скорость шпинделя: 3,500–4,500 rpm; скорость корма: 0.01–0.02 mm/rev; глубина разрезания: 0.3–0.6 mm). Используйте фрезерование (tool rotates with the workpiece) Чтобы уменьшить трение.
- Бурение: For holes (Скорость шпинделя: 2,500–3,500 rpm; скорость корма: 0.01–0.015 mm/rev). Use peck drilling (pause every 1–2 mm) to clear stringy POM chips—prevents jamming.
- Threading (При необходимости):
- Use single-point carbide threading tools (60° thread angle). Cut threads in 3–4 passes (depth per pass: 0.1–0.15 mm; Скорость шпинделя: 2,000–2,500 rpm). Avoid coolant during threading (prevents thread distortion).
- Поверхностная отделка:
- For Ra ≤0.8 μm (functional samples): No post-processing needed if finish turning is done correctly.
- For Ra ≤0.4 μm (aesthetic samples): Polish with 1,000–1,500 grit sandpaper (wet-sanding) or a soft abrasive wheel (1,000 об/мин). Avoid high-speed polishing (causes heat damage).
Key Technique Tips
- Контроль чипа: POM produces long, stringy chips—use tools with chip breakers or adjust feed rate (increase by 0.005 мм/rev) to break chips into 2–3 cm pieces.
- Tool wear monitoring: Check tools every 20–30 samples. Dull tools (visible rounded edges) increase cutting temperature—replace carbide tools after 200–300 POM parts.
- Coolant usage: Use water-soluble coolant with 5–10% concentration. Clean the coolant tank weekly (POM chips degrade coolant over time).
5. Контроль качества и проверка: Ensure POM Sample Reliability
POM samples often serve critical roles (НАПРИМЕР., передачи, втулки, or medical device components), so strict quality control is essential. Inspect for dimensional accuracy, Качество поверхности, and functional performance to ensure the sample meets design goals.
Контрольный список проверок & Методы
| Inspection Aspect | Стандарты | Инструменты/Методы |
| Проверки размеров | Meet design specifications: НАПРИМЕР., outer diameter ±0.02 mm; hole position ±0.03 mm. | Микрометры (accuracy ±0.001 mm) Для маленьких диаметров; суппорты (digital, ± 0,002 мм) for lengths; Координировать измерительную машину (ШМ) Для сложной геометрии. |
| Поверхностные дефекты | No burns, царапины, or chips. Шероховатость поверхности: RA 0,4-1,6 мкм (функциональный); RA ≤0,4 мкм (эстетика). | Surface roughness meter; visual inspection under natural light (hold sample at 45° angle). |
| Tolerance verification | Придерживаться ISO 286-1 допуски: НАПРИМЕР., H7 hole (диаметр 10+0.015/-0 мм) fits g6 shaft (10-0.009/-0.025 мм). | Gages (pin gages for holes; ring gages for shafts); go/no-go gages for quick batch checks. |
| Functional performance | For wear-resistant parts (НАПРИМЕР., передачи): Pass 10,000-cycle wear test (no excessive wear). Для структурных частей: Withstand 1.5x design load (Нет трещин). | Wear tester; universal testing machine (for tensile/compression tests). |
| Quality standards | Следуйте за ISO 9001 (Общее качество) and specific industry standards (НАПРИМЕР., Iso 10993 for medical POM parts). | Document inspection results (дата, inspector, измерения) for traceability. |
Для чаевого: For batch production (10+ POM samples), use statistical sampling—inspect 20% of the batch for dimensional accuracy and 100% для поверхностных дефектов (fast to check visually). This balances thoroughness and efficiency.
Yigu Technology’s View
В Yigu Technology, we tailor Swiss CNC processing to POM’s unique traits. We use Swiss CNC lathes with high-precision guide bushings (± 0,001 мм) to avoid deflection and TiAlN-coated carbide tools to resist POM’s abrasion. For setup, we optimize toolpaths via CAM software to reduce heat buildup, cutting sample waste by 35%. Our quality control combines CMM for dimensions and wear testing for functional parts. Whether it’s a POM gear or medical component, we deliver samples that meet strict standards—blending precision and efficiency to help clients validate designs fast.
FAQs
- Q.: Can Swiss CNC machines process thin-walled POM samples (НАПРИМЕР., 0.5 mm thick tubes)?
А: Да! Use a guide bushing for support, reduce clamping force to 10–15 N·m, and make shallow cutting passes (0.05–0.1 mm depth). We’ve successfully processed 0.3 mm thick POM tubes with ±0.01 mm dimensional accuracy.
- Q.: What’s the best coolant for Swiss CNC processing of POM?
А: Водорастворимая охлаждающая жидкость (5–10% mineral oil + вода) Идеально. It cools effectively (critical for POM’s low thermal conductivity) and doesn’t leave residues that affect POM’s surface or износостойкость. Avoid oil-based coolants (attract dust) and solvent-based coolants (damage POM).
- Q.: Why do my POM samples crack during drilling?
А: Cracking often comes from excessive feed rate or dull drills. Fix it by: 1) Using a sharp carbide drill (135° point angle); 2) Reducing feed rate to 0.008–0.01 mm/rev; 3) Using peck drilling (pause every 1 мм) to relieve stress—this prevents POM from cracking under pressure.