The Four Constraints Unique to Food and Pharma Helical Gear Specification
Every food processing or pharmaceutical plant engineer specifying spiralformade kugghjul must satisfy four constraints that do not appear in any other industrial application category. These constraints are legally binding (EU Regulation 1935/2004, US FDA 21 CFR) for food contact applications, and commercially critical (GMP manufacturing standards) for pharmaceutical drives. Failing to satisfy any one eliminates the gear from regulatory compliance, regardless of mechanical performance.
1 — Food Contact Material
Gear material must not migrate harmful substances into food at concentrations above established migration limits. EU Regulation 1935/2004 and FDA 21 CFR 170–199 specify permitted materials in food-contact zones. Carbon steel and standard alloy steel grades (45#, 42CrMo, 20CrMnTi) are not approved for direct food contact — SS316L (with low carbon content <0.03%), food-grade SS304, and approved engineering polymers (POM, UHMWPE, PEEK) are the correct choices.
2 — H1 Lubricant Compliance
NSF International H1 registration (formerly USDA H1) is mandatory for lubricants in applications where incidental food contact is possible. H1 gear oils use FDA-approved white mineral oil or synthetic PAO base stocks with food-grade additive packages. Standard ISO VG 320 industrial gear oil with conventional EP additives is not H1 compliant — it cannot be used in a food processing spiralväxel drive where gear oil mist, weepage, or splash could reach the food product.
3 — Hygienic Geometry
EHEDG (European Hygienic Engineering and Design Group) and 3-A Sanitary Standards require that gearbox external surfaces have no blind holes, recesses, crevices, or horizontal flat surfaces where food debris can accumulate and harbour bacteria. Key grooves on exposed gear shafts must be filled or covered. Housing bolt holes must be of the through-type, not blind threaded holes that retain moisture.
4 — Washdown IP Rating
Food processing equipment is washed down at the end of each production shift using hot water (70–80°C) at high pressure (20–100 bar), often with alkaline or acid CIP cleaning solutions. The gearbox and any instrumentation on the drive must withstand this without ingress. IP65 for light washdown zones; IP67 for submersion risk; IP69K mandatory for direct high-pressure hot washdown in meat processing and dairy environments.
Helical Gear Materials for Food and Pharmaceutical Applications
SS316L soft tooth flank helical gear for food processing — no surface pits or roughness that can harbour bacteria, smooth bore without exposed keyway slots, and material compliant with EU 1935/2004 and FDA 21 CFR for direct food contact environments
| Material | Food Contact Approved | Max Hardness Achievable | Corrosion Resistance | Typisk tillämpning |
|---|---|---|---|---|
| SS316L | Yes — EU 1935/2004, FDA 21 CFR | HB 160–200 (soft); HRC 40–45 nitrided | Excellent — resistant to CIP acid/alkali cycles | Direct food contact zones, dairy, pharmaceutical API area |
| SS304 | Yes — food contact grades | HB 150–190 | Good — not for chloride-rich CIP solutions | General food processing, non-aggressive CIP |
| POM (Delrin/Acetal) | Yes — FDA 21 CFR 177.2470 | No hardness equivalent; compressive strength ~70 MPa | Excellent chemical resistance; not for strong acids | Fine-pitch gear trains, packaging machines, medical devices |
| UHMWPE | Yes — FDA 21 CFR 177.1520 | Lower than POM | Excellent; accepted by NSF 61 | Conveyor sprocket gears, light-duty drives in wet zones |
| TITT | Yes (FDA-grade compound required) | Moderate; highest of food-grade polymers | Excellent — rated to 250°C sterilisation temperatures | Autoclave-sterilised pharmaceutical equipment, high-temp applications |
| 42CrMo / 20CrMnTi (alloy steel) | Not permitted for food contact zones | HRC 50–62 | Poor — requires coating or plating for food environments | Non-contact zones only, with barrier between gear drive and food zone |
Why SS316L Rather Than SS304 for Dairy and Meat Processing
SS316L (316 Low Carbon, also written as 1.4404 in the European EN system) differs from SS304 in its 2–3% molybdenum content, which provides substantially better resistance to pitting corrosion in chloride-containing environments. Dairy and meat processing CIP cycles use hypochlorite-based sanitisers at concentrations of 100–200 ppm active chlorine — sufficient to pit SS304 gear flanks over months of daily exposure but unable to attack SS316L at the same exposure frequency. The surface pitting that develops on SS304 gears in chloride CIP environments is a direct bacterial contamination risk: the pits provide protected sites where bacteria survive the sanitiser cycle and re-colonise the food zone between shifts. SS316L avoids this entirely, which is why it is the mandatory material specification in the EU and FDA dairy and meat processing rules for direct food contact surfaces.
Food-Grade H1 Gear Lubrication — NSF Certification and Performance Limits
H1 gear oil for food processing spiralväxel drives uses either white mineral oil (highly refined food-grade mineral oil from which aromatic compounds have been removed) or synthetic PAO (polyalphaolefin) as the base stock, with additive packages that are approved under FDA 21 CFR 178.3570. NSF International maintains the H1 registration database; any gear oil used in food processing drives where incidental food contact is possible must appear in the NSF H1 registry.
The lubrication performance limitation of H1 gear oils compared with standard industrial gear oils is the absence of sulfur-phosphorus EP (extreme pressure) additives, which are not approved for H1 use. This means H1 oils rely entirely on EHL film formation for tooth flank protection — they cannot withstand the boundary lubrication conditions that EP additives are designed for. The practical implication: food processing spiralformade kugghjul using H1 lubrication must be sized conservatively (SF = 1.5–2.0 rather than SF = 1.25 for equivalent industrial gears), and the pitch-line velocity must be sufficient to develop a full EHL film (above 3–5 m/s for ground gears at operating temperature).
| H1 Lubricant Grade | Base Stock | Viscosity (ISO VG) | EHL Film vs Standard Oil | Typical Spiralväxel Ansökan |
|---|---|---|---|---|
| H1 Gear Oil 220 | White mineral or PAO | VG 220 | ~80% of equivalent non-food gear oil at same viscosity | General food processing gearboxes, conveyors, mixers at moderate speed |
| H1 Gear Oil 320 | PAO synthetic | VG 320 | ~85–90% of equivalent non-food gear oil | Higher-load drives: dough mixers, meat grinders, extruder gearboxes |
| H1 Grease | White mineral or PAO with food-grade thickener | NLGI Grade 2 | Lower film performance than H1 oil; acceptable for open gearing at low speed | Open gearing on packaging machines, labellers; slow conveyor drives |
Application-by-Application Specifications
POM and PEEK plastic spiralformade kugghjul for food contact drive mechanisms — self-lubricating, FDA-compliant, no metal contamination risk, and suitable for autoclave sterilisation (PEEK grade only)
Bakery — Dough Mixer and Divider Gearboxes
Industrial planetary dough mixers (200–800 litre capacity) use spiralväxel reducers driving the spiral hook at 30–120 RPM from a 2–15 kW motor. The duty cycle is intermittent but mechanically demanding: dough at the beginning of a mixing cycle is stiff and high-viscosity, creating start-up torque peaks of 2–3× rated torque. Service factor SF = 1.75–2.5 applies. Material: SS316L soft tooth flank (HB 160–190) for small drives in direct food contact zones; alloy steel with H1-oil-sealed housing for large drives where the gearbox is outside the food zone but the output shaft penetrates into it through a sanitary shaft seal.
Meat Processing — Grinder and Mixer Drives (IP69K)
Meat grinders and bowl choppers operate in the most aggressive washdown environments in food processing: IP69K rating (80°C water at 80–100 bar from 10–15 cm distance) is the standard for meat processing equipment in compliance with EU Regulation 853/2004. The gearbox housing must withstand daily high-pressure hot washdown without ingress. Spiralväxel drives for meat processing are typically: SS316L housing and gear shafts, with food-grade grease or sealed-for-life H1 oil bath, radial lip seals rated for 80°C continuous and resistant to the cleaning chemicals (sodium hydroxide, peracetic acid) used in meat plant sanitisation cycles.
Pharmaceutical — Granulator and Tablet Press Drives
Pharmaceutical manufacturing operates under GMP (Good Manufacturing Practice) rules that require complete traceability of all materials contacting or potentially contacting the pharmaceutical product — including gear drive lubricants. Granulator spiralväxel drives require H1 NSF-certified lubricants with batch certificates, and the gearbox design must prevent oil migration from the drive cavity to the granulation chamber. Tablet press transmission gears are often polymer (PEEK) precision gears that run dry without any lubrication — eliminating the oil-migration contamination risk entirely, at the cost of lower load capacity (PEEK gears for tablet presses typically transmit below 2 kW, adequate for the precise position-controlled cam drives in pharmaceutical tablet presses).
Korea Ever-Power — Stainless and Food-Grade Helical Gear Supply
Korea Ever-Power produces SS316L and SS304 spiralformade kugghjul for food processing and pharmaceutical applications, with material certification to EN 10088-3 and food contact compliance documentation for EU 1935/2004 and FDA 21 CFR requirements
Korea Ever-Power tillverkar spiralformade kugghjul in SS316L and SS304 for direct food contact applications, and in POM for fine-pitch polymer gear trains in packaging and pharmaceutical equipment. Material certification to EN 10088-3 confirms compliance with EU food contact regulations. As a direct tillverkare av spiralväxlar, Korea Ever-Power provides all material documentation required for food plant equipment qualification audits. For high-accuracy SS316L gears at DIN Class 5–6, nitriding heat treatment (case depth 0.1–0.3 mm, HV 1000+ surface) is available to improve tooth surface hardness while retaining full corrosion resistance.
Vanliga frågor
NSF H1 lubricants are approved for applications where incidental (accidental, non-intentional) contact with food may occur — typically the zone within which food is processed, packaged, or handled. H2 lubricants are approved for use in food processing equipment where there is no possibility of food contact (completely enclosed, sealed drives that cannot drip or leak into the food zone). H2 oils can contain conventional EP additives that H1 oils cannot, giving better EHL film performance under high load. For a spiralväxel drive mounted directly over a food conveyance zone: H1 mandatory. For a sealed drive mounted in a separate machine room with no proximity to food: H2 acceptable (with containment measures to prevent migration).
Not in food-contact zones. Paint or coating does not give regulatory food-contact approval to an unapproved substrate material — EU 1935/2004 and FDA 21 CFR require that the material itself be approved, not a surface treatment applied to an unapproved material. Carbon steel or alloy steel spiralformade kugghjul can be used in food plants in completely sealed, no-contact positions (completely enclosed drive in a machine room), but this requires engineering assessment and documentation confirming zero food contamination risk. Where the gear is within the food zone or could have incidental contact, SS316L or an approved food-grade polymer is mandatory.
EHEDG Document 8 (Hygienic Equipment Design Criteria) and Document 13 (Hygienic Design of Food Gear Drives) specify: (1) external surface Ra ≤ 0.8 µm on all food-contact surfaces — specify Ra ≤ 0.8 µm turned and polished finish on the external housing and shaft; (2) no exposed threads, keyways, or crevices in food-contact zones — specify closed-end or blind shaft ends in exposed positions; (3) permanent identification marking (laser-etched serial number) rather than stamps or recesses that retain contamination. For the gear teeth themselves, EHEDG recommends that the gear drive be fully enclosed with a sealed housing so that the internal tooth surfaces never form part of the external food-contact surface.
Yes. Korea Ever-Power produces SS316L spiralformade kugghjul with EN 10088-3 material certification confirming compliance with food-grade stainless specifications. For customers requiring EHEDG design review documentation, Korea Ever-Power provides surface roughness Ra certificates, dimensional verification confirming no exposed crevices on the gear body, and a declaration of conformity for EU food contact compliance under 1935/2004. Documentation is provided in English as standard. Lead time for SS316L spiralformade kugghjul M2–M16: typically 10–18 working days.
Food-Grade or Pharmaceutical Helical Gear Enquiry
Specify your material (SS316L, SS304, POM, PEEK), module, application, CIP exposure level, and required documentation. Korea Ever-Power provides food-grade gear specification and compliance documentation within 24 working hours.
SS316L · SS304 · POM · PEEK · NSF H1 compatible · EHEDG documentation · IP69K rated housings · MOQ 1 piece
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