1. Airless Bottle Cylinder & Piston Engineering Tolerance Table (15–150 ml)
| Airless Parameter | Vella Engineering Tolerance | Contract Filling Line Requirement |
|---|---|---|
| Cylinder Bore Roundness & Taper | ±0.04 mm cylindricity across full stroke length | Prevents air bypass around piston lip during upward travel |
| LDPE Double-Lip Piston Interference Fit | +0.25 mm to +0.40 mm larger than cylinder ID (Pre-lubricated with 0.8 mg medical PDMS or formula-compatible ester) | Ensures smooth breakaway friction (<3.5 N) and >98.5% evacuation |
| Supported Brookfield Viscosity Window | 500 cPs (watery essence) to 65,000 cPs (rich night cream) | Select 0.15–0.25 ml micro-valve for serums; 0.50–1.00 ml wide-stem for creams |
| Top-Fill Headspace Air Clearance | 0.5 mm to 1.5 mm maximum air gap below pump sealing skirt | Guarantees priming in ≤3–5 actuator strokes (excess headspace causes airlock) |
| Base Vent Hole & Bottom-Fill Option | Ø1.2–1.5 mm atmospheric intake port (Bottom-fill snap-base available) | Never cover the bottom intake hole with a non-perforated batch sticker! |
Request Physical Bottling & Pump Compatibility Sample Kit + 24h Tiered FOB Quote (48h DHL Dispatch)
Managed directly by Alex Gao (Managing Director, Vella · Guangzhou Yanchuang Packaging Co., Ltd. · USCC 91440111MA59DBE04B · [email protected] · WhatsApp +86 139 2512 2895). Low trial MOQs (~500–1,000 pcs stock, ~2,000–3,000 pcs custom Pantone with cross-component ΔE <= 1.5), -0.08 MPa vacuum leak testing, and 30/40/30 100% client mould ownership.