injection pen pre-assembly line

injection pen pre-assembly line

Product Overview

The DROFEN MACHINERY High-Speed Insulin Pen Pre-Assembly Equipment is a fully automated production system designed to assemble all plastic and mechanical components into a complete pen body — ready to receive the pre-filled drug cartridge at the downstream final assembly stage. Operating at a stable output of 160 pens per minute, this system handles the precise assembly of dosing mechanisms, clutch systems, drive sleeves, dose buttons, and outer shells into a single integrated pen body unit.

As a core component of DROFEN MACHINERY's Turnkey CDMO solution, the pre-assembly equipment is engineered to work seamlessly with our final assembly line, creating a unified production flow from raw plastic components to finished patient-ready injection pen devices. This integrated approach eliminates the compatibility risks that arise when pre-assembly and final assembly equipment are sourced from different vendors.

Why Pre-Assembly is the Foundation of Pen Quality

Pre-assembly is where the mechanical precision of an injection pen is established. Every component assembled at this stage directly determines the device's dosing accuracy, user feel, and long-term reliability. The key challenges include:

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Micro-component handling — pen mechanisms contain dozens of small plastic parts (some under 3mm) that must be oriented, fed, and assembled with sub-millimeter precision

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Force-sensitive assembly — snap-fit connections, press-fits, and thread engagements require precisely controlled forces to avoid cracking, deformation, or incomplete engagement

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Cumulative tolerance management — when 15–25 individual components are assembled sequentially, dimensional tolerances stack up; the pre-assembly system must compensate in real-time to maintain final assembly quality

A poorly designed pre-assembly system produces pen bodies with inconsistent mechanical properties, leading to high rejection rates at final assembly and, worse, potential dose accuracy failures in the finished device. This is why DROFEN MACHINERY treats pre-assembly equipment as a precision instrument, not a simple pick-and-place machine.

Technical Specifications

Parameter
Specification
Production Speed
160 pens/min (stable continuous output)
Number of Assembly Stations
12–18 stations (configurable per pen design)
Component Count per Pen Body
15–25 components (platform dependent)
Compatible Pen Types
Disposable insulin pens, reusable pens, GLP-1 pens, fixed-dose and variable-dose configurations
Assembly Precision
±0.02 mm positional accuracy
Feeding Systems
Vibratory bowl feeders, step feeders, and vision-guided robotic pick-and-place
Force Monitoring
Servo-controlled with real-time force-displacement curve recording
Inline Inspection
100% vision inspection at critical stations + end-of-line functional verification
Rejection Rate
< 0.5% (typical operating condition)
Changeover Time
< 60 minutes between pen variants
Line Footprint
Approximately 15 meters × 3 meters (configurable)