Key Responsibilities and Required Skills for Injection Operator

🎯 Role Definition

As an Injection Operator, you will set up, operate, monitor and continuously improve plastic injection molding machinery and associated automation to produce quality thermoplastic and thermoset parts that meet customer specifications. This role requires hands-on experience with press setup, mold installation, process parameter optimization, part inspection, preventive maintenance and collaboration with engineering, quality and maintenance teams to drive safe, efficient, and repeatable production.

📈 Career Progression

Typical Career Path

Entry Point From:

Machine Operator / Production Technician with experience on injection or compression presses
Apprenticeship or technical diploma graduate in plastics or manufacturing technology
Mold Technician / Tooling Assistant

Advancement To:

Senior Injection Operator or Lead Operator
Process Technician / Process Engineer (Injection Molding)
Production Supervisor / Manufacturing Team Lead
Mold Maker / Tooling Specialist
Quality Engineer (plastics) or Continuous Improvement Specialist

Lateral Moves:

Extrusion or Blow Molding Operator
Assembly / Automation Technician
CNC Machinist or Maintenance Technician

Core Responsibilities

Primary Functions

Set up and fully commission injection molding machines for production runs, including mold loading, clamp and shot-size adjustments, parameter programming, and verification of hydraulic/servo systems to ensure first-article conformity and consistent cycle times.
Execute mold changeover and quick mold change (QMC) procedures according to SOPs and lean best practices to minimize downtime and meet production schedules.
Monitor cycle-by-cycle machine performance, perform in-process adjustments to shot size, injection speed, hold pressure, cooling time, screw speed and barrel temperature to maintain dimensional accuracy and part quality.
Perform detailed part inspections using calipers, micrometers, go/no-go gauges, and optical comparators; log dimensional data and SPC charts and escalate trends outside control limits to quality/engineering.
Interpret engineering drawings, customer specifications, tolerance tables and mold drawings to verify part geometry, gate location and acceptable cosmetic standards; implement corrective actions when deviations occur.
Troubleshoot machine faults, mold issues (short shots, flash, flow marks), and peripheral equipment malfunctions; perform basic mechanical, hydraulic and electrical diagnostics and coordinate with maintenance for repairs.
Conduct preventive maintenance tasks: clean and lubricate molds, check heaters, thermocouples, hydraulic fluid levels, filter changes and basic mechanical adjustments to maintain press reliability and extend mold life.
Prepare, update and maintain process documentation including setup sheets, mold parameter recipes, changeover checklists, and production logs in paper form or within MES/ERP systems.
Manage material handling and resin preparation: weigh and batch colorants, compound additives, follow resin drying procedures (desiccant dryers) and control moisture-sensitive materials per material data sheets.
Operate and program secondary and auxiliary equipment: part pick-and-place robots, robotic end-of-arm tooling, conveyors, granulators, blowers and assembly fixtures to ensure integrated automated cell performance.
Implement quality control procedures such as PPAP, ISIR, control plans and FMEA inputs for assigned parts; support internal and customer audits with documented evidence of process control.
Initiate and lead root cause analyses for recurring defects using 5 Whys and Fishbone diagrams; propose and implement corrective actions and process improvements to reduce scrap and rework.
Validate and maintain calibration records for measuring devices and gauges; coordinate with metrology/quality to ensure all instruments remain in calibration per ISO requirements.
Enforce and model strict safety practices: conduct lockout/tagout, follow LOTO procedures, maintain PPE compliance, and participate in safety audits and toolbox talks to reduce incident rates.
Train, mentor and cross-train junior operators on machine set-up, inspection techniques, safety protocols and continuous improvement tools to build team capability and redundancy.
Maintain accurate production, downtime and scrap records and contribute to OEE reporting and daily production review meetings to help meet on-time delivery and efficiency targets.
Collaborate with tooling vendors and mold designers to schedule preventative mold maintenance, coordinate on-site repairs and provide detailed defect reports to support design for manufacturability (DFM) revisions.
Support change control and engineering change notices (ECN) by performing trial runs, documenting process parameter changes and validating new or revised toolings and molds before release to full production.
Monitor and control material usage, track lot numbers and FIFO rotation, and assist inventory control in ordering raw materials and spare tooling components to prevent stockouts.
Implement lean manufacturing and continuous improvement initiatives—Kaizen events, value-stream mapping, standard work updates—to reduce cycle times, lower cost per part and improve throughput.
Program basic PLC or HMI sequences and troubleshoot interface issues for presses and cell automation, working with controls engineers to implement robust operator screens and interlocks.
Participate in cross-functional problem solving with quality, engineering, purchasing and production planning to meet customer requirements and resolve supply chain or quality disruptions.
Ensure compliance with environmental, regulatory and customer-specific requirements (RoHS, REACH, food-grade, medical) when handling resins and additives; maintain appropriate documentation.

Secondary Functions

Support manufacturing process documentation updates and continuous improvement projects (5S, Kaizen) targeted at lowering cycle variability and improving cleanliness and safety of molding cells.
Assist in production scheduling and communicate changeovers and priority shifts to the production planning team to maintain customer delivery windows.
Participate in apprenticeship programs and internal training initiatives, helping develop structured on-the-job training (OJT) plans and competency checklists for new hires.
Collect and transmit process data to engineering and operations analysts for capacity planning, throughput optimization and correlation with SPC trends.
Contribute to tooling lifecycle management by logging tool hours, wear patterns, and recommendations for refurbishment or replacement.
Support ad-hoc quality investigations, including sample collection, photographic documentation and submission of parts to lab testing as requested by Quality or R&D teams.
Assist the maintenance department during planned shutdowns and assist with larger mold overhauls and preventive maintenance events as required.
Collaborate with health, safety and environment (HSE) representatives to maintain material safety data sheets (MSDS) and ensure proper storage and disposal of chemical agents and off-spec material.
Help sustainboard activities — summarize daily metrics, highlight immediate concerns and recommend corrective actions to leadership during shift handover.
Participate in new product launch activities: mold trials, process capability studies, pilot runs and ramp-to-rate to ensure smooth transfer from R&D to production.

Required Skills & Competencies

Hard Skills (Technical)

Proven hands-on experience setting up and operating hydraulic, pneumatic and servo-driven injection molding machines (piston, toggle, and hybrid presses).
Mold changeover and mold maintenance: mechanical mold installation, purge procedures, mold lubrication, and mold cooling troubleshooting.
Process parameter optimization: shot size, melt temperature, injection speed, packing/hold control, cooling profiles and screw/hold profiling.
Material knowledge: behavior of thermoplastics and thermosets, resin drying and handling (hygroscopic resins), color compounding and regrind management.
Dimensional metrology: use of calipers, micrometers, height gauges, pin gauges, optical comparators and basic CMM awareness.
Statistical Process Control (SPC), basic data collection, capability studies (Cp, Cpk) and control chart interpretation.
Quality systems and documentation: PPAP, ISIR, control plans, NCRs, CAPA and compliance with ISO 9001 and customer-specific standards.
Automation and robotics: integrating and adjusting pick-and-place robots, robot hand-offs, vision systems and end-of-arm tooling.
Basic PLC/HMI troubleshooting and understanding of machine control logic and interlocks.
MES/ERP system experience for logging production data, work orders, and maintaining traceability; familiarity with Excel for data trending.
Preventive maintenance tasks and basic mechanical/electrical troubleshooting to reduce MTTR and support uptime initiatives.
DFM/Lean manufacturing tools: 5S, Kaizen, root cause analysis, FMEA and experience participating in continuous improvement projects.

Soft Skills

Strong attention to detail and commitment to producing defect-free parts under high-volume production conditions.
Excellent troubleshooting and analytical thinking: root cause identification and methodical implementation of corrective actions.
Clear verbal and written communication skills to collaborate with engineering, quality and maintenance teams and to document process changes.
Team player who mentors others, shares best practices, and fosters a culture of continuous improvement.
Time management and ability to prioritize tasks during shift changeovers and production incidents.
Safety-focused mindset with consistent application of LOTO, PPE and machine guarding best practices.
Adaptability to frequent changeovers, customer priorities and evolving production requirements.
Customer-oriented mindset with a focus on meeting delivery schedules and technical specifications.
Initiative and ownership: able to lead troubleshooting efforts and see corrective actions through to completion.
Ability to train and document procedures, create effective SOPs and support structured on-the-job training programs.

Education & Experience

Educational Background

Minimum Education:

High School Diploma or GED with hands-on machine operation experience or vocational training.

Preferred Education:

Technical diploma or associate degree in Plastics Technology, Manufacturing Technology, Mechanical Engineering Technology, or equivalent trade certification.
Certifications in injection molding (e.g., SPI Mold Making/Molding Certification), CNC/PLC fundamentals, or Six Sigma/Lean are a plus.

Relevant Fields of Study:

Plastics Technology / Polymer Science
Manufacturing Engineering / Production Technology
Mechanical Engineering Technology
Industrial Maintenance / Automation

Experience Requirements

Typical Experience Range:

1–5 years of direct injection molding experience for entry to experienced operator roles; 3+ years preferred for lead/operator-in-charge roles.

Preferred:

3–7 years of injection molding experience across a range of press sizes and product types, including experience with automated robotics, SQL/ERP/MES data entry, and documented contributions to quality or continuous improvement projects.