Injection Moulding Engineer in London

At Notpla, we’re at the forefront of sustainable innovation, creating natural alternatives to single-use plastic packaging that are carefully engineered to help build a healthier planet. Founded on the belief that Nature is our North Star, we’re an innovative, action‑oriented scale‑up developing and manufacturing uncompromisingly natural packaging solutions from seaweed and plants.

As an Injection Moulding Engineer you will operate across Technology Readiness Levels 3 to 8; you will lead complex, critical projects that ensure robust, repeatable and scalable injection moulding processes across pilot and commercial production. This is an exciting time to join Notpla — we’re on the brink of a record‑breaking year for revenue and on track for major growth in the next 18–24 months. On top of this our Series A+ fundraise, which closed in 2024, is enabling us to scale our growth and environmental impact faster than ever.

Beyond offering meaningful roles and a vibrant working environment, Notpla provides competitive compensation, including EMI Share Options, a zero‑carbon pension scheme, discounts with local businesses, and subsidised social activities. Our office‑first working culture promotes a dynamic and collaborative atmosphere while maximising productivity. We’re a social business with regular clubs and events, and we’re proud of how our diverse, mission‑driven community works together to make plastic disappear.

Led by strong values, all Notpla employees are encouraged to take ownership of their domain, enjoying a high degree of autonomy. Our aim is to build an inspiring culture reflected in our working policies, environment, and people.

As an Injection Moulding Engineer you will spend your time executing factory trials both at internal pilot facilities and external manufacturing sites developing and optimising injection moulding processes for new and existing polymer formulations. You will act as the primary technical interface between the company and external moulding factories, coordinating and overseeing joint development and optimisation trials.

In order to succeed in this role you will need deep expertise in polymer processing and factory‑based manufacturing environments. You will bring strong hands‑on knowledge of injection moulding processes, tooling interactions and material behaviour. Proven track record confidently leading factory trials while working closely with contract manufacturers and equipment operations is essential. You feel comfortable operating at the interface of material science, tooling design and real‑world production constraints.

Key Responsibilities

• Injection Moulding Process Development & Optimisation: Develop, establish, and optimise injection moulding processes for new and existing polymer formulations. Define and document robust processing windows (temperature, pressure, cooling time, screw speed, back pressure, etc.). Conduct structured process optimisation using Design of Experiments (DOE) methodologies and statistical analysis. Apply Process Capability (CP) and Process Capability Index (CPK) analysis to assess process capability and ensure production robustness in line with Six Sigma principles (ISO 13053). Establish scientifically grounded relationships between material properties and moulding performance (flow, shrinkage, warpage, weld lines, surface finish). Define material specifications suitable for industrial moulding environments.
• Factory Trials & Production Scale‑Up: Lead and execute factory trials at internal pilot facilities and external manufacturing sites. Translate R&D‑scale learnings into full industrial moulding environments. Adapt processes across different machine platforms, tooling configurations, and factory setups. Ensure all trial parameters, deviations, and results are clearly documented and translated into Standard Operation Procedures (SOPs). Support handover from development to steady‑state production. Anticipate and mitigate scale‑up risks through structured planning and pre‑trial analysis. Ability to operate within production constraints such as uptime requirements, operator skill variability and machine limitations.
• Technical Troubleshooting & Root Cause Analysis: Diagnose and resolve moulding defects (short shots, sink marks, flash, burn marks, voids, warpage, dimensional instability). Lead structured root cause analysis using methodologies such as FMEA and 8D. Address material‑related processing issues including moisture sensitivity, degradation, thermal stability, and rheological variability. Implement corrective and preventative actions to improve yield and reduce scrap rates.
• Tooling & Equipment Interaction: Work closely with toolmakers to optimise gate design, runner systems, cooling channels, and venting strategies. Provide DFM (Design for Manufacture) input to product and tooling design teams. Evaluate and specify injection moulding equipment suitable for new product requirements. Support tool trials (T0, T1, T2 stages) and drive improvements prior to production release.
• External Manufacturing & Partner Management: Act as the primary technical interface between the company and external moulding factories. Build strong working relationships with factory engineers, production managers, and machine operators. Ensure manufacturing partners adhere to defined process windows and quality standards. Coordinate and oversee joint development and optimisation trials with external partners.

Salary: Total compensation package depending on experience: £38,000 – £57,500 (base salary + EMI Share Options)

Diversity and Inclusion: Notpla Limited takes inclusion and diversity seriously. It is important for us that we live by our values and our policies outline how – We work better together. Notpla is committed to encouraging equality, diversity and inclusion among our workforce, and eliminating unlawful discrimination.