Interview with Prof. Kevin Potter - A134

 

Interview with Prof. Kevin Potter
Perspectives article
Document Type	Article
Document Identifier	134
Themes	Material deposition management Flow and consolidation management
Tags	Process modelling Forming Deposition Resin flow Process-induced deformation Defects

Introduction

Emeritus Professor Kevin Potter has an unusual biography for today’s academic world in that he has extensive experience in both industry and academia. Graduating from Imperial College of Science and Technology with a BSc in Materials Science in 1974, he then went on to work in Industry for a number of years before pursuing a career as an academic so that he could reach a wider audience.

His time in industry was spent gaining practical experience with the UK Ministry of Defence’s Propellants Explosives and Rocket Motor Establishment (PERME), BP Research (including collaboration with Moore Plastics), BP Advanced Materials and BP Norway. He then moved on to consulting and writing textbooks before joining the University of Bristol in 1995; first as a contract researcher, then as a Faculty member, and finally as Chair in Composites Manufacturing. There Professor Potter led research on the forming of prepreg materials (including woven, continuous UD and short fibre aligned materials), resin transfer moulding, manufacturing defects and variability, and recycling of composite materials. He also contributed to the founding of the UK’s National Composites Centre.

In this interview, Professor Potter gives us an overview of his career along with the challenges faced and the lessons learned throughout. His thoughts on four of the main areas where effort should be focused in the near term provide useful insight into what companies and researchers should be focusing on to improve their products, business and the industry as whole. These four main areas are:

• Improving factory productivity
• Costing & new product introduction
• How to grow the composites industry
• Improving structural optimization

His mixture of industrial and academic experience through a large portion of the modern day development of composites makes his perspectives particularly insightful. In addition to the interview below, we refer you to his book chapter 'But How Can We Make Something Useful Out of Black String?' The Development of Carbon Fibre Composites Manufacturing (1965-2015) (see the reference page for a link to a freely available (open access) copy.

Additional information for select chapters

Chapter	Chapter Title	Links to related information in the Knowledge in Practice Centre
1	Kevin Potter's personal history	N/A
2	Lack of flow-control in early carbon fibre prepreg	Composite materials engineering webinar session 4 - Thermal management and resin cure: Chapter 5
3	Making complex geometries through forming	Future content
4	Early focus on recycling carbon fibre	Future content
5	Early process modelling of forming	Future content
6	Kevlar® (Aramid) fibres and degradation	Future content
7	BP Research (Moore Plastics) development projects	N/A
8	Spring-in and carbon-carbon composites	Composite materials engineering webinar session 4 - Thermal management and resin cure: Chapter 6
9	Mechanical fastening of brittle composites	N/A
10	RTM for aerospace applications	Composite materials engineering webinar session 7 - Manufacturing processes - Liquid composite moulding
11	Switching from R&D to production environments	Future content
12	Importance of having defect taxonomies & databases	ICCM17 paper by Kevin Potter
13	Failure investigations & the importance of design	Future content
14	Coupling of geometry complexity, stress & defects	Future content
15	From industry to academia	N/A
16	Utility & limitations of mechanical test results	Future content
17	Tailored stiffness of helicopter main rotor hubs	Future content
18	Morphing & multi-stable structures	Composite materials engineering webinar session 9 - Mechanics of composites - Part 2: Laminate level: Chapter 18 & Q&A (@1:00:36)
19	Improving rate & quality of composites manufacture	Practice for developing a nominal cure cycle and cure cycle specifications
20	Highly aligned, short fibre composites	Future content
21	UK's National Composites Centre (NCC)	N/A
22	Challenges: Improving factory productivity	Future content
23	Challenges: Costing & new product introduction	Future content
24	Challenges: How to grow the composites industry?	Future content
25	Challenges: Improving structural optimization	Future content
26	Technology that has been overhyped	N/A
27	Why does academia not focus on the factory?	N/A
28	What practice advances have been led by academia?	N/A
29	Advice for new people in the composites field	N/A

Related pages

Page type	Links
Introduction to Composites Articles
Foundational Knowledge Articles	Conduction - A118 Convection - A106 Glass transition temperature (Tg) - A210 Heat of reaction - A114 Viscosity (resin) - A203
Foundational Knowledge Method Documents
Foundational Knowledge Worked Examples
Systems Knowledge Articles
Systems Knowledge Method Documents
Systems Knowledge Worked Examples
Systems Catalogue Articles
Systems Catalogue Objects – Material
Systems Catalogue Objects – Shape
Systems Catalogue Objects – Tooling and consumables
Systems Catalogue Objects – Equipment	Rheometer - A357
Practice Documents	Practice for developing a thermal transformation process step - P105
Case Studies	Troubleshooting of room temperature processes for large recreational and industrial parts - C100
Perspectives Articles	Case Study: Optimizing a Press Moulding Process - A324 Composite materials engineering webinar session 11 - Defects - A130 Composites Process Simulation: A Review of the State of the Art for Product Development - A283 Dr. Anoush Poursartip's cdmHUB global composites expert webinar - A136 Fabric Forming: how it affects design and processing, and how simulation can address this - A310 Fibre Architecture: Availability, pros and cons, and selection for my application - A309 Interview with Prof. Kevin Potter - A134 Porosity in Composite Materials - Part I - A336 Porosity in Composite Materials - Part II - A337 Simulation models for rapid liquid composite molding - A333.0

References

About	Help

Pre-impregnated (prepreg) material refers to fibre that is already combined with resin. It is the most common material form used in aerospace.

During prepreg production, (e.g. fibres are run through a resin bath), prepreg is heated and partially cured to B Stage (< 5 % degree of cure). Thermoset prepregs (e.g. epoxy prepreg) have to be kept in a freezer at around -20 °C. At room temperature, the epoxy starts to cure.

For polymer matrix composites (PMCs), resin refers to the matrix; the continuous material phase that binds the reinforcement together, maintains shape, and transfers load. Resins are divided into two main groups: thermosets and thermoplastics.

Engineered materials (designed to have specific properties) made from two or more constituent materials with different physical or chemical properties. The constituents remain separate and distinct on a macroscopic level within the finished structure.

Carbon fibres are composed of large aromatic sheets similar to those in graphite. These graphitic layers form the basic structural units in the shape of ribbons. The structure of carbon fibre ribbon is believed to be a columnar arrangement of disoriented graphite crystallites parallel to the ribbon length. The idealized tetragonal crystallites are stacked above one another, with slight disorientation between the crystals in the direction of fibre axis, trapping sharp needle like voids, where the boundaries between the stacks represent the disordered regions.

The use of multiphysics models to predict the outcome of real-world scenarios. May be analytical (closed form, "hand calculations") or computational (implementation on computers is required due to the large number of calculations involved. e.g. finite element method, finite difference method)

Most often in composite materials engineering, modelling refers to either:

• Process modelling (predicting manufacturing outcomes, or the inverse problem of predicting manufacturing parameters to achieve a desired outcome), or
• Performance modelling (predicting the stiffness/strength/suitability of a structure, or the inverse problem of the material properties and dimensional requirements to achieve a desired stiffness/strength/suitability of a structure)

(same as "Simulation")

Resin transfer moulding (RTM) involves loading a preform into a two (or more) piece, matched tool, closing it, and injecting resin under pressure (~15-100 psi, or ~1-7 bar).

Well suited to small to medium sized parts, limited to large sizes due to injection pressure loads and tool cost.

Any manufacturing and/or decision making activity that occurs during any stage of the development design cycle (e.g. conceptual design to production).

In the context of Knowledge in Practice, practice refers to the systematic use of science based knowledge to reduce composites manufacturing risk, cost, and development time.