Composites, more than a matter of choice - White papers

In order to give you the opportunity to make sound and well-informed choices for composite materials through their life-cycle, the SLC-Laboratory and the experts in sustainability at Sirris are going to publish a series of white papers in which all the issues surrounding composites will be discussed in detail.
You will be able to regularly download the latest white paper on composites here.

WP9: Non-destructive testing

Fibre reinforced plastics (or composites) are gaining popularity in a wide range of industries due to their excellent properties, such as specific stiffness and strength and good resistance to environmental conditions. However, their complex structure brings also some challenges, detecting damage being one of them. This ninth white paper focusses non-destructive testing.

While destructive testing and inspecting a finished product gives insight in the production quality and certainly plays an important role in quality assessment and control, in most cases, it renders the subject useless. Instead, non-destructive testing (NDT) approaches should be adopted. A broad overview of various NDT approaches is provided in this ninth white paper:

  • Visual testing
  • Penetrant testing (PT)
  • Tap testing – experimental modal analysis
  • Eddy current testing (ET)
  • X-ray 2D radiography
  • X-ray (micro-)computer tomography (CT)
  • Digital image correlation
  • Active infrared thermography
  • Shearography
  • Scanning laser doppler vibrometry
  • Ultrasonics

You can read our ninth white paper here :



WP8: Liquid moulding processes in composites manufacturing

With its eighth white paper the SLC-Lab wants to pass on some essential information on liquid moulding processes for thermoset composites.

Many thermoset composite parts are produced by a type of liquid moulding (LM) process. In general terms, liquid moulding involves placing a fibrous reinforcement into the cavity of a mould, after which it is impregnated with resin under the influence of a pressure difference between the mould cavity and the resin supply. The resin is then left to harden (cure) before the part can be removed from the mould.

Proper impregnation and cure are paramount to the performance of the resulting part. To achieve this, the manufacturer must understand the properties of the liquid moulding process. The whitepaper provides insight in the process and describes the most important parameters to achieve a good product and to select the right liquid moulding process from the broad range of processes currently available.

  • It gives an overview of the most-used LM processes for thermoset composites
  • it discusses the main parameters that are of importance in this type of process.

You can read our eighth white paper here :



WP7: Tooling methods and materials for composite tooling

The use of lightweight components stands or falls on the choice of materials. Product value, product costs, production costs, development costs and risks are, however, difficult to estimate when dealing with lesser known materials such as composites. The seventh white paper focusses on tooling for composites.

Each tool design, whether for thermoset or thermoplastic composites, is a new story that can result in a major win or a major loss situation. Fluctuations in cycle time, increased material consumption, thickness variations, high levels of parts repair or even parts rejection, tool wear resulting in reduced tool life, etc., can all result from the tool design.   

In this white paper we will discuss:

  • types of tooling methods (direct and indirect)
  • materials for master models and moulds
You can read our seventh white paper here :



WP6: Cost estimation of composite production during early design phase

The use of lightweight components stands or falls by the economic use of material with a high performance. The product value, product costs, production costs, development costs and risks are, however, difficult to estimate when less well-known materials, such as composites, are applied. Having a clear picture of production costs is important. Our sixth white paper focuses on the early design phase, as the greater part of the product cost is committed during this stage.

In this white paper we offer you: 

  • a classification of cost estimation techniques;
  • cost modelling on three different levels;
  • a case study, in which cost models with low and high fidelity are applied.

You can read our sixth white paper here:


WP5: Composite laminate design, not complicated with the right tools

In the white paper ‘Do Composites and their anisotropic behaviour only lead to advantages?’, we have shown the importance of the stacking sequence of several fibre reinforced layers, not only in terms of stiffness, but also in terms of unexpected behaviour. In view of the importance of the lay-up sequence, this fifth white paper shows how a lay-up can be defined from given load cases by calculating stiffness matrices.

The white paper will dig deeper into the following topics: 

  • Stacking sequences and the ‘Classical Laminate Theory’, a fast and easy method to be used for relatively simple geometries
  • ‘Laminate theory’ calculator tools that do the job and explanation of the difference with finite-element software
  • Case study: the wheel-chair ramp ‘Rollo’

Read our fifth whitepaper now:


WP4: Do composites and their anisotropic behaviour only lead to advantages?

In terms of properties materials are quite often ranked on the basis of their anisotropic behaviour. What does this mean for the materials and how can knowledge of this behaviour be used to design better products? In our fourth white paper we mainly discuss mechanical anisotropy in composite materials.

The white paper offers a better understanding of mechanical anisotropy (i.e. physical material properties which have different values when measured in different directions) in regard to composite materials and its (unexpected) effects.

  • What are isotropic, anisotropic and orthotropic materials?
  • What are the unexpected effects related to the behaviour of orthotropic composites?
  • How to apply these unexpected effects?

You can find the answers in our fourth white paper.:


WP3: Composites and material selection process, a systematic approach

While the first two white papers discussed composites and the environment, the third white paper introduces a whole new topic: a systematic approach to the material selection process with the Ashby methodology and the CES Selector tool.

To avoid subjectivity in the materials selection process, objective and systematic methods for materials selection should be used. One such method, primarily oriented to mechanical designs, was developed by Prof. Michael Ashby of the University of Cambridge.

This white paper will dig deeper into:

  • the Ashby method,  which separates the materials selection process into four steps.
  • the CES Selector tool, a software developed by Granta in cooperation with prof. Ashby to significantly facilitate the material selection process.

Read the third white paper here:


WP2: Recycling composite

Despite increasing advances in sectors such as aerospace and the automotive industries, another sustainability aspect is putting the material to the test: two materials joined together form an inherently strong and tough entity that is difficult to separate again. This results in substantial consequences for the material complexity of waste flows on product disposal. Because of this complexity a closed recycling loop can only be achieved by deploying energy-intensive separation processes. The second white paper goes further into the issue of 'recycling composites'.

The following processing routes for recycling composites are normally suggested: mechanical milling, thermal processing (e.g. pyrolysis and processing in the cement industry) and solvolysis (the chemical route). Although these technologies can be applied to both carbon and glass composites, a shift has taken place in practice. Glass fibre composites are mostly processed using mechanical milling and end up in the cement industry, while carbon fibre composites are processed using either pyrolysis or solvolysis.

The white paper discusses recycling both types of materials individually:

  • Recycling composites: hopeful developments for the Belgian circular economy (introduction)
  • Recycling carbon fibre composites: high quality recyclate in answer to ambitious legislation
  • Recycling glass fibre composites: what is the cheapest way of disposing of this enormous waste mountain?

Read the second white paper here:


WP1: Composites as a sustainable solution

The first white paper looks at composites within the scope of the emerging circular economy that endeavours to fit material cycles into the various biological and technological cycles, thereby keeping the value of the raw materials as high as possible and being able to use them for as long as possible. There are a number of possible strategies for deploying composite materials in the circular economy.

Choosing the most suitable strategy depends greatly on the type of product, the technological maturity and market acceptance.

Possible approaches include:

  • extending the life-cycle, 
  • aiming for product reuse, 
  • reworking products into new products, 
  • high quality recycling. 

Enormous potential, although difficult to open up.

Read the white paper here

Two steering projects

This white paper was written within the scope of two projects: 'CompositeBoost' and 'Eco-compliance as a competitive weapon'.

'Eco-compliance as a competitive weapon', a collaborative project with Sirris and Agoria, gives active support to companies including manufacturing companies, where the impact falls on production or production design in order to take advantage of innovation opportunities presented by eco-compliance:

  • cost savings, 
  • improved market access, 
  • extended production life-cycles, 
  • lower total costs of ownership 
  • and the design of new ecological products.

This acts as leverage for sustainable innovation through a proactive approach towards changing environmental legislation and standards, and market demands. This is how the barriers to innovation are lowered and the technology choices for participating companies become clearer.

'CompositeBoost' is a collaborative project involving Sirris, UGent and KU Leuven. Based on these six highly relevant issues, the project partners want to use these essential tools and methodologies to allow designers and OEMs to make the right choices. The masterclasses, demonstrations and exploratory case studies will help transform the composites processor into a reliable production company and partner. This will mean that our companies will retain their competitiveness over foreign competitors.

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