Defects in Plastics Processing – I Am Looking for Real Cases from Production
I am currently working on the second, expanded edition of my book “Plastic Extrusion. Pipes • Profiles • Sheets • Films”, which will also be published in English and German as part of “The Great Book of Plastics” series.
In the new edition, I would like to develop the topic of defects in plastic products in much greater depth. Not only from a theoretical point of view, but above all from a practical one: what really happens in production, quality control, complaints, line start-ups and the analysis of products after use.
Why I Am Looking for Real Cases
In plastics processing, the most important question is often not only:
What does the defect look like?
but above all: What caused it?
The same visible defect may have several different causes.
Streaks may result from the material, contamination in the processing system, unstable temperature, poor mixing, degradation, moisture or a problem with the die or tooling.
Cracking may be related to the formulation, excessive internal stresses, cooling, material ageing, a design error or the conditions in which the product is later used.
Deformation may result from the process itself, but also from incorrect haul-off, calibration, cooling, storage or later use of the product.
This is why I am interested in real photos of defects that have occurred in industrial practice.
What You Will Receive in Return
Every person who sends me an interesting defect case will receive a short technical comment from me.
I will try to indicate what may be the most likely cause of the defect, which factors should be checked first, and in which direction the further analysis should go.
Where possible, based on the information provided, I will also suggest how the risk of the same or a similar defect occurring again in the future could be reduced.
This will not be a formal expert opinion or a laboratory report. It will be a practical technological interpretation of the case — one that may help to narrow down the possible cause of the problem more quickly and better understand the mechanism behind the defect.
What Types of Defects I Am Looking For
I am particularly interested in cases involving:
- plastic pipes,
- profiles,
- sheets,
- films,
- other technical products manufactured by extrusion.
These may include, for example:
- surface defects,
- streaks,
- discolouration,
- loss of gloss,
- chalking,
- microcracks,
- cracking,
- embrittlement,
- deformation,
- delamination,
- gels,
- inclusions,
- black specks,
- dimensional problems,
- waviness,
- uneven thickness,
- marks caused by process instability,
- problems after UV degradation,
- cases where the cause of the problem was difficult to identify.
I am interested in both typical production defects and more unusual cases that required deeper technological or material analysis.
What You Can Send
If you have encountered such a defect and can send me a photo in a private message, I will be happy to analyse it.
In return, I will try to indicate the possible cause of the problem and the direction for further analysis.
It is not always possible to make a clear diagnosis based on a photo alone. However, in many cases it is possible to narrow down the area of investigation quite quickly. The cause may be related to the material, additives, moisture, temperature, screw, barrel, die, calibrator, cooling, haul-off, internal stresses, storage or later conditions of use.
What Information Will Be Helpful
The most useful submissions are photos with a short description. A few pieces of information are usually enough:
- what material was used,
- what product it was,
- whether it was a pipe, profile, sheet, film or another component,
- at what stage the defect appeared,
- whether the problem was a one-off case or recurring,
- whether the defect concerned the surface, dimensions, colour, structure, cracking or mechanical properties.
I do not need confidential data. There is no need to provide the name of the company, customer, supplier, formulation or production parameters. My aim is to understand the type of defect and the mechanism that may be behind it.
Confidentiality and Use of Materials
The most interesting cases may be described in the book as examples of technological, material or application-related problems.
However, I want to make this very clear: I will not publish the photos you send me in the book.
I will also not disclose company names, production sites, customers, suppliers or any production data.
The photos will be used only as inspiration for developing the topic. If a case is used, it will be described in a neutral way. The original photo will be replaced with another illustration, a diagram, a general graphic or a technical description, so that the source cannot be identified.
If, however, a company would like its name to appear in the book next to a specific example or case study, I am also open to discussion. This would only be possible if it is technically justified and valuable for readers. In such cases, the scope of the description, the way the company is presented and the use of materials would be agreed individually.
Why This Matters
I want the second edition of the book to be even more practical.
Plastic extrusion is not only about temperature settings, screw speed, die geometry, calibration and cooling. It is also about the ability to observe the product, understand symptoms and connect them with possible causes.
In industrial practice, a defect is rarely “just a defect”. Very often, it is information that something is happening with the material, the process, the tooling, the machine or the conditions of use.
If we can read this information correctly, we can identify the source of the problem more quickly, reduce scrap, lower the number of complaints and improve production stability.
Areas of Particular Interest
For films, I am particularly interested in problems such as thickness variation, gels, bubble breaks, uneven cooling, blocking, wrinkling, streaks and bubble stability.
For pipes, profiles and sheets, the most relevant areas include deformation, cracking, waviness, dimensional problems, surface defects, delamination, cooling issues and changes after use.
I am also interested in cases related to UV degradation, material ageing, loss of gloss, chalking, embrittlement and changes in the functional properties of products used outdoors.
Invitation to Contact Me
In the book, I want to show a practical approach: from the visible symptom on the product to the possible technical cause. From a defect photo to process analysis. From a production problem to knowledge that helps technologists, operators, production managers, quality control teams and everyone responsible for plastics processing.
If you have an interesting photo of a defect in a pipe, profile, sheet, film or another plastic product, please feel free to send it to me in a private message.
In return, I will try to help interpret the case, and the most interesting topics may become inspiration for practical examples in the second edition of my book.