Apparently invisible. Chemistry in ceramics.

In the wet preparation of ceramic bodies, dispersants play an essential role in controlling slurry rheology, allowing high solids content to be maintained while ensuring flow properties compatible with the production process.

In this episode, we examine the main factors affecting slurry rheology: viscosity and thixotropy, raw material characteristics, composition of the aqueous phase, and the different chemical families and mechanisms of action of deflocculants. We also explore the role of dosage and the deflocculation curve, explaining why there is no universal solution and why the optimal working range must be determined experimentally for each specific ceramic body...

The growing use of large ceramic slabs, with increasingly larger formats and reduced thicknesses, has introduced new challenges in terms of processing, handling, installation and safety. In this context, back-meshing is a post-firing process in which a reinforcing mesh is bonded to the back of the slab, helping to retain fragments in the event of breakage while providing additional support during subsequent processing, handling and use.

In this episode, we explore the back-meshing process, from mesh selection and the role of the two-component polyurethane adhesive system offered by Z&S Ceramco to different application technologies and the cross-linking...

Producing digital inks, glues and ink effects for ceramic decoration is a highly sophisticated process that relies on the careful integration of multiple formulation components. Achieving consistent performance, long-term stability and reliable production quality requires the use of a range of specialized additives, each playing a critical role in ensuring proper product functionality and processability.
In this episode, we revisit the concept behind the DECOFLUX DP range: a modular additive platform developed to support ink manufacturers and ceramic companies that produce their own digital inks and glues in-house. From pigment grinding to final dilution, we explore how each element...

Ceramic grit binders are often regarded as simple fixing agents, but their role within the production process is far more complex. 

In this episode, we explore how the management of rheology, particle suspension and application behavior directly influences the quality of the final result, and why the selection of a binder cannot be based solely on its adhesive strength.

We trace the technological evolution of the GRANICER range, examining the characteristics and application logic behind its different product families. From solutions designed for dry applications to formulations developed for wet grit application, and up to the m...

This episode addresses the control of bacterial contamination in ceramic processes, a factor that is often invisible yet crucial for the stability of compounds and the quality of the final product. In a production context characterized by the unavoidable presence of organic substances, bacteria can rapidly proliferate, altering rheological properties and causing application defects.
The episode analyzes the main intervention strategies, distinguishing between sanitizers, biocides, and preservatives, and presents the role of the PREVENTOL range in controlling contamination throughout the entire process.

Chemical product labelling plays a key role in ensuring safety and regulatory compliance across the entire industrial value chain. In this episode, we explore the European regulatory framework, focusing on how CLP, REACH and BPR interact, and how together they balance health protection, environmental safety and market access.

We take a closer look at different product categories, highlighting their distinctions, areas of application and regulatory implications. We also examine the main technical communication tools — from labels and safety data sheets to the UFI — explaining their practical function and their importance in emergency response.

A structured overview desi...

This episode explores the technological development of temporary binders for the ceramic industry, starting from the TENACER range developed by Zschimmer & Schwarz. In today’s ceramic manufacturing environment—marked by large-format tiles, ultra-thin slabs, super white bodies with high glass content, and increasing variability in raw materials—maintaining the mechanical strength of the green body has become a key factor for ensuring both process stability and final product quality.
The podcast introduces the main product lines within the TENACER range, outlining their different technological approaches and formulation strategies, while also highlighting the industrial considerations that guide their application in produc...

Zschimmer & Schwarz did not enter the water-based digital adhesives arena overnight; its position today is built on more than a decade of dedicated research, hands-on industrial testing, and continuous product refinement.

In this podcast episode, we take a closer look at the AQUABOND range of water-based digital adhesives, exploring how the line has evolved, the technical principles behind it, and the development strategy that shaped it.

Alongside essential background insights into the technological and market landscape, we provide a structured comparison of the different products within the range—highlighting their distinctions, intended functions, and performance profiles, an...

The pivotal role of rheological additives in ceramic processes: how deflocculants and binders shape the stability, viscosity, and workability of ceramic suspensions.

The discussion explores particle interactions, colloidal stability, the electric double layer, and the main electrostatic and steric stabilization mechanisms.

The goal is to highlight how the right use of additives can optimize production processes and enhance the quality of the final ceramic product.

This episode provides a quick overview of the “black core” effect—an internal discoloration in porcelain tiles, typically caused by incomplete oxidation of the ceramic body due to trapped organic residues.

It highlights the production conditions that make the defect more likely to appear and then outlines practical corrective strategies to prevent it.

All in just ten minutes.

In ceramic manufacturing, aqueous suspensions play a crucial role in shaping processes and determining the final quality of products.

However, foam formation can disrupt production, leading to defects and lower efficiency.

This episode dives into the world of foaming phenomena, exploring how they arise and how they affect the properties of suspensions. 

We discuss surfactants, which can encourage foam formation, and defoamers, which help keep it under control.

What key insights are needed to effectively manage these challenges?

A closer look at one of the most common flaws that can affect both the performance and the appearance of ceramic glaze.

In this episode, we break down the key causes, explain how they arise, and share practical ways to prevent them.

For a deeper dive into the topic, check out episode #39.

What is rheology and what is it used for?

This episode answers exactly these questions. Without delving into complex details, it presents a few key concepts to help navigate topics such as viscosity, material behavior, and process control.

It’s a first step toward understanding the practical role of rheology in improving quality and production efficiency. In ten minutes.

Wettability is, in general terms, the property that describes a liquid's ability to adhere to a solid surface.

It can also be understood as the process through which effective contact is established between a liquid and a solid.

In some cases, solid surfaces exhibit low wettability—a characteristic that, while not inherently problematic, can lead to significant issues in the ceramic industry.

When raw ceramic bodies or suspended particles display poor wettability, production inefficiencies may arise, ultimately affecting the quality of the final product.

Wetting additives play a crucial role in creating th...

The electrical conductivity of water is a key parameter in industrial production processes, as it reflects the amount of dissolved ions that can directly impact the stability and efficiency of operations.

When conductivity levels go unchecked, they can compromise the quality of the final product, cause corrosion in equipment, or alter the reactivity of the materials used.

In this episode, we explore why continuous monitoring is essential and what strategies companies adopt to keep conductivity within optimal limits.

We discuss not only direct treatments like reverse osmosis and deionization, but also indirect approaches: the...

In this episode, we dive into the essential role of chemical additives used during the grinding phase of ceramic glazes—a crucial step that sets the stage for successful application on the glazing line. 

We focus on dispersants and binders, compounds that give the glaze the right balance of cohesion, stability, and flow. But there’s no one-size-fits-all solution here: the type of additive must be tailored to the specific application method, whether it's airless spraying, bell, or curtain coating.

A technical yet accessible look at how chemistry drives performance—right from the start.

Digital printing has transformed the ceramic industry, opening the door to highly sophisticated, versatile, and customizable designs.

At the core of this shift are ceramic digital printers—advanced machines that use inkjet technology to precisely apply both functional and decorative materials.

While the focus is often on inks and printing performance, there’s another category of fluids working quietly behind the scenes: maintenance fluids.

Though they don't directly impact the final aesthetic result, they play a vital role in keeping printers running smoothly and extending their lifespan.

In this episode, we explore thre...

In the world of ceramics, temporary binders play a crucial role in improving the cohesion and workability of slips.

These substances, often polymer-based, act on a chemical level by creating bonds between particles, increasing the mechanical strength of the mixture.

In this episode, we explore what they are, how they work, and why they are essential in modern ceramic processes.

This episode takes inspiration from the thesis work of the Head of Research at Zschimmer & Schwarz Ceramco. The goal is not to focus on the specific topic explored in that study (in this case, the well-known issue of the "black core"), but rather to highlight the research methodology and the meticulous, in-depth work that takes place every day in the laboratories of chemical companies serving the ceramic manufacturing industry.

Although it begins in an academic context, the process described closely mirrors the structured, methodical approach followed by laboratory professionals in real-world industrial settings.

In the ceramic field, a “top glaze” refers to the glaze applied as the final layer onto the unfired ceramic substrate. 

This glaze can serve multiple functions, but it primarily protects the underlying decoration and imparts specific technical and aesthetic properties to the surface.

This episode focuses on this particular class of glazes, taking a closer look at the key functions and rheological characteristics (among others) that the suspension must exhibit, depending on the chosen application method and the type of ceramic product being manufactured.

After more than fifty episodes exploring topics of general interest—always through the lens of chemistry and ceramic production—we’ve decided to have some fun.

We posed a few simple questions to artificial intelligence, asking it to write a short text about chemistry with complete freedom to choose the themes and highlights.

The result? Amusing, sometimes absurd—mostly accurate, but not always.

As we know, Large Language Models (the technology behind AI’s ability to understand and generate text) can produce content that sounds convincing and is often correct, yet it’s not immune to er...

Melting materials used in ceramics, often in glazes and digital glues, are capable of lowering the melting point of a material or compound, thus accelerating the sintering process.

This action, which occurs through the breaking of the molecular structure of the compound (in our case, silica) by certain ions, affects several factors and must be carefully calibrated each time to achieve the desired result.

Some of the areas influenced by this process include the grit application, the glossy or matte finish of the surface, interaction with colors, and energy savings.

How do these materials...

Industrial productivity is a top priority for any manufacturing enterprise, regardless of its field of operation.

The ceramic industry, too, must adhere to rules and parameters that enhance productivity while avoiding any form of waste.

However, process interruptions—representing the most extreme scenarios—can be triggered by numerous factors and can occur at various stages along the production line.

Even the digital printing process, including all the micro-processes that occur immediately before and after the printer, can be prone to issues that, in the most severe cases, lead to machine downtime.

This disc...

Water is one of the most widely used natural resources in numerous applications and across various sectors of industrial production.

For example, process water forms the basis of different production phases and ensures their proper development.

However, not all waters are the same.

Depending on its source, water can have very different properties, which may make it suitable or unsuitable for a specific process.

In general, water quality is often a necessary precondition.

For this reason, there are various processes capable of purifying water efficiently and, most importantly, safely.
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Suspending agents belong to a broad category of additives whose primary purpose is to provide ceramic suspensions (slips, glazes, engobes, or frits) with good internal stability, counteracting potential sedimentation phenomena.

Available in both liquid and solid forms, these products act within the suspension to ensure the right balance.

There are various mechanisms that can be employed to properly maintain the solid phase of the mixture in suspension.

Among these, the most significant are about viscosity, electrostatic repulsion, and concentration (solid/liquid ratio).

This episode, after reviewing the properties of suspending agents, focuses...

Complexing agents are capable of catching multivalent cations present in suspension to prevent them from negatively affecting the ceramic process. 

They are responsible for one of the main mechanisms underlying the deflocculation process: complexation.

Complexing agents (or chelating agents) are chemicals that bind to specific ions (such as calcium, magnesium, iron, etc.), forming stable complexes.

This property allows them to "sequester" metals, making them less reactive or preventing their precipitation in solutions.

These are simplified and very short descriptions of this particular category of additives. 

The episode takes a closer lo...

The topic of non-planar surfaces, which develop on multiple micro-levels and are sometimes improperly identified as 3D surfaces, plays a crucial role in giving ceramic surfaces not only a more natural appearance but also a broader and more extensive expressive potential.

This is not a new requirement: it took its first steps with the help of traditional technologies, but it has found new momentum with the arrival of the latest digital techniques.

The episode offers an overview of the main methodologies currently used to achieve textured surfaces, delving into the chemical mechanisms that occur on the...

In the previous episode (#45) we discussed the technical aspects of digital printing systems in relation to ceramic bricks.

This second part looks at the necessary preparatory work for the printing phase, going through the various steps involved in preparing a print file.

Regardless of the media on which you will work.

Some key words: standardized lighting, colorimeter, spectrophotometer, linearization, chart...

At present, in the heavy clay industry, products are decorated mainly by applying engobe with the aid of scattered granules or by means of reduction effects created by the firing process.

These techniques are suitable to produce traditional products for the existing market. 

What added value does digital printing offer in this field?

The operating temperature is an important parameter that ceramic producers must take into account in order to avoid application problems that can also negatively affect the quality of the finished product.

However, this parameter is not always easy to manage, especially if we consider the fluctuations promoted by seasonability.

The episode addresses the topic with the help of specific examples, highlighting the main scenarios and the different levers on which one can act to better manage the anomalies that may occur along the production lines.

Most ceramic production processes involve the dispersion of ceramic powders in a liquid medium - mostly water - to obtain a suspension or, more generally, a dispersed system.

To provde the suspensions with the desired stability and workability, depending on the different applications, we use the addition of small quantities of suitable chemicals that, interacting with the solid particles, change the rheological behaviour of the whole system.

The episode offers a picture of two categories of chemical - deflocculants and binders - almost always involved in order to achieve the right result and therefore the correct...

All analysis of ceramic suspensions carried out by those companies that supply chemicals for ceramic production are fundamental to properly develop the processes that take place along the production line.

The episode provides an overview about the role of these important investigations, with a focus on the data and on the operations of the involved tools.

We will talk about jars, pycnometers, laser granulometers, sieves, rheometers, pointing out how all these tools are important in providing ceramic producers with the correct information to proceed without problems or unexpected critical issues.

After addresing the impact that seasonality can have on the the fluidization of ceramic mixtures and on bacterial proliferation within semi-finished products, this second part of the episode 41 tries to show and explain the consequences that temperature changes may produce on the drying time of ceramic suspension, leading to alterations that often force producers to revise the parameters of the glazing line.

After offering the usual suggestions to handle the problem, the episode ends with a focus on the solubility of surfactants that can be also susceptible to seasonal and temperature changes.

In ceramics, the use of chemicals plays a fundamental role in providing the final product with high technical and aesthetic results and in promoting a proper application process.

However, their actions can be sometimes less effective or compromised. 

There are several reasons for this performance change and seasonality is surely one of the most interesting.

Through a series of examples, the episode addresses the actions that should be taken to prevent the temperature to negatively affecting both processes and products.

Glaze and grit suspensions are made up of a liquid part (usually made-up of water and one or more rheological chemicals) and a dispersed solid part.

However, these two different suspensions show a lot of differences that may lead to very contrasting results, also implying a different approach about chemicals, both during the grinding phase and along the glazing line.

From this point of view, all chemicals involved must be marked by specific features according their intened use. What do we need to know about the subject?

Cratering phenomena are defects that appear as microscopic craters on the surface of ceramic bodies on which an aqueous (and still drying) suspension has been discharged.

It is an application problem that leads to a misalignment of the suspension due to the presence of one or more dips.

The problem, that is already visible along the glazing line and not only after the firing process, may arise for several reasons: for example due to the presence of impurity within the ceramic raw materials or because of an improper use of defoamers.

The episode try...

CMC are organic compounds, water-soluble polymers derived from cellulose, widely used in several fields of industrial production. In ceramics, sodium CMCs perform multiple functions within suspensions and solutions and can be marked by very different properties depending on the situation.

What is the main role of this substance in the ceramic production process, and what needs to be done to properly manage it?

The plasticity values of ceramic mixtures is a very important issue, since it affects the values and features of the mix and therefore the proper development of the ceramic production process.

In general, the use of clays marked by high plasticity values is usually synonymous with easier process management.

However, high-performing clays are not always available and it is therefore important to keep in mind other production parameters, finding a balance or even good compromises.

After a short definition of this amazing physical property, the episode offers a general overview on the issue.
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In ceramics, digital technology (use of digital glues and digital inks) has definitely riform the sector, making the production process much more flexible and expanding creative and aesthetic possibilities.
The extraordinary precision with which the ink is discharged on the ceramic support, in fact, has opend to new extraordinary results.

However, the topic "printing definition" must be addressed with great attention, being subjected to several variables that can affect the final product.

What are these variables? What mechanisms are behind them and what can be done to not compromise a good resolution?

Scanning Electron Microscope is a sophisticated tool used in many fields of scientific research, even in ceramics.

The use of an electron beam instead of light allows to get not only outstanding high resolution images but also detailed information on the composition of the sample.

Insights are so accurate and exhaustive that offer manufacturers clear solutions or, at least, suggestions about the actions that should be taken to properly solve production critical issues.

How does the tool work and what are its most important functions to support ceramic industry?