A porcelain tile body must survive several handling stages before it reaches the kiln. When pieces chip or break along that route, bentonite may be considered to improve cohesion. The useful question is whether the improvement occurs at the stage where the production line needs it, while keeping body preparation and forming manageable.
Evaluating bentonite for porcelain tile bodies therefore means following the material from slurry preparation through granulation, pressing, drying and firing. A stronger laboratory specimen is a promising result, but the production decision needs a wider set of observations.
Before changing the formulation, identify where damage appears. Does the piece lose an edge during demoulding? Does it crack on transfer to the dryer? Does breakage become visible only after drying or during subsequent handling?
Record the location, frequency and appearance of the damage alongside the current body composition and operating conditions. This creates a practical target for the trial: improved performance during a defined operation, supported by strength measurements at the relevant stage.
Keep equipment and handling observations in the record as well. A formulation trial is easier to interpret when changes in transfer settings, tooling or drying conditions are documented rather than introduced unnoticed.
The term green strength can refer broadly to unfired material. For purchasing and formulation work, identify the sample condition more precisely.
Record specimen dimensions, forming pressure, moisture, test method and measurement timing. Distinguish breaking load from calculated flexural strength, and use comparable specimen geometry and loading arrangements.
Research on spray-dried ceramic powders has examined how water content and forming pressure relate to compaction and mechanical behaviour. These variables belong in the comparison record, so a change in strength can be interpreted alongside the conditions used to produce the specimen. [2]
Published work on porcelain stoneware bodies investigated bentonite-containing formulations through rheological, mechanical and fired-property testing. Some formulations achieved higher dried strength than the reference body, while increased viscosity and thixotropy created a processing trade-off. The findings support testing the complete formulation rather than choosing an addition rate from the strength result alone. [1]
| Production stage | What to record | Decision to make |
|---|---|---|
| Slurry preparation | Solids content, viscosity, flow after standing, dispersant addition and measurement temperature. | Can the candidate formulation be prepared and transferred within the plant’s operating limits? |
| Granulation | Preparation route, granule moisture, size distribution and powder feeding behaviour. | Does the resulting powder remain suitable for consistent press feeding? |
| Pressing and initial handling | Forming settings, compacted density, as-pressed strength and visible handling damage. | Is the improvement repeatable under comparable forming conditions? |
| Drying | Drying procedure, residual moisture, dried strength, shrinkage and cracking. | Does the body meet handling requirements after the intended drying cycle? |
| Firing | Fired shrinkage, water absorption, dimensions, colour and visible defects. | Does the processing improvement remain compatible with finished-tile requirements? |
Where spray drying is used, include representative granulation in the evaluation. SACMI describes powder preparation as the conversion of ceramic slip into spray-dried powder for subsequent pressing. Laboratory specimens prepared by another route provide useful screening data, but a pilot should also assess powder produced through the intended process. [3]
Start with the existing production body as the control and prepare a limited series of candidate formulations. Express the additions on a clearly stated dry-material basis, correcting weighed quantities for moisture where necessary. Document whether bentonite replaces another ingredient or is added to the existing recipe.
For the first comparison, keep the agreed preparation and forming conditions consistent. If a candidate needs extra water, a different dispersant level or a revised preparation procedure, record that requirement as part of the result.
A subsequent optimisation trial can investigate those adjustments. Keeping the two stages distinguishable shows what changed when bentonite was introduced and what additional work was needed to make the formulation practical.
Use replicate specimens and review the spread of results alongside the average. For production approval, a repeatable improvement is more useful than the highest result from one specimen.
Agree on the decision criteria before selecting the preferred candidate. These may include the required strength at the problem stage, acceptable slurry behaviour, manageable additive demand and compliance with the plant’s dried and fired quality requirements.
During the plant trial, track actual handling damage and process adjustments alongside laboratory measurements. Compare the cost of the revised formulation and any preparation changes with the observed production benefit. Keep the approved recipe, material batch and trial records together for subsequent supply checks.
An inquiry for “high-strength bentonite” leaves several questions open. Specify the porcelain tile body type, preparation route, stage of breakage, current strength-test procedure and any limits on slurry behaviour or fired appearance.
Request representative samples with moisture, particle-size information and relevant mineral data. Connect the powder specification to results obtained in your formulation under agreed preparation conditions.
HERMANO supplies ceramic-grade bentonite for formulation evaluation. Share your tile-body process and the handling stage you want to improve to discuss candidate materials and sample assessment.
