Culminal™ Plus Extends Workability: The Perfect Solution for Large-Format Tiles

As Ashland, we are a passionate and committed solution partner that continuously pushes the boundaries of our capabilities and advances the competitiveness of our customers in the construction industry by delivering practical, innovative and elegant solutions to complex problems arising from the challenges of bonding large-format tiles. To this end, Ashland has developed Culminal Plus, a new modified methylcellulose series for use in cement-based tile adhesives that meet high standards. Cement-based tile adhesives are explicitly defined in EN 12004/ISO 13007 in terms of their performance. All tests are typically conducted under well-controlled laboratory conditions, with temperature, humidity and surface specification defined. Formulations are frequently designed to comply with standards. However, when application occurs in the field, conditions can always vary and may result in lower performance and, in the worst-case scenario, costly customer complaints. Culminal Plus was designed by Ashland research and design experts to improve cement-based dry mortar properties and provide additional safety. The benefits of using Culminal Plus compared to commonly used methylcellulose-based thickeners are as follows:

Better Application of Adhesive Through Improved Open Time

When applying adhesive, tile installers typically cover a wider area with adhesive before tiles are placed. Due to the longer visual open time and resulting expansion of the contact area, Culminal Plus provides better adhesion and higher bond strength values. This is especially important when larger-format tiles are installed. Ideally, the back of each tile should be completely covered with mortar when the tile is bonded to the surface, even long after the adhesive has been applied to the vertical or horizontal surface. The use of Culminal Plus is critical to ensure maximum adhesion.

Optimized Fracture Patterns

Culminal Plus improves the fracture pattern in the three formulations shown in the figure. All tested products show improvement in fracture pattern, and it is clear that products containing Culminal Plus exhibit 100% adhesion when tested under standard conditions.

Higher Strength Values After Longer Embedding Time

It is particularly important to maximize open time when field application conditions (high temperature, low humidity, wind, highly absorbent surfaces) increase the risk of early skinning on the adhesive surface. Culminal Plus enables easier development of formulations classified as "long open-time tile adhesives (for example C2TE)". The higher the strength values even after long embedding time, the greater the likelihood that the tile adhesive will perform excellently under practical conditions. Comparison of Culminal Plus with standard methylcellulose shows that strength values are similar even after short embedding time. However, the product containing Culminal Plus clearly exhibits significantly higher strength values after tiles have been embedded for extended periods.