Product description:
The Starpheres product range from KPT consists of visual beads. A basic distinction is made between the following types.
 
1) The first type are visual beads that soften in aqueous systems. These are primarily intended to provide a visual appeal and attract the consumer's eyes.
 
2) The second type are visual beads that remain hard in aqueous systems and are therefore suitable as a polyethylene alternative for peeling.
 
3) The third type are so-called Color Changing beads, which are additionally provided with a high proportion of pigments. The special feature here is that they usually contain two different colors. The CC-beads soften in aqueous systems and when the beads burst open we observe a color change.
 
All types of Starpheres have in common that they are based on natural fibers such as corn starch, cellulose, sucrose or mannitol. Hydrogenated lecithin is usually added as the "glue" and, last but not least, the color pigments and the loading of the beads are added. In the case of Color Changing beads, the loading can again consist of pigments, while the normal Visual beads usually contain a vitamin E derivative.
 
Furthermore, Starpheres are basically available in different sizes and with or without pearlescent coating.
 
In principle, the Visual beads can also be adapted with a different loading, but the loading must be lipophilic. The reason for this is simple, as the beads are not a closed system. Water must penetrate the one formulated beads to soften them, and any hydrophilic loading would therefore be very quickly solubilized and dissolved in the surrounding formulation.
 
Consequently, the good news is that we have no scary or frightening ingredients in the composition!
 
There are three main aspects that must be considered if you want to work with such beads:
 
1) The formula must have a free water content of about 30% to soften the beads. This is absolutely necessary so that the beads break easily when used without much pressure.
 
2) The second point is more relevant if you are formulating a gel or shampoo, as emulsions usually already have sufficient internal structure. Internal structure is already the key word and you need to make sure that your gel not only has some viscosity, but sufficient internal structure to disperse the beads well and avoid sedimentation.
 
3) Mechanical stress is the third major challenge! This is even more true for Color Changing beads and KPT's products have a very strong advantage here because they are smaller than competitors' products, which reduces the risk of breakage quite significantly.
In general, we recommend adding the beads only at the very end and at low temperatures, and then stirring the formulation only at a very low speed.
 
It is also important to leave a gap between the blades of the stirrer and the walls of the reactor, otherwise the beads will be crushed against the walls of the reactor. This is usually not a problem at lab scale, but it does mean that you can use scrapers or similar devices during production.
 
The last major challenge is also more relevant to production scale and this time relates to filling. The first advice would be to process the product and formulation as quickly as possible. The beads take some time to soften, and they are naturally much more resistant while they are still hard. It is therefore advisable to avoid long storage times for the bulk with the beads and fill them into the final packaging as soon as possible.
 
In general, we recommend doing a short test run, especially with Color Changing beads, before moving into commercial production, to avoid unpleasant surprises from the start.