Special Effect Pigments/ Fragrance - FAQs
A: Yes, directly integrate photochromic dye into plastic materials. Then the photochromic effect may potentially last for around a half year outdoor (under sunshine)! Special technical know-how will be needed. If interested, please contact us.
A: The change of pigment colours successes via opening and closing the ring of the aromatic structure.
A: As masterbatches, the processing is feasible up to 200°C with a max duration of 5 minutes. Otherwise, the thermochromic pigments would decompose, losing its colour changing effect.
A: Duration of colour changing effect could be 4000-8000 times or 2 years if the thermochromic pigment is properly stored.
A: Cool, e.g. 4°C and in the dark. Sunlight and UV light must be avoided.
A: Thermochromic colours appear somehow glass like (little bit transparent) due to its organic nature (no exception worldwide). Thus, their colour appearances are not so strong as the usual pigments.
A: The "realistic" thermochromic temperatures difference between 2 colours chosen have better to be more than 10oC in order to deliver the best multi-coloured thermochromic effect.
A: Application of thermochromic pigment onto textile is possible via printing or something similar to finishing process in textile:
1. The thermochromic pigment can be mixed with printing paste and then printing the pattern you want on T-shirt (Silk screen printing).
2. A dying bath can be prepared by mixing thermochromic pigment together with the binder. Thereafter, the clothes need to be incubated in this bath for about 20 minutes and then sent for drying.
The drawback could be that the attachment is not so strong so that the thermochromic pigment may gradually detach after 10-20 times washes.
The thermochromic pigment is not a dye and only is possible to attach on the clothes by binders.
You can use the same binder as those taken for the usual pigments. Nevertheless, binders containing acetone and alcohol solvent, such as PU binder should be avoided, which may decompose thermochromic pigment.
A: The thermochromic pigment is in general non-toxic. It has been widely in application for toy for kids, e.g. colour changing slime (https://youtu.be/Do7P-SkhfV0). Another example is the plastic product made of our thermochromic masterbatch, which is FDA approved.
A: Pleaase avoid its contact with organic solvents such as alcohol, ether and keton...etc.
A: No, it is impossible
Q: What is the mechanism of discolouration for irreversible thermochromic ink?
A: When the temperature of the irreversible thermochromic ink exceeds 60 ° C, the core-shell applied to the outer layer of the colour rendering reagent and the dye melts, and the colour rendering reagent reacts with the dye to initiate a chemical reaction, and then appears magenta colour (magenta 60 ° C as an example).
Q: Why is the colour appearance after coating and drying is lighter than before?
A: The reason is purely the optical effect caused by water! The plane surface of the powder stack is rough, causing the incident light to scatter, making the observation angle insufficient due to the collected reflected light. This leads to a decrease in chroma; if water is added to the plane surface of the powder stack, the water will fill the pores and make the surface smooth. After the surface is smoothed, the reflection of incident light can be more concentrated, the light scattering condition is improved, and the observation angle is collected. Since the luminosity and the chroma increase, the visual colour becomes more intense.
A: Not recommended. Namely during preparing masterbatch, a very large porportion of fragrance added will lose its scent.
Q: Fragrance masterbatch possible?
A: Making fragrance masterbatch is possible, however making no sense. Fragrance (perfume) mostly consists of several different volatile substances and evaporate rapidly by heating. Thus, it undergoes high losses during production of fragrance masterbatch. Taking PLA, whose processing temperature is around 180°C, as an example, preparing fragrance PLA masterbatch will lose ca. 50% of added fragrance.
Q: How long could the smell of the fragrance in plastic products list?
A: Approximately 3 months if stored in an opened system. If in closed system, the effectiveness of the smell may extend to 6 months.
Q: What is the adding amount of fragrance to plastic products?
A: Usually 1% w/w