Part I - About photoluminescent techniques
Q1. What is photoluminescence?
A1 : Photoluminescence is a special kind of luminescence, which can absorb light energy then release the energy in light, mostly abbreviated as PL. It covers any material containing phosphors that will absorb light energy and then release that energy in the form of light.
In a simple word, photoluminescent is a kind of light-lead lighting, different to electronic-lead lighting(LED) or chemical-lead lighting.
There are two types of photoluminescence: fluorescence and phosphorescence.
Fluorescent materials absorb light and then emit light instantaneously under condition of no continuous energy supplying, short as to 10-8second and unable to distinguish by human eyes. They are commonly seen in a TV screen or computer monitor.
Phosphorescent materials absorb and store light, then emit visible light slowly over time. There are many glow-in-the-dark products containing phosphorescent materials in the market nowadays, from mobile phone covers to toys. If you have ever seen any of these products, you know that they all have to be "charged", sounds like a storage battery. You hold them up to a visible or UV light for a few minutes, and then take them to a dark place where they glow for several hours.
Q2. What is photoluminescent(PL) pigment?
A2: Photoluminescent pigment is a kind of light-excited and light-storing luminescent powdery crystals, which can absorb and store light energy as being exposed to light source, then re-emit visible light in certified wavelength range, which indicate a certain color perceived by human eyes.
Q3. What is Zinc Sulfide?
A3: First generation of long glow decaying photoluminescent material. Some of the first phosphors to be developed were inorganic zinc sulphide compounds. (German submarine commanders during “World War I” reportedly rubbed these compounds on their hands to read documents during blackout conditions.) These phosphors typically absorb energy from deep blue and ultraviolet light and emit it as yellow-green light. This is useful in that the p*ak(*=e) spectral distribution of the emitted light roughly coincides with the p*ak(*=e) spectral sensitivity of the human visual system under isotopic (low-level) lighting conditions (which is around 510 nanometers).
Zinc sulphide occurs in crystalline form, but is not photoluminescent by itself. This requires the addition of activator ions to the crystals, such as copper atoms. These ions absorb the excitation energy of the ultraviolet or visible light and later release it as visible light.
The copper-activated zinc sulphide crystals (identified with the chemical symbol ZnS:Cu) are typically ground into a fine powder with a grain size of 3 to 15 micrometers to avoid light trapping and light piping effects. This must be done carefully however, because the crystals can darken (or gray) if subjected to heavy pressure or excessive mechanical stress, due to disruption of the crystalline structure.
Q4: What is Strontium Aluminate?
A4: New generation of long glow decaying photoluminescent material. Recent research efforts have produced several new inorganic compounds whose photometric characteristics greatly exceed those of zinc sulphide compounds. These materials include oxides of strontium aluminate (identified as SrAl) and other proprietary inorganic compounds. These compounds offer much brighter and longer-lasting photoluminescence, and introduced in the near future, including those with different emission colors.
They can formulate (unlike zinc sulphide compounds) to produce a range of colors.
While there are many different strontium aluminate compounds, the following is an example of comparative performance characteristics:
Strontium aluminate products are currently available in flexible vinyl and rigid PVC sheets, and can be substituted wherever commercial zinc sulphide products are used for life safety applications. For the example shown above, it is some fifteen times brighter than commercial zinc sulphide products, and is clearly visible after many hours of total darkness.
SrAl and other proprietary compounds represent a revolution in the photoluminescent industry, which has relied on zinc sulphide pigments for the better part of a century. There will undoubtedly be new and better photoluminescent pigments and products.
Q5: Why PL pigment is called glow-in-the-dark pigment? Is there any alias of Zhongbang’s PL pigment?
A5: PL pigment can absorb and store light energy then emit light in dark place over a period of time, even after it is moved away from light source to a dark place. So people also call it as glow-in-the-dark pigment. Rare earth base PL pigment is also known as luminescent pigment, photo luminescent material, phosphorescent powder, luminous crystal, strontium aluminate, night glow luminofor, luminophor crystal powder, etc.
Q6: Is Zhongbang’s PL pigment GREEN, safe?
A6: Yes. Zhongbang’s PL materials are non-radioactive, toxic-free, non-flammable and harmless, containing no phosphorus or lead, or any other hazardous element or chemical, and can be recharged an infinite number of times. The term phosphorescence is sometimes used to describe luminescence, but Zhongbang’s PL materials contain no phosphorus.
Q7: Is Zhongbang’s PL pigment toxic?
A7: No. Zhongbang’s PL pigment is made of di-aluminum trioxide, strontium carbonate, rare earth metals oxides compounds with certain ratios, being heat up to 1400 Celsius Degree for a certain period, sieving after being grinded. Zhongbang’s pigments are non-toxic, environmentally safe and meet established international standards including:
Normal Cargo under IATA Dangerous Good Management
Q8. International standards, norms, legislation in the PL industry?
A8. See the list below,
Q9. How does Zhongbang's PL pigments comply with international norms?
A9. Exceed ALL norms including PSPA Class D, JIS Z9107-2008, ASTM E2072, APTA, IMO, etc.
Q10. How does Zhongbang's PL pigment work?
A10. Photon boost the electron to jump into a higher level energy orbit, the energy is released in light form as the electron returns to its ground level.
Q11: What lights are best to charge Zhongbang’s pigment?
A11: Sunlight, lamp light, all visible light with sufficient luminance intensity and UV light.
Q12: How long does it take to "charge" Zhongbang’s pigment?
A12: Depends on illuminance intensity of charging source.
Zhongbang’s pigment will charge with as little as 10 l*x(*=u) of light. Thirty minutes of light at 110-120 l*x(*=u) is enough for Zhongbang’s pigment to glow safely for 10-12 hours. The higher illuminance, the shorter fully-charged period.
Q13: Why the pigment with asserted glow duration over 12hours doesn’t glow any more 1hour later?
A13: Because of disturbing on human eyes’ surveying from ambient light.
The glow duration of PL pigment often makes the new entrants of PL purchasers puzzled, why doesn’t the pigment with asserted glow duration over 12 hours glow any more 1hour later after removing from light? Was the supplier telling a lie? Hence leading to some unnecessary misunderstand.
The common luminance unit of glow materials is cd/m2(abbr. For candela per square meter), while the unit for PL pigment is mcd/m2(milli-candela per square meter) normally. We will get a clearer sense as looking through the following examples,
So to perceive luminance of PL pigment in daytime, its glowing is not conspicuously visible one hour later even when we survey it in a relative dark room, in which the luminance is usually higher than 1cd/m2 because of ambient light. Besides, the surveyor’s eyes are not well adjusted to the darkness immediately as he moves from light room to a dark place. The luminance might be even imperceptible in twenty minutes as it is surveyed in a locker or through a paper-circled tube.
Then what is the persistence meant by the PL pigments manufacturers? The most common end point used in the industry is the time to reach a luminance of 0.32mcd/m2 or 100 times the threshold perception level of the human eye in pure dark condition. And the duration for pigment’s luminance decaying to such level is normally over 10,000minutes(=167hrs). To identify rare earth base long afterglow PL pigment from traditional sulfide base one, which glow duration is about 1hour, the persistence was asserted as 10hours, 12hours, 30hours, ...
Q14: How bright and long does Zhongbang's pigments actually glow?
A14: The amount of glow depends upon one's perception. The powder will glow for over 12 hours, but how well you see the glow depends upon a number of factors. If there is ambient light, your eyes will have a tendency to adjust for that ambient light. If your eyes are not well adjusted to the dark, you may have trouble seeing the glow. If you get up in the middle of the night and walk into a dark room with the powder, you will see it very well. If you come from outside on a sunny day and walk into the same room, the glow will be very bright but you will not see the glow until my eyes adjust to the darkness. In dark room, by emitting-light from fully-charged Zhongbang's PL pigment in a bottle(diameter 35mm, height 50mm), the 12# Times New Roman characters are readable for one hour at a distance of 10cm. And it has been scientifically tested to emit light for up to 21 days in laboratory conditions.
Q15: Appearance color & glowing color of Zhongbang’s PL pigments.
A15: White to yellowish under daylight.
Lemon green, aqua blue as they emit light in dark. See the picture below,
Q16: Featured characters?
A16: Unlike electric and battery powdered products, Zhongbang' s PL materials:
1) Consume no electricity and need no electrical circuits to work,
2) Require no battery backup and are maintenance free,
3) Are explosion proof, vap*r(*=o) proof, are energy efficient and cost effective,
4)Are failsafe. They always work.
Unlike radioactive tritium products, Zhongbang’s PL materials:
1) Are non-radioactive, non-toxic, and environmentally friendly,
2) Generate no hazardous radioactive wastes,
3) Do not expire and create no disposal problems,
4) Last more than 20 years
Unlike traditional Zinc Sulfide PL material, Zhongbang’s PL materials:
1) 15times in luminance, 10+ times in afterglow decay duration,
2) Do not turn black after being exposed to UV light.
Q17: Same with reflective materials or fluorescent materials?
A17: No. Zhongbang’s photoluminescent materials differ from reflective materials, which amplify and increase relative brightness when light is applied. Fluorescent materials are quite different from photoluminescent materials. Fluorescent materials (such as the 3M fluorescent work zone film or a "hot pink" tag) actually serve to borrow nearby light energy in nearby wavelengths and concentrate the amount of light returning to the viewer in a certain (for example, day-glo orange) wavelength. Fluorescent films are especially useful in dawn and dusk viewing times, when they appear particularly bright. Zhongbang’s photoluminescent materials require prior exposure to a light source before its glowing in the dark.
Q18: Will it replace traditional electrical emergency lighting?
A18: In some extent, yes. But it is mostly used as a necessary supplement nowadays. Zhongbang’s photoluminescent materials were originally designed to complement existing emergency lighting systems but continuous improvements in luminance performance mean that in certain circumstances high quality photoluminescent products can replace emergency lighting. They can be sited at waist or skirting level so they can still function if the ceiling lights become obscured by smoke. Similarly, life saving appliances and fire fighting equipment become more visible and are easily located in an emergency. Some emergency lighting can take up to 15 seconds to activate. In these instances, photoluminescence can be a lifesaver.
Q19: May PL material is used in pavement to replace street lamps light?
A19: No. The PL material do emit light as bright as a street light at the beginning, but its decaying figures a hyperbolic curve, which means, PL materials’ luminance intensity fade out very fast at the first several minutes then fall down to an intensity not that strong enough to emit light as street lamps.
Q20: May I use PL material outdoors?
A20: Yes, in some applications. Zhongbang’s PL material resists UV light, applicable in temperature range of -40 to 500 Celsius Degree, has excellent weather and heat resistance. All Zhongbang’s SrAl PL pigments are in good lightfastness, to use directly under sunlight is OK.
Q21. May I mix photoluminescent pigment directly to normal concrete and make it glow in the dark?
A21. No. Concrete powder will block pigment grains from being charged. See the picture below,
Q22. Is Zhongbang's photoluminescent pigment edible?
A22. It is not recommended to eat, even though Zhongbang's PL pigment is not proved to be harmful to human. To drink some water or consult a doctor for advice if ingest by accident.
Q23. Water/high moisture condition?
A23. Most SrAl pigment can’t be used in water, or under high moisture conditions. The specified pigment items and those water-proof-treated are applicable.
Q24. Heat resistance?
A24. As being heated, Eu2+ will be oxidized to Eu3+ then make the PL pigment lose its glowing property. Such losing is permanent and irreversible. Lemon green items start changing at 500°C and will rapidly change @850°C, aqua blue items start changing @800°C and will rapidly change @1050°C.
Part II - About using PL pigments
Claim: This document is intended to aid the use of the photoluminescent pigment and to be used as general information purposes. Zhongbang will not responsible for the damage to machines, loss of products or labor due to the misuse of the photoluminescent pigment.
Q25. What can I do with the PL pigment?
A25. Almost anything that you want to make it glow.
You can mix it into a transparent or semi-transparent medium such as resin, wax, paint, ink, paste, plastics, rubber, fabric, caulking, ceramic glaze, glue, nail-polish etc. There are numerous industrial applications for safety, for novelty, for fun, for household using in arts and crafts. PL pigment can meet expectation of all purposes above-mentioned. Some detailed applications, such as PL egress signs, sudden darkness orientate system, outline marking, cell phone case, keyboard cover pad, art-candles, screen-printing ink, night-glow shirts, toys, clothes, pavement walk-brick, glass mosaic, glass drinking cups, garden decoration lights, etc., have been applied.
More application ideas are welcomed to share with us, we are pleased to work with you together to get a perfect finished product. See some application samples in picture below,
Q26: How much Photoluminescent pigment does it take?
A26: It depends on your expectation on luminance intensity of finished product. The dosage ratio of photoluminescent pigment to medium will depend on how much glow desired, your cost budget, market positioning, application method, medium type, pigment type, etc. A general guideline shows that rates 3% to 50% by weight are all OK.
In a simple word, a lower dosage rate and a more economic pigment grade will be better if the target market is at low-end side, in which a lower price is more important and the cost budget is more strict and tight. Anyway, experimentation will be the best method to determine the dosage ratio.
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Q27: How to select a suitable Photoluminescent pigment?
A27: Shall balance the cost and workability.
1, In PL pigments world, the finer of PL pigment particle grains, the lower of the pigment glowing luminance intensity, and the better workability. So at the same luminance intensity, the finer in particle size, the higher in cost. Consequently to select pigment in workable particle size range as coarse as it can be to save cost.
2, Generally speaking, the higher dosage ratio of Rare Earth metals as raw material in a certain range, the higher pigment glowing luminance intensity. Accordingly, the higher in cost because that the cost of rare earth metals’ prices are much higher than other raw materials. To select pigment in a more economic grade to save cost.
Contact us for suggestion and recommendation in pigment item selection.
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Q28: What pigment particle size range does Zhongbang supply?
A28: Three main ranges.
1, 50-110 um or 120-250 mesh size - Large
* Relatively large particle size
* Very high afterglow intensity
* Suitable for many applications such as brush painting, spray painting, candle making, and glass molding
2, 25-50 um or 250-400 mesh size - Medium
* Relatively moderate particle size
* Moderate afterglow intensity
* Suitable for many applications such as silkscreen printing and plastic molding
3, ~25 um or 500 mesh size - Fine*
* Relatively small particle size
* Moderately low afterglow intensity
* Suitable for certain applications that require very fine particle size such as thread and fiber production.
Section A - Glow in the dark paint / ink / paste
Q29. How much percentage shall glow in the dark paints contain Zhongbang's PL pigments?
A29. The applicable rate is 8~50% by weight. And 20% by weight is the recommendation. I.e. 1oz pigment to mix with 4oz blank paint to get 5oz glow in the dark paint.
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Q30. How much area does glow in the dark paint cover?
A30. This strictly depends on how much is applied, but the rule on coverage is. At a 5 mil thickness coat.
Approximately 300 sq. ft. per gallon.
Approximately 80 sq. ft. per quart.
Approximately 40 sq. ft. per pint.
Approximately 2 sq. ft. per 1 oz
Q31. Can I mix two Zhongbang's glow in the dark pigment colors and get a different glow color?
A31. No. In the world of glow, yellow and green do not make blue. So you can not mix the powder and paints to achieve a true different color. You can make different hues of glowing colors by using layering techniques.
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Q32. Can I add Zhongbang's glow in the dark powder to water to make it glow or make paint?
A32. No. The powder will simply sink to the bottom of container. It will glow there, but not be dispersed throughout the mixture. You need something that will suspend the powder and be clear so light can charge it.
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Q33. Can I add Zhongbang's PL powder to regular paint and make glow paint?
A33. Zhongbang's PL powders need special polymers and emulsions to make glow paint. The pigmented paints shall allow light to get through to charge the powder particles and still have a daytime color. Regular latex paints can not do this because they have heavy pigments added.
Q34. How to make a glow in the dark paint?
A34. Glow paint consists of glow powder mixed with clear organic resin, organic solvents and in some cases other materials. Once mixed, it can absorb light and glow in the dark for hours.
- Mixing Instructions for Luminous Paints
- Choose transparent, neutral or weak acid organic resins like polyurethane resin, acrylic acid resin, epoxy resin, polyester resin, etc..
- For painting purposes, particle size of pigments can be between 10~15um or 25~50 um is recommended.
- Mix about 20 to 50% of luminous pigment, measured by weight, to the clear resin. This is just a guideline. You could add more or less according to your requirements
- Do not grind the luminous pigment.
- Use containers with ceramic or glass interiors and stir the mixture at high speed.
- To avoid deposits, you should use high viscosity resins or anti-settling agents. Stir well prior to application, process small batches at a time.
- Do not use heavy metal components as additives.
- The more powder or higher the percentage, the brighter and longer the glow will last.
- Add Medium to powder, not powder to medium. That way you can stop when desired glow effect is reached.
- Use a white or light color as a background for best results. Any color other than white will diminish glow.
- If painting a black surface with powders, brilliance will be much less.
- Use the clearest vehicle possible. Any color in the vehicle will decrease the brightness and length of glow.
- The thicker (to a point) the layer of Glow Powder will produce longer and brighter luminosity.
- Try to prevent moisture in the manufacturing process. A yellowing of resin may indicate moisture. Apply a final clear overcoat to protect the material from humidity and to improve gross.
- Strontium based pigments should only be mixed into oil/solvent bases. If your project requires a water based medium, then you need to purchase one of our pigments that are treated for water protection.
Notice: A glass or Plastic spatula should be used when stirring the powder and paint. A metal implement may react with powder.
- Usage Instructions for Luminous Paints
- By brush painting, roll painting or spray-painting.
- For good luminous effects, the luminous layer should be at least 100~150um, adding layers enhances the glow intensity.
- A prime coating in white or very light color is preferred. Applying luminous paint on dark colors reduces the glow effect by as much as 50%.
- Use a layer of varnish over the luminous surface to add a glossy effect to the paint. A layer or two of clear varnish also provides a certain level of surface protection.
- Adjust the viscosity to suit your application method and stir well prior to painting.
- One kilogram of Luminous Powder can be mixed to product up to 2~4 litres of glow paint.
- One litre of glow paint or UV paint can cover an area of about 3.5~7 square meters.
- Colorless transparent resins are preferred to be used as base materials.
- Don't add opaque pigments, such as TiO2 to the paint; Do not add too much transparent pigment to the paint;
- When the luminous pigments are dispersed, the pollution from iron, sulphur and arsenic should be prevented.
- Special luminous pigments are required for application in waterborne resins.
Q35. How to make and use airbrush spray glow in the dark paint?
A35. Follow these steps and you are on your way to making great art.
- Use the clearest airbrush medium possible. Liquitex airbrush medium is very good with our powder. Glow in the dark powder works great in clear coats and varnishes and lacquers. Do not mix too much powder to paint. The usual ratio is one ounce of powder to four of clear medium. Add a little at a time and then test it by exposing it to a bright light 150 watt or above, or black light to activate the glow. Test your mixture on a piece of thick paper first, letting it dry, then check with a black light. Black lights are rich in Ultra Violet light and charge the powder well.
- Use a gravity feed airbrush. This will allow the medium to mix with the powder and flow through the brush better.
- Spray in a dark room with a black light. This will let you to see the glow activated so you know what it will look like while glowing.
- Always use light thin coats and layer many times for best results.
- For larger areas use a small HVLP (High Volume Low Pressure) detail spray gun. These work great for spray painting larger objects.
- Clean your brush between each coat. This helps avoid clotting.
So that's all there is to it! You can make some really great looking art with glow in the dark paint. It adds an extra dimension to your craft that maybe you have not thought about.
Q36. How to make a bike glow in the dark?
A36. To make a bike frame glow ideally you need to strip the bike to bare metal. Prime it then with a white or light color. Then mix 1 oz of our glow in the dark powder to 4 oz of a good automotive clear coat. Then spray paint the bike with a HVLP spray gun for a professional look. Several coat are required for best glow effect. You can also use Zhongbang's Glow in the Dark Tape cut into strips and placed on the bike frame if painting is too much of a project.
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Q37. How to make PL screen printing ink?
A37. Luminous Printing Ink is the Product of Luminous Pigment with Clear Printing Inks. Luminous Printing Inks can glow in the dark for hours after absorbing surrounding light. With good heat resistant and anti friction properties, these inks are suited for application on many materials like paper, textile, wood, plastic, metal, ceramic, etc..
- Mixing Instructions for Luminous Printing Ink
- Choose neutral transparent printing inks
- Choose pigments with small particle size like 25~50um, 10~15um
- Add about 30~50% of luminous pigment, by weight, into the clear printing ink.
- You could add more if brighter ink is required. Adding more powder thickens the solution.
- Do not grind the pigments.
- Use containers with ceramic or glass interiors and stir the mixture at high speed.
- To avoid deposits, you should use high viscosity resins or anti-settling agents.
- Do not use heavy metal components as additives.
- Select a printing ink that is suitable for the surface it is to be printed on. For example, use metal abrasive oil it the surface to be printed on is metal.
- Usage Instructions for Luminous Printing Ink
- Viscosity of mixed inks should be between 3000-5000 poise.
- Viscosity can be adjusted during the printing process with a diluting agent.
- A base coat of white or very light color is preferred. Applying luminous paint on dark colors reduces the glow effect by as much as 50%.
- For good luminous effects, the luminous layer should be at least 100-150um.
- Ideal mesh size for silkscreen printing screens is 80-100 mesh. Smaller screen mesh size are okay as these create a thicker printed layer.
- One kilogram of Luminous Powder can be mixed to produce up to 2~4 litres of glow ink.
- One litre of ink can cover an area of about 3.5~7 square meters.
Important: A glass or Plastic spatula should be used when stirring the powder and printing ink. A metal implement may react with powder.
Q38. How to make PL paste?
A38. Following is a general instruction,
1. Preparation on materials
1.1 Fabric to be printed, synthetic fabric in white is better. Light colors such as yellowish / light greenish / light blueish are applicable with a 10~20% losing in glowing. Dark colors, esp. dark-black, are not recommended for the glowing performance might be decreased by up to 60%.
1.2 Glow in the dark pigment. Zhongbang’s D series, such as TPY-8D(lemon green glowing) & TPG-9D(aqua blue glowing), and finer pigments are applicable. The finer of the pigment, the better in printing performance, while the less glowing luminance accordingly.
1.3 Printing binder. The printing binder shall be colorless, clear & transparent solvent liquid. Such as Acramin F series oil type binder, acrylic ester type low temperature self-crossing adhesive KG-101, etc.
1.4 Printing thickener. For example, Acrapon A paste, PTF etc.
1.5 Additives. Such as printing softener, defoamer.
1.6 Possibly to use: Cover Printing White Paste, CMPVC, Cyclohexanone.
2. Preparation on facilities
2.1 Fabric printing machine;
2.2 Screen printing mesh & frame(80~100mesh), Nylon photoresists stencil or film stencil, the thickness to be 100+um. The thicker, the better of printed performance;
2.3 Heating oven;
2.4 Color fasten steamer;
3. Flow chart
Preparing for print -- Print -- Heating / foaming -- Steaming -- Washing -- Stretching -- Packing after dry.
4. Formula example
4.1 Direct Printing Paste(g/kg)
|Glow in the dark pigment||100~150|
|Low temp. Self-crossing adhesive||250~300|
|Acrapon A paste||50~150|
|Printing thickener||0~25 (appropriate)|
4.2 Cover-print paste(g/kg)
|Cover Printing White Paste||650~750|
|Glow in the dark pigment||200~250|
4.3 Screen printing
CMPVC + Cyclohexanone 700~850
Glow in the dark pigment 200~250
5.1 Add glow in the dark pigment into a ceramic or glass container, then adding appropriate solvent/resin for wetting the pigment.
5.2 To pre-mix the primary paste.
- For direct printing. To add Low temp. Self-crossing adhesive, Printing softener, Acrapon A paste, Printing thickener to solvent in sequence then stir in high speed to get viscous liquid primary paste.
- For cover printing. To add solvent to printing binder to get the viscous liquid paste with appropriate viscosity.
- To put CMPVC(Chlorinated polyvinyl chloride resin) into Cyclohexanone, 24hours later, the CMPVC will be dissolved into cyclohexanone and form an viscous clear liquid. To put more CMPVC into cyclohexanone to get a high viscosity.
5.3 To add appropriate solvent into primary paste to get blank paste at an appropriate viscosity.
5.4 To add blank paste into the wet pigment, stir and get the glow paste as an even mixture. To test performance by drawing with the glow paste and stop adding blank paste as the performance is accepted.
5.5 To cover print the white paste if any as prime printing, then print the fabric with the glow paste.
5.6 To heat the printed fabric in heating oven (130°C x 2min), which is unnecessary for formula 4.1.
5.7 To steam for fastening the printed pattern(102°C x 6min), which is unnecessary for formula 4.1.
5.8 To wash, stretch, make the fabric dry, and pack the finished cloths.
6.1 Zhongbang’s strontium based pigments are solvent applicable ONLY. For formulas with water added, aqua blue glowing series, special treated lemon green series are applicable.
6.2 To add other fluorescent pigment into glow pigment before wetting will make a good looking in both daylight and dark place. While such adding will decrease the glowing performance of finished cloths.
6.3 Besides the glow pattern, the fabric might be printed with other non-glow pattern with color coating. To print glow pattern later, and never print glow paste onto color pattern if a very bright glowing is requested when both patterns types are needed.
6.4 The narrower of glow line, the lower it glows. To print a continuous pattern instead of lines to get a better glowing performance.
6.5 The thicker of glow printing, the better it glows. To print several times will make the printing thicker and glowing brighter accordingly.
6.6 White background will make the glow printing brighter in dark. To print a white prime layer on a non-white fabric before print glow paste will do help to obtain a brighter printed-pattern glowing.
6.7 The clotting on screen-printing mesh may be cleaned and dredged after soaking the mesh in Cyclohexanone without hurt to the mesh.
Section B - Glow in the dark plastic
Q39. How to make glow in the dark plastic?
- Application in plastic:
- This new type of luminous powder of is compatible with acrylic, polyester, epoxy, PVC, polypropylene and polyethylene (HDPE, LDPE etc.) polymers. The plastic resin shall be transparent or semi- transparent. Never add opaque filling or additives into such raw materials mixture, opaque material will quench the phosphor.
- To use plastic resin in colorless or light color, dark colors will decrease the glowing property of finished product. To get a similar performance, more pigment shall be added for a dark-color plastic resins.
- Material can be cast, dipped, coated, extruded or molded.
- Preferably use master batches or compounds for incorporating luminous powder into plastics.
- As luminous material is a very hard substance and the particles have a needle like shape, it is difficult to incorporate into plastic resins directly. Never stir PL pigment with steel/iron container or stick for the abrasion will make the material dirty by steel dust. A glass, glaze, ceramic container and propeller is recommended.
- To add diffusion oil into plastic resin then stir for 1 minute first, then add the pre-mixed PL pigment (Pre-mix the pigment with wax or lubricant) and stir for another 1 min. prior to mixing with fluorescent color pigment and stir for 2minutes.
- Stirring with a high speed or stir a long time may cause the resin/pigment blacken.
- Normally 2~10% dosage rate by weight is OK for plastic industry(i.e. 1kg pigment to mix with 25kgs plastic resins), more PL pigment shall be added if the plastic resin is not good in transparency. The lower MI the resin, the higher pigment dosage rate is required. To add some reflective glass beads will do help to increase glowing performance.
- Prior to starting a manufacturing of a masterbatch, the interior of the extruder should be thoroughly cleaned to remove all contaminations.
- It is recommended to use an extruding temperature as low as possible. 20 degrees lower than its normal running temp. can be an optional start. The extruder shall be cleaned again by running clear resin through until clear resin can be seen coming out of the machine.
- The recommended machine configuration is one with a distributive screw design and twin hoppers. Use the first to feed the resin and additives and the second to dose the pigment into the polymer melt. This will decrease the PL pigment’s abrasion to the extruder, hence avoid blackening in some extent. If the above method is impossible, keep melting & extruding time of the mixture as short as possible.
- Master batches containing luminous material must be fully dried up before using.
- Plan on using less than classical phosphorescent pigment loading.
- General Precautions:
- Do not grind or mill the pigment, breaking the pigment structure will destroy the afterglow properties!
- Avoid exposing the pigment to strong acids or mixing with resins containing heavy metal properties.
- Keep out of reach from children, this substance is non-toxic but not intended for human’s ingestion.
- Keep pigment as dry as possible.
- Photoluminescent pigment is a hard material and this may cause abrasion to the extruding machines, In order to avoid this problem either use especially hardened barrels and screw fixtures or a wax / lubricant to wet the pigment prior to extruding, or use a machine with two entry ports.
- Avoid moisture and aqueous systems. Once the pigment is incorporated into a solvent based resin, it is not affected by moisture.
- We have tested our pigments thoroughly but the afterglow properties depend on the pigment quantity used and manufacturing processes used. The efficiency of phosphorescent pigment containing articles can only be observed when installed properly and excited under correct lighting conditions as required by the proper authorities. Therefore we can not guarantee that the end product containing our pigment conform to your company expectations.
- Molded parts and extruded strips as well as products made thereof are manufactured with a variety of base plastic compounds, to which luminous material are added.
- For processing of photo luminescent plastic compounds, it is best to use machinery such as plunger-type injection molding machines or single-screw extruders, which ensure delicate handling of the luminous material. Consult extruding machine manufacturers' specifications for processing temperatures and injection speed.
- Suggest using paraffin to cling to the surface of raw plastic resin as it is molding.
- The higher MI of the plastic resin, the lower dosage rate of pigment needed to get a same performance.
- Pre-mix the pigment with wax or diffusion oil prior to mixing with plastic resin may avoid pigment’s direct contact to metals of production machine, consequently decrease possibility of blackening.
Q40. How to avoid blackening during making glow in the dark plastic?
A40. Following aspects will do help to decrease possibility of blackening, make sufficient expirements to get a suitable production conditions or contact us for advice.
- Clean the interior of the extruder before manufacturing with the plastic master batch.
- Keep the resin and pigment dry before the extruding process is started.
- It is recommended to use a machine with twin hoppers and a distributive screw design. Use one of the hoppers to feed the resin and additives and the second for the photoluminescent pigment. Doing so will decrease the abrasion to the extruder surfaces.
- Do not stir for a long time because this might darken the pigment/resin.
- Keep the processing temperature 10~20 degrees lower than a normal run of plastic.
- Clean the extruder again by running clear resin through until clear resin can be seen coming out of the extruder.
- Use ceramic, glass or hard metal containers because the photoluminescent pigment will react to heavy metals causing discoloration.
- Mix the photoluminescent pigment with liquid paraffin. Ratio of the liquid paraffin to the plastic particle is 1 -1.5% of the plastic particle.
- Using the white mine oil makes the photoluminescent pigment stick evenly with the plastic.
Q41. How to make glow in the dark master-batch?
- Preferably use master batches or compounds for incorporating photoluminescent pigment into plastics. As the pigment is a very hard substance and the micro particles have a sha*p(*=r) edged, it is difficult to incorporate into plastic resins directly ( they can be classified as a glass or ceramic ).
- Prior to starting a manufacturing of a masterbatch, the interior of the extruder should be thoroughly cleaned of contamination.
- The processing temp should be 20 degrees lower than normal run of plastic. The extruder should be cleaned again by running clear resin through until clear resin can be seen coming out of the machine.
- The recommended machine configuration is one with a distributive screw design and twin hoppers. Use the first to feed the resin and additives and the second to dose the pigment into the polymer melt. This will decrease the abrasion to the extruder surfaces.
- If the above method is not possible keep the mixing time of the pigment and resin as short as possible.
- Stirring with a high speed for a long period may cause the resin/pigment to darken, this is not good!
- The resin and pigment should be kept dry before the extruding process is started!
- Using carrier resins in powder form minimize blackening.
- Masterbatches containing up to 50% glow pigment can be manufactured.
Q42. Extrusion molding
- For extrusions a small bore machine would be preferable as to minimize residence time. Extruders with large inside wall areas or equipped with complicated screw geometry tend to cause darkening of the end product.
- It is recommended to use an extruding temp. as low as possible (only experimentation will give the correct temp level).
- The optimum back pressure should be determined by experimentation.
- The color of the pellets being produced should be observed, they should be the same color as the pigment itself.
- The best temp. level inside the barrel is closely related to screw geometry and back pressure, these should be determined by repeated experiments.
Q43. Injection molding
- The use of an injection mold machine equipped with a small chamber is recommended. For Instant, for injection molding a piece of 50 grams per shot with a duration time of 3 minutes, do not use a machine with a barrel capacity of 5kg it is enough for 100 shots. This will maybe darken the end product. An adequate sized chamber would be one that the resin stays in no longer than 30 minutes.
- A trial run with a blank resin is recommended before injection molding is started.
- Masterbatches or pellets containing luminescent pigment must be fully dried before using!
- Temp. should be determined by experimentations, to make the temperature as low as possible to avoid plastic blackening.
- It is difficult to inject mold resins containing a stabilizer or resins which are hygroscopic or containing water.
Part III - About sample, order, shipping.
Q44. Order chart for bulk / Customized order
44. See the chart below,
Q45. May I request free sample? How can I buy in a small quantity?
A45. Yes. Zhongbang offers viewing samples 50-grams free of cost with freight collect. Please obtain and test our quality with our 20grams glow powder sampler package from our online store http://www.aliexpress.com/store/800244. This will give you a great idea of what to expect from larger quantities.
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Q46. Do you ship internationally?
A46. Absolutely. Anywhere, anytime at any speed you prefer.
Q47. How long it will take to get the items I ordered?
A47. The shipping period / Lead time:
- For sample/trial order
- China Post--------7~30days;
- Commercial Express such as UPS / TNT / DHL / FedEx--------2~5days.
- For bulk order / Customized order
2~10 working days as lead time. Contact us for detailed lead time and shipping period.
Q48. Can I return the pigment I ordered and request refundment?
A48. 15days return. Within 15days after you receiving the cargoes you order from us, for any reason such as your dog/cat dislikes, etc., every your order is returnable with initial package in well conditions and round-trip freight paid by buyer. After deducting relative bank transferring fees, China Customs declaration charges, freight we paid, the net amount will be refunded to you within 3working days after the package is received and checked for approval. Such returning shall be performed after informing us and being approved.