PAD PRINTING AUXILIARIES AND ADDITIVES
APPROPRIATE USE OF MARABU’S ADDITIVES AND AUXILIARIES FOR PAD PRINTING INKS
Pad printing is a universal printing method of virtually unlimited potential, most commonly used for the decoration of 3D objects, and information purposes in industrial production processes. Considering the wide variety of applications and pad printing devices, naturally the pad printing ink must be fine-tuned individually, according to the required demands. The relevant auxiliaries and additives are described in this TechINFO.
Marabu offers a range of solvent-based inks, and a UV-curable ink for pad printing. The specific characteristics and applications for the different types of ink are described in detail on the Marabu homepage.
1. VISCOSITY
Viscosity describes how thin (low viscous) or thick (highly viscous) an ink system is or how it is adjusted. Before starting the print run, it is important to adjust the ink to the correct viscosity, as this will have a very strong influence on the release of the ink from the pad, ink flow, edge definition, possible drying-in in the cliché, as well as adhesion of the ink.
Owing to the variety of machines and requirements in the market, solvent-based inks are not press-ready. Before printing, the ink´s viscosity must be adjusted by adding solvents. The UV-curable ink series Tampa® Cure TPC is no exception to this.
Basic shades are always adjusted to a relatively similar viscosity range, with two exceptions:
- Due to high pigment levels in White, Opaque Whites, and high-opaque shades, the viscosity is always higher than all other shades
- 4-colour process inks feature a higher viscosity than the basic shades in order to ensure best dot definition
Thinner
The addition of thinner influences the viscosity, flow properties, and release characteristics of the ink from the pad but also has a substantial influence on the drying speed, packaging characteristics, as well as adhesion to the substrate. Special thinners offering specific characteristics are also available. The standard range of thinners includes thinner TPV and the fast thinner TPV 2. The recommended thinner is listed in the Technical Data Sheet of the respective ink series.
Retarder
Retarders are solvents with a significantly slower evaporation rate. They are only added to the ink if the drying of the ink on the pad or in the cliché is to be slowed. This may be necessary if the cycle time is very slow or if a shuttle is used on multi-colour machines. The ink-specific Retarder WV 1 is added to the Maqua® Pad MAP without thinner.
Product overview and properties
Thinners and retarders are generally a combination of different solvents that are formulated to achieve specific properties. Important criteria are the rate of evaporation as well as the dissolving strength. In general terms, thinners dry faster than retarders.
Thinner
| Evaporation rate* | Solving strength | Odour |
|---|---|---|---|
GLTPV | 10-20 | very good | average |
GLV | 180-200 | good | mild |
PPTPV | 30-50 | average | average |
QNV | 200-220 | good | average |
TPV | 30-50 | good | average |
TPV 2 | 10-20 | very good | average |
TPV 3 | 200-250 | very good | mild |
TPV 6 | 30-40 | good | average |
TPV 7 | 30-40 | good | average |
TPV 8 | 65-75 | good | mild |
TPV 9 | 20-30 | goog | average |
TPV 10 | 65 | good | mild |
TPGLV | 35-55 | good | average |
TPLV | 65-85 | good | average |
UKV 1 | 30-50 | very good | strong |
*compared to Ether = 1
Retarder
| Evaporation rate* | Solving strength | Odour |
|---|---|---|---|
SV 1 | 450-500 | good | mild |
SV 3 | 1800 | low | mild |
SV 5 | 250-300 | good | mild |
SV 9 | 3000 | low | mild |
SV 11 | 380-400 | good | mild |
SV 12 | 1500 | good | mild |
WV 1 | 1100-1300 | low | mild |
*compared to Ether = 1
Cleaner
| Evaporation rate* | Solving strength | Odour |
|---|---|---|---|
UR 3 | 30-50 | good | mild |
UR 4 | 80-100 | good | mild |
UR 5 | 180-200 | good | mild |
WR 1 | 800-1000 | low | mild |
*compared to Ether = 1
Remarks
The evaporation data is based on proportional figures of the relevant solvents and theoretically calculated values without considering the interactions occurring through solvent mixtures and the influence of binders. In practice, one may not draw an automatic conclusion from the evaporation value to the direct quality of the ink transfer.
The data in the “odour” column is subjective and may be judged differently from one person to another.
2. INK ADJUSTMENT
All pad printing inks must be adjusted by adding thinner before printing. The adjustment of the ink generally depends on a number of parameters such as ink type, type and depth of cliché, ink cup system (closed/open), machine speed, as well as shape, size, and hardness of the pad.
The quantities given from page 6 onwards are based on a room temperature of 20 °C and are intended to provide a quick start formulation. However, both temperature and humidity have a huge influence upon the evaporation rate of any solvent ink system.
3. OPACITY
Almost all pad printing ink series feature 17 standard shades according to System Tampacolor. This ink system embraces a combination of opaque and transparent shades, allowing brilliant colour shades to be mixed. If a high opacity is required for printing onto dark substrates, the following options are available. Keep in mind, however, that an increase in opacity will likely lead to a slight reduction in brilliance.
High-opaque shades
Most Marabu pad printing inks have been complemented with 4 high-opaque shades:
122 Light Yellow
130 Vermilion
152 Ultramarine Blue
162 Grass Green
Opaquing paste OP 170
The addition of OP 170 significantly increases the opacity of colour shades without substantially reducing the resistance to chemicals or dry abrasion. Max. addition amounts to 15 %. OP 170 is not suitable for use with white inks.
The Marabu-ColorManager MCM includes optimized opaque and high-opaque colour match formulas, enabling good matches with colour references such as RAL, HKS, and PANTONE®.
4. MATTING
The degree of gloss of a solvent-based ink can be reduced by adding auxiliaries.
Matting Paste ABM
With an addition of 5–20 % matting paste to the ink, the degree of gloss is reduced, according to the percentage used. As a result of this, a roughening of the ink surface is created which reduces the reflection of the incident light and thus leads to a matt appearance. Depending on the quantity of ABM added, opacity and abrasion resistance will be reduced. Alternatively, especially for 2-component inks and the UV-curable TPC, the Matting Powder MP must be used.
Matting Powder MP
If a printing ink should have a matt surface, without reducing the opacity, this can be achieved by adding the universal Matting Powder MP. An addition of 1-4 % MP, for White/Opaque White max. 2 %, is recommended. The powder must be stirred mechanically into the ink.
5. INK FLOW
All ink systems contain flow agents to minimize the risk of air being entrapped in the printing ink by intensive stirring. If flow problems arise, in most of the cases this will be the result of ink-repelling residues on the surface of the print substrate. The cleaning of the substrate may be recommended (see chapter 9).
Printing Modifier ES
This may also be due to the viscosity of the ink being too high which can be avoided by adding further thinner. If this does not improve the situation, Printing Modifier ES can be added. This auxiliary contains silicone which reduces the surface tension of the ink with an additional defoaming function. The quantity added must not exceed 1 % as, otherwise, adhesion problems may occur, especially when over-printing.
Levelling Agent UV-VM
UV-VM is used instead of Modifier ES for the ink systems Tampa® Pur TPU und Tampa® Cure TPC.
6. STATIC CHARGE
Antistatic Paste AP
When printing onto non-polar plastics and plastics sensitive to static charge, we recommend adding 1015 % of the Antistatic Paste AP to the ink. This paste decreases the viscosity of the ink and reduces at the same time the static charge through polar solvents.
7. ADHESION PROMOTER
Polyethylene (PE) and polypropylene (PP) must be pre-treated before printing to achieve proper adhesion of the ink. An exception to this is polypropylene if Mara® Prop PP is used. In addition to the traditional pre-treatments such as Corona or flame, a special product is available – Primer P 2.
Primer P 2
This special “solvent” is manually applied to the entire surface with a cloth or a spray gun before printing. It is then possible to print onto polypropylene with a single or 2 component ink. The effect of this pre-treatment is limited in time, so it should be applied max. 1-2 days before printing.
8. ABRASION RESISTANCE
Surface Additive SA-1
The addition of this auxiliary can increase the resistance against abrasion and other mechanical stress in all pad printing inks (with the exception of Maraprop PP). At the same time, it is possible to improve the ink transfer from pad to substrate. Recommended addition: 3 – 5 % (max. 10 %).
9. PRE-CLEANING
Many materials such as plasticized PVC or powder coated or wet painted substrates are invisibly contaminated by additives or plasticizers. This contamination may act as a separation layer and, therefore, may lead to adhesion problems due to a lack of contact between substrate and print.
Tarpaulin Cleaner PLR
Using this mild alcohol-based cleaner, residues can be removed with a cloth soaked in PLR, often resulting in better ink adhesion. Please change the cloth from time to time.
10. HARDENERS
There are ink systems which can be optionally used as single or 2 component ink systems. In these cases the addition of hardener can increase adhesion to difficult substrates as well as increasing the chemical and mechanical resistance. It should be noted, however, that the addition of hardener will reduce pot life to 8-16 hours (except with Hardener HT 1), depending on the ink type. For 2component inks, hardener must be added. The following hardeners are available for the Marabu ink systems:
Hardener H 1
Hardener H 1 is non-yellowing and is, therefore, suitable for outdoor applications. Other characteristics: relatively flexible ink film, long pot-life, slow drying.
Hardener H 2
Hardener H 2 is not suitable for outdoor applications because it yellows when exposed to UV-radiation which will be visible especially with varnishes or whites, and light-coloured shades mixed with white. Other characteristics: rigid ink film, shorter pot-life, quick drying.
Hardener H 4
Hardener H 4 is non-yellowing and is, therefore, suitable for outdoor applications. Other characteristics: significantly increased resistance to water and humidity.
Hardener HX
Hardener HX is non-yellowing and is therefore suitable for outdoor applications. Other characteristics: relatively flexible ink film, long pot-life, slow drying. HX is made without the use of aromatic hydrocarbons.
Hardener HT 1
HT 1 is a heat-reactive hardener which only reacts with the ink if force-dried at 150 °C for 30 min. HT 1 can be used instead of H 1 or H 2, provided the same quantity of hardener is added. Caution: HT 1 can only be used on heat-resistant substrates.
Hardener MGLH
This hardener is specifically for the use with Tampa® Glass TPGL and is not recommended for any other ink type.
Hardener HW 1
This hardener is specifically for the use with the waterbased ink system Maqua® Pad MAP on textiles for improved wash resistance and is not recommended for any other ink type.
Adhesion Modifier TP-HV 1
TP-HV 1 is used with Tampa® Sport TPSP for textiles that are difficult to print such as DWR (“durable water repellent”)-coated PU material (sports textiles, bags, rain jackets, shoes, umbrellas, backpacks, rain protection for prams, etc.). Preliminary trials are essential! As the printed ink film could be tacky immediately after printing it is important to dry it afterwards at room temperature or at temperatures appropriate to the textile. TP-HV 1 has to be used always in combination with Hardener H 4 (addition of 5 % TP-HV 1 and 20 % H 4).
General information on hardeners
All hardeners are sensitive to humidity. Therefore, the drying process must take place at the lowest possible ambient humidity in the first 24 hours, otherwise parts of the hardener will react with the water instead of the ink. During storage of the hardener any contact with humidity must also be strictly avoided (containers must always be completely closed after use!). Furthermore, the degree of cross-linking of hardener and ink, subsequently the chemical and mechanical resistance of the printed 2-component ink, is highly dependent on the temperature. By a forced drying of the ink at 140 °C-150 °C for 20-30 min. directly after printing, best possible cross-linking and thus the highest resistances will be achieved.
2-component ink systems can also be dried at room temperature; the complete cross-linking will, however, take up to 7 days and may have a reduced resistance. On difficult substrates such as glass, some metals, thermosetting plastics, and for high requirements, (e.g. dishwasher-resistance), forced drying of the ink in the oven may be essential.
11. CLICHÉ PROTECTION
Anti-Rust Additive AR
AR is an ink-specific additive that prevents rusting of low-quality steel clichés when using the water-based pad printing ink Maqua® Pad MAP.
12. REMARK
Besides the regular addition of thinner or hardener, further modification of the ink with auxiliaries should be well-considered. Auxiliaries show their positive effect only if added in the adequate quantity. Please refer to the Technical Data Sheets for quantity indications. The quantities are based on percentage by weight and not by volume. Overdosing will in most cases adversely affect the printing results and will lead to difficulties such as levelling problems or loss of adhesion, especially for multicolour prints. For these reasons, a scale and accurate working are a necessity. Any addition of an auxiliary will change the characteristics of the respective ink system. Preliminary trials are always essential.
Contact
In the event of any queries, please contact:
Technical Hotline
Phone: +49 7141 691140
technical.hotline[at]marabu.de
| Tampa® Star TPR | Tampa® Plus TPL | Tampa® Pol TPY |
|---|---|---|---|
Ink adjustment | 1- or 2- component ink, precise adjustment necessary otherwise ink may build up on pad, and may cause static problems | 1- or 2- component ink, easy processing and full ink film transfer; free of aromatic compounds | 1- or 2- component ink, easy and trouble-free processing with full ink film transfer |
Hardener H 1, slow | • | • * | • |
Hardener H 2, fast | • | • | • |
Hardener H 4, resistant | • | • | • |
Hardener HX | • | • | • |
Hardener HT 1, heat-reactive | • | – | • |
Addition hardener | 10 % | 10 % | 10 % |
Steel cliché, etch depth | 18 – 21 µm | 18 – 28 µm | 20 – 28 µm |
Ink well (open) | 10 – 20 % TPV | 10 – 20 % TPV | 15 – 20 % TPV |
Ink cup < 25 prints/min | 10 – 20 % TPV | 10 - 20 % TPV / TPLV | 15 – 20 % TPV |
Ink cup > 25 prints/min | 15 % TPV 2 | 15 % TPV 2 | 15 – 20 % TPV 2 |
Rotary pad printing | – | 25 – 30 % TPV | 15 – 25 % TPV |
Retarder | SV 1, VP, TPV 3 | TPV 3 *, SV 11, VP | SV 1, VP, TPV 3 |
| Tampa® Pur TPU | Tampa® Tech TPT | Tampa® Tex TPX |
|---|---|---|---|
Ink adjustment | 2-component ink with excellent chemical and mechanical resistance, must be adjusted accurately (not too thin) | Fast 2-component ink with long pot life (up to 16h). Generally a full ink transfer is achieved | 2-component ink for textile printing, universal use for different applications, good adhesion on many substrates |
Hardener H 1, slow | • | – | – |
Hardener H 2, fast | • | • | • |
Hardener H 4, resistant | • | – | • |
Hardener HX | • | – | • |
Hardener HT 1, heat-reactive | • | • | – |
Addition hardener | 25 % | 25 % | 20 % |
Steel cliché, etch depth | 20 – 24 µm | 20 – 24 µm | 20–28µm / > 35 µm (textile) |
Ink well (open) | 10 – 15 % TPV | 10 – 15 % TPV | 10 – 15 % TPV 2/7/9/10 |
Ink cup < 25 prints/min | 10 – 15 % TPV | 10 – 15 % TPV | 10 – 15 % TPV 2/7/9/10 |
Ink cup > 25 prints/min | – | 10 – 15 % TPV 2 | 10 – 15 % TPV 2/7/9/10 |
Rotary pad printing | 25 – 35 % TPV / TPV 2 | 25 – 30 % TPV / TPV 2 | – |
Retarder | SV 1, VP, TPV 3 | SV 1, VP, TPV 3 | TPV 3 *, GLV, SV 1 * |
* not for sensitive applications
| Tampa® RotaSpeed TPHF | Tampa® Cure TPC | Tampa® Sport TPSP |
|---|---|---|---|
Ink adjustment | 1- or 2- component ink with preadjusted viscosity for rotary pad printing, free of halogen- and aromatic compounds | 1- or 2- component UV-curable pad printing ink; must be adjusted to printing viscosity before use; prints with full ink transfer without build up on pad | 2- component ink for natural or synthetic fabrics, EVA, boost, and DWR-coated materials; very flexible and resistant |
Hardener H 1, slow | – | • | – |
Hardener H 2, fast | • | • | • |
Hardener H 4, resistant | • | • | • |
Hardener HX | – | • | – |
Adhesion Modifier | – | • 2 % UV-HV 1 | • 5 % TP-HV 1 |
Addition hardener | 10 % | 5 % | 10 - 20 % (H 2) |
Steel cliché, etch depth | gerastert: 22 – 30 µm | 18 – 22 µm | 33 – 35 µm |
Ink well (open) | 5 – 20 % TPV 8 | 5 – 10 % TPV 2, ggf. TPV / TPV 7 | 5 – 15 % TPV 2 / 10 |
Ink cup < 25 prints/min | 5 – 20 % TPV 8 | 5 – 10 % TPV 2 | 5 – 15 % TPV 2 / 10 |
Ink cup > 25 prints/min | – | 5 – 10 % TPV 2 | 5 – 15 % TPV 2 / 10 |
Continua / Big Wheel: Rotoprint / Mini Wheel: | 5 – 15 % TPV | 5 – 15 % TPV 2 | – |
Retarder | TPV 3 * | – | GLV |
| Tampa® Glass TPGL | Mara® Tech MGO | Mara® Prop PP |
|---|---|---|---|
Ink adjustment | Fast drying 2-component ink with very good printing properties and resistances, excellent printing results | 1-component baking ink for glass and metals, very high chemical resistance and opacity | 1-comp. ink for untreated and pre-treated PP; requires a higher amount of thinner than other inks; the transfer from pad is not complete, however, ink does not build up strongly |
Hardener | MGLH | – | – |
Addition hardener | 5% | – | – |
Steel cliché, etch depth | 18 – 24 µm | 20 – 22 µm | 18 – 25 µm |
Ink well (open) | 15 – 25 % TPGLV | 10 – 20 % TPV | 20 – 25 % PPTPV |
Ink cup < 25 prints/min | 15 – 25 % TPGLV | 15 – 25 % TPV 2 | 20 – 25 % PPTPV |
Ink cup > 25 prints/min | max. 20 % TPGLV | 15 – 25 % TPV 2 | 5 – 35 % PPTPV |
Rotary pad printing | – | – | 30 – 35 % PPTPV |
Retarder | TPV 3 | GLV, SV 3* | SV 1 |
* not for sensitive applications
| Maqua® Pad MAP |
|---|---|
Ink adjustment | Fast drying 2-component ink with very good printing properties and resistances, excellent printing results; no full ink transfer |
Hardener | HW 1 |
Addition hardener | 10% |
Steel cliché, etch depth | 20 – 35 µm / + 5 % AR |
Ink well (open) | – |
Ink cup < 25 prints/min | 5 – 10 % WV 1 |
Ink cup > 25 prints/min | 5 – 10 % WV 1 |
Rotary pad printing | – |
Retarder | WV 1 |