1 - General Information about Plastisol Inks:
Plastisol inks are widely used in garment printing because they are easy to print, do not dry in the screen, can be opaque on dark garments, and can adhere to most textiles. They are composed primarily of PVC resin (a white powder) and plasticizer (a thick, clear liquid). Plastisol must be heated to 300°- 340° F (143°-166° C) to dry (cure).
Plastisol inks can be printed on virtually any surface that can withstand the heat required to cure the ink and is porous enough to permit good ink penetration. Plastisol inks do not dye the fibers. Instead, the ink wraps around the fibers and makes a mechanical bond with the fabric. For this reason, they will not adhere to non-porous substrates such as plastic, metal, and glass. They will also not adhere well to woven, water-proofed nylon without adding a bonding agent.
2 - Health, Safety, and Environmental Concerns:
Plastisol inks are innocuous when used with reasonable care. A true plastisol ink contains no air-polluting solvents or volatile organic compounds. The manufacture, transportation, storage, use, and disposal of plastisol inks do not cause injury, illness, or environmental contamination as long as the appropriate safety and environmental protection procedures are followed.
3 - Mesh Selection Guide:
Threads/in Threads/cm Printing Type
30 - 40 12 - 16 Glitter Inks
60 - 95 24 - 38 Athletic printing, opaque ink deposits, thick puff ink,
shimmer inks.
86 - 110 34 - 43 Heavy coverage on dark shirts, solid underbase,
puff, metallic, shimmer Inks and transfers.
125 - 150 49 - 59 General printing on light shirts and light nylon
jackets.
180 - 230 71 - 90 Multi-color printing on light shirts and light nylon
jackets.
230 - 305 90 - 120 Detailed multi-color printing on light shirts, light
nylon jackets, overprinting on dark shirts.
305 - 355 120 – 140 Process color (CYMK) on light shirts and
overprinting on dark shirts.
Also: When printing on fleece goods use 20 threads lower.
When printing on an automatic press use 30 threads higher.
4 – Emulsion Selection:
It’s recommended to use solvent resistant emulsions or Duals, preferably Diazo.
We have 6 different emulsions according the application and the ink to use:
Vortexol Emulsion (Diazo), Emulsion “M”, Universal L Emulsion, Ulano 925WR and SBQ Photoemulsion (Photopolimeric)
5 - Plastisol Ink Additives:
A word of caution about ink additives: It's easy to upset the chemical balance of plastisol inks by adding too much or by using the wrong additives. The result can be a print that never cures properly, a problem that may not be discovered until your customer washes a shirt and the design falls off. To avoid this, use only those additives recommended by Union Ink, read the technical Data Sheets for each ink and additive, and carefully follow their instructions.
Never add mineral spirits to plastisol ink:. Although mineral spirits will make it easier to print at first, later the ink will thicken up on standing. Also, it is possible that mineral spirits will prevent the ink from curing properly.
6 - Ink Storage:
Store plastisol inks at room temperature. Prolonged exposure to temperatures above 90 F (32 C) can cause the ink to start to cure while still in the container.
7 - Screen Wash-up:
Clean plastisol ink off your screens with either mineral spirits or any of the various brand name screen washes available from your screen printing supplier.
There is available WASH 8020, an Ecological Screen Cleaner with a pleasant citric fragrance.
8 - Print Washability:
The washability of properly cured direct and transfer prints is excellent. Do not dry clean. Do not iron the printed part of the garment.
9 - Controlling Dye Migration:
Dye migration is the problem caused by dyes in polyester fibers transferring to and changing the color of plastisol inks. The colors most likely to migrate are red, maroon, kelly green, and some of the darker blues.
Dye migration may appear immediately after the ink is cured, or hours, days, or up to two weeks later.
To control dye migration use the following procedures:
- Print with high-opacity, low-bleed inks.
- Use no more heat than necessary to cure the ink. Excessive heat can trigger
dye migration.
- Print and flash-cure a low-bleed white underbase, then print the desired color
over that.
- Avoid the problem entirely by printing on 100% cotton fabrics.
10 - Preventing build-up with plastisol inks:
Build-up is exactly what the name implies, the build-up of ink on the backs of screens. This can interfere with the print, throw off-registration, and slow print speeds. Buildup would not be a problem except for the luxury that plastisol printers have to be able to print most of their work wet-on-wet. If each color were cured before the next color was printed, there would be no build-up.
Build-up is more common with automatic printing and opaque inks. Build-up never shows on the first screen in the sequence, it's always on the subsequent screens in a design. Some colors have a stronger tendency to build-up than others do. One of the main causes of build-up is that more ink is printed than the fabric can hold. If the fabric cannot hold it, then the ink readily transfers back to the subsequent screens. In other words, the excess ink has greater adhesion to the screen than it does to the substrate. The following steps will help you control build-up and improve overall print quality.
Use Inks Designed to Reduce Buildup: Union Ink's Autoline, Automatch, Mixopake, and Tru-Tone ink lines are much less liable to cause build-up problems.
Reduce Inks With Extender Bases and Flow Additives: MIXO-9070 and PLUS- 9090 are great for reducing build-up. For Mixopake inks Flow Additive (MIXO-9020) is also recommended.
Use Higher Mesh Counts: Use the highest recommended mesh count for a particular ink series. This practice will not only decrease the amount of ink used; it will improve the hand of print.
Use Well Tensioned Screens: Screen tensions should be greater than 20 Newton's/cm and all screens on a particular job should be the same tension.
Reduce Off-Contact: Low off-contact distances (no more than 0.080" or 2.0 mm) reduce the amount of squeegee required to print the ink. Low squeegee pressure reduces the amount of ink printed.
Use the Correct Squeegee Angle: Set the squeegee angle at no more than 15 degrees from vertical. Reduced squeegee angle reduces ink laydown.
Use A Medium-Hard Squeegee: Use 70/90/70 or 75 durometer squeegees.
Increase Squeegee and Floodbar Speed: Increase the speed until the laydown suffers then back off just enough to print correctly. Union Ink's newer plastisol formulations are designed to reduce build-up. However, poor printing practices can result in build-up. By following the suggestions outlined above you can minimize buildup and improve your print quality and production speeds at the same time.
11 – Printing Tips
Transfer Printing: Most plastisol heat transfers fall into one of three categories, hot-split, cold-peel, or puff. When hot-split transfers are applied, the paper is stripped off the garment immediately after the heat transfer press is opened. The ink layer splits, leaving part of the ink on the garment and part on the transfer paper. Hot-split transfers are nearly indistinguishable from a soft-hand direct print. When cold-peel transfers are applied, the transfer is allowed to cool before the paper is removed. All of the ink transfers from the paper to the garment. Coldpeel transfers have a glossy surface and are preferred for glitter and athletic transfers. Some transfers can be either hot-split or cold-peel. Puff transfers are printed with special puff transfer inks and produce a puff design. Transfers that have been properly printed and applied are as durable as a direct print.
Curing Transfer Prints: When printing heat transfers, the ink is gelled or brought to a semi-cure at between 180°-250° degrees F (82°-121° degrees C) just past the wet state. If they are over-cured, the ink will not transfer well. Transfers that have been semi-cured become fully cured when they are applied to the garment.
Testing For Cure: To determine the correct dryer settings for transfers, increase the conveyor speed, or decrease the temperature of the curing unit until the stacked prints begin to stick together or show a slight amount of set off on the back of the upper sheet. Then decrease the conveyor speed enough to eliminate the sticking. Another test for gel (though not always accurate) is to peel the ink off the release paper and roll it into a ball. If the ball unrolls when laid down, the transfer is uncured. A third test is the stretch test. The ink layer should be gelled just enough that you can peel it off the paper, but if you stretch it, it should break with every little stretch.
Hot-Split Transfer Tips: For medium-opacity transfers use Ultrasoft or Autoline ink. For high-opacity transfers use Mixotrans. Print through an 86 threads/inch (34 metric) mesh. Cure to 250° degrees F (121 C). See below for curing procedures. Use Super-Trans, Trans-Lith, or Trans 55 paper, available from Union Ink. Transfer to the garment at 350° degrees F (177 C) for 10-15 seconds at 25-30 ldb/in² (1.75-2.1 kgf/cm²). Peel the paper off the garment immediately after the press is opened.
Cold-Peel Transfer Tips: Use the same inks, mesh, and curing procedures as for hot-split transfers. Use TransFrench T-75, Super-Trans, or TransLith paper, available from Union Ink. Transfer to the garment at 350° degrees F (177° degrees C) for 10-20 seconds at 25-30 lbf/in² (1.75-2.1 kgf/cm²). Allow the transfer to cool completely before stripping off the paper.
Glitter Transfer Tips: For glitter transfers, use Super Glitter printed through a 30 thread/inch (12 thread/cm) mesh. Cure as for hot-split transfers. Use TransFrench T-75 or TransLith papers. Glitter transfers are generally applied using the cold-peel procedures.
Puff Transfer Tips: For puff transfers, use Transpuff ink printed through a 60 threads/inch (25 metric) mesh. Print a very thick layer of ink onto Trans-55 paper. After printing the transfer, apply a transfer adhesive powder such as Union's Ulon Heat Transfer Powder, either by sprinkling the powder over the print, or by passing the transfer through a tray containing the powder. The ink should be cured enough that it does not smear or offset, but enough to puff. The temperature window for curing puff transfers is 180°-200° degrees F (82°-93° degrees C). Apply the transfer at 375° degrees F (190° degrees C) for 5-10 seconds at 30-40 lbf/in² (2.1-2.8 kgf/cm²). Remove the paper from the garment immediately after opening the transfer press.
Testing for Transferability: It is essential that you test your heat transfers at the start of each production run. This is particularly important when using a new paper or ink. You should also do accelerated aging tests which will indicate how well the transfer will release after 6-12 months on the shelf. Accelerated aging tests can be done by will simulate approximately one year of shelf storage. While this test does not exactly duplicate the effects of aging, it will definitely help you determine whether a particular transfer will release well after aging. Accelerated aging tests can be done by placing the printed transfer in an environment of 120° degrees F (49° degrees C) for 100 hours. This will simulate approximately one year of shelf storage. While this test does not exactly duplicate the effects of aging, it will definitely help you determine whether a particular transfer will release well after aging.
Always Test Inks Prior To Production Runs Always test inks to determine their fitness for your particular applications, especially new types of inks or when printing on new products. Before printing a production run, print a sample for testing for adhesion, crocking, opacity, washability and specific job requirements.
Warranty Disclaimer:
Vortex Argentina believes that the information contained in this catalog is accurate and opinions expressed are those of qualified experts. However, the information is not to be taken as a warranty or representation for which Vortex Argentina assumes legal responsibility. It is offered solely for your consideration, investigation, and verification.
Vortex Argentina will replace or refund any defective product returned to us within 1 year of the purchase date. This warranty is in lieu of any implied warranty of merchantability or fitness, and no other warranty shall apply. The user is responsible to determine whether the product is suitable for each particular substrate and application. The user must test thoroughly (including wash and storage tests) before using in production. In no event will Vortex Argentina be responsible for indirect or consequential damages such as damaged substrates or printing labor.
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