HOT PEEL OR HOT SPLIT TRANSFERS
“Hot peel” or “hot split” refers to transfers made by peeling away the transfer paper immediately after they are applied in the transfer press – or while they are still hot. Both hot peel and hot split are used interchangeably.
Hot split transfers split the ink film between the paper and the fabric after heat and pressure are applied. As the paper is peeled from he fabric, some of the ink remains on the transfer paper while the majority melts into the fabric. This splitting of the ink film produces a very soft, breathable print when using standard opacity inks. Some types of transfer inks melt almost entirely into the fabric and leave very little, if any, residual ink on the paper. The paper and/or the ink used, along with application time, temperature and pressure of the heat seal machine, all govern whether the ink melts entirely into the fabric or not. Hot peel transfers that release almost the entire ink film may not be quite as soft and breathable as hot split transfers. The difference between these products may in fact be too slight to notice in some applications.
A variety of papers are recommended for printing hot split or hot peel transfers. These range from noncoated papers to specialty-coated papers. Both types perform well, but the specially coated papers are usually more forgiving to the novice transfer printer. The better release of the coated paper, as compared to a non-coated paper, allows for a slight over gelation of the inks. Gelation is the term used for partial fusing (surface drying) of the inks when printed. Over gelation of the inks, when printing transfers, can cause poor release, spotty transfers, or poor adhesion. To print transfers, inks must be gelled between each color (not printed wet on wet as in direct printing).
Gelation temperatures range from 225°F to 275°F (107°C to 135°C) depending on ink film thickness, and the ink being used. Properly gelled ink is dry to the touch and should break apart easily if removed from the paper. If ink is severely under gelled and stored before application, plasticizer (an ingredient in the ink) may exude from the ink and form a clear uneven border around the outside of the print on the paper. If this exudation occurs, it is a sign that the transfer is losing an ingredient needed for proper adhesion and fusing. Adding too much reducer to the transfer ink may exacerbate this problem. The final fusing of a transfer ink occurs when the transfer is applied to the garment.
Fusing is the proper term for “drying” plastisol inks. Curing is a generally accepted term when referring to the drying of plastisol inks, but is really what happens to most water or solvent based inks when heated or catalyzed.
It is important to only use papers designed for transfer printing, because they are usually more temperature stable than conventional bond papers. This is very important when printing hot split, multicolor transfers. Papers tend to shrink when heat is applied to them. Since hot split transfers need to be butt registered (colors touch or almost touch each other but do not overlap), too much shrinkage will lead to poor registration. Poor registration, in turn, leads to noticeable gaps between colors in hot split transfers, or muddy looking colors where colors overlap. It is important to preheat transfer paper before printing multicolor transfers and to keep the paper warm between colors until the job is finished. Many printers use hot boxes – a cabinet that is heated to 120°F to 130°F (49°C to 54°C), to store printed paper overnight or between colors.
Hot split or hot peel inks are plastisol inks that have a lower melt point than standard plastisol inks. The lower melt point allows the inks to release or split quickly from the paper and to penetrate into the garment. This gives the inks a very soft hand and excellent durability. International Coatings has developed an additive, Quick Trans 500, which can be added to its Multipurpose, 700 Series and 1100 Series Plastisols to convert them to hot split or hot peel transfer inks. The mixed inks will work on non-coated or specially coated transfer papers. The ratio of ink to additive is 3 to 4 parts ink, to 1 part additive. For light colored fabrics, mixed Quick Trans 500 inks should be printed through a 110 to 305 monofilament screen mesh. To achieve a more opaque color, use the 500 additive with HP (High Pigment) colors printed through 60 to 86 monofilament screen mesh. The screen mesh selected should be based on the detail of the design being printed and the type (T-shirt, or sweatshirt) and color of fabric to which the transfer is being applied. Use a 60 to 70 durometer squeegee (hardness of squeegee blade) with a sharp edge. The ink deposit should be about 3 to 4 mils (ink film thickness after gelling) for light colored fabrics. For darker fabrics, a 6 to 10 mil film thickness is necessary.
Transfer application times for both coated and non-coated papers will range from 4 to 7 seconds with medium pressure (40 lbs on most air operated transfer machines) at 375°F to 400°F (191°C to 204°C). Peel transfer hot. Correctly calibrated transfer machines are an important part of the transfer process. If transfers do not apply properly, don’t forget to check the transfer machine, as well as your printing and transferring procedures.
OPAQUE HOT PEEL TRANSFERS
Opaque transfers should be printed using International Coatings 500 Series Opaque inks. These inks were specifically formulated for making very opaque hot peel transfers. They will make a better opaque transfer than the high pigment, 500 additive combination. The 500 Series inks work best on the specially coated hot peel transfer papers. They require lower gelation temperatures (180°F to 225°F or 82°C to 107°C) than a standard mixed hot peel transfer ink. Application time is 3 to 7 seconds with medium pressure, at 375°F to 400°F (191°C to 204°C). For further information on this product see International Coatings product bulletin on the 500 Series Opaque
PUFF HOT PEEL TRANSFERS
Use International Coatings' 300 Series Puff Transfer Inks to achieve hot peel puff transfers. 300 Series inks should be printed through a 60 to 110 monofilament screen mesh using a 60 to 75 durometer squeegee with a sharp or beveled edge. Use non-coated or specially coated hot peel transfer papers. Gelation temperatures are very important when using this ink. The gelation temperature range is 180°F to 200°F (82°C to 107°C). Over gelation of this ink may cause the ink to puff on the paper, or not release properly. International Coatings #303 adhesive powder must be applied to the ink while it is still wet, to give the ink proper adhesion and durability on the garment. The powder adhesive is usually applied by dipping the wet transfer in a box of adhesive or by sprinkling. Shake off the excess adhesive and run through the dryer at the proper temperatures. Brush off excess powder adhesive with a soft brush after the transfer exits the dryer. For multicolor puff transfers, each color of puff must be coated with the powder adhesive. Application time is 3 to 7 seconds with medium pressure, at 375°F to 400°F (191°C to 204°C). Peel transfer while hot.
If a transfer does not puff properly, it is usually due to over gelation.
COLD PEEL TRANSFERS
International Coatings Multipurpose, 700, 1100 or 500 Series Plastisols can be used to make cold peel transfers. The inks should be printed straight from the container on a coated, cold peel release paper. The most common cold peel paper is known as T-75, Transfert-75 or French paper. Parchment paper can also be used, especially where it might be helpful to see through the paper. Parchment paper is best suited for one-color transfers since it shrinks considerably when heated. When ordering paper for cold peel transfers, make sure to specify cold peel application. Inks can be printed through a 61 to 160 monofilament screen mesh. The screen mesh used will depend on design detail and the ink being used. Glitter inks should be printed through 16T to 25T monofilament
mesh for best results. The gelation temperature for Multipurpose, 700 and 1100 Series inks is 225°F to 275°F (107°C to 135°C). The gelation temperature for the 500 Series inks used as a cold peel ink is 180°F to 225°F (82°C to 107°C). Use a 60 to 70 durometer squeegee with a sharp to rounded edge. The squeegee edge used will depend on the ink being printed, detail of the design and ink deposit required. Colors for cold peel transfers can be overlapped, because the ink is not split when applied. Poor adhesion and/or elongation (stretch) may result from over gelation of the inks.
Adhesive powders, such as International Coatings 304 powder adhesive, can be sprinkled on wet ink and gelled for better adhesion to problem fabrics such as polyester. Make sure to brush off excess adhesive from the gelled transfer to prevent adhesive spotting on dark fabrics. Quick Trans 500 additive can be added to the cold peel inks to give a little better release and a softer hand. The ratio is 6 to 8 parts ink to 1 part 500 additive.
Completed transfers are applied at 350°F to 375°F (178°C to 191°C), for 10 to 15 seconds, medium pressure. Cold peel transfers, when made correctly, can be very durable. If they are not, it is usually due to over gelation or poor application procedures. Since the entire ink film is removed from the cold peel transfer when applied, they are not as breathable and soft as most hot peel hot split transfers.
Two adhesives are recommended for making foil transfers. 3801LF1 is a plastisol foil adhesive and is used for foil applications on cotton, cotton/polyester blends and 100% polyester fabrics. 3901LF is a water-base foil adhesive. It can be used on cotton, cotton/polyester blends, some nylons, Lycra-Spandex, and leather. It is important to test adhesion and durability of these products before beginning a production run. Both of these adhesives can be directly printed to the garment for foil applications.
3801LF-plastisol foil adhesive should be printed through a 60 to 110 monofilament screen mesh. Use a 65 to 70 durometer squeegee with a sharp edge. The adhesive, when used for making foil transfers, should be printed on the dull, silver side of the foil, mirror image. Gel the adhesive on the foil at 250°F to 275°F (121°C to 135°C). Since this is a heat activated adhesive, gelation temperatures are not as critical as they are with hot peel transfers. Application temperature is 325°F to 350°F (163°C to 178°C). Try 325°F (163°C) first, for best results. Application time is 10 to 15 seconds. Wait till the transfer cools before removing the foil carrier sheet. When doing the foil
application as a transfer only, it is suggested that the garment be preheated for 5 seconds before the transfer is applied. This will remove any moisture from the fabric. For more information, refer to International Coatings' product bulletin on 3801LF.
3901LF water-base foil adhesive should be printed through a 60 to 86 monofilament screen mesh coated with a water-resistant stencil or emulsion. This product can be air-dried or heat cured at 250°F (121°C). The ink, when used for making foil transfers, should be printed on the dull silver side of the foil, mirror image. 3901LF waterbase adhesive will dry quickly in the screen if left unattended for any time. Leave screen flooded with adhesive between prints and use International Coatings 416 or 415 Retarder on warm days. Immediately clean the screen with water and a cleaner such as Formula 409 after use. Once the adhesive has set up, (dried) in the screen, it is very difficult to remove.
Nylon transfers can be made using International Coatings 900 series inks (with no catalyst), 210 solvent based adhesive and 290T heat resistant silicone paper. The 900 Series inks should be printed through a 110 to 125 monofilament screen mesh and completely fused at 325°F to 375°F (163°C to 191°C) on the 290T paper. The ink must be completely fused so that it resists the solvent in the 210 adhesive. The 210 adhesive is then printed over the 900 ink. The adhesive must overlap the entire printed ink film by at least 1/32". It is the 210 adhesive that bonds the ink to the nylon, so it must cover the whole ink film, and form a slight border a outside the edges of the design. The 210 adhesive should be printed through a 61-monofilament screen mesh coated with a solvent resistant
emulsion. Use a 65 to 80 durometer squeegee. Completely fuse the adhesive at the same temperatures as the ink. Colors may overlap each other (as with a cold peel transfer) and should be dried between each color. The 290T paper is necessary for proper performance of the transfer. It has an excellent release and will not break down from the high heat needed to make nylon transfers. Use International Coatings # 275 thinner for cleaning and thinning the 210 adhesive. With the 900 inks, use mineral spirits or plastisol screen wash to wash up.
When heat sealing finished transfers to nylon, it is recommended that the fabric be preheated for 5 seconds at 325°F to 375°F (163°C to 191°C) to remove surface moisture and wrinkles. Depending on the stability of the nylon to heat, try lower application temperatures for best results. Place the transfer in position and heat seal for 10 to 15 seconds at 325°F to 375°F (163°C to 191°C). After heat sealing and before removing transfer, immediately rub the hot transfer with a cloth to eliminate bubbling. Be careful not to rub too hard or the transfer may move before cooling. Remove transfer when cool. An edge of adhesive may show around applied nylon transfers on
darker fabrics. Testing must be conducted to determine the suitability of any transfer for nylon applications.
RECOMMENDATIONS AND STATEMENTS MADE ARE BASED ON INTERNATIONAL COATINGS’ RESEARCH AND EXPERIENCE. SINCE INTERNATIONAL COATINGS DOES NOT HAVE ANY CONTROL OVER THE CONDITIONS OF USE OR STORAGE OF THE PRODUCT SOLD, INTERNATIONAL COATINGS CANNOT GUARANTEE THE RESULTS OBTAINED THROUGH USE OF ITS PRODUCTS. ALL PRODUCTS ARE SOLD AND SAMPLES GIVEN WITHOUT ANY REPRESENTATIONS OF WARRANTY, EXPRESSED OR IMPLIED, OF FITNESS FOR ANY PARTICULAR PURPOSE OR OTHERWISE, AND UPON THE CONDITION THAT THE BUYER SHALL DETERMINE THE SUITABILITY OF THE PRODUCT FOR ITS OWN PURPOSE. THIS APPLIES ALSO WHERE RIGHTS OF THIRD PARTIES ARE INVOLVED. IT DOES NOT RELEASE THE USER FROM THE OBLIGATION TO TEST THE SUITABILITY OF THE PRODUCT FOR THE INTENDED PURPOSE AND APPLICATION. REV70100
For greater durability, garments with applied foil transfers should be hand or machine washed (delicate cycle) inside out and line or air-dried. Use proper precautions and adequate ventilation when using 210 adhesive and 275 thinner.