How to screen print heat transfer plastic?

Screen printing heat transfers are a convenient way to increase the efficiency of your store.

In the textile and T-shirt screen printing industry, thermal transfer printing is an effective way to improve printing. If you already own a screen printer, you can create and use plastisol heat transfer equipment with minimal investment in additional tools and equipment.

First the basics: What is plastisol heat transfer?

Thermoplast heat transfer is the reverse image of screen printing on special transfer paper. The ink on the paper is partially cured, then when it is ready to be placed on the substrate, the paper is placed face down on the material and heated to approximately 400 degrees. The paper is peeled off, leaving a fully cured plastisol image on the substrate.

Advantages of Using Plastisols for Heat Transfer

While thermal transfer won't replace your normal screen printing operation, there are several applications that can make thermal transfer valuable. Plastisol heat transfer printing is ideal for thick, sharp prints on difficult-to-print substrates such as baseball caps and jerseys.

Plastisol heat transfers are also great for printing in small runs when you're not sure which items or sizes you need, such as custom or event printing. If you are creating your own custom images to sell individually, you can make a large batch of heat transfers and then print them on individual products when you receive the order. Likewise, you can apply heat transfers to events and prints to shirts, hats or bags when purchased. In both cases, plastisol heat transfer allows you to meet customer demand without overprinting large quantities of unsold merchandise in your store.

Plastisol heat transfer also saves time. Because transfers place the ink on the surface rather than allowing it to work into the texture of the substrate, they are popular in mesh jerseys. This means that while you have some downtime at the store, you can heat transfer simple capital letters and numbers, then quickly apply them to the jersey when the order comes in.

Important to know: How does plastisol heat transfer work?

In order to successfully print with sublimation plastics, it is important to understand how they are made. Plastisol heat transfers are made in much the same way you would make any screen print, with a few minor changes. The main difference with heat transfers is that you are actually printing backwards because when the top layer of the heat transfer is applied to the shirt it will be the bottom layer. You will also strive to produce a heavier ink deposit on plastisol heat transfer than on typical substrates.

You start with a coarser mesh and apply a thick layer with your lotion. The screen printing surface should be coated with at least three layers of emulsion, and the screen scraper surface should be coated with at least one or two layers of emulsion. Using a mirror image of the stencil you will be exposing the screen, keep in mind that the exposure may take longer due to the heavier emulsion coating.

Print Now: The Foundation for Success

To print, you will establish a higher non-contact distance on the screen printer, usually about 1/16 inch. If you are experimenting with sublimation transfers or only do them occasionally, you can use spray glue to secure the transfer paper to the platen. If you plan to do a lot of heat transfers or use them as a regular part of your screen printing business, you will want to look into a vacuum platen that keeps the transfer paper flush with the platen during printing. If you're printing multiple colors, you'll start with the top layer of the image and work your way down to the bottom layers. You can't print sublimation wet-on-wet; you need a quick cure between each color. For a crisp print, apply the ink one at a time with the squeegee, pressing down with medium pressure.

After completing the plastisol heat transfer, you will need to partially cure the image. This means heating your thermoplastic ink to between 180 and 240 degrees Fahrenheit. Your plastisol heat transfer will be ready to be applied to your end product.

How do you apply plastisol heat transfer?

Applying your plastisol heat transfer is a simple process, but there are two application options: heat split transfer and cold transfer. You will place the substrate into the heat transfer machine and place the plastisol heat transfer where desired. With your heat transfer press set to between 330 and 350 degrees Fahrenheit, you will be pressing the heat transfer onto the substrate for 10 to 12 seconds. If you're using thermal break transfers, you'll be tearing off the paper right away, which splits the ink in two, depositing some ink on the substrate while leaving the rest on the paper. This type of transfer provides a softer feel. With cold transfers, you will allow the substrate and transfer paper to cool for about 40 seconds before peeling off the paper. The entire plastisol transfer will remain on the shirt.

What equipment do you need for thermoplastic heat transfer?

In addition to your regular screen printing equipment, you can perform heat transfer printing with very little consumables and equipment. You'll need screens and transfer paper with a mesh count between 86 and 156. Some printers prefer to apply transfer bonding powder to their plastisol transfers prior to partial curing. This can help plastisol heat transfer adhere more effectively to the final substrate. You'll also use regular screen printing equipment: emulsion, squeegee, thermoplastic ink, and screen printing press. Of course, to apply your plastisol heat transfers, you'll need a heat transfer machine.

How do you get started with plastisol heat transfer?

Once you have added the necessary supplies and equipment to your screen printing shop, you can start making plastisol heat transfers. You should find this an easy process as it's not too different from the normal screen printing process, but it may take some experimentation to perfect your heat transfer. Before you know it, you'll be using plastisol heat transfer to make your store more efficient and profitable!