Introduction to heat transfer printing
Heat transfer printing is a widely used printing technology with numerous uses. This printing method transfers a design or image from a specifically designed paper to a product or substrate using heat and pressure. In the textile industry, Heat transfer printing is commonly used to adorn T-shirts, caps, and other clothing. It’s also used to make promotional things like key chains, mugs, and pens.
Heat transfer printing is comprised of three essential components: transfer paper, substrate, and heat press. The design or image that will be transferred to the substrate is printed on transfer paper. The substrate is the substance onto which the image will be transmitted. The substrate for printing images on garments is the apparel itself. A heat press is a machine that transfers an image from paper to a substrate by using heat and pressure.
How does heat transfer printing work?
The procedure begins with the creation or selection of a design to be transferred onto the target surface. This pattern is often printed with suitable inks on special sublimation paper. If you enjoy cute animals, for example, you should print the animal pattern on sublimation paper.
The printing surface, such as fabric or a hard substrate, must be clean and free of dust, dirt, or wrinkles. This promotes adequate adherence and easy design transfer. If the surface of the substrate is not smooth, the printing will be poor and may slide off at any time.
Temperature settings for a heat press
Thermal transfer printing is done with a heat press. The machine is made up of two parts: a heated platen (top part) and a flat surface (bottom part). Temperature and pressure parameters are modified based on the type of transfer paper and the surface material.
Placement of transfer paper
Place the printed iron-on transfer paper on the surface, face down, and align the design in the desired place. For exact transfer, precise location must be ensured.
The use of hot pressing
Heat pressure is provided to the transfer paper and surface while the heat press is turned off. Heat and pressure activate the ink pigments, causing them to sublime or transfer to the substrate’s surface.
The dwell time is the amount of time that the transfer paper and surface are exposed to heat and pressure. During this time, the ink might penetrate the surface and make a lasting connection.
Removal and cooling
Turn on the heat press after the dwell time is over and carefully remove the transfer paper off the surface. It must be peeled carefully and at the proper angle to avoid damaging the transferred pattern.
The printed design is permanently bonded to the surface after the transfer paper is removed. Additional procedures, such as curing or post-treatment, may be required depending on the material to improve durability or colorfastness.
What are the pros and cons of heat transfer printing?
Pros of heat transfer printing
Thermal transfer is applicable to a wide range of substrates, including fabric, metal, paper, and plastic. As a result, it is a versatile printing technology that may be employed in a wide range of sectors.
2. Quick turnaround
Thermal transfer printing is a reasonably quick manufacturing method. Once a design is complete, printing may be completed in minutes, making it ideal for meeting tight deadlines or printing on demand.
Thermal transfer printing, unlike other printing technologies such as screen printing, does not require a substantial upfront investment in equipment or consumables, making it the first choice for early-stage businesses.
Cons of heat transfer printing
1. Short lifespan
Thermal transfer printing may be less durable than other printing technologies such as screen printing or direct-to-garment printing. Transferred graphics may crack, fade, or peel with time, especially if washed frequently or used excessively.
2. The life of the heat press is limited
Heat presses have a limited lifespan and must be serviced on a regular basis to perform effectively. This can be a drawback for individuals who primarily print via thermal transfer.
3. Limited breathability
Heat transfer printing on textiles affects the fabric’s breathability. This is due to the ink forming a layer on top of the cloth, which can compromise comfort, particularly in sports or performance wear.
How to distinguish sublimation printing and heat transfer printing？
Both sublimation printing and heat transfer printing are popular ways of transferring designs to diverse surfaces, although their processes and applications differ. Here’s how to distinguish between the two:
- Sublimation printing employs heat and pressure to transform solid dye particles into a gas, which then penetrates the material’s surface and cures, establishing a permanent bond. The ink is directly transferred from the sublimation paper to the substrate.
- Heat transfer printing is the application of heat and pressure to transfer a design from a carrier paper or film to the material’s surface. Designs are often printed on transfer paper with specific inks before being applied to the substrate.
- Sublimation printing is most effective on polyester or polyester coated substrates. To bind properly, dye particles require a polymer-rich environment, hence the material must have a high polyester content (usually greater than 65% polyester).
- Heat transfer printing is more adaptable and may be utilized on a wide range of materials, including cotton, polyester, mixes, porcelain, metal, and others.
- Sublimation printing provides high durability since the ink becomes a part of the material rather than remaining on the surface. These designs are fade, crack, and peel resistant, making them ideal for long-term use.
- Heat transfer printing’ durability may be compromised. Heat transfer printing may fracture, fade, or peel with time, depending on the transfer substance and quality, especially if washed frequently or worn excessively.
Feel and Breathability
- Sublimation Printing: Because the ink is embedded in the material, sublimation printing provides a smooth surface. The print preserves the fabric’s inherent texture and breathability for a comfortable fit.
- Heat transfer printing can have a somewhat raised or rubbery feel depending on the type of transfer medium utilized. This has an impact on the feel and breathability of fabrics, particularly textiles.
- Sublimation printing enables for rich and detailed graphics with brilliant colors and gradients. It is capable of reproducing photorealistic visuals as well as complicated patterns.
- Heat transfer printing is ideal for designs that feature solid colors, straightforward graphics, and striking artwork. Fine details and gradations may not be as accurately reproduced as with sublimation printing.
Heat transfer printing is a versatile and affordable printing process that is utilized in a wide range of industries. Despite some limitations, including as durability and air impermeability, it can produce high-quality, detailed prints on a range of materials. By following these heat transfer instructions, you can ensure that your designs transfer correctly and look beautiful on the fabric or substrate of your choice.