A Direct to Film or DTF uses a heat-press mechanism to transfer prints onto several types of fabric. The printer allows a design on a film to transfer to the fabric. The dtf printer is known for its flexibility and chooses almost any surface to print on such as polyester, cotton, silk, or synthetic. Plus, it also works on different colored fabrics without needing to use expensive paper.
Requirement of a DTF Printer
A dtf printer is quite an affordable investment for someone in the digital printing business. Each part f a printer is crucial for the entire printing process to be done smoothly. A dtf printer has the following requirements;
- Films
Dtf printers use PET films which are commonly known as DTF Transfer Films in their printing process. the films are usually 0.75mm thick and have better transfer quality. PET films are commonly used in DTF printing. these films can be used on a small scale (which is in the form of Cut sheets) and can be used in a large commercial setup (In form of Rolls). The PET films are also known for peeling after the transfer. The films can be a hot-peel type or cold-peel type based on the temperature.
- Software
The software of the DTF printer is an important part of the process. it has a great impact on the color performance which largely handles white colors and CMYK. It is also crucial in the printing quality, drop sizes, and ink levels.
Hence, having proper software can gradually increase the quality of the finished print. The DTF printer governs all factors which provide the best print outcome.
- Hot-melt adhesive Powder
Three are several grades of the hot-melt adhesive powder but normally the powder is white and binds colored pigments together with its adhesive properties. The grades are specified in microns which can barely be seen by the naked eye. Based on the printing requirement a suitable grade will be used for proper printing on the material.
- DTF Printing Inks
DTF printing inks come in several colors specially designed for the printer. The inks are available in magenta, yellow, white, cyan, and white. The white color acts as a foundation for other colors to be printed on the film. It is laid out on the film first before the colored designs are printed.
- Automatic Powder Shaker
This powder shake is used in large commercial setups making sure that the powder is applied evenly throughout the rolls to get rid of any excess powder.
- Curing Oven
This is a small oven used for melting then hot powder. However, in case of no contact with the powder a heat press machine can also be utilized to melt the powder. The hot melt powder is then applied to the film.
- Heat Press Machine
A heat press machine is one of the main requirements in the DTF process because it transfers the image from the film onto the fabric. Apart from that it also heats the melted powder that is to be applied to the film.
Direct to Film Printing Process
1 – Print on Film
Use a PET film instead of paper and place it inside the printer trays. The first image is in white which is printed on the film as the foundation or base. Then, adjust the settings to the preferred color and print it on top of the white base or layer. During this process, it is crucial to keep in mind that the image printed on the film should be the exact image that will be printed onto the fabric.
2 – Powdering
Powdering involves applying the hot melt powder evenly throughout the PET film where the image is to be printed. The powder must be applied when the ink is west and should be distributed throughout the PET film without leaving any excess powder. If there is any excess it must be carefully removed to avoid distorting the image.
To make sure that the powder is spread evenly it is recommended that the film be placed or held in a straight landscape (floor) and the powder is poured slowly and carefully from the top to the bottom. After this bend the film slightly inwards and rock it lightly so that it is spread across the film evenly.
In large commercial setups, people can use automated shakers as they are easy to use for a bigger project.
3 – Melting the powder
Several ways can be used to melt the powder. One of the main ways is to utilize a curing oven, especially on a large setup for a commercial project. The powder is applied to the film and placed in the curing oven for heating. In case there is no curing oven a heat press machine can be used as an alternative. Although while using a heat press one must be careful not to touch the film.
When placing the heat press on the film make sure that there is a slight gap of about 4mm to 7mm from the film. To make this process easier the operator can use a metal wire to hold the press.
To avoid any damage or mistakes it is best to follow the specifications given by the manufacturer when melting the powder. The heating can be done in 2 to 5 mins at 160 to 170 degrees Celsius depending on the DTF printer power.
4 – Pre-pressing
The fabric must also be pressed using a heat press and this can be done in a few seconds up to 5. Before placing the fabric and transferring the image it is important to press it under heat.
This is for removing any humidity or excess moisture on the fabric and flattening it. This will help smoothen the transfer to give out the best results.
5 – Transfer
This is the most crucial if not the main part of the DTF process. the transfer process is commonly known as curing. This can be done by placing the film which already has the image on it onto the fabric with a strong force to ensure the image is printed on perfectly.
This process goes on for about 15 seconds if not 20 seconds at 160 or 170 degrees Celsius to ensure the proper transfer of the image. The film is now attached to the fabric.
6 – Cold Peel
This process involves cooling down the fabric with the film placed on it at room temperature before pulling it out. The powder has an amide nature which as it cools holds the ink more firmly and tightly onto the fabric.
After it has cooled down, the film is then peeled off from the fabric leaving the printed design in ink perfectly held on.
7 – post-pressing
This is the final step in the DTF process which is recommended by manufacturers for the best quality of the print. After the design has been transferred to the fabric it is important to press the for about 15 seconds for the last time to ensure that the design is perfectly attached.
