For the uninitiated, heat transfer decorating is the use of a preprinted graphic on a carrier (either paper or mylar) that is applied to a substrate (usually plastic) with the use of a hot stamp machine. Heat transfers are usually printed by one of three printing methods: Screen Printing, Rotogravure or Flexography.
There are advantages and disadvantages to each method, but the most popular and most cost effective for the majority of the projects is Screen Printing.
Heat transfers offer unique performance and appearance advantages superior to all other means of decorating. The application of heat transfers is a simple and efficient production process that is highly cost effective. Multi- color, high performance transfers can be applied permanently in a few seconds utilizing low cost hot stamping equipment. The entire operation requires a minimum amount of floor space and uses unskilled labor. Since it is a completely dry process- unlike other wet decorating methods- the decorated product can be handled and moved to its next process immediately. Also, as a dry process, heat transfers pose no environmental concerns within your facility.
Characteristics of heat transfers:
* Cleaner, faster, more cost efficient, provide more graphic flexibility
* Always applied automatically to the plastic part versus manually applied labels
* Ability to reproduce the most complex design with strict registration accuracy, consistency and in crisp sharp detail.
* Ability to adhere to many substrates such as virtually all plastics:
ABS, Acrylic, PP, Polycarbonate, polyphenylene, HDPE, LDPE, PVC and Styrene (GP & high impact), Polymides (nylon), Urethanes, Polyester (including glass filled), Vinyl
* Successful adherence to apparel, various fabrics, wood and metal.
Heat transfers find application in various industries including :
Consumer Products
L awn and garden products, power tools, sporting goods, protective gear, POP displays, footwear, leather goods, protective equipment, consumer electronics, kitchen appliances, etc.
Automotive Products
Dashboard, seatbelts, visors, disclaimers, auto parts, batteries, etc
Cellular Phones
In-mold applications, lenses, leather and vinyl cases, battery packs, accessories, etc.
Computer Products
Monitors, mouse, towers, keyboards, software packaging, cables, networking hardware, etc.
Fabric Systems
Shoe inner sole, fabric bags, special nylon medical products, baby products, etc
Medical Products
Medical equipment, synthetic braces and casts, specialty containers, etc.
Baby Products
Toys, swings, high chairs, strollers, car seats, etc.
There are many challenges to be faced when the decision is made to use heat transfer decals as the decorating method for your project. These challenges are not necessarily unique to heat transfer decals but are also present to some degree within the hot stamping family.
The greatest challenge to both the company that produces the transfers and the ultimate user of the product is the chemistry issue. If the ink chemistry is not correct it will affect everything from the print quality of the image to the ability to make the ink transfer and adhere properly as well as pass any testing that may be applicable
Among other challenges are:
1) The correct choice of the type of hot stamp machine; either a roll on or a vertical press with the correct tonnage.
2) The correct stamping parameters for the particular ink system to ensure proper adhesion to the substrate, ie. heat, pressure and dwell time must be determined as well.
3) The correct choice of the ink system for the substrate to be decorated.
4) The correct choice of the durometer of the silicone rubber pad.
5) Making sure that the tooling is designed properly
6) Making sure that the carrier does not peel too quickly after the stamping head comes into contact with the part – to give the ink system enough time to cure and bond to the substrate.
The ink and coating chemistry is one that is constantly changing and being improved both because more specialized substrates continue to be introduced and increased improvement in abrasion and chemical resistance is a constant demand from product development engineers.
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