Heat-sensitive substrate

E-beam is a relatively cold process and so is more suitable for heat-sensitive substrates. UV lamps emit about one third UV light and the rest is visible and IR. Consequently substrates can get very hot, even causing fires if they become stuck beneath the lamp. Safety shutters which close if the line stops are installed on many UV bulbs. 

It minimizes the risk of damaging heat-sensitive substrates since it operates at a relatively low temperature (as low as 300°C in the case of Si02 deposition). 

The irradiation of a polymer surface with the high intensity, pulsed, fer-UV radiation of the excimer laser causes spontaneous vaporization of the excited volume. This phenomenon was first described by Srinivasan (1) and called ablative photodecomposition. The attention of many researchers was drawn to the exceptional capabilities of photoablation (2). Etching is confined to the irradiated volume, which can be microscopic or even of submicron dimensions, on heat-sensitive substrates like polymers. In most experimental conditions, there is no macroscopic evidence of thermal damage, even when small volumes are excited with pulses of... 

Preassembled parts Preassembled parts may contain components made from heat-sensitive substrates (e.g., plastic inserts, wiring). In contrast to the conventional method, where individual components are coated prior to assembly to avoid heat damage, UV powder coating permits the manufacturer to fully assemble a part prior to coating. 

Because IR radiation is not produced, the lamps are relatively cold, with the surface temperatures ranging from 35-40°C (95-104°F).12 This makes them suitable for heat-sensitive substrates. 

We developed polysiloxanes which can be cured or crosslinked by UV radiation at low temperatures in order to increase the curing rate and to open the field of application on heat sensitive substrates. In this paper some special properties and applications of photo-crosslinked polysiloxanes are described. 

HFCVD is performed by placing a heated filament or wire above the substrate. Precursor molecules are pyrolyzed above the wire, and reactive intermediates or products adsorb to the deposition surface. This technique is advantageous because the substrate can be kept at a lower temperature, since the heated filament provides the necessary energy for cracking the precursor molecules. As a result, high temperature reactions can still be used to deposit refractories on heat sensitive substrates. Thus far, HFCVD has been used mainly for the deposition of diamond films, but implementation of this technique for the growth of ceramics is not far in the future. 

VIC . [Ashland] Pcdyester and acrylic urethane resins fw gas curing finishes for plastics, metal, heat-sensitive substrates. 

Advantages. An important ecological advantage is that only reactive products are used this means that there is no solvent recovery problem and no pollution. Energy consumption is low. Curing is performed at room temperature so heat-sensitive substrates can be used. 

Chem. Descrip. Tetrafluoroethylene/hexafluoropropylene/vinylidene fluoride terpolymer disp. with ionic emulsifier Uses Fluoropolymer for coating heat-sensitive substrates such as polyester fabrics in low temp, fabric composites Features Useful for applies, requiring performance and flexibility Properties Cone, water disp. sp.gr. 1.95 melt flow 35-60 (265 C/5 g) m.p. 140-150 C 50% solids Dyneon THV 400 G [Dyneon]... 

Uses Crosslinking agent for heat sensitive substrates, e.g., wood and plastic... 

One of the major advantages of hquid deposition techniques for the formation of SWNT networks is that they occur at room temperature this allows inclusion of heat sensitive substrates like polymers plastics and glass (7 7). A second major advantage of liquid deposition techniques is the they deconstruct network formation into two separate steps, therefore SWNT growth and deposition occurred in two separate steps. This facilitates the deposition of SWNTs onto a wide variety of substrates. Additionally, this also allows the introduction of purification and/or modification steps between SWNT growth and deposition. 

Heat-Sensitive Substrates May Be Used Improved Adhesion to Substrate Due To Grafting... 

Heat, if required, is too low to affect heat-sensitive substrates. 

Collano, for example, has developed a series of moisture-curing PU hot-melt adhesives for textiles (Collano, 2013). These provide high initial strength due to their hot-melt mechanism, but they cross-link to a heat- and moisture-resistant adhesive on exposure to ambient moisture once the joint is made. As a result, these adhesives have excellent resistance to dry-cleaning, washing detergents, and even sterilization processes. In addition, PU adhesives have low processing temperatures (90—140 °C) and are ideal for heat-sensitive substrates. 

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