3 сентября, 2015 
Malyar EVA hot melts consist basically of the following:
1. EVA copolymer
2. Tackifying and adhesion-promoting resins (e. g., hydrocarbon, rosin esters, coumarone-indene, terpene resins)
3. Fillers, usually barium sulfate (barytes) or calcium carbonate (whiting)
4. Antioxidants
1. EVA Copolymer
EVA copolymer is the main binder in the system and largely influences the following: (a) viscosity and rheology characteristics, (b) cohesive strength, (c) flexibility, and (d) adhesive strength. A variety of EVA grades are available, allowing the formulator a choice of varying vinyl acetate contents coupled with varying viscosities (melt index). Higher vinyl acetate contents generate greater adhesion to plastics, coupled with increased flexibility. The higher the vinyl acetate content, however, the higher the cost. Broadly speaking, EVA-based edge-veneering hot melts utilize grades averaging 28% vinyl acetate, and formulations usually contain 40% binder.
2. Resins
A certain percentage of resin is almost always incorporated into formulations, with resin content varying from 8 to 25%. Hydrocarbon resins are used most often, but rosin esters, terpenes, and indene resins, which are more heat stable, are also common. Resins provide better flow, hot-tack, adhesion, and wetting characteristics.
3. Fillers
The heavy fillers, such as barytes, are used at levels of up to 50% by weight, but more commonly at around 35 to 40%. The filler imparts cohesive strength and body to the adhesive, and also reduces the cost considerably. Barium sulfate is the filler chosen in most cases because of its high density and hence low pigment volume concentration. Barium sulfate grades vary from beige to dark brown, and this assists in formulating specific opaque colors to match color requirements. Finely ground calcium carbonate is sometimes used as a filler where very light colors are required. Titanium dioxide pigment is commonly used as a toner, at levels of 2 to 5%.
4. Antioxidants
Antioxidants are added to protect the organic components, especially resins, from oxida- tion/discoloration at high temperatures. A large choice exists. These materials are usually added at levels of 0.2 to 0.5%.
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