Anti-blocking

Many other specific properties have been noted, e.g., decreased flammability and anti-blocking. 

In addition, polyester bottles may contain colorants in the form of pigments, dyes or lakes. The colorants may be dispersed or dissolved in the polymer or may be covalently bound to the polymer backbone. Polyester packaging, which may be collected for depolymerization, may include nucleators for enhanced crystallization, anti-slip agents, branching agents, anti-blocking agents and anti-stats. 

Imparts softness and anti-blocking to foam-backed drapery fabrics... 

Processing aids - additives such as viscosity depressants, mold-release agents, emulsifiers, lubricants, and anti-blocking agents (3). 

Additive used for thermoplastic applications requiring lubrication, slip and anti-blocking properties. Commonly used in polyethylene and polypropylene films, as a lubricant in polyvinyl chloride, mold release agent, dyestuff dispersant for printing inks and surface coatings, and a blending agent for polyamide resins. 

For hundreds of years sticky surfaces have been dusted with powder (e.g., talc) to keep them separated. Talc is broadly used in cable and profile extrusion to obtain a smooth surface. Similarly, in injection molding, the application of aluminum trihydroxide gives a better surface finish. Talc, CaCOs, and diatomite provide anti-blocking properties. Graphite and other fillers decrease the coefficient of friction of materials. PTFE, graphite and M0S2 allow the production of self-lubricating parts. Here, PTFE, a polymer in powder form, acts as a filler in other polymers. Matte surfaced paint is obtained by the addition of silica fillers. 

In industrial products, the use of fumed silica will confer thixotropy, sag resistance, particle suspension, emulsifiability, reinforcement, gloss reduction, flow enhancement of powders, anti-caking, anti-slip, anti-blocking, etc. Because of its effect on these important properties, fumed silica is widely used in many industries. 

Series (9810), 9900 Series (9910) - economical grades Ultra (2000, 3000, 4000, 5000) - cosmetic grades Gel, Body medium. Fine - polyester talcs MV Series (310, 305, 610, 607, 603) - talcs for coating industry Clear Block 80 - anti-blocking additive in LDPE... 

In plastics, the addition of talc improves their heat distortion temperature, dimensional stability, scratch resistance, impact resistance, and reduces the process cycle due to nucleation. Other important properties include high brightness, blocking of infrared in agricultural film, anti-blocking properties, and low absorption of packaged components. 

China clays and calcium carbonates can be used to impart anti-blocking properties to films produced from polyester, and cellulose acetate. Figure 19.19 shows the effect of coated ground calcium carbonate. Even such a small addition as 10 wt% has a substantial effect on blocking. Many other properties such as impact strength, modulus of elasticity, and opacity are improved. ... 

Perhaps the simplest use of colloidal silica in this area is its use to firictionize and coat the film base material to both make it easier to be conveyed through the process and also to prevent it from blocking or adhering to itself when rolled up. The use of colloidal silica as an anti-blocking agent is discussed above under the Surface Modification of plastic films. 

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