Some of the main characteristics of the role of a stabilizer and
2013-12-24 by seoer8
Environmental problems due to the toxicity of lead and , in the most common case of a zinc , barium and calcium -zinc stabilizers are quickly replaced by a more efficient formulation of barium -lead . Lead systems can be provided close to the processing stability of the novel stabilizer is continuously developed in order to achieve lead-free stabilizer. This occurs due to government regulations and the high cost of waste disposal .
A combination of zinc and secondary phosphite stabilizer components with food grade calcium in the food packaging film has been applied aspects .
Most PVC heat stabilizer used in soft products , the plasticizer -containing epoxy esters, such as diglycidyl ester , epoxy fatty acid ester. Reacting the epoxide with hydrogen chloride as an auxiliary stabilizer.
Because of the unique electrical properties of the lead compound , in the wire and cable coating dominate the market , some of the metal in the coating mix applied as an auxiliary stabilizer.
Hard products : rigid PVC products in the North American market , although there are some wrong , mixed metal , antimony esters using flow -based , but most are using stabilizers containing tin . In other parts of the world , especially when used as a profile, is gradually replacing lead stabilizers barium a stabilizer, which is due to the problems discussed above pan . However , due to the potential environmental factors in these applications CKS gradually calcium -zinc and organic tin instead of lead .
Pipe : PVC rigid PVC pipe is unique to the largest market , the majority of the pipe is in the twin-screw extruder processing . Since the heating time is short , and therefore the use of lower concentrations of organotin stabilizers stream . These pipe grade tin content of the stabilizer may use to 4-10 % less , per 100 parts of the polymer is generally 0.4 parts ( twin screw extrusion ) , while the single screw extruder 0.6-1 .0 copies. Stabilizer for drinking water pipes must comply with the requirements of independent certification bodies .
Injection : With the emergence reciprocating screw injection molding resins suitable for the requirements , and has successfully developed a highly efficient stabilizers and obtained a very large part ( 35 pounds ) .
While the lower molecular weight resin is more easily processed , but the high shear injection mold typically require a 25% containing 14% tin organotin ester stream .
Blow molding : the proper selection of the organic tin blow molding is critical because there is a starting color , fragrance , transparency additional requirements play a decisive role in the generic article are sulfuric acid ester and dibutyltin tin methyl ester . Although the methyl esters of tin and tin have FDA permission , but the main use of food-grade applications octyl tin.
Membrane and sheet : extrusion and calendering are used to process rigid PVC sheet and membrane , the membrane and the sheet is typically used as stabilizers for use with bottles .
Siding and outer profiles : For stabilizers for PVC siding and window frame materials , weather resistance and durability to maintain color of the additional requirements. Long term studies have determined the structure of these organotin optimal use .