Polypropylene compounding equipment

Blends of isobutylene polymers with thermoplastic resins are used for toughening these compounds. High density polyethylene and isotactic polypropylene are often modified with 5 to 30 wt % polyisobutylene. At higher elastomer concentration the blends of butyl-type polymers with polyolefins become more mbbery in nature, and these compositions are used as thermoplastic elastomers (98). In some cases, a halobutyl phase is cross-linked as it is dispersed in the polyolefin to produce a highly elastic compound that is processible in thermoplastic mol ding equipment (99) (see Elastomers, synthetic-thermoplastic). ... 

Substitute for Conventional Vulcanized Rubbers, For this application, the products are processed by techniques and equipment developed for conventional thermoplastics, ie, injection molding, extrusion, etc. The S—B—S and S—EB—S polymers are preferred (small amounts of S—EP—S are also used). To obtain a satisfactory balance of properties, they must be compounded with oils, fillers, or other polymers compounding reduces costs. Compounding ingredients and their effects on properties are given in Table 8. Oils with high aromatic content should be avoided because they plasticize the polystyrene domains. Polystyrene is often used as an ingredient in S—B—S-based compounds it makes the products harder and improves their processibility. In S—EB—S-based compounds, crystalline polyolefins such as polypropylene and polyethylene are preferred. Some work has been reported on blends of liquid polysiloxanes with S—EB—S block copolymers. The products are primarily intended for medical and pharmaceutical-type applications and hardnesses as low as 5 on the Shore A scale have been reported (53). 

F). To prevent degradation it is necessary to take account not only of the stability or instability of a compound but also of questions such as the period of time at the temperature, whether oxygen is present or the surrounding atmosphere is inert, and what materials are in contact with the plastic. As an example of the last, copper causes rapid degradation of polypropylene, and therefore copper cleaning pads should not be used on equipment for processing this material. 

BurnEx 2000 polypropylene flame retardant concentrates are made from nano-dispersible antimony pentoxide and an organic bromine compound. Polypropylene resins of different Melt Flow Index (MFI) are used for different applications. Nyacol Nano Technologies, Inc. can design other concentrates or work with your compounder to formulate a custom product for you. They have a fully equipped compounding laboratory at their Ashland, MA facility. 

Europrene compounds, especially oil-extended grades, are used in shoe soles and other footwear. Principal applications are impact modifiers in PS, HOPE, LDPE, polypropylene (PP), other thermoplastic resins and asphalt extruded hose, tubing, O-rings, gaskets, mats, swimming equipment (eye masks, snorkels, fins, rubberized suits) and rafts and pressure-sensitive adhesives (PSA) and hot melts. SIS types are used in PSA and hot melts SBS types are used in footwear. ... 

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