Polypropylene applications extrusion

Extrusion Films, Polypropylene Applications, Atofina. (http //www.petrochemicals.atofina.com/ sidel/alla.asp lg=en sid=l ent=A biz=b2)... 

Leung K L, Easteal A and Bhattacharyya D (2008) In situ formation of poly(ethylene naphthalate) microfibrils in polyethylene and polypropylene during extrusion. Compos Part A 39 662-676. Shields R J, Bhattacharyya D and Fakirov S (2008) Fibrillar polymer-polymer composites morphology, properties and applications, J Mater Sci 43 6758-6770. 

Polypropylene film is found in a variety of applications. Films are thin plastic sheets with thicknesses less than 250 pm. Applications for these films include candy mappers, plastic label material, electrical capacitors (which requires very pure polymer), and fiber glass insulation backing. There are two general categories of polypropylene films unoriented and oriented. Films are manufactured through either a cast or a blown film extrusion process. Oriented films exhibit improved strength relative to unoriented films. This means that they can be... 

The production of foamed films and sheets from polypropylene and polystyrene is discussed, with particular reference to packaging applications. Advantages of foamed materials for this application are examined, and the chemical and physical foaming processes are described. Extrusion technology for film and sheet by chemical and physical foaming processes is discussed, and recent developments in the coextrusion of multilayer packaging trays for the food industry are considered. 

Flexible film applications are much more demanding regarding the stiffness/ toughness ratio of the Ecoflex /PLA compound. Usually, polypropylene with a stiffness of 1,600 MPa is the stiffest product to be used in blown film extrusion. But,... 

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). 

Many thermoplastics can be thermoformed, including polystyrene, polypropylene, APET, CPET, and PVC. EVOH is commonly incorporated into a co-extrusion for its superior barrier properties in food. Co-extrusions of these materials are commonly used to provide precise properties for specific applications. 

Products A wide range of polypropylene products (homopolymer, random copolymer and impact copolymer) can be produced to serve many applications, including injection molding, blow molding, thermoforming, film, extrusion, sheet and fiber. Impact copolymer produced using this process exhibits a superior balance of stiffness and impact resistance over a broad temperature range. 

Extrusion-Applied Insulations. The polymers used in extrusion applications can be divided into two classes low-temperature applications and high-temperature applications. Polymers in the first category are poly(vinyl chloride), polyethylene, polypropylene, and their copolymers along with other elastomers. Polymers in the second category are mainly halocarbons such as Teflon polytetrafluoroethylene (which requires special extrusion or application conditions), fluoroethylene-propylene copolymer (FEP), perf luoroalkoxy-modified polytetrafluoroethylene (PFA), poly(ethylene-tetrafluoroethylene) (ETFE), poly(vinylidene fluoride) (PVF2) (borderline temperature of 135 °C), and poly(ethylene-chlorotrifluoroethylene). Extrusion conditions for wire and cable insulations have to be tailored to resin composition, conductor size, and need for cross-linking of the insulating layer. 

Polypropylene. Like polyethylene, polypropylene and propylene-ethylene copolymers are used as insulation for telephone wires. Howeyer, polypropylene itself is also used in the fabrication of components for low-yoltage automotive devices such as switches, connectors, and terminal blocks. As will be shown later, polypropylene plays another important role as an insulating material in an application where it is applied as a free film rather than as a formulation for coating or extrusion on wires and cables. 

Polyolefin - Polyolefins are a large class of carbon-chain elastomeric and thermoplastic polymers usually prepared by addition (co)polymerization of olefins or alkenes such as ethylene. The most important representatives of this class are polyethylene and polypropylene. There are branched and linear polyolefins and some contain polar pendant groups or are halogenated. Unmodified polyolefins are characterized by relatively low thermal stability and a nonporous, nonpolar surface with poor adhesive properties. Processed by extrusion, injection molding, blow molding, and rotational molding. Other thermoplastic processes are used less frequently. This class of plastics is used more and has more applications than any other. Also called olefinic resin, olefinic plastic. 

Polypropylene, produced by an oriented extrusion process, has been uniquely successful as a fiber. Its excellent wear, inertness to water, and microorganisms, and its comparatively low cost have made it extensively used in functional applications, such as carpet backing, upholstery fabrics, and interior trim for automobiles. 

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