Technology Foam film

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. 

Espoo, Technical Research of Finland, 1998, pp.l03. 10 ins. 15/4/99. VTT Publn. 361 NEW TECHNOLOGY TO MANUFACTURE POLYPROPYLENE FOAM SHEET AND BIAXIALLY ORIENTED FOAM FILM Raukola J 1... 

Chicago, II., 29th Aug-2nd Sept.l993,p.403-6. 6A MULTILAYER EXTRUSION DIE GEOMETRY FOR THERMOFORMED POLYPROPYLENE FOAM SHEETS AND BIAXIALLY ORIENTED FOAM FILMS Raukola J Savolainen A Tampere,University of Technology (TAPPI)... 

Foams play an important role in several fields of human Hfe in food technology, medicine, cosmetics, oceanography, environmental technology, fire extinguishing technology, etc. Therefore, foams were investigated very early by natural scientists. Foam films and Plateau borders were characterized, and the formation and structure of foams were described. The mechanical, optical and electrical properties of foams and theories for foam stability were presented [1]. 

Foam Film Technology - An Innovative Solution to Fully Automate the Manufacture of Automotive Sound Deadening Parts... 

Mould cleaning is required because of the chemical nature of the polyurethane process. The objective in developing the Foam Film technology was to eliminate the tedious, time-consuming manual operations, which must be performed on the moulds as part of a discontinuous polyurethane foaming process. 

The second type of film, the releasing one, sticks to the mould and not to the polyurethane part. In the releasing Foam Film technology, there are two main types of film that can be... 

A good example of such a continuous moulding process that incorporates Foam Film technology is a system developed for the production of industrial vehicle carpets. These products are usually made out of a sandwich of two or more layers of different materials. Individually, they provide different features aesthetics and function (a textile carpet or a synthetic mat), sound deadening (a layer of polyurethane foam) and protective (a cheap layer to protect the foam from moisture and degradation). 

Figure 3.18 A large full-automated production plant for truck floor-covering mats using the Foam Film technology. The parts are made of thermoformed PVC (or thermoplastic elastomer) foam-backed with PU, which is kept separate from the mould with a film (adhesive type).

This technology has already been used on turnkey plants for sound insulation parts, carpet back foaming and seat cushions. No limitations for this technology are foreseen and, actually, Foam Film can be implemented in almost every kind of polyurethane process needing either release agent or a cover/surface film. 

Figure 3.19 Turnkey installations using the Foam Film technology are producing numerous parts for the automotive industry.

Thanks to this, vacuum panel technology is becoming a technically viable and cost effective solution to the need to reduce energy consumption in household appliances and in commercial and industrial applications. To successfully achieve this target, additional efforts are necessary to further improve the component quality and reliability (foam, film and adsorbent), to optimise panel production and to reduce costs. 

Raukola J (1998) A new technology to manufacture polypropylene foam sheet and biaxially oriented foam film. Ph.D. thesis. Technical Research Centre of Finland. VTT Pubhcation... 

Multilayered films can be formed by various processes to create a structure with specific mechanical and physical properties. Microlayers of foam/film were formed by microlayer coextrusion technology [176], resulting in unique mechanical properties studied by optical microscopy. Cohen et al. [177] studied... 

EB radiation-cured PVC film surface induces a big improvement in tensile strength and excellent printing ink adhesion and adhesive receptance [302]. PVC foams containing plasticizers, thermally activated blowing agents, cross-linkers, and heat stabilizers have been manufactured by EB radiation technology [303]. 

Although silicone oils by themselves or hydrophobic particles (e.g., specially treated silica) are effective antifoams, combinations of silicone oils with hydrophobic silica particles are most effective and commonly used. The mechanism of film destruction has been studied with the use of surface and interfacial tensions, measurements, contact angles, oil-spreading rates, and globule-entering characteristics for PDMS-based antifoams in a variety of surfactant solutions.490 A very recent study of the effect of surfactant composition and structure on foam-control performance has been reported.380 The science and technology of silicone antifoams have recently been reviewed.491... 

Some important everyday items that are made from polymers with widely different properties Include billiard balls, plastic dishes, soda bottles, barrier and decorative films, egg cartons, polymeric drinking glasses, foam seats, and automotive tires. These applications for synthetic polymers have developed over about 150 years. As shown in Table 2.1, modern polymer material science and technology can be traced back to as early as 1770 [1]. Some Important advances In the understanding of polymer production were developed before World War II. 

Shawbury, Rapra Technology Ltd., 2001, Paper 28. 012 FOAMING OF FILM AND SHEET FROM POLYPROPYLENE AND POLYSTYRENE Berghaus U Reifenhauser GmbH (Rapra Technology Ltd.)... 

Journal of Vinyl and Additive Technology 2,No.3, Sept. 1996, p.258-62 COMPATIBILISER SYSTEM FOR EXTRUDED PE FOAM AND FILM... 

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