Moulded foam

Such conditions are particularly prevalent in the car industry where moulded foam is used for chair backs, chair seats, head restraints and knee strips. The furniture industry also widely uses moulded products. 

The surface finish of injection-moulded foamed articles are not ideal because of external defects, burst bubbles, etc. This can be avoided by sandwich moulding. This is accomplished by initially injecting a slug of polymer melt into the mould followed immediately by a polymer containing a blowing agent, which chases the initial polymer into all the interstices. 

Extrusion, injection, compression, blown film, blow moulding, rotational moulding, foam, coating, powdering, co-extrusion, for thin or thick parts, for crosslinking, electrowelding. .. 

Patent Number US 6166096 A1 20001226 PRE-EXPANDED PARTICLES OF POLYPROPYLENE RESIN, PROCESS FOR PRODUCING THE SAME AND PROCESS FOR PRODUCING IN-MOULD FOAMED ARTICLES THEREFROM... 

Patent Number US 5783611 A 19980721 COMPOSITION AND PROCESS FOR ROTATIONAL MOULDING FOAMED ARTICLES Strebel J J... 

BLOW MOULDED FOAM TECHNOLOGY GOES INTO PRODUCTION FOR PALLETS... 

Patent Number US 5576080 A 19961119 POLYETHYLENIC FOAMING COMPOSITIONS AND MOULDED FOAMS... 

The polyether triols are the most important class of polyether polyols and they are used in flexible PU foam fabrication. The majority of polyether triols used in flexible foams are copolymers of PO-EO. Random copolymers are used in continuous slabstock flexible foams and block copolymers (PO-EO), with terminal poly[EO] block, are used in moulded foams (hot moulding and cold cure moulding processes). 

The Lost Foam process (Figure 2.36) starts with the 3D-CAD design and production of a precision moulded foam pattern, made from expanded polystyrene (EPS) or PMMA, produced by automated injection moulding machines. These patterns can be made from one piece or by assembling a number of parts by adhesives. Here usually, a number of patterns, dependent on size, are fixed to a runner-down gating system, made from the same material as the pattern, thereby generating a cluster. 

The formation of moulded foam is a complicated chemical process which involves several reactions occurring simultaneously. There are rapid volume and temperature increases and the concurrent development of phase separated polymer networks. To understand how foam properties can be affected by catalyst and surfactant chemistries several techniques are used to identify key performance benefits and issues. A force to crush... 

Machine runs for the MDI flexible moulded foam were conducted on a Krauss-Maffei, cylinder displacement series, high pressure machine. Fresh premixes, consisting of the appropriate polyols, water, crosslinker, surfactants and catalysts for each formulation were charged to the machine. Modified MDI was used throughout the entire study. All chemical temperatures were held at 25 °C 2 °C via the machine s internal temperature control units. Foam pours were made into an isothermally controlled heated aluminium mould maintained at 60 °C 2 °C. The mould was a typical physical property tool designed with... 

Figure 1.9 Example of a Collapse/Blowout Moulded Foam (Reproduced with permission from APCI)...

A scanning electron microscopy study of moulded foam parts was carried out to understand what affect the additives might have on the morphology of the foam cell structure. It is clear from the SEM photomicrographs in Figures 1.27, 1.28 and 1.29 that there is no... 

Flexible Moulded Foam Machine Physical Property Data... 

Dimensional Stabilising Additives for Flexible Polyurethane Foams 1.3.2.21 TDl Flexible Moulded Foam Review... 

Table 1.34 illustrates moulding foams at a density of 47-48 kg/m similar physical properties are obtained for ILD, resilience, airflow, 50% dry sets and extensive properties. However, slight nominal improvements in 50% humid aged compression sets (HACS) and wet sets are achieved with Dabco DC2517 and Dabco DC5258. 

Low Emissions Moulded Foam Machine Standard Physical Properties... 

Table 1.45 TDI flexible moulded foam model system...

Details on the development and use of foam model systems for flexible moulded foam have been published [14]. In this section the features characteristic of slabstock foams will be highlighted. Table 1.47 illustrates the conversion of the formulations from Table 1.42 into a model system. 

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