Hollow profiles

Fig. 6 Examples of poor (on left) and improved extrusion product designs (on right) to achieve uniform product thickness (1) profile (A) made into a hollow profile and (2) profile (B) made into an open profile.

Avoid or minimize hollow profiles as they increase die fabrication costs and complicate the cooling process of the extrudate. 

U.S. Pat No. 6,827,995 [53] discloses a single coextrusion process of making a WPG as a hollow profile comprising a weatherable outer layer made of a first polymeric material, a core layer made of a thermoplastic polymeric foamed composition including a wood component, and an inner layer made of a third thermoplastic material. The first and second polymeric materials are PVC or acrylonitrile-styrene-acrylic polymer or a combination thereof. The third polymeric material is PVC. 

U.S. Pat. No. 6,844,040 [54] discloses a coextrusion process of making reinforced WPC structural members comprising hollow profiles formed from a thermoplastic-cellulose fiber composite material and reinforcing sections bonded to the hollow profile. 

K. Gehrmann, M. Busch, S. Meinicke, R. Starke, and A. Krombholz. The influence of fibre geometry of different natural fibres and different PP grades on key properties of composites and extruded hollow profiles. First experiences with the industrial profile... 

A detailed study of deck boards filled with fly ash has been done with GeoDeck 2X6 hollow profiles (Table 4.19). 

DENSITY OF CROSS-SECTIONAL AREAS OF HOLLOW PROFILES OF GEODECK WPC BOARDS... 

Note of the author The above material ( density of cross-sectional areas of hollow profiles of GeoDeck boards ) shows how significantly nonhomogeneous a product can be in terms of its density at different segments of its cross-section. 

That is, a direct comparison of two moments of inertia, that of solid Trex board (/ = 0.895 in." ) and hollow GeoDeck board (/ = 0.771 in. ), immediately shows that if they were made from the same material and tested in the same conditions and at the same span, a transition from the solid profile to the hollow profile would result in... 

This simple calcnlation illnstrates a whole concept of hollow profiles. In the above example, a loss of 16% of the mechanical properties gives almost a double economy in the material. What is more important is a matter of judgment of the manufacturer (or a commissioner) in every particular case. 

As it will be shown below, water absorption mainly occurs at the outer layers of composite materials and progressively decreases into the bulk of the matrix. Therefore, numerical figures of water absorption are related to only total weight increase of the material and have nothing to do with a distribution of water across the material. From this viewpoint, hollow profiles absorb almost a double (well, less than that, depending on the configuration of the hollow profile) amount of water compared to the same material in the form of a solid profile. 

Deck boards (solid or hollow) Profile Manufacturer Principal ingredients Flame spread index... 

Figure 15.22 Temperature at the top surface (light-colored bars) aud at the bottom (dark bars) of a Cedar-colored composite deck (GeoDeck, hollow profile) iu the course of a summer day iu Bedford, MA. The midday (12 p.m-2 p.m) air temperature was 83 (degree Fahreuheit). Vertical axes temperature, °F. Florizoutal axes, daytime, a.m —> p.m.

The plastics gave a good quality composite deck boards (hollow profiles, plastic filled with rice hulls and minerals). 

Hindered amine light stabilizer (HALS), 533 Hindered amines, 526 Hindered phenolic antioxidant, 528 Hindered phenolic compounds, 526 Hollow deck boards, 2, 36, 267, 212, 213, 280 Cross-sections, density, 212, 213 Ribs, 212, 213 Hollow boards, 36 hollow profiles, 229 Homopolymers, 57, 67 Honeywell A-C 950P, 189 Hot melt viscosity, 104, 129, 131 Hot tub (on a deck), 15, 289 Deflection of a deck, under, 290 Dimensions, 289 load, 15... 

Cutting laminations are mainly caused by fixtures in the die. Such fixtures are always unavoidable if a die with cores is employed in order to produce a perforated column, as with pipes, hollow profiles, common bricks, honeycombs, etc. The core bows, which are fitted crosswise to the flow direction, separate the body. If the distance between the core bow and column exit is too narrow or if the flow pressure is too low, the parting planes cannot sufficiently weld together. (5)... 

Cores are frequently installed in the die to produce voids, for instance in the case of extruded pipes, hollow profiles, hollow bricks, etc. These cores are fixed to core bars, which in turn are fitted onto core bows. There must... 

Utilizing bar extrusion, long profiles can be produced (Ostermann 2007 Fritz and Schulze 2008). The variety of producible profile cross sections is immense solid sections of bars and rods and hollow sections with open and closed profiles as well as tubes (Fig. 5). Closed hollow profiles and tubes can be further processed by hydroforming and bending for the manufacturing of profile structures. 

The profile cross section changes with large true strains by lateral contraction of the zone under tension and by lateral extension of the zone under compression. The assumption that the profile walls remain plane during bending loses its validity in particular in the case of hollow profiles with thin wall thicknesses. 

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