Abstract:
The present invention discloses an assembly and process for creating a co-extruded pipe which includes the steps of extruding a first elongated component exhibiting an open interior. Additional process steps include co-extruding at least one, and typically a pair, of additional elongated components each having an arcuate or lobe cross sectional shape or profile. The additional components are bonded to exterior locations of the first component to establish a pair of additional open interiors between the components and prior to cooling and hardening.
Abstract:
A die and method for impregnating at least one fiber roving with a polymer resin are disclosed. The die includes an impregnation section. The impregnation section includes an impregnation zone configured to impregnate the roving with the resin. The impregnation zone includes a plurality of contact surfaces. At least one of the plurality of contact surfaces is configured such that a normal force of the roving is less than or equal to a lift force of the resin at an impregnation location on the contact surface during impregnation of the roving with the resin by the contact surface.
Abstract:
The invention concerns an installation for manufacturing a drip irrigation pipe (8) formed of a pipe (8) provided with drippers (4), including a dripper feed station (37), followed by an extrusion station (10), including an extrusion head (14) producing a tubular blank (22) and means for welding the drippers (4) to the inner wall of said blank (22), characterized in that the dripper welding means (4) include a support surface (50) and a counter-support surface (56) between which the drippers (4) are pressed against said tubular blank (22) so as to be welded thereto, said support (50) and counter-support (56) surfaces being arranged upstream of the calibrating means (24).
Abstract:
The invention concerns an installation for manufacturing a drip irrigation pipe (8) formed of a pipe (8) provided with drippers (4), including a dripper feed station (37), followed by an extrusion station (10), including an extrusion head (14) producing a tubular blank (22) and means for welding the drippers (4) to the inner wall of said blank (22), characterized in that the dripper welding means (4) include a support surface (50) and a counter-support surface (56) between which the drippers (4) are pressed against said tubular blank (22) so as to be welded thereto, said support (50) and counter-support (56) surfaces being arranged upstream of the calibrating means (24).
Abstract:
A device is described which eliminates the pre-drying of particulate plastic prior to processing by an extrusion or injection molding machine. A tubular guide member directs particulate plastic under gravity into the feed inlet of the machine. During delivery, the temperature of the particulate plastic is raised with heated air flows to between about 150.degree.-200.degree. F. Suction is applied to the feed inlet of the machine to remove volatiles (primarily water) released when the temperature of the particulate plastic is increased by contact with the heated barrel and screwdriver of a machine. Temperature and suction controls permit selection of operating temperature and suction levels that ensure removal of volatiles prior to any extensive plasticization and transfer along the barrel which would otherwise preclude proper removal of volatiles.
Abstract:
A volatile cross-linking agent such as liquid peroxide is introduced, at ambient temperature and under atmospheric pressure directly into the input of an extruder at the same pressure as a polyolefin compound to be cross-linked. The resulting compounds are put under pressure within the extruder as the temperature increases so that the mixture reaches its definitive shape at the extruder output and may be fed directly into a hot cross-linking enclosure which is maintained under pressure. The peroxide is thus incorporated in a single operation permitting complete control of the ingredients mixed and allowing perfect homogenization of the mixture while defusion and consequent loss of the highly volatile peroxide are avoided. The system for introducing the highly volatile cross-linking agent includes a peroxide storage tank, a filling pump, a feed vessel, an incremental feed pump with a pressure meter, a flow meter and numerous safety features. These elements control the flow, temperature and ambient conditions of the cross-linking agent feed system within a controlled environment to ensure the safe and precise handling of a highly volatile liquid while at the same time controlling the feeding of the liquid as a function of the material processed by the extruder so that the percentage of the cross-linking agent inserted at the input to the extruder remains at a constant, predetermined percentage, regardless of extruder speed variations. Additionally, various additives which are soluble in the volatile cross-linking agent may be introduced within the feed system therefor in sufficient amounts for effecting protection of the resulting polymer without altering the efficiency of the feed system or that of the additive so that the entire process may be carried out at the processing site without initial preparation of various mixtures to be further processed.