摘要:
The present invention relates to a method of transforming multilayered and/or multi-component streams into tubular shapes prior to or during extrusion by passing the streams over a deflector. The invention also relates to dies containing spiral, bowtie, circumferential and/or wrapping deflectors and products made by such methods.
摘要:
A multilayer, heat-shrinkable film generally includes at least one bulk layer and a microlayer section comprising a plurality of microlayers. The ratio of the thickness of any of the microlayers to the thickness of the bulk layer ranges from about 1:2 to about 1:40.
摘要:
An extrusion blowmolding apparatus has an extrusion die having an upstream portion for receiving the thermoplastic polyester material and a downstream portion having a die head through which molten thermoplastic polyester material is flowed to form a parison suitable for extrusion blowmolding. The extrusion die has extending therethrough a generally cylindrical barrel and an extrusion screw disposed within the barrel having spiral flights along its length. In some aspects, the flight depths are lengthened so to provide a good melt at a suitable throughput. By also selecting an appropriate extrusion temperature profile, it is possible to eliminate or minimize unmelts, which can contribute to processing difficulties as well as defects in the resulting article. In other aspects, a closed-loop drying system is provided for achieving very low moisture levels in the polyester material to improve processing.
摘要:
A system and method are presented in which a flow of plastic is extruded to obtain nano-sized features by forming multiple laminated flow streams, flowing in parallel through the non-rotating extrusion system. Each of the parallel laminated flow streams are subjected to repeated steps in which the flows are compressed, divided, and overlapped to amplify the number of laminations. The parallel amplified laminated flows are rejoined to form a combined laminated output with nano-sized features. The die exit is formed to provide a tubular shape.
摘要:
The invention relates to a device for the production of multi-layer, co-extruded, tubular pre-forms made from thermoplastic plastic. A co-extrusion head (10) comprises co-axially arranged flow channels (FK1, FK2), each supplied by a single inlet opening (ZF1, ZF2) with a material melt, distributed annularly in a distribution ring (26, 28). The gap width in each distribution ring (26, 28) is greater in the vicinity of the inlet opening (ZF1, ZF2) than the gap width (s2, s6) in the region of the side opposing the inlet opening (ZF1, ZF2). The flow channels (FK1, FK2) are also asymmetric with regard to the gap widths.
摘要:
An endoscope flexible tube comprises: a tubular structure having flexibility; and a shell layer on an outer peripheral surface of the tubular structure, wherein the shell layer has a two-layer structure including a rigid resin layer of a rigid resin and a soft resin layer of a soft resin, and wherein the two-layer structure is maintained over the entire flexible tube in its length direction.
摘要:
A method and apparatus is provided for distributing material through a multilayer pipe extrusion die. A first flow passageway, having a first cross-sectional area and extending along a first flow direction, may be connected to a second flow passageway, having a second cross-sectional area substantially the same as the first cross-sectional area of the first flow passageway, to provide a second flow direction different from the first flow direction of the first flow passageway. A conical passageway may extend from the second passageway toward a dispensing outlet. Material may be distributed from the first flow passageway into the second flow passageway. The method and apparatus may generally maintain the same flow properties of the material at a point before and after the connection of the first flow passageway and the second flow passageway. The flow properties of the material may be altered proximate to the outlet.
摘要:
The invention relates to a device for the production of multi-layer, co-extruded, tubular pre-forms made from thermoplastic plastic. A co-extrusion head (10) comprises co-axially arranged flow channels (FK1, FK2), each supplied by a single inlet opening (ZF1, ZF2) with a material melt, distributed annularly in a distribution ring (26, 28). The gap width in each distribution ring (26, 28) is greater in the vicinity of the inlet opening (ZF1, ZF2) than the gap width (s2, s6) in the region of the side opposing the inlet opening (ZF1, ZF2). The flow channels (FK1, FK2) are also asymmetric with regard to the gap widths.
摘要:
Using a balanced flow path, multiple layers of extruded plastic are supplied to a chamber having independently rotating surfaces. Said rotating surfaces apply a shear force to at least the inner and outer layers of said extruded plastic to orient said materials in said layers in different helical patterns, thereby forming a multi-layer tubular product in which at least inner and outer layers have different helical patterns to strengthen the product.
摘要:
In an extrusion die flow channels supply molten plastic to a pair of distribution grooves constructed in the upstream face of the die component adjacent to the die body. The die body becomes more universal and can be used for a variety of applications by replacing the die component with alternate designs of distribution grooves.