Patent classifications
B29C48/918
Formed Thermoplastic Article Having Smooth Edges
The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.
SHAPING ROLL FOR MELT EXTRUSION MOLDING, SHAPING ROLL ASSEMBLY FOR MELT EXTRUSION MOLDING, AND MELT EXTRUSION MOLDING METHOD
A shaping roll for melt extrusion molding used for melt extrusion molding of thermoplastic resin, the shaping roll for melt extrusion molding comprises a metal roll body, a first cylinder, and a second cylinder. The metal roll body has a heat medium passage internally. The first cylinder covers a surface of a middle portion of the roll body part. The second cylinder covers surfaces of both end portions of the roll body part. The first cylinder comprises a first metal material having a thermal conductivity of 40 W/m.Math.K or more. The second cylinder comprises a second metal material having a thermal conductivity of 20 W/m.Math.K or less. The first cylinder and the second cylinder are at least partially joined to each other.
Forming methods
This invention relates to methods for forming a polymer, including continuously depositing a polymer extrudate that is above its glass transition temperature onto a lower molding surface of a first mold in a manner that reduces shear stress in the polymer extrudate, heating the lower molding surface to maintain the polymer extrudate above the glass transition temperature, applying an upper molding surface of a second mold to at least the exposed upper surface of the polymer, allowing the polymer to transition to below the glass transition temperature while within or between the upper and lower molding surfaces, and providing heat sinks spaced relative to each other through the pressure forming zone, wherein a heat sink more advanced through the pressure forming zone is controlled to a lower temperature to progressively reduce the temperature of the polymer as it advances through the pressure forming zone.
Rolled Edge Trays Having Smooth Edges and Stacking Extensions
The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.
Apparatus for the production of inline stretched tubular foils by blowing process
The present invention relates to an apparatus for producing inline stretched tubular foils by the blowing process, having a blown foil system comprising an extruder, a blowing head, a cooling ring, a calibrating basket, a flat laying unit and a reversing turret haul-off, having a stretching system for monoaxially stretching the laid flat foil in the machine direction and with a first thinness control system which operates segmented control zones in the cooling ring to form thinness sections so that, during stretching, a foil is produced with a thickness profile having the smallest possible deviations from the medium foil thickness over the complete foil width. To increase the accuracy and speed of the first thinness section control system, a second thinness section control system is provided which controls two opposing heat sources between the calibrating basket and the flat laying unit and which can be connected to the first thinness section control system.
Method of Making Rolled Edge Trays
The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and irreversibly bending, without heating, at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.
Rolled edge trays having smooth edges and stacking extensions
The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.