Abstract: This invention relates to a process and apparatus for forming a polyester polymer into particles. More particularly, this invention relates to a process and apparatus for forming crystalline, uniform pellets from an amorphous polyester melt. The polyester pellets have utility, for example, as feedstock for a process for producing higher molecular weight polyesters.

Abstract: The present invention relates to a process for forming robust, uniform, low molecular weight crystalline polyester particles. Such particles are useful for forming higher molecular weight polyesters, for example, by solid-state polymerization. Either conventionally-formed, essentially amorphous, non-molten polyester pellets at ambient temperatures or, alternatively, essentially amorphous molten polyester droplets, can be crystallized by rapidly subjecting the droplets or pellets to a thermal shock according to the process of the present invention.

Abstract: Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene terephtalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

Abstract: Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene terephtalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

Abstract: A high solids replenishable electrostatic liquid developer concentrate contains toner particles formed from a friable thermoplastic resin The composition created can be concentrated up to 100% toner solids and subsequently sonicated to a working strength dilution. The composition may be formed by reducing the size of toner particles while they are mixed with a toner dispersant, and concentrating the resultant mixture.

Abstract: An apparatus and method for controlling an injection molding device having a mold cavity therein use of periodically generated signals representative of the mold cavity pressure and mold cavity volume. These signals are used to control the magnitude of the clamping force imposed on a movable mold member. During a first time period following closure of the gate, in response to the signals representative of cavity pressure and cavity volume, the clamping force imposed on the movable mold member is adjusted to maintain, in closed loop fashion, cavity pressure constant. During a second time period following closure of the gate, in response to the signal representative of the cavity volume, the clamping force imposed on the movable mold member is adjusted to maintain, in closed loop fashion, cavity volume constant.

Abstract: A continuous process for the preparation of a dispersion of liquid and resin or polymer particles having at least one additive dispersed in the resin comprisingA. introducing an intimate blend of resin and at least one additive continuously into or blending the ingredients in an apparatus having means for melting the resin and dispersing the additive in the resin,B. melting the resin in the apparatus at an elevated temperature but below that at which the resin and/or additive decomposes,C. moving continuously the blend of melted resin and additive through at least one mixing element of the apparatus dispersing thoroughly the additive in the melted resin (molten blend),D.

Abstract: Method for free surface casting an annular layer of film-forming liquid onto a substrate in a single pass by means of laminar flow through a slot die while the substrate and slot die are undergoing rotation relative to each other.

Abstract: A control system for controlling the edge thickness of an extrudate includes an arrangement responsive to a signal representative of the monitored thickness of the extrudate emanating from a die slot controlled by a transversely inward heating element for generating a control set point for that heating element and for a heating element controlling the die slot adjacent a lateral edge thereof.

Abstract: A thickness control system for controlling the thickness of an extrudate includes a host computer for controlling the temperature of a heat responsive element based upon a predetermined temperature set point. A back-up duty cycle controller is provided for control in the event of host failure.

Abstract: A thickness control system for controlling the thickness of an extrudate includes a nested temperature control loop for controlling the temperature of a heat responsive element based upon a predetermined temperature set point. The temperature set point for the temperature control loop is computed based upon the measured thickness of the extrudate.