Systems and approaches for controlling a molding machine having a mold forming a mold cavity and being controlled according to a mold cycle include injecting a molten polymer into the mold cavity. A first and a second sensor are used to obtain first measurements of respective first and second variables during the injection cycle. The second sensor is positioned downstream from the first sensor. The first and second sensors are used to obtain second measurements of the respective first and second variables during the injection cycle. A first difference value is determined between the first measurements of the first and second variables. A second difference value is determined between the second measurements of the first and second variables. The first and second difference values are compared, and at least one control parameter is adjusted based on a difference between the first and the second difference values.

A shrinkage detection device for a polymer injection molding apparatus detects a shrinkage experienced by an injection molded element for assessing a quality of the molded element. Shrinkage, along with temperature and pressure of the melt within the mold during cooling, indicates a sufficiency of the resulting molded element for intended purposes. Sufficiency includes parameters such as flexibility, shear strength and longevity, and is accurately performed can replace conventional sample testing of molded articles that are expensive and time consuming.

A method of monitoring and controlling a sequential valve gate molding apparatus in an injection molding or other molding process is disclosed. The method includes creating a target strain profile, receiving a deviation limit, receiving a change in strain relating to a first valve gate from a first strain gauge, identifying whether a deviation exists from a first portion of the target strain profile based on the output from the first strain gauge, determining whether any existing deviation exceeds the deviation limit, and adjusting the position of a first valve gate pin in the first valve gate if it does. The method may further include control of subsequent valve gates. Multiple strain gauges may be used to control a single valve gate, and/or each strain gauge may control more than one valve gate.

Embodiments within the scope of the present disclosure are directed to external sensor kits that may be included in new injection molds or retrofitted into existing injection molds in order to approximate conditions within a mold, such as pressure or the location of a melt flow front. Such kits are designed to amplify meaningful measurements obtained by the external sensor kit so that noise measurements do not prevent the approximation of conditions within a mold. In some embodiments within the scope of the present disclosure, an external sensor kit includes a strain gauge sensor, a coupon, a support bracket, and a hammer. The strain gauge sensor is placed on a surface of the coupon and measures the strain in the coupon.

Embodiments within the scope of the present disclosure are directed to external sensor kits that may be included in new injection molds or retrofitted into existing injection molds in order to approximate conditions within a mold, such as pressure or the location of a melt flow front. Such kits are designed to amplify meaningful measurements obtained by the external sensor kit so that noise measurements do not prevent the approximation of conditions within a mold. In some embodiments within the scope of the present disclosure, an external sensor kit includes a strain gauge sensor, a coupon, a support bracket, and a hammer. The strain gauge sensor is placed on a surface of the coupon and measures the strain in the coupon.

A fastener sealing tool that utilizes curable material to seal the area around a fastener connected to a surface. In one embodiment of the invention the fastener sealing tool is a manually operated tool, hand operated by a user who visually identifies the fastener to be sealed and then operates the fastener sealing tool to seal the desired fastener. In a second embodiment of the invention the fastener sealing tool is an end of arm tool for a robot that automatically identifies or is programmed to move to the location of the fastener, and then seal the fastener using the fastener sealing tool. The fastener sealing tool utilizes a load cell to control the flow of material and to detect certain unwanted conditions.

A injection molding method involves measuring, using at least one strain gauge sensor, a change in strain in a mold side of a mold cavity, approximating a pressure within the mold cavity based on the change in strain, comparing the approximated pressure to a pre-set trigger point, and if the approximated pressure equals or exceeds the pre-set trigger point, activating a virtual cavity sensor having an optimal pre-defined pressure-time curve, wherein upon activation, the virtual cavity sensor tracks approximated pressures calculated from the change in strain measurements measured by the at least one strain gauge sensor over time and compares the results of the approximated pressure tracking to the optimal pre-defined pressure-time curve.

A injection molding method involves measuring, using at least one external sensor, a change in a parameter of a mold side of a mold cavity, approximating a condition within the mold cavity based on the change in the parameter, such as pressure within the mold cavity or flow front position, and comparing the approximated condition to a trigger point,. If the approximated condition equals or exceeds the trigger point, activating a virtual cavity sensor having an optimal pre-defined pressure-time curve, and upon activation, the virtual cavity sensor tracks an approximated condition calculated from the change in parameter measurements measured by the at least one external sensor over time. In an embodiment, results of the approximated parameter tracking can be used in conjunction with an optimal pre-defined pressure-time curve.