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 monitoring apparatus for molds includes a control unit connectable to a first and second sensor associable with the mold and configured for emitting respective signals representative of a deformation parameter and temperature parameter of the mold. The control unit, in order to define an alert condition, is configured for: defining a value of a threshold parameter as a function of the temperature of the mold and comparing such value of the deformation parameter with a value of a threshold parameter defined as a function of the temperature of the mold; or normalizing, at a reference temperature, the value of the deformation parameter determined at the temperature of the mold and comparing a value of a threshold parameter, defined at the reference temperature, with the value of the normalized deformation parameter at the same reference temperature. Also forming the object of the present invention is a monitoring method and a data medium.

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 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.

A strain gauge nozzle adapter that may be placed between a barrel end cap and a nozzle body of an injection molding system, the strain gauge nozzle adapter having a strain gauge pin that measures strain within the strain gauge nozzle adapter for use in approximating conditions within an injection molding system, such as pressure or the location of a melt flow front. The strain gauge nozzle adapter may include a plurality of strain gauge pins. An alternative material insert in the strain gauge nozzle adapter may surround a strain gauge pin to amplify meaningful measurements obtained by the strain gauge pin so that noise measurements do not compromise the accuracy of approximation of conditions within a mold.

Non-time dependent calculated variables based on measured strain are used to effectively determine an optimal hold profile for an expanding crosslinking polymer part in a mold cavity. A system and/or approach may first inject molten expanding crosslinking polymer into a mold cavity, then measure strain at the mold cavity or at another location within the injection molding system, and then calculate at least one non-time dependent variable during an injection molding cycle. Next, the system and/or method commences a hold profile for the part, and upon completing the hold profile, the part is ejected from the mold cavity, whereupon a cure profile is commenced.

Non-time dependent measured variables are used to effectively determine an optimal hold profile for an expanding crosslinking polymer part in a mold cavity. A system and/or approach may first inject molten expanding crosslinking polymer into a mold cavity, then measure at least one non-time dependent variable during an injection molding cycle. Next, the system and/or method commences a hold profile for the part, and upon completing the hold profile, the part is ejected from the mold cavity.

Non-time dependent measured variables are used to effectively determine an optimal hold profile for an expanding crosslinking polymer part in a mold cavity. A system and/or approach may first inject molten expanding crosslinking polymer into a mold cavity, then measure at least one non-time dependent variable during an injection molding cycle. Next, the system and/or method commences a hold profile for the part, and upon completing the hold profile, the part is ejected from the mold cavity, whereupon a cure profile is commenced.

A method of monitoring and controlling a molding clamping 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 mold while it is closing from a first strain gauge, identifying a deviation from a target strain profile based on the output from the first strain gauge, determining that the deviation exceeds the deviation limit, and adjusting the rate or force of clamp movement. The target strain profile may have a first portion relating to a clamp closing process, a second portion relating to a filling process, and a third portion relating to a clamp opening process. The first portion relating to the clamp closing process may include an intermediate portion relating to a coining process having an intermediate clamp force setpoint.

A strain gauge nozzle adapter that may be placed between a barrel end cap and a nozzle body of an injection molding system, the strain gauge nozzle adapter having a strain gauge pin that measures strain within the strain gauge nozzle adapter for use in approximating conditions within an injection molding system, such as pressure or the location of a melt flow front. The strain gauge nozzle adapter may include a plurality of strain gauge pins. An alternative material insert in the strain gauge nozzle adapter may surround a strain gauge pin to amplify meaningful measurements obtained by the strain gauge pin so that noise measurements do not compromise the accuracy of approximation of conditions within a mold.