An injection molding device includes an injection machine, a molding die, and a high frequency oscillation device. The injection machine injects a resin material containing a dielectric heat generating material while keeping fluidity by temperature control. The molding die includes a cavity being a channel of flow of the resin material, and a pair of electrodes, each of which faces the cavity, the pair of electrodes being disposed to sandwich the resin material therebetween in a direction crossing a direction of the flow. The high frequency oscillation device applies a high frequency alternate-current voltage to the pair of electrodes.

To provide a new foam molding method and injection molding machine capable of solving variation in a wall thickness and a foamed state, sensor corrosion, a complexity of sensor positioning, and the like. The above-described problem is solved by a foam molding method comprising a resin filling step of filling a mold (2), clamped by a predetermined mold clamping force (Pc), with a resin (R) at a predetermined molding injection pressure (Pi), a filling stopping step of stopping the filling of the resin (R) when, while monitoring a mold gap (Lm) of the mold (2) during the filling, a predetermined mold gap value set in advance is reached, a surface layer curing and filled resin cooling step of curing a surface layer of the resin (R) for a certain time and cooling the filled resin (R) for a certain time after the filling of the resin (R) is stopped, a volume controlling step of controlling a volume increase by reducing the mold clamping force after curing the surface layer of the resin (R) for a certain time, and a taking out step of taking out a foam-molded product by opening the mold (2) after the volume control is performed and after cooling the filled resin (R) for a certain time.

To provide a new foam molding method and injection molding machine capable of solving variation in a wall thickness and a foamed state, sensor corrosion, a complexity of sensor positioning, and the like. The above-described problem is solved by a foam molding method comprising a resin filling step of filling a mold (2), clamped by a predetermined mold clamping force (Pc), with a resin (R) at a predetermined molding injection pressure (Pi), a filling stopping step of stopping the filling of the resin (R) when, while monitoring a mold gap (Lm) of the mold (2) during the filling, a predetermined mold gap value set in advance is reached, a surface layer curing and filled resin cooling step of curing a surface layer of the resin (R) for a certain time and cooling the filled resin (R) for a certain time after the filling of the resin (R) is stopped, a volume controlling step of controlling a volume increase by reducing the mold clamping force after curing the surface layer of the resin (R) for a certain time, and a taking out step of taking out a foam-molded product by opening the mold (2) after the volume control is performed and after cooling the filled resin (R) for a certain time.

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.

A method of molding a thermosetting resin, in particular of the epoxy resin type, in which a first mold is filled with the resin while causing the temperature of the resin to vary in application of a first temperature program, without exceeding the Tg of the resin. After the first mold has been filled, the resin is put under pressure while causing the temperature of the resin to vary in application of a second temperature program, without exceeding Tg, and a drop in the pressure exerted by the resin on the mold is detected with the instant at which this pressure presents a break of slope being identified as the instant t1. A second mold is filled with the thermosetting resin in application of the first temperature program. After the second mold has been filled, the resin is put under pressure in application of the second temperature program until an instant t2 close to t1. As from t2, the temperature of the resin is increased to exceed Tg.

A technique for managing a shear heating value of a molding material is provided. A control device of an injection molding machine individually controls outputs of a plurality of heating units for a plurality of zones, respectively, into which a cylinder is divided in a flow direction of a molding material. The control device acquires the output of the heating unit provided in a predetermined zone both in a steady state in which an operation of a screw provided inside the cylinder is stopped and at a time of molding at which the operation of the screw is performed, and calculates a difference in output of the heating unit provided in the predetermined zone between at a time of molding and in the steady state.

Non-time dependent measured variables are used to effectively determine an optimal ejection time of a part from a mold cavity. A system and/or approach may first measure at least one non-time dependent variable during an injection molding cycle. The part is ready to be ejected from the mold upon the measured variable reaching a threshold value indicative of, for example, a part temperature dropping below an activation temperature.

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 ejection time of a part from a mold cavity. A system and/or approach may first measure at least one non-time dependent variable during an injection molding cycle. The part is ready to be ejected from the mold upon the measured variable reaching a threshold value indicative of, for example, a part temperature dropping below an activation temperature.

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.