A vacuum loader for feeding powder to a molding machine, said loader comprising: a vacuum operated pickup for conveying powder / dust, said pickup being connected to a vacuum source; a generally frusto-conical loading chamber having an inlet opening oriented tangentially into an upper portion of said frusto-conical loading chamber; a separation chamber also of frusto-conical shape and having a bottom portion communicating with said loading chamber upper portion, said separation chamber having a closed top portion; an intensifying chamber inside said separation chamber, said intensifying chamber having a closed top portion where an opening to the vacuum source is defined, said intensifying chamber defining a plurality of tangentially oriented inlets from said separation chamber opening into said intensifying chamber adjacent said top portion thereof; a vortex tube centered inside said frusto-conical intensifying chamber, with an open top of the vortex tube communicating with said top opening of said intensifying chamber; dual valve elements; and a control system for opening and closing said dual valve elements, in timed relation to operation of the vacuum source; whereby said vacuum source draws air downwardly inside said intensifying chamber thence upwardly into said vortex tube, separating the upwardly moving air from the downward movement of the plastic powder / dust; characterised in that: the loader further comprises a collection tube carried by a lower portion of said intensifying chamber and extending downwardly into said loading chamber, said collection tube having an open lower end spaced above an open lower end of said loading chamber, in that said vortex tube has an open lower end spaced above the upper open end of said collection tube, and in that said dual valve elements are configured to selectively close the open lower ends of said loading chamber and said collection tube, said control system opening and closing said dual valve elements in response to an input signal indicative of the needs of the processing machine. a vacuum operated pickup for conveying powder / dust, said pickup being connected to a vacuum source; a generally frusto-conical loading chamber having an inlet opening oriented tangentially into an upper portion of said frusto-conical loading chamber; a separation chamber also of frusto-conical shape and having a bottom portion communicating with said loading chamber upper portion, said separation chamber having a closed top portion; an intensifying chamber inside said separation chamber, said intensifying chamber having a closed top portion where an opening to the vacuum source is defined, said intensifying chamber defining a plurality of tangentially oriented inlets from said separation chamber opening into said intensifying chamber adjacent said top portion thereof; a vortex tube centered inside said frusto-conical intensifying chamber, with an open top of the vortex tube communicating with said top opening of said intensifying chamber; dual valve elements; and a control system for opening and closing said dual valve elements, in timed relation to operation of the vacuum source; whereby said vacuum source draws air downwardly inside said intensifying chamber thence upwardly into said vortex tube, separating the upwardly moving air from the downward movement of the plastic powder / dust; characterised in that: the loader further comprises a collection tube carried by a lower portion of said intensifying chamber and extending downwardly into said loading chamber, said collection tube having an open lower end spaced above an open lower end of said loading chamber, in that said vortex tube has an open lower end spaced above the upper open end of said collection tube, and in that said dual valve elements are configured to selectively close the open lower ends of said loading chamber and said collection tube, said control system opening and closing said dual valve elements in response to an input signal indicative of the needs of the processing machine. the loader further comprises a collection tube carried by a lower portion of said intensifying chamber and extending downwardly into said loading chamber, said collection tube having an open lower end spaced above an open lower end of said loading chamber, in that said vortex tube has an open lower end spaced above the upper open end of said collection tube, and in that said dual valve elements are configured to selectively close the open lower ends of said loading chamber and said collection tube, said control system opening and closing said dual valve elements in response to an input signal indicative of the needs of the processing machine.