Tool, tool system and method for the production of particle foam parts

Tool for production of particle foam parts through welding of foam particles by means of electromagnetic waves, comprising two mould halves which bound a mould cavity, wherein at least one of the two mould halves is made of a material which is transparent to electromagnetic waves and has a boundary wall which bounds the mould cavity and one or more supports serving to support the boundary wall on a capacitor plate on a side facing away from the mould cavity and forming one or more hollow spaces,

• wherein at least one mould half of the two mould halves is designed for trimming the at least one mould half by means of the one or more supports and/or the one or more hollow spaces, in order to influence an electromagnetic field in the mould cavity such that a resulting relative permittivity of the tool coincides well with a relative permittivity of the foam particles.