MULTI-CAVITY MOULD WITH A KNIFE PRESSURE-BOX FOR A THERMOFORMING MACHINE USED IN THE PROCESS OF HIGH-VOLUME, CONTINUOUS THERMOFORMING OF THIN-GAUGE PLASTIC PRODUCTS

摘要

A multi-cavity mould (1) comprising: - an upper tool (11) and a lower tool (12) arranged in a cooperating manner; characterized in that the upper tool (11) comprises a knife pressure box (13) comprising: - a horizontal top plate (131); - first and second end plates (132) and first and second side plates (133) extending orthogonally downwardly from a lower surface of the plate (131); the plates (132, 133) are connected such that the plate (131) and the plates (132, 133) form a downwardly open rectangular parallelepiped enclosure; the plates (132, 133) are made from tool steel with a thickness (t) from 6.35 - 10 mm and a cutting surface (130) defined along an orthogonally downwardly projecting end of plates (132, 133) wherein - the surface (130) has a substantially V-shaped profile comprising a micro flat face (M) with a width from 0.02 - 0.1 mm and is positioned such that when the pressure box (13) is pressed against the sheet (3), the surface (130) partially penetrates the sheet (3) in order to form a seal around the pressure box (13) by pressing a zone of the sheet (3) which was partially trimmed and situated inside the enclosure against the surface (130).