Abrégé

In a method and an injection-molding nozzle for producing injection-molded parts from plastic with an injection mold, the plastic melt in the form of at least one ribbon-like strand of melt is injected through a nozzle slit into a cavity of the injection mold before the injection-molded part is demolded once the plastic melt has solidified. The plastic melt is exposed to heat in the region of the sprue during solidifying in the cavity and the sprue is torn off during demolding of the injection-molded part along the nozzle slit in the region of the sprue as a result of the temperature gradient between the solidified injection-molded part and the plastic melt.

Classes IPC  ?

• B29C 45/27 - Canaux d'injection
• B29C 45/30 - Moyens de commande de l'écoulement placés dans les canaux d'injection, p. ex. construction "torpedo"

Abrégé

The present invention refers to an injection molding nozzle for introducing a molten plastic to a mold cavity (15) of an injection molding tool via a slot gate (2, 2, 3). The injection molding nozzle includes a nozzle core (2, 3, 3) having an elongate edge (3B) and is received in an opening (1A, 1) in a housing (1, 1). A portion of the nozzle core (2, 3, 3) is spaced apart from the housing (1, 1) so as to define a nozzle flow channel that is in fluid communication between a source of the molten plastic and the slot gate (2, 2, 3), and at least a downstream portion of the nozzle flow channel that is between the housing (1, 1) and the nozzle core (2, 3, 3) surrounds the nozzle core (2, 3, 3) on all sides.

Classes IPC  ?

• B29C 45/30 - Moyens de commande de l'écoulement placés dans les canaux d'injection, p. ex. construction "torpedo"
• B29C 45/27 - Canaux d'injection
• B29K 105/00 - Présentation, forme ou état de la matière moulée

Abrégé

The present invention refers to an injection molding nozzle for introducing a molten plastic to a mold cavity (15) of an injection molding tool via a slot gate (2, 2, 3). The injection molding nozzle includes a nozzle core (2, 3, 3) having an elongate edge (3B) and is received in an opening (1A, 1) in a housing (1, 1). A portion of the nozzle core (2, 3, 3) is spaced apart from the housing (1, 1) so as to define a nozzle flow channel that is in fluid communication between a source of the molten plastic and the slot gate (2, 2, 3), and at least a downstream portion of the nozzle flow channel that is between the housing (1, 1) and the nozzle core (2, 3, 3) surrounds the nozzle core (2, 3, 3) on all sides.

Classes IPC  ?

• B29C 45/27 - Canaux d'injection
• B29C 45/30 - Moyens de commande de l'écoulement placés dans les canaux d'injection, p. ex. construction "torpedo"
• B29C 45/38 - Équipement de coupe et d'enlèvement de carottes d'injection

Abrégé

A description is given of a method and an injection-moulding nozzle for producing injection-moulded parts from plastic with an injection mould, wherein the polymer melt in the form of at least one ribbon-like strand of melt is injected through a nozzle slit (2) into a cavity (15) of the mould before the injection-moulded part is demoulded once the polymer melt has solidified. In order to create advantageous injection-moulding and demoulding conditions, it is proposed that, while it is solidifying in the cavity (15), the polymer melt is exposed to heat in the region of the sprue and that, while the injection-moulded part is being demoulded, the sprue tears off along the nozzle slit (2) as a result of the temperature gradient between the solidified injection-moulded part and the polymer melt in the region of the sprue.

Classes IPC  ?

• B29C 45/27 - Canaux d'injection
• B29C 45/30 - Moyens de commande de l'écoulement placés dans les canaux d'injection, p. ex. construction "torpedo"
• B29C 45/38 - Équipement de coupe et d'enlèvement de carottes d'injection

Produits et services

Bags of plastic (packaging sleeves); Carrier bags of plastic. Containers of plastic; Plastic storage containers; Plastic boxes. Household or kitchen containers of plastic.

Abrégé

The invention describes a process for the production of a polymer moulding (2) with an internal space (3), in which a main cavity (9) is entirely filled with melt (14), and after solidification of the melt (14) at the cavity walls (20), at one end of the main cavity (9), liquid (16) is passed under pressure through a feed (15) into the melt (14), and, at the opposite end of the main cavity (9), an ancillary cavity (10) is opened, thus displacing melt (14) from the moulding (2) into the ancillary cavity (10) and producing the internal space (3) in the moulding (2), where the ancillary cavity (10) has a discharge opening (18). Attached to the discharge opening (18), there is a discharge cavity (24), where through filling of the ancillary cavity (10) with melt (14) a portion thereof is passed under pressure through the discharge opening (18) into the discharge cavity (24), and the liquid (16) is passed under pressure through the discharge opening (18), and the melt (14) located behind this is passed under pressure into the discharge cavity (24).

Classes IPC  ?

• B29C 45/17 - Éléments constitutifs, détails ou accessoiresOpérations auxiliaires
• B29C 33/10 - Moules ou noyauxLeurs détails ou accessoires comportant des évents incorporés
• B29C 33/30 - Montage, échange ou centrage

Abrégé

The invention relates to a method for producing a carrier element (1), especially a transport pallet, from a plastic material, according to which a mould cavity (23) is formed by mould walls (33, 34) defining the same in an injection mould (20) comprising at least two mould halves (21, 22), in the closed position of said mould halves. The first mould half (21) is designed such that it can be displaced in relation to the other mould half (22). The pressure in the mould cavity (23) is lowered to a pressure below the ambient pressure at least during the injection process of the plastic material for forming the carrier element (1). The invention also relates to an injection mould (20) for producing the carrier element (1).

Classes IPC  ?

• B29C 45/17 - Éléments constitutifs, détails ou accessoiresOpérations auxiliaires
• B29C 45/56 - Moyens pour plastifier ou homogénéiser la matière à mouler ou pour la forcer dans le moule utilisant des éléments de moules mobiles pendant ou après l'injection, p. ex. pour le moulage par injection-pressage