SU1395520A1 - Hot-channel mould for making thermoplastic articles - Google Patents

Abstract

The invention relates to the field of processing of polymeric materials by casting under pressure, in particular, by using mines. The goal is to reduce energy consumption and simplify the design of the casting mold, for which the gating system is equipped with heat transfer tires located on both sides of the spreader block 6. The coils of the electric heater of the sprue bushing 9 and nozzles 11 are made with variable pitch and increasing diameter in the direction of the sprue block, and the sleeves are made in the form of cones and have a wide base facing the heat transfer bus. 4 1sh.

Description

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The invention relates to the processing of polymeric materials by injection molding, in particular to hot-rolled injection molds, and can be used for faceless molding of products from thermoplastics according to waste-free technology.

The purpose of the invention is to reduce energy consumption and simplify the construction of the mold form.

FIG. Figure 1 shows the hot canal- On the casting mold for products from thermoplastics, general view; in fig. 2 - Heated gating system of mountains - | minting mold form; FIG. 4 - section AA in FIG. 2J in FIG. 3 - section BA in FIG. 2,

The hot runner casting form cuts the movable half-form 1 with the embellishing details 2 and the pushing system 3, the fixed half-form 4 with the decorating parts 5 and the heated gating system which consists of block 6 with the spacing gating channel 7 and heat transfer tires 8, spruing bush 9 with electric heater 10, nozzles 11 from electron-: heater 12.

Gating electric heaters: bushings and nozzles are made in the form of a spiral with a variable pitch, increasing the diameter of the coils towards the block 6

and are filled with material with high thermal conductivity ..

The steel housings of the sprue bushing: 9 and nozzles 11 contain holes 13, due to which the material has high thermal conductivity in contact with block 6. At the same time, more turns of the heater are concentrated in the contact zone of the sprue bushing and nozzles with the block than temperature control gating sleeve 9, nozzles 11 and block 6 are installed thermocouple 14, 15 and 16.

 Between the block b and the decorating parts 5 of the fixed half-form, support sleeves 17 are installed, made of a material with a low thermal conductivity coefficient,

The hot runner casting form works as follows.

After closing: movable 1 and fixed half-form, through the sprue bushing 9, separating the casting channel 7 of the block 6 and the nozzle 11 polymer melt from the main cylinder of the injection molding machine (not shown) under pressure

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After the melt cools, the movable half-form 1 moves away from the fixed half-form 4 and the pushing system pushes the finished products that do not require additional processing to collect sprues. Dp to ensure the health of hot channel form, it is necessary to maintain the temperature of the sprue bushing 9, block 6 and nozzles 11 at a given level,

The set temperatures provide the electric heaters of the gating sleeve 9 and the nozzles 11, their thermocouples 14, 15 and 16 are in contact with the secondary automation devices. Installed in block 6 tires 8, transferring a significant part of the heat from heaters 10 and 12, equalize the temperature in the body of the block along the entire length with a minimum temperature difference in the zone of contact of the sprue bushing and nozzles with the block. Support sleeves 17, made of a material with a low heat transfer coefficient (for example, titanium), isolate the decorating parts 5 from heating. Electric heaters filled with a material (e.g. aluminum) with a greater thermal conductivity than steel are used to heat the spreader block from the heating sprue bush and nozzles, the heat conductive material is in direct contact with the block, and electric heaters 10 and 12 are in the form of spirals with a step and increasing diameter of the turns towards the block, the release of a larger amount of heat in the zone 1 of contact with the block than in zone 2 (FIG. 2). Those. The power distribution of the electric heater is proportional to the masses of the metal being heated, including the corresponding part of the mass of the block 6.

Claims (1)

Invention Formula A hot runner casting mold for thermoplastic products containing a movable half-form with clearance parts and a pushing system, a fixed half-form with decorating parts and a heated runner system including a spreader sprue, runner bush and nozzles with electric heaters made in the form of a spiral, characterized in that, in order to reduce energy consumption and simplify the form design, the runner system is equipped with tag-transfer tires located on both sides of the gate spreader unit, coils of the electric heaters of the runner bush and nozzles are filled with variable pitch and an increasing diameter in the direction of the sprue gate unit, and the sleeves are made in the form of cones and face a broad base in the direction of the heat transfer bus. ; / / 7 FIG 2 AT 6 Fig.Z Aa / J Fy