JPS60242033A - Preventive construction against leakage of resin at fitting surface of synthetic resin molding flat die - Google Patents

Abstract

PURPOSE:To eliminate trouble in tightening bolts, by a construction wherein a metallic connector provided between a cylinder head and a flat die is provided with a cooling pipe, and a molten resin leaking between the component parts is solidified by cooling, thereby preventing further leakage. CONSTITUTION:The metallic connector 12 for connecting a cylinder 1 and a flat die 6 is provided with an annular peripheral groove 16 and an outwardly extending groove 16' in its surface on the die 6 side, and the cooling pipe 17 is disposed in the grooves 16, 16'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for preventing leakage of molten resin from the assembly surface of a flat die and cylinder by cooling and solidifying it in a synthetic resin molding apparatus. It is.

[Prior Art] In a conventional synthetic resin extrusion molding apparatus, for example, as shown in FIG. The bolts 21 and 22 are joined together by tightening them one after the other to prevent leakage of molten resin, but it takes a lot of effort to tighten a large number of bolts 21 and 22. If there are any parts that are not tightly tightened, resin may leak from there. Furthermore, when cleaning or replacing the screen pack 3 attached to the outlet of the cylinder 1, all the bolts 2 and 22 arranged circumferentially as described above must be removed. Also, each bolt 21 and 22 had to be tightened.

[Problems to be Solved by the Invention] The present invention solves problems such as leakage of molten resin, difficulty in tightening bolts, and complexity in cleaning and replacing screen packs.

[Means for solving the problem] An annular circumferential groove is formed on the surface facing the flat die of the coupling metal that connects the cylinder outlet and the flat die inlet, and an outer end of the coupling metal is formed in the circumferential groove. The grooves extending into the grooves are communicated with each other, and cooling pipes are embedded in each groove.

[Function] Cooling is performed by passing cold water through the cooling pipe, and the molten resin leaking from the flat die inlet is cooled and hardened, thereby preventing resin leakage.

[Example] In FIG. 1, 1 is a cylinder of an extruder, and 2 is a screw installed in the cylinder 1.

A breaker plate 4 with a screen pack 3 attached thereto is inserted into the outlet end of the cylinder 1.

Reference numeral 5 designates a metal fitting as a brake force receiver for supporting the breaker plate 4. 6 is a flat die which is divided into an upper half 6a and a lower half 6b, which are joined together by tightening a connecting bolt 7, and the braking force receiver is formed in the mounting groove 8 of the metal fitting 5 on the inlet side.
has been established. Furthermore, the flat die 6 has an extrusion hole 9 for extruding the molten resin, and a doctor knife 10 is provided near the outlet of the extrusion hole 9 (=I).

Reference numeral 11 denotes an engraving roll disposed in front of the flat die 6 in opposition to and close to it.

Reference numeral 12 designates a flange-like connecting metal fitting that connects the cylinder 1 and the flat die 6 to each other, and has a circular hole 13 in the center through which the breaker plate 4 can be inserted, and has a circular hole 13 on the side as shown in FIG. A coupling screw hole] 4 facing the cylinder head la is bored circumferentially, and a coupling bolt facing the lower half 6b of the flat die 6 is provided in the lower half of the other side as shown in FIG. A hole 15 is formed in a semicircular shape at the bottom.

Furthermore, an annular circumferential groove 16 is provided at a position near the inner circumference of the other side surface.
At the same time, the circumference Wt16 is communicated with a groove 16' extending to the outer end of the joint metal fitting 12, and a cooling pipe 17 is embedded in each of the grooves 16 and 16'.

Then, this joining metal object 12 is attached to the lower half 6 of the flat die 6.
6b, insert the bolt] 9 through the connecting bolt hole 15 and tighten it into the connecting bolt hole 15 provided in 6b, and then insert this connecting metal fitting 1 into the outlet of the cylinder 1.
2 and the coupling hardware 12 and the cylinder head 1a.
and insert the bolt 1 into the connecting hole 14 provided in the connecting metal fitting 12.
8, the connection between the cylinder 1 and the flat die lower half 6b is completed. After that, insert the breaker plate 4 with the screen pack 3 attached to the circular hole 13, fit the fitting 5 into the fitting 1118 of the breaker force receiver, and then place the upper half 6a of the die 6 on the lower half 6b. 6a and 6b are stacked and tightened with the connecting bolt 7 to unite them. When the extrusion device assembled in this way is operated, the molten resin extruded by the rotation of the screw 2 passes through the connecting metal fitting 12 and flows into the flat die. Sent to 6.

At this time, cooling water is circulated through the cooling pipe 17 attached to the metal joint 12 to cool and harden the molten resin leaking from the opposing surfaces of the metal joint 12 and the flat die 6, thereby stopping the leakage. can be done.

Moreover, the connection between the upper half body 6a of the flat die 6 and the lower body 6b can be separated by unfastening the connecting bolts 7, and the upper half body 6a can be removed by pulling it upward. For the brake force receiver, remove the metal fitting 5,
The screen pack 3 can be easily removed together with the breaker plate 4 for cleaning or replacement.

[Effects of the Invention] As described above, the structure for preventing resin leakage from the assembly surface of the flat die for synthetic resin molding of the present invention has a cooling pipe running around the side surface of the joining metal fittings facing the assembly surface of the flat die. By installing the cooling pipe in a recessed manner and cooling it by circulating a refrigerant through the cooling pipe, leaking molten resin can be cooled and hardened to seal the gap and prevent resin leakage. Further, the cooling pipe can be used as a heating pipe for passing a heating medium to preheat the flat die at the start of operation of the extruder.

[Brief explanation of the drawing]

The figures relate to the present invention, and Fig. 1 is a sectional view, Fig. 2 is a side view of the joint metal fittings with cooling pipes attached, and Fig. 3 is the first X-
FIG. 4 is a sectional view taken along the y-X line in FIG. 1, and FIG. 5 is a sectional view showing a conventional example. 1...Cylinder, 6...Flat die, 12
...Connecting hardware, 16... Circumferential groove, 16'...
...Groove, 17...Cooling pipe. Patent applicant: Towa Co., Ltd. Patent attorney: Takeshi Ito 1j... 1.515
．．・Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] An annular circumferential groove is formed on the surface facing the flat die of the coupling metal that connects the cylinder outlet and the flat die inlet, and a groove extending to the outer end of the coupling metal is communicated with the circumferential groove. A flat die for synthetic resin molding, characterized in that a cooling pipe is embedded in the die and the cooling pipe is cooled to cool and harden the molten resin leaking from the inlet of the flat die. Resin leakage prevention structure.