JPH0349860Y2 - - Google Patents

Description

[Detailed explanation of the invention] <Industrial application field> This invention is a method for continuously vulcanizing rubber extrudates with sponge parts using microwave dielectric heating (hereinafter referred to as "microwave heating"). The present invention relates to vulcanization equipment in which a preheating hot air stove is arranged between a microwave dielectric heating tank (hereinafter referred to as "microwave heating tank") and an extruder. <Prior art> When microwave heating is used to continuously vulcanize a rubber extrudate (hereinafter referred to as an "extrudate") having a sponge part, such as a weather strip, the extrudate is directly vulcanized from the extruder. When introduced into the tank, the inside of the extrudate is vulcanized before the surface side due to internal heating, so it is difficult to obtain a clean skin layer in the sponge part - the sponge part is usually a sealed part and requires a clean skin layer. −. Therefore, as shown in No. 10, there is a vulcanization equipment in which a preheating hot air stove 5 is disposed between an extruder 1 and a microwave heating tank 3. In the illustrated example, 7 is a post-heating hot air stove, 9 is a take-up machine, and 10 is a hot air generator. The hot air outlet formed on the extrudate introduction side of the preheating hot blast furnace 5 is normally used to prevent the extrudate (which has very low shape retention ability in an unvulcanized state) from deforming due to wind pressure. It was not facing directly towards the object, but was formed on the bottom or side wall. <Problems to be solved by the invention> For this reason, it takes time to heat up the surface of the extrudate, the thermal efficiency is low, and it is also difficult to reliably obtain a beautiful skin layer on the sponge part. . Therefore, as a result of intensive research into a method that prevents the extrudate W from deforming due to wind pressure even when hot air is directly blown onto the extrudate W, the inventor of the present invention found that the fifth
Instead of blowing hot air orthogonally as shown in the figure, a blower duct 11 is installed diagonally as shown in Figures 6 and 7, or a rectifier plate 14 is formed in the hot air outlet 12, so that the hot air flows in parallel direction. It has been found that if the extrudates W (sponge portion S) are sprayed at different angles, the extrudate W (sponge portion S) is hardly deformed due to wind pressure. However, in this case, it has been found that a phenomenon in which external cold air is sucked in from the extrudate introduction side of the hot air stove causes the temperature inside the tank to decrease, which also leads to a decrease in thermal efficiency. <Means for solving the problem> The microwave continuous vulcanization equipment of this invention, in which a preheating hot air stove is arranged between the extruder and the microwave heating tank, has a hot air outlet of the preheating hot air furnace. In addition to being directed toward the sponge part of the extrudate being conveyed, most of the air flow from the hot air outlet flows parallel to the extrudate being conveyed from diagonally outward, and part of the air flow is directed toward the extrudate being conveyed. The above-mentioned problem is solved by forming the air flow guide member at the hot air outlet so that the air flow is counter-current. <Examples> This invention will be described in detail below based on various examples. (1) First Example (Figures 1 and 2) As in the conventional case, as shown in Figure 10, an extruder 1
A preheating hot air stove 5 is disposed between the microwave heating tank 3 and the microwave heating tank 3 . Note that the post-heating furnace 7 is not limited to the hot air method, and may be of a fluidized bed (FB) or salt bath (LCM) method. In this hot air stove 5, a hot air outlet 11 located on the extrudate introduction side is formed in a ceiling wall 13 toward a sponge portion S of an extrudate (weather strip) W conveyed by a feed belt 6. At this time,
The direction of the air outlet 12 of the air duct 11 is perpendicular to the conveyed extrudate W. At the opening end wall of the blower outlet 12 on the opposite side to the extrudate conveying direction, most of the air flow flows parallel to the conveyed extrudate W from obliquely outward, and a part of the air flow flows parallel to the conveyed extrudate W. A rectangular rectifying plate (air flow guide member) 15 is attached obliquely to the conveyed extrudate W so as to flow counter-currently to the flow W. The oblique angle θ of the current plate 15 with respect to the conveyed extrudate W is set to 30 to 60°, and the plane closure rate with respect to the air outlet 11 is set to 20 to 60%. Note that the hot air outlet 11 may be formed on the side wall (one side or both sides) depending on the form of the extrudate. Next, how the vulcanization equipment of this embodiment is used will be explained. As in the past, the extrudate W from the extruder 1 is heated on the surface and pre-vulcanized in a preheating hot air oven 5, then heated inside in a microwave heating tank 3, and then heated in a post heating hot air oven 9. The temperature is maintained at the set temperature (vulcanization temperature) and vulcanization is completed. At this time, in the preheating hot blast furnace 5, hot air is blown out from the hot air outlet 12 directly toward the conveyed extrudate W, but the current plate 15 directs most of the air flow toward the conveyed extrudate in a cocurrent direction. Since the air is sprayed obliquely from the outside, there is almost no possibility that the sponge portion S will be deformed by the wind pressure. That is, when the blowing angle of the air flow with respect to the conveyed extrudate is θ, the wind pressure is theoretically sin θ times that in the case where the baffle plate 15 is not provided. Further, a part of the airflow is disturbed by the current plate 15 and flows countercurrently to the conveyed extrudate W. For this reason, external cold air is hardly sucked in from the extrudate introduction side. (2) Second embodiment (Figure 3) In the first embodiment, the air flow guide member 17 disposed at the hot air outlet 11 is shaped like a "human" as shown in the figure, and the air flow conveys the extrudate W. This ensures reliable distribution in parallel and countercurrent directions. The airflow guide member 17 may be slidable in a direction parallel to the conveyed extrudate W. The manner of use of this embodiment is the same as that of the first embodiment. (3) Third embodiment (Fig. 4) In the first embodiment, the blower duct 11 is provided obliquely so that the direction of the hot air outlet 12 is obliquely crossed in the parallel flow direction with respect to the conveyed extrudate W, and the air A rectifying plate portion 18 bent at the tip so that a part of the flow becomes countercurrent.
An air flow guiding member 18 formed of a perforated plate with a hole a is attached to the open end wall of the hot air outlet 12 in the extrudate conveying direction. The manner of use of this embodiment is the same as that of the first embodiment. <Effects of the invention> The microwave continuous vulcanization equipment of this invention has the above-mentioned configuration, and in the preheated hot air oven, the conveyed extrudate (sponge part) is deformed by wind pressure, and external cold air is introduced into the extrudate. Directly blow hot air into the extrudate (sponge part) without the risk of it being sucked in from the side.
can be sprayed on. Therefore, the thermal efficiency is improved, and a beautiful skin layer can be reliably formed on the sponge portion. In order to confirm this effect, an extrudate (weather strip) with a cross-sectional shape as shown in Fig. 8 was prepared.
1 (Example 1) and 5 to 7 (Comparative Examples 1 to 3) were placed between the extruder 1 and the microwave heating tank 3 for microwave vulcanization. Table 1 shows the test results of vulcanization using the equipment. The test conditions were a set temperature inside the furnace of 180℃ and an outside temperature of 24℃.
In addition, the furnace temperature is B (center of hot air outlet), A, and C (positions 100 mm each from point A) in Figure 9.
The appearance is the sponge part S in Fig. 8.
The surface roughness and dimensional defect rate between Z and Z were determined. From the results shown in Table 1, it can be seen that when the continuous microwave vulcanization equipment of this invention is used, the thermal efficiency is good, and the sponge portion can be vulcanized smoothly and with a small dimensional defect rate. 【table】

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional side view showing an example of a preheating hot blast stove used in the microwave continuous vulcanization equipment of this invention, Figure 2 is a front view of Figure 1, and Figure 3 is the preheating of Figure 1. FIG. 4 is a cross-sectional view of a main part showing a modified form of the hot air outlet in a hot air stove; FIG. Figure 7 is a partial cross-sectional side view showing comparative examples of preheating hot air stoves used in microwave continuous vulcanization equipment, Figure 8 is a sectional view of a weather strip that is an example of an extrudate, and Figure 9 is a preheating hot air stove. FIG. 10 is a partial cross-sectional side view showing temperature measurement positions within the chamber, and FIG. 10 is an overall view of the microwave continuous vulcanization equipment. 1... Extruder, 3... Microwave dielectric heating tank,
5... Preheating hot air stove, 12... Hot air outlet, 1
5, 17, 18... Air flow guide member, W... (transportation) extrudate, S... sponge portion.

Claims (1)

[Claims for Utility Model Registration] Equipment for continuously vulcanizing rubber extrudates having sponge parts using microwave dielectric heating, which includes preheating between an extruder and a microwave dielectric heating tank. In the equipment configured to include a hot air blower, a hot air outlet formed on the extrudate inlet side of the preheating hot air oven faces the sponge portion of the conveyed extrudate, and the air flow from the hot air outlet is An air flow guide member is formed at the hot air outlet so that most of the air flow flows in parallel with the conveyed extrudate from an obliquely outward direction, and a part of the air flow flows in a countercurrent direction with respect to the conveyed extrudate. Microwave continuous vulcanization equipment characterized by: