JP2005104075A - Cleaning method of slush molding mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method of a slush molding mold which suppresses blowing surplus amount of abrasive particles to a part and prevents a pattern on a surface of the molding mold from being abraded due to abrasion. <P>SOLUTION: In the cleaning method of a slush molding mold by honing, the slush molding mold has a concentration portion. When the abrasive particles are blown to the surface of the mold other than the concentration portion, the concentration portion is masked. The present method has an injecting process of cleaning liquid, a process of inserting a heating fixture, and a cleaning process. Thus, the abrasion of the molding mold is suppressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for cleaning a slush mold.

  Slush molding is one of the skin molding methods for soft molded parts used in vehicle interior materials such as instrument panel safety pads. Slush molding is a molding method in which a raw material made of resin is put into a heated mold, and the raw material is melted and gelled in the mold to obtain a thin film molded product. The slush molding includes powder slush molding and sol slush molding depending on the form of the raw material put into the mold. In recent years, the powder slush method has become mainstream because the process is simple and a molded product having a uniform thickness can be obtained. For example, see Patent Documents 1 and 2.

  In the slush molding die used for slush molding, when molding is repeated about 300 times, there has been a problem that the component of the additive (silicon resin or the like) in the deposited raw material is deposited on the mold surface.

  When the additive is deposited on the surface of the mold, there arises a problem that the quality of the product obtained by the molding is deteriorated. For example, in a product having a wrinkle pattern, the wrinkle pattern disappears and the gloss increases. Specifically, when slush molding is performed with silicon deposited on the mold surface and the molded product is removed from the mold, the silicon deposited on the mold surface peels off from the mold surface, and silicon is deposited on the molded product surface. Things begin to form. The surface formed by the silicon deposit is supposed to erase the wrinkle pattern planned in the design stage of the molded product and give the surface of the molded product gloss. That is, it was a defective product.

  In order to suppress the occurrence of such a problem, it was necessary to remove the deposit on the mold surface of the mold that was repeatedly molded.

  As a cleaning method for removing deposits from the mold surface of a conventional slush mold, a honing method in which an abrasive is sprayed onto the mold surface for cleaning, and a cleaning chemical (cleaning liquid) is injected into the mold to remove the deposits. There is a chemical cleaning method to dissolve. Here, the honing method includes a dry honing method in which an abrasive is sprayed using air, and a liquid honing method in which a liquid such as water is sprayed.

  However, the honing method has a problem that depending on the shape of the molding die, there is a portion where the abrasive is concentrated, and when the abrasive is concentrated, the wrinkle pattern on the mold surface is worn. Here, when the abrasive is sprayed on the mold surface, it is reflected by the mold surface. The portion where the reflected abrasive is easy to hit becomes the portion where the abrasive is concentrated. In general, the portion where the abrasive is concentrated is an undercut portion.

  This undercut portion is a portion where mold contamination due to the seizure of the raw material resin is severe, and is a portion that takes time for cleaning. For this reason, it is necessary to lengthen the time for spraying the abrasive on the undercut portion. When the abrasive is sprayed for a long time, the wrinkle pattern on the mold surface tends to be worn.

  For this reason, the undercut portion is not only for cleaning the portion itself, but also when other portions are cleaned, the abrasive pattern is easily worn on the mold surface.

Further, the chemical cleaning method has a problem that the amount of the chemical used is large and the cost is high because the chemical must be injected into the mold and filled in the mold. Further, in the chemical cleaning method, when the deposit on the mold surface is dissolved in the chemical, the temperature is required to be higher than a predetermined temperature. However, since a normal mold has no heating means, Had to be injected into the mold. A large amount of chemicals would be heated, and it took a lot of time and cost to heat. Furthermore, in the chemical cleaning method, since temperature control during cleaning cannot be performed, extra cost is required for cleaning.
JP-A-4-77216 JP-A-3-275320

  This invention is made | formed in view of the said actual condition, and makes it a subject to provide the cleaning method of a slush molding die.

  In order to solve the above problems, the present invention has been found as a result of repeated studies on a cleaning method for a slush mold.

  The first slush mold cleaning method of the present invention is a slush mold cleaning method in which abrasive particles are sprayed onto a slush mold surface with fluid to remove deposits attached to the slush mold surface. The mold has a concentrated portion where the abrasive particles sprayed together with the fluid are concentrated, and the concentrated portion is masked when the abrasive particles are sprayed onto the mold surface other than the concentrated portion.

  In the first cleaning method of the present invention, the amount of abrasive particles hitting the mold surface is adjusted by masking. As a result, it is possible to suppress an excessive amount of abrasive particles from being sprayed and to suppress wear on the surface of the mold.

  Further, the second slush mold cleaning method of the present invention includes a cleaning liquid injection process for injecting a cleaning liquid into the slush mold, and a heating having an outer peripheral surface facing the mold surface of the slush mold at a small interval. It has a heating jig insertion process for inserting a jig into a slush mold, and a cleaning process for maintaining the cleaning liquid at a predetermined temperature by the heating jig.

  In the second cleaning method of the present invention, the cleaning liquid is poured into the mold together with the heating jig, and the amount of the cleaning liquid corresponding to the volume of the portion immersed in the cleaning liquid of the heating jig can be saved. Further, the temperature of the cleaning liquid can be controlled by heating with a heating jig.

  The first cleaning method of the present invention is a cleaning method using a honing method in which abrasive particles are sprayed onto the mold surface of a slush mold to clean the mold surface, and the amount of abrasive particles hitting the mold surface is reduced by masking. It is adjusting. As a result, it is possible to suppress partial spraying of an excessive amount of abrasive particles and to prevent the pattern on the surface of the mold from disappearing due to wear.

  The second cleaning method of the present invention is a cleaning method using a chemical cleaning method in which a cleaning liquid is injected into a cavity of a slush mold and the mold is cleaned with the cleaning liquid, and the cleaning liquid injected into the mold is heated and treated. The mold is cleaned while the tool is immersed and the temperature of the cleaning liquid is adjusted. Since the heating jig is immersed in the cleaning liquid, the amount of the cleaning liquid used can be reduced. Further, the cleaning liquid can be heated by the heating jig, and the temperature of the cleaning liquid can be adjusted. In addition, the second cleaning method of the present invention is a cleaning method in which deposits adhering to the mold surface are dissolved by the cleaning liquid and the mold is not worn.

(Honing method)
The first cleaning method of the present invention is a cleaning method for a slush mold in which abrasive particles are sprayed onto the surface of the slush mold together with a fluid to remove deposits attached to the surface of the slush mold. That is, when the abrasive particles are sprayed (honed) on the mold surface, the abrasive particles polish the deposits attached to the mold surface, and as a result, clean the mold surface.

  In the first cleaning method of the present invention, the slush mold has a concentrated portion where abrasive particles sprayed with the fluid are concentrated. The abrasive particles sprayed are reflected after hitting the mold surface. The reflected abrasive particles come into contact with portions other than the sprayed portion of the mold surface. Depending on the shape of the slush mold, there is a portion where the reflected abrasive particles are likely to hit, and this portion becomes a concentrated portion.

  The concentrated portion is not determined unconditionally because it varies depending on the shape of the slush mold. For example, when the slash mold has a shape having an undercut, the undercut portion is a concentrated portion.

  In the first cleaning method of the present invention, when the abrasive particles are sprayed on the mold surface other than the concentrated portion, the concentrated portion is masked. By masking the concentrated portion, even if abrasive particles are sprayed on portions other than the concentrated portion, the abrasive particles do not hit the concentrated portion. As a result, wear on the mold surface at the concentrated portion is suppressed.

  In the concentrated portion, the mold surface is cleaned by spraying abrasive particles without masking. Here, the abrasive particles may be sprayed (honed) onto the concentrated portion either before masking (before honing to other than the concentrated portion) or after honing to the concentrated portion. That is, it is preferable that abrasive particles are sprayed on the concentrated portion before masking or after masking is removed.

  Masking is not particularly limited as long as the abrasive particles do not hit the concentrated portion when honing is performed on a portion other than the concentrated portion. Masking is preferably performed by attaching a soft resin composition to the concentrated portion. The soft resin composition is preferably a denture base soft resin composition. The denture base soft resin composition is a so-called denture stabilizer and is excellent in adhesion to the mold surface and releasability from the mold surface. The composition of the denture base soft resin composition is not particularly limited.

  In the cleaning method of the present invention, honing is performed on other portions in a state where the concentrated portion is masked, and honing of the abrasive particles is the same as that of conventionally known honing. That is, either a dry honing method in which abrasive particles are sprayed using a gas such as air, or a liquid honing method in which a liquid such as water is sprayed may be used.

  Further, the hard particles sprayed on the mold surface are not particularly limited as long as they have a predetermined hardness. For example, alumina particles, cone particles, dry ice particles, and resin particles can be used. The Mohs hardness of the hard particles is preferably 2.5 or more.

  The force (or speed) when spraying the hard particles is not particularly limited.

  In the cleaning method of the present invention, since hard particles are sprayed on other portions while masking the concentrated portion, excessive amounts of hard particles do not hit the concentrated portion, and wear of the concentrated portion of the mold is suppressed. It is done.

(Chemical cleaning method)
The second cleaning method of the present invention includes a cleaning liquid injection step, a heating jig insertion step, and a cleaning step.

  The cleaning liquid injection step is a step of injecting the cleaning liquid into the slush mold. The cleaning liquid injected into the mold in the cleaning liquid injection step is not particularly limited as long as it is a solution that can dissolve deposits present on the surface of the mold.

  The cleaning liquid is preferably a polar organic solvent. The polar organic solvent can dissolve deposits on the mold surface. As the polar organic solvent, benzyl alcohol is preferably used.

  The heating jig insertion step is a step of inserting a heating jig having an outer peripheral surface facing the mold surface of the slush molding die with a small gap into the slush molding die. By inserting the heating jig into the mold, the cleaning liquid can be heated by the heating jig in the subsequent steps. By heating the cleaning liquid, deposits on the mold surface can be dissolved in the cleaning liquid.

  The heating jig inserted in the heating jig insertion step has an outer peripheral surface facing the mold surface of the slush molding die with a small interval. The heating jig has a volume by having an outer peripheral surface that is separated from the mold surface by a small distance, and when the heating jig is present in the mold together with the cleaning liquid, the liquid level of the predetermined cleaning liquid is obtained. The amount of cleaning liquid can be reduced. Here, having the outer peripheral surface facing the mold surface of the slash mold with a small interval only indicates that the heating jig has a constant volume, and the small interval is constant on the outer periphery of the heating jig. It does not indicate that the length is. It is more preferable that the small interval is constant over the entire circumference of the outer periphery of the heating jig.

  The cleaning step is a step of maintaining the cleaning liquid at a predetermined temperature using a heating jig. By maintaining the temperature of the cleaning liquid at a predetermined temperature, the deposits attached to the mold surface can be dissolved. Here, since the predetermined temperature at which the cleaning liquid is maintained differs depending on the kind of deposits and cleaning liquid to be dissolved, it is not generally determined, but is preferably room temperature or higher.

  In the cleaning method of the present invention, the front-rear relationship between the cleaning liquid injection step and the heating jig insertion step is not particularly limited. That is, the heating jig may be inserted with the cleaning liquid injected into the mold, or the cleaning liquid may be injected with the heating jig inserted into the mold.

  The heating jig preferably has a thermometer for measuring the temperature of the cleaning liquid. By measuring the temperature of the cleaning liquid, the temperature of the cleaning liquid can be maintained at a predetermined temperature. Further, it is possible to prevent the cleaning liquid from being heated excessively and boiling. Furthermore, it is more preferable that there are a plurality of thermometers.

  The heating jig preferably has positioning means for positioning when it is put into the slush mold. By having the positioning means, the heating jig can be easily inserted. Further, the heating jig can be held at a predetermined position in the mold by the positioning means.

  The cleaning liquid injected in the cleaning liquid injection step is preferably heated to a predetermined temperature or higher. By injecting the preliminarily heated cleaning liquid, the amount of heating by the heating jig can be suppressed, and the time for holding the cleaning liquid in the mold can be shortened.

  The cleaning method of the present invention preferably has a drying step of drying the mold from which the cleaning liquid and the heating jig have been removed after the cleaning step. By having the drying step, the cleaning liquid can be completely removed from the mold.

  In the cleaning method of the present invention, the condition of the material and the like of the heating jig is not limited as long as the above characteristics can be obtained. For example, it is preferably made of a metal having a heater capable of adjusting the amount of heat generation.

  In addition, since the cleaning liquid has polarity to dissolve deposits attached to the mold surface, it is preferable that the heating jig is formed of a material that does not corrode the cleaning liquid on the outer peripheral surface.

  Hereinafter, the present invention will be described using examples.

  As an example of the present invention, a slush mold was cleaned. The mold 1 to be cleaned in the embodiment has an undercut portion 10 as shown in FIG.

  The mold 1 is a mold for an instrument panel for a vehicle, and is a mold in which slush molding is repeated 300 times. The mold 1 has a silicon deposit deposited from the raw material resin on its surface by repeated slush molding.

(Example 1)
First, a masking material 2 made of a denture stabilizer (manufactured by Earth Pharmaceutical Co., Ltd., trade name: Polygrip) was attached to the undercut portion 10 of the mold 1 so that its thickness was 1 mm or more.

Subsequently, the surface portion of the mold 1 other than the undercut portion 10 contains water containing an irregular shaped alumina having an average particle size of 10 to 30 μm at a ratio of 10 to 30 wt% at a pressure of 2 to 4 kg / cm ² for 2 to 20 seconds. The air was sprayed from the honing nozzle 4. The state during the honing is shown in FIG. By this honing, silicon adhered to the surface of the surface portion other than the undercut portion 10 could be removed.

  Subsequently, the masking material 2 adhered to the undercut portion 10 was removed, and honing similar to that applied to the surface portion other than the undercut portion 10 was performed. By this honing, the silicon in the undercut portion 10 could be removed.

  In this embodiment, when honing is performed on the surface portion other than the undercut portion 10, the deformed alumina does not hit the undercut portion 10. Then, only predetermined honing can be performed on the undercut portion 10. As a result, wear of the undercut portion 10 is suppressed. In the past, it was necessary to repair the wrinkle pattern that had disappeared due to the wear of the mold, but the mold that was cleaned in this example was not required to be repaired because the mold wear was suppressed. . As a result, the cost required for cleaning can be reduced. Moreover, the surface quality of the instrument panel molded using this mold was improved by suppressing the wear of the mold.

(Example 2)
First, a heating jig 3 that can be inserted into the mold 1 was manufactured. The heating jig 3 is shown in FIG. The heating jig 3 has a shape in which the outer peripheral surface is located at a position spaced apart from the inner peripheral surface of the undercut portion 10 of the mold 1 when inserted into the mold 1. In the present embodiment, the heating jig 3 has a body portion 30 made of aluminum. The heating jig 3 has a plurality of heaters 31 and a thermometer 32 attached to the tip thereof. And the outer peripheral surface of the heating jig 3 is coated with the resin film 33.

  The heater 31 and the thermometer 32 are connected to temperature control means (not shown) so that the heater 31 can be operated based on the temperature measurement result of the thermometer 32. Specifically, when the measurement result of the thermometer 32 becomes lower than the set temperature, the heater 31 can be operated to cause the heating jig 3 to generate heat.

  Further, the heating jig 3 has positioning means 35 so that a predetermined position can be held when the heating jig 3 is inserted into the mold 1.

  For cleaning the mold 1, first, a cleaning liquid made of benzyl alcohol heated to 60 ° C. in advance was poured into the mold 1. FIG. 4 shows the mold 1 in a state where the cleaning liquid is injected.

  Then, the heating jig 3 was inserted into the cavity of the mold 1. When the heating jig 3 was inserted, the heating jig 3 was guided to a predetermined position by the positioning means 35 and held at the predetermined position. The mold 1 in a state where the heating jig 3 is maintained at a predetermined position is shown in FIG.

  After that, when the measurement result of the thermometer 32 becomes equal to or lower than the set temperature, the heater 31 is operated to cause the heating jig 3 to generate heat, and the cleaning liquid is held for 0.5 to 1 hour while being heated above the set temperature. . By this holding, silicon adhering to the mold surface of the mold 1 was removed.

  In the present embodiment, the removal of silicon from the undercut portion 10 of the mold 1 has been shown. However, in other portions, the mold 1 is inclined and the outer peripheral shape of the heating jig 3 is changed. Thus, the entire inner peripheral surface of the mold may be cleaned at a time.

  In the present embodiment, the undercut portion 10 is cleaned, but other portions may be cleaned using a conventionally known honing method. At this time, the undercut portion 10 may or may not be masked. It is preferable to perform honing in a masked state as in the first embodiment.

  In this embodiment, silicon adhering to the surface of the mold 1 is dissolved in a chemical and removed. That is, silicon can be removed without wearing the mold surface of the mold 1. Since the mold wear is suppressed, it is no longer necessary to repair the mold.

  In addition, since the cleaning solution for dissolving silicon only needs to be present between the heating jig 3 and the mold 1, the amount of the cleaning solution used can be greatly reduced. Furthermore, since the heating jig 3 heats the cleaning liquid, the cleaning liquid can be easily heated as compared with the case where the mold 1 is heated to heat the cleaning liquid. As a result, the cost required for cleaning can be reduced.

It is sectional drawing of the slush shaping | molding die cleaned in an Example. It is sectional drawing of the slash shaping | molding die which is honing in the state which masked the undercut part. It is the figure which showed the structure of the heating jig. It is the figure which showed the slush shaping | molding state of the state which inject | poured the washing | cleaning liquid. It is the figure which showed the slush shaping | molding state of the state which inserted the heating jig.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Slash shaping | molding die 2 ... Masking material 3 ... Heating jig 30 ... Main-body part 31 ... Heating heater 32 ... Thermometer 35 ... Positioning means 4 ... Honing nozzle

Claims (7)

In the cleaning method of the slush mold, the abrasive particles are sprayed onto the mold surface of the slush mold together with the fluid to remove deposits attached to the surface of the slush mold,
The slush mold has a concentrated portion where the abrasive particles sprayed together with the fluid are concentrated,
A method for cleaning a slush mold, wherein the concentrated portion is masked when the abrasive particles are sprayed onto the mold surface other than the concentrated portion.   The slush mold cleaning method according to claim 1, wherein the abrasive particles are sprayed before the masking is applied or after the masking is removed.   The slush mold cleaning method according to claim 1, wherein the masking is performed by attaching a soft resin composition to the concentrated portion.   The slush mold cleaning method according to claim 3, wherein the soft resin composition is a denture base soft resin composition. A cleaning liquid injection process for injecting a cleaning liquid into the slush mold;
A heating jig insertion step of inserting a heating jig having an outer peripheral surface facing the mold surface of the slush molding mold at a small interval into the slush molding mold;
A cleaning step of maintaining the cleaning liquid at a predetermined temperature by the heating jig;
A method for cleaning a slush mold, comprising:   The slush mold cleaning method according to claim 5, wherein the heating jig includes a thermometer for measuring a temperature of the cleaning liquid.   6. The method for cleaning a slush mold according to claim 5, wherein the heating jig has positioning means for positioning when the heating jig is put into the slush mold.