Thermoplastic core dissolving material, removable core and application thereof

Abstract

The invention discloses a thermoplastic core-dissolving material, a removable core and application of the removable core, and the thermoplastic core-dissolving material comprises the following components by mass: 20-50% of a water-soluble thermoplastic polymer material; 40-80% of a filling agent; and 0-10% of a flow promoter. Compared with the prior art, the invention has the following improvement points: 1, the water-soluble thermoplastic resin and the combination thereof are selected, so that the water solubility and the injection molding processability of the material are ensured; the material is non-toxic, non-corrosive and harmless to the product; 2, a high filling mode is adopted, so that the rigidity and the temperature resistance of the material are ensured, and the material can bear secondary molding of a resin melt as high as 320 DEG C; and 3, the processability of the material is improved by adjusting a resin combination, a filling combination or adding a flow promoter, the conditions of decomposition, incapability of injection molding and the like are avoided, and the core can be completely removed by water dissolution or water flushing.

Description

Technical Field

[0001] The invention relates to the technical field of cores, in particular to a thermoplastic core-soluble material, a removable core and applications thereof. Background Art

[0002] For some bathroom products with hollow structures, such as the H-shaped water channel structure of faucets, they cannot be manufactured by core pulling due to structural limitations, and therefore cannot be injection molded in one step.

[0003] The industry often uses removable cores for support molding, such as sand cores, salt cores, and tin-bismuth alloy melting cores. The surface of the sand core is hard and can easily scratch the injection mold; the salt core is corrosive and the part in contact with the mold is easily corroded; the tin-bismuth alloy is a heavy metal with high price and needs to be molded by casting, which is difficult to mold and has a risk of residue when it is melted out. The heavy metal is absorbed by the human body and is harmful to the human body. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a thermoplastic core-soluble material, a removable core and applications thereof to improve the above-mentioned problems.

[0005] The embodiment of the present invention provides a thermoplastic core-soluble material, which comprises, by weight:

[0006] Water-soluble thermoplastic polymer material: 20-50%;

[0007] Fillers: 40-80%;

[0008] Flow aid: 0-10%.

[0009] Preferably, the water-soluble thermoplastic resin material is one or more of starch, polyacrylamide PAM, polyvinyl alcohol PVA, PVP or polyethylene glycol PEG.

[0010] Preferably, the filler is one or more of talc, calcium carbonate, alumina, kaolin, mica, wollastonite, glass fiber, glass microspheres, potassium chloride, magnesium hydroxide, aluminum hydroxide, barium sulfate, potassium sulfate, montmorillonite, and silicon dioxide.

[0011] Preferably, the flow aid is one or more of ethylene glycol, glycerol, water, caprolactam, ethylene glycol amine, and diethylene glycol.

[0012] The embodiment of the present invention further provides a removable core, which is made of the thermoplastic core-soluble material as described above.

[0013] Preferably, the removable core is capable of withstanding melt overmolding up to 320°C.

[0014] The removable core as mentioned above is used in the injection molding of hollow products which are difficult to pull out the core.

[0015] Compared with the prior art, the present invention has the following improvements:

[0016] 1. Select water-soluble thermoplastic resins and combinations to ensure that the materials are water-soluble and injection moldable; the materials are non-toxic, non-corrosive, and harmless to the product;

[0017] 2. High filling method is adopted to ensure the rigidity and temperature resistance of the material, which can withstand secondary molding of melt at up to 320℃

[0018] 3. Improve the material processing performance by adjusting the resin combination, filling combination or adding flow aids to avoid decomposition and inability to injection mold. The core can be completely removed by water dissolution or water flushing. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] Referring to Table 1, in Example 1, the water-soluble thermoplastic polymer material is selected from PEG10000 and PVA, with a mass ratio of 10% and 30%, and the filler is selected from Al2O3, with a mass ratio of 60%.

[0022] During the implementation process, the three raw materials are added into a mixer at room temperature and mechanically stirred to be uniform.

[0023] Subsequently, the thermoplastic core-soluble material is granulated by an extruder at a temperature of 150-200° C., and then the thermoplastic core-soluble material is injection-molded by an injection molding machine at a temperature of 200-230° C. to obtain a removable core with a desired structure.

[0024] Example 2

[0025] Please refer to Table 1. In Example 2, the water-soluble thermoplastic polymer material is selected from PEG10000 and PVA, with a mass ratio of 10% and 30%, and the filler is selected from KCl, with a mass ratio of 60%.

[0026] During the implementation process, the three raw materials are added into a mixer at room temperature and mechanically stirred to be uniform.

[0027] Subsequently, the thermoplastic core-soluble material is granulated by an extruder at a temperature of 150-200° C., and then the thermoplastic core-soluble material is injection-molded by an injection molding machine at a temperature of 200-230° C. to obtain a removable core with a desired structure.

[0028] Example 3

[0029] Please refer to Table 1. In Example 3, the water-soluble thermoplastic polymer materials are PVA and PVP, with the mass ratios being 30% and 10% respectively, the fillers are TAlC 20% and KCl 32%, and the auxiliary agent is EG, with the mass ratio being 8%.

[0030] During the implementation process, TAlC and KCl are added into a mixer at room temperature, mechanically stirred evenly, EG is added in batches while stirring, and finally PVA and PVP are added and stirred evenly.

[0031] Subsequently, the thermoplastic core-soluble material is granulated by an extruder at a temperature of 150-200° C., and then the thermoplastic core-soluble material is injection-molded by an injection molding machine at a temperature of 200-230° C. to obtain a removable core with a desired structure.

[0032] Example 4

[0033] Please refer to Table 1. In Example 4, the water-soluble thermoplastic polymer material is PEG10000 and PVP, with the mass ratios being 10% and 30% respectively, the filler is TAlC 20% and Al2O3 40%, and the auxiliary agent is EG, with the mass ratio being 5%.

[0034] During the implementation process, at room temperature, the three raw materials are added into a mixer and mechanically stirred evenly.

[0035] Subsequently, the thermoplastic core-soluble material is granulated by an extruder at a temperature of 130-160° C., and then the thermoplastic core-soluble material is injection-molded by an injection molding machine at a temperature of 160-200° C. to obtain a removable core with a desired structure.

[0036] Please refer to Table 1. In Example 5, the water-soluble thermoplastic polymer materials are PVA and PVP, with the mass ratios being 25% and 10% respectively, the fillers are TAlC 25% and KCl 32%, and the auxiliary agent is EG, with the mass ratio being 8%.

[0037] During the implementation process, TAlC and KCl are added into a mixer at room temperature, mechanically stirred evenly, EG is added in batches while stirring, and finally PVA and PVP are added and stirred evenly.

[0038] Subsequently, the thermoplastic core-soluble material is granulated by an extruder at a temperature of 150-200° C., and then the thermoplastic core-soluble material is injection-molded by an injection molding machine at a temperature of 200-230° C. to obtain a removable core with a desired structure.

[0039] Table 1

[0040]

[0041]

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermoplastic core-soluble material, characterized in that: In terms of quality, it includes: Water-soluble thermoplastic polymer material: 20-50%; Fillers: 40-80%; Flow aid: 0-10%.

2. The thermoplastic core material according to claim 1, characterized in that: The water-soluble thermoplastic resin material is one or more of starch, polyacrylamide PAM, polyvinyl alcohol PVA, PVP or polyethylene glycol PEG.

3. The thermoplastic core-soluble material according to claim 1, characterized in that: The filler is one or more of talc, calcium carbonate, aluminum oxide, kaolin, mica, wollastonite, glass fiber, glass microspheres, potassium chloride, magnesium hydroxide, aluminum hydroxide, barium sulfate, potassium sulfate, montmorillonite, and silicon dioxide.

4. The thermoplastic core-soluble material according to claim 1, characterized in that: The flow aid is one or more of ethylene glycol, glycerol, water, caprolactam, ethylene glycol amine and diethylene glycol.

5. A removable core, characterized in that: The thermoplastic core-soluble material is made of the thermoplastic core-soluble material as described in any one of claims 1 to 4, wherein during the preparation, the water-soluble thermoplastic polymer material, the filler and the flow aid are evenly stirred, granulated by an extruder to obtain the thermoplastic core-soluble material, and then the thermoplastic core-soluble material is injection molded by an injection molding machine to obtain a removable core of the desired structure.

6. The removable core according to claim 5, characterized in that The injection molding temperature is 160-240°C.

7. The removable core according to claim 5, characterized in that The removable core can withstand secondary molding with resin melts up to 320°C.

8. Use of the removable core as described in any one of claims 5 to 7 in injection molding of hollow products that are difficult to pull out the core.

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