CN101733858B - Film forming method using in-mould injection - Google Patents

Abstract

The invention provides a film forming method using in-mould injection, comprising the following steps of: (1) providing a film; (2) preheating an upper mould and a lower mould of an embossing mould to the set temperature; (3) placing the film on the lower mould; (4) compounding the embossing mould; (5) transferring heat between the film and the embossing mould for a period of time so that the temperature of the film is raised; (6) vacuumizing the lower mould through a vacuum pipeline so that a state similar to vacuum is formed between the film and a grain mother plate for reducing residual air between the film and the grain mother plate when embossing; (7) injecting high-pressure air to a mould cavity between the upper mould and the film through a high-pressure air pipeline so that the film can be glued with the grain mother plate, copying grains and keeping high pressure for a period of time; (8) removing vacuum; (9) removing high pressure; (10) opening the embossing mould; (11) cooling the film; and (12) taking the film. The embossed pattern obtained by the method has the characteristics of good scratch resistance and obvious touch feeling.

Description

The film forming method of in-mould injection

[technical field]

The present invention is the film forming method of a kind of forming method of plastic sheet, particularly a kind of in-mould injection.

[background technology]

The in-mold decoration print injection mo(u)lding is a cover half of prior film being put into injection mold, then the plastics material is injected mould, the Shooting Technique that plastics material and sheet material are integrated.Patent application No. 200610060137.1 patent in China's Mainland discloses a kind of in-mold decoration print injection moulding (In_Mold Decoration; IMD) film forming method; Comprise the preparation sheet material, with the sheet material for preparing put into ready mould, make fixed half and moving half close up, by the heater that is positioned at dynamic model top to sheet material heating and certain time make sheet material softening, send into the air of moment certain pressure and the step that makes sheet forming at last to mould.

Film commonly used has two kinds, and a kind of be light face film, after light face film is applied to injection mold and carries out injection mo(u)lding, and problem such as can occur shrinking, the stress trace is obvious, and the surface of light face film is prone to generation scratching phenomenon.Another kind of film (coated sheet) for the tool figure line that processes through coating process though coated sheet can reduce problems such as shrinks, stress trace be obvious, and has certain resistance to scraping ability; But because coating layer is thinner, sense of touch is not obvious.

[summary of the invention]

The object of the present invention is to provide that a kind of resistance to scraping is good, the film forming method of obvious touch feeling in-mould injection.

For reaching above-mentioned purpose, the present invention provides a kind of film forming method of in-mould injection, through mould film is impressed to obtain required figure line; Wherein, Said mould comprises counterdie, is provided with the lines motherboard in the counterdie, and is provided with vacuum line with the said counterdie die cavity place of communicating; Said counterdie one side is provided with patrix, and the place of communicating is provided with high pressure airline with said patrix die cavity; And said forming method may further comprise the steps: (1) provides film; (2) patrix and the counterdie of embossing mould are heated in advance, till design temperature; (3) film is placed on the counterdie; (4) with embossing mould matched moulds; (5) heat is transmitted a period of time between film and the embossing mould, makes the film self-temperature promote; (6) through vacuum line counterdie is inhaled vacuum, make to form the empty shape of likelihood between film and lines motherboard, the air when reducing embossing between film and the lines motherboard is residual; (7) through injecting gases at high pressure in the die cavity between the said patrix of high-pressure air tube road direction and the said film, make the film lines motherboard of fitting, and duplicate lines, and maintenance high pressure a period of time; (8) vacuum is removed, and makes to form antivacuum shape between said lines motherboard and said film; (9) high pressure is removed, and makes that the interior gases at high pressure of die cavity between said patrix and the said film discharge outside the embossing mould; (10) with the die sinking of embossing mould; (11) film is cooled off; (12) film of taking.

Compared with prior art, the present invention adopts stamping technique to make the imprinted line of film surface, and the imprinted line of being obtained has that resistance to scraping is good, the obvious touch feeling characteristics, can effectively avoid simultaneously shrinking, the tangible problem of stress trace.

[description of drawings]

Fig. 1 is the forming die structure sketch map that the present invention adopted.

Fig. 2 is the flow chart of the film forming method of in-mould injection of the present invention.

Fig. 3 is the hookup of Fig. 2.

[specific embodiment]

See also Fig. 1, Fig. 2 and shown in Figure 3; The present invention provides a kind of film forming method of in-mould injection; It impresses to obtain required figure line film 30 through the embossing mould, and wherein, said embossing mould comprises counterdie 10; Be provided with lines motherboard 11 (can be the lines motherboard that forms through the letterpress processes) in counterdie 10 bottoms, and be provided with vacuum line 12 with the said counterdie 10 die cavity places of communicating; Said counterdie 10 1 sides are provided with patrix 20, and the 20 die cavity places of communicating are provided with high pressure airline 21 with said patrix; And said forming method may further comprise the steps:

Step 1: film 30 is provided, and puts film 30 into baking box in addition preliminary drying, reduce the water content in the film 30; (preliminary drying is not a steps necessary, decides by actual conditions are required);

Step 2: patrix 20 and counterdie 10 to the embossing mould are heated in advance, till design temperature;

Step 3: film 30 is placed on the counterdie 10;

Step 4: adopt infrared heating device (figure does not show) to film 30 heating; (the infrared ray heating is not a steps necessary, decides by actual conditions are required);

Step 5: with embossing mould matched moulds;

Step 6: heat is transmitted a period of time between film 30 and the embossing mould, makes film 30 self-temperatures promote, and wherein the film 30 required temperature that reach are less than or equal to glass transition temperature (temperature level depends on the thermoplasticity of selected film 30);

Step 7: through vacuum line 12 counterdie 10 is inhaled vacuum, make 11 of film 30 and lines motherboards form the empty shape of likelihood, the air when reducing embossing between film 30 and the lines motherboard 11 is residual;

Step 8: through injecting gases at high pressure in the die cavity of high pressure airline 21 between said patrix 20 and said film 30, make the film 30 lines motherboard 11 of fitting, and the good lines that duplicates, and keep high pressure a period of time; (the line thickness minimum of lines can be 0.02～0.03mm, can set the line thickness of lines according to the requirement of sense of touch)

Step 9: vacuum is removed, and makes 30 of said lines motherboard 11 and said films form antivacuum shape;

Step 10: high pressure is removed, and makes that the interior gases at high pressure of die cavity between said patrix 20 and the said film 30 discharge outside the embossing mould;

Step 11: with the die sinking of embossing mould;

Step 12: with film 30 coolings;

Step 13: the film 30 of taking;

Step 14: film 30 is carried out printing treatment;

Step 15: baking film 30 makes ink setting;

Step 16: film 30 is placed on the mould;

Step 17: carry out the mode moulding that vacuum, high pressure or vacuum add high pressure;

Step 18: the film 30 of forming is placed on the punch die, and punches out the film 30 that meets mold die cavity shape;

Step 19: film 30 is placed in the injection membrane chamber;

Step 20: injection mo(u)lding;

Step 21: take out the product that film 30 and plastics fit together.

Wherein, step 14, step 15 also can be moved to and put film 30 into baking box in addition before the preliminary drying.

The present invention adopts stamping technique to make the imprinted line on film 30 surfaces, and the imprinted line of being obtained has that resistance to scraping is good, the obvious touch feeling characteristics, can effectively avoid simultaneously shrinking, the tangible problem of stress trace.

Claims (9)

1. the film forming method of an in-mould injection impresses to obtain required figure line film through mould, and wherein, said mould comprises counterdie, is provided with the lines motherboard in the counterdie, and is provided with vacuum line with the said counterdie die cavity place of communicating; Said counterdie one side is provided with patrix, and the place of communicating is provided with high pressure airline with said patrix die cavity; It is characterized in that may further comprise the steps:

(1) film is provided;

(2) patrix and the counterdie of embossing mould are heated in advance, till design temperature;

(3) film is placed on the counterdie;

(4) with embossing mould matched moulds;

(5) heat is transmitted a period of time between film and the embossing mould, makes the film self-temperature promote;

(6) through vacuum line counterdie is inhaled vacuum, make to form the empty shape of likelihood between film and lines motherboard, the air when reducing embossing between film and the lines motherboard is residual;

(7) through injecting gases at high pressure in the die cavity between the said patrix of high-pressure air tube road direction and the said film, make the film lines motherboard of fitting, and duplicate lines, and maintenance high pressure a period of time;

(8) vacuum is removed, and makes to form antivacuum shape between said lines motherboard and said film;

(9) high pressure is removed, and makes that the interior gases at high pressure of die cavity between said patrix and the said film discharge outside the embossing mould;

(10) with the die sinking of embossing mould;

(11) film is cooled off;

(12) film of taking.

2. the film forming method of in-mould injection according to claim 1 is characterized in that: between step (1) and step (2), also comprise and put film into baking box in addition preliminary drying, reduce the water content in the film.

3. the film forming method of in-mould injection according to claim 1 is characterized in that: the required temperature that reaches of the baking of film described in the step (5) is less than or equal to glass transition temperature.

4. the film forming method of in-mould injection according to claim 1 is characterized in that: between step (3) and step (4), also comprise and adopt infrared heating device that film is heated.

5. the film forming method of in-mould injection according to claim 1 is characterized in that: the line thickness of figure line is 0.02～0.03mm in the step (7).

6. the film forming method of in-mould injection according to claim 2 is characterized in that: further comprising the steps of film being put into baking box in addition before the preliminary drying,

Film is carried out printing treatment;

The baking film makes ink setting.

7. the film forming method of in-mould injection according to claim 6 is characterized in that: further comprising the steps of in step (12) afterwards,

Film is placed on the mould;

Carry out the mode moulding that vacuum, high pressure or vacuum add high pressure;

The film of forming is placed on the punch die, and punches out the film that meets mold die cavity shape;

Film is placed in the injection membrane chamber;

Injection mo(u)lding;

Take out the product that film and plastics fit together.

8. the film forming method of in-mould injection according to claim 1 is characterized in that: further comprising the steps of afterwards in step (12),

Film is carried out printing treatment;

The baking film makes ink setting;

Carry out the mode moulding that vacuum, high pressure or vacuum add high pressure;

The film of forming is placed on the punch die, and punches out the film that meets mold die cavity shape;

Film is placed in the injection membrane chamber;

Injection mo(u)lding;

Take out the product that film and plastics fit together.

9. the film forming method of in-mould injection according to claim 1, it is characterized in that: said lines motherboard forms through the letterpress processes.

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