JPH0785909B2 - Method of joining foamable plastic members to each other - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining foamable plastic members to each other, and more specifically, a foamable plastic material having a restoring elasticity such as foam material, and more particularly,
A flat-plate foamable plastic member formed of a foam-molded plastic material (hereinafter also simply referred to as a foam-molded plastic material) that has already-foamed restoration elasticity, and a flat-plate foamable plastic member that has at least partially lacked a space. The present invention relates to a method for joining a plastic member to each other, or a flat plate-shaped foamable plastic member having at least a partially lacking space portion.

[0002]

2. Description of the Related Art Conventionally, for example, a foamable plastic having a restoring elasticity such as a foam material of this kind for holding or packaging the stored articles in accordance with the shape of the articles stored in the container. A holder as a molded article (hereinafter, also referred to as a foamable plastic holder, or simply a holder) according to is well known and widely used.

In the broad sense of the invention, as described above, a flat-plate foamable plastic member made of a foam-molded plastic material as described above and a flat-plate foamable plastic member having a partially punched space portion are used. Mutual with plastic parts,
Or it is a method of joining flat foamable plastic members having a partially punched space portion, but in order to clarify the content of the invention, in the following description, mainly,
For example, as seen in this type of foamable plastic holder, a flat plate-shaped lower member made of foamed plastic material and a space portion for fitting the article to be housed therein are made of foamed plastic material. In the case of joining the above-mentioned flat plate-shaped upper members together, that is, in the narrow sense, when joining the expandable plastic members together, the description will be made specifically.

[0006] Here, in the usual case, for a molded product for holding or packaging a general storage article formed by using a foaming plastic material having a restoring elasticity such as a foam material, It is formed by using a mold that encloses the outer shape and heating and foaming a foamable plastic material in the mold. In heat foam molding using such a mold, a normal mold is used. Unlike the case of heat molding, due to the type of foamable plastic material and the subtle changes in foaming conditions, there are extreme differences in the foaming state, and it is possible to mold molded products of uniform composition according to the prescribed shape and size. In addition, the foaming itself is often partially different and effective surface restoration elasticity cannot be obtained, and when coloring the entire product in a desired shade, There are disadvantages, such as unfavorable there is also the pigment to enter the biased partially. Also, in heat foam molding using a molding die, for example, if the foaming is about twice as low, it is possible to mold without causing such a disadvantage, but the practical range itself is limited. By the way, it is desirable to have a high foaming ratio that is a multiple of more than 10 times.
It is assumed that the foaming is about twice as high.

On the other hand, the expandable plastic holder described above is used, for example, for holding or packaging the articles stored in the container, as described above, and therefore When it is necessary to match the shape and size with the outer shape and size of the stored article as accurately as possible, and when forming a foaming plastic holder that requires such highly accurate shape and size. In this case, the heat foam molding using the general molding die as described above is not suitable.

Therefore, conventionally, a material which has been foam-molded in advance by a foaming plastic material having a restoring elasticity such as a foam material, that is, an already-foamed material by the normal foaming without the above disadvantages. By using the foam-molded plastic material, the foam-molded plastic material is shaped to form a lower member that will be a substrate part and an upper member that will be a holding part, each of which has a desired shape and size. By joining each of these members again, the intended holder made of expandable plastic is obtained.

An example of the most simplified form of the expandable plastic holder formed as described above is as shown in FIG. 1 which will be described later. By using a plastic material,
A lower member 2 having a set predetermined thickness and cut into a predetermined shape and size, and an upper part similarly cut into a predetermined shape and size and having a space 4 of a predetermined shape and size punched therein. The member 3 is provided, and these members are vertically combined and joined together to form the foamable plastic holder 1 having a desired shape.

However, the conventional forming means for obtaining the above-mentioned holder 1 is (A). By shaping the foamed plastic material into a desired shape by cutting or the like, and by reheat molding using a molding die. Joining, and (B). Various means such as shaping by foaming molded plastic material into the required shape, and joining by bonding with an adhesive are used.

[0009]

In the former (A) means, first, a foam-molded plastic material, for example,
A foamed plastic material sliced to a specified thickness is used, and the required lower member and upper member are formed by cutting the material into a shape slightly larger than the shape and size of the holder to be obtained. Then, the lower and upper members are combined in a predetermined manner, the whole is set in a separately prepared molding die under pressure, and the two members are heat-molded and joined again. As a result, a foamable plastic holder having a desired shape and size is obtained.

However, when the means (A) is used, the number of steps for forming the entire object holder is relatively large, the labor cost is high, and the manufacturing cost is high. In forming the holder 1, of the lower and upper members 2 and 3 joined to each other, the space 4
At the time of heating and pressure-bonding, the upper member 3 having the shape is likely to lose its shape such as so-called “sag” or “dag” at the inner edge of the space 4, and the shape and dimensional accuracy after formation are high. It has the drawback of not being sufficient, and in addition,
Since all the combined lower and upper parts are set in the mold and heat-molded, a hardened skin layer is formed on the entire surface that will be in direct contact with the mold surface. However, there is a problem that the restoring elasticity is hindered.

In the latter (B) means, first, as in the former case, for example, a foam-molded plastic material sliced into a predetermined thickness is used, and this time, the shape of the holder to be obtained, A lower member and an upper member having the same dimensions are formed on each of them, and then the required adhesive is used to adhere the lower and upper members to each other in a predetermined manner. We have obtained a foamable plastic holder as expected by.

[0012] This means (B) also has the drawback that it cannot be automated or semi-automated in terms of the shape-retaining power of the material, and the hand-tensioning cost is relatively high. In the case of bonding with an adhesive, the adhesive permeates inside and does not form a good adhesive form, and the shape retention is weak, which causes peeling, and the characteristics of the material itself due to the solvent, sulfur component, etc. in the adhesive. In addition to the damage, olefin plastics such as polysilicon ethylene and polysilicon propylene, in particular, cause various problems such as not being suitable for joining with an adhesive.

In order to automate the joining process,
For example, as shown in FIG. 8, a pair of heating and pressing rolls 51 and 52 are provided between the lower and upper members 2 and 3, respectively.
When attempting to heat and press between the members, the materials of the respective members 2 and 3 are both foams, and as described above, there is a bad effect due to the heat effect due to the overall heating. Or, as shown in FIG. 9, each heating / pressurizing roll 51,
The inner edge portion of the space portion 4 is crushed by 52, and there is a disadvantage that the same "depression", "sag", and other shape collapses as described above occur more severely.

The present invention has been made in order to solve the above-mentioned conventional problems, and its purpose is, in a broad sense, a flat-plate foaming property formed by an already foamed molded plastic material. When joining a plastic member and a plate-like foamable plastic member at least partially lacking a space, or a flat-plate foamable plastic member at least partially lacking a space The present invention is to provide a method of joining foamable plastic members of this kind that facilitates the joining, and in a narrow sense, mainly forms a foamed plastic material that has already been foamed. It is processed and provided with a lower member to be a substrate part and an upper member to be a holding part according to the shape of a desired shape and size, and to combine these respective members with each other. In the case of joining by joining, the method of joining the foamable plastic members of this kind, which facilitates the combination and the joining of the respective members, in this case, the foamable plastic material is used. A method for forming a holder is provided.

[0015]

In order to achieve the above-mentioned object, a method for joining foamable plastic members to each other according to the present invention is a joining surface in which a space portion of the foamable plastic members is filled with an auxiliary jig. The heating surface of each foamable plastic member is heated by a heating unit and pressure-bonded by a pressure roll. After the fusion, the auxiliary jig is removed to bond the members.

That is, the present invention uses a foamed plastic material that has already been foamed, and a foamable plastic member formed in a flat plate shape, and a foamable plastic member formed in a flat plate shape and at least partially lacking a space portion. A method for joining mutually to each other or to each foamable plastic member formed in a flat plate shape and at least partially lacking a space portion, the elastic deformation rate being close to that of the foamed plastic material, and Has a higher melting point than this,
In addition, an auxiliary jig that is formed so as to fill at least the space portion of the foamable plastic member by using a material of the same quality having appropriate flexibility and assists the space portion of the foamable plastic member. After embedding with a jig to make both foamable plastic members form a flat plate with at least almost the same plane shape without at least a space part, first, with a required space from the joint surface heating part. Then, each foamable plastic member is transferred to heat the bonding surface layers of both members to a temperature at which they can be fused, and then, both of them are passed through a pressure roll to be pressure fused, and after this fusion The method for joining foamable plastic members to each other is characterized in that the auxiliary jig is removed.

[0017]

Therefore, according to the method of the present invention, in the state where the space portion of the foamable plastic member is filled with the auxiliary jig, it is a flat plate having substantially the same plane shape, and regardless of the presence or absence of the space portion, the same condition is satisfied. After transferring each foamable plastic member maintained below, heat the joining surface layer surface with the joining surface heating unit and press and fuse with the pressure roll, then remove the auxiliary jig and join Because of this, the bonding of each foamable plastic member that was maintained under almost the same conditions by embedding the auxiliary jig in the space in this way completely eliminates the possibility of causing the shape to collapse in the space. As a result, it is possible to perform the joining with a predetermined shape and size with high accuracy and easily, and the joining operation can be automated with a relatively small number of steps.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for joining foamable plastic members to each other according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a perspective view schematically showing the structure of a foamable plastic holder to which the method of the first embodiment of the present invention is applied, and FIGS. 2 and 3 show the first embodiment of the same as above. FIG. 6 is a cross-sectional view schematically showing a pressure fusion state in the method for forming a foamable plastic holder in FIG.

As described above, the expandable plastic holder 1 of the first embodiment shown in FIG. 1 uses a foamed plastic material sliced according to the thickness of the article to be stored, and has a predetermined outer periphery. Lower member 2 cut into shape and dimensions
And an upper member 3 whose outer periphery is cut into the same shape and size, and which is punched out in the plane inner side with a space 4 having a predetermined shape and size according to the outer shape of the article to be stored. The members 2 and 3 are combined vertically and joined to each other.

In the first embodiment, as shown in FIG.
In joining the lower and upper members 2 and 3, the auxiliary member 11 provided with a space portion 4 that is cut in the upper member 3 is embedded without any gap, and an arbitrary joint surface heating unit 21 is provided.
Of each of these members 2 and 3 is heated to a temperature at which only the mutual surface layers of the joints can be fused, and a pair of lower and upper pressure rolls 31 and 32 are used to press and fuse each other. After the joining, one set of lower cooling rolls 33 and upper cooling rolls 34 are provided after the joining.
Cooling facilitates removal of the auxiliary member 11 from the space 4.

The auxiliary jig 11 has an elastic deformation rate (shrinkage rate, extension rate, etc.) close to that of the foamed plastic material used for the lower and upper members 2 and 3, and a melting point higher than this. In addition, the material having the same effect and having an appropriate flexibility is used to form at least the entire shape of the space portion 4, in other words, the dimension corresponding to the outer shape of the housed article. Well, when this auxiliary jig 11 is used to embed the space 4, the space on the plane of the upper member 3 disappears, and welding by heat fusion under the same conditions as the lower member 2 is possible. become.

As the joint surface heating unit 21, it is advantageous to use a rod-shaped heater 22 which is controlled and set to a predetermined heating temperature, or a plate-shaped heater as appropriate, and if necessary, the setting. A heating means by blowing hot air at a temperature can also be adopted, and the joint surface heating unit 21 includes the pair of lower and upper pressure rolls 31 and 3 respectively.
It is placed in front of 2.

Next, the joining process will be specifically described. As shown in FIG. 2, first, the auxiliary jig is provided with the lower member 2 through the lower side thereof and the space 4 through the upper side thereof while being spaced apart from the joint surface heating unit 21 by a corresponding distance. 11
The upper member 3 embedded with is transferred to the pair of lower and upper pressure rolls 31 and 32 from the positions indicated by the solid lines, and in the process of transfer, the upper surface as the joint surface of the lower member 2, and Only the respective bonding surface layers of the lower surface serving as the bonding surface of the upper member 3 are heated to a temperature at which they can be fused by the rod-shaped heater 22, but for the corresponding lower surface of the auxiliary jig 11 embedded in the space 4, Since the melting point is set high, it does not reach the fusion temperature.

Then, the lower and upper members 2 and 3 whose respective surface surfaces of the joints are heated to the fusion temperature as described above are clamped between a pair of lower and upper pressure rolls 31 and 32. By doing so, the respective joint surfaces are in contact with each other and are pressure-fused with a required pressing force. At this time, since the auxiliary jig 11 that fills the space 4 of the upper member 3 has an elastic deformation rate close to that of the lower and upper members 2 and 3, these lower and upper members are not affected. The two and three are maintained under almost the same conditions, and the pressing force at this point is almost evenly applied so that good fusion can be achieved. As shown in FIG.
The space 4 embedded by the auxiliary jig 11 does not lose its shape such as “sag” or “sag”, and the lower surface temperature of the auxiliary jig 11 does not reach the fusion temperature. Since it has not reached, it will not be fusion-bonded to the lower member 2.

Thereafter, the lower and upper members 2 and 3 fusion-bonded as described above are cooled through a pair of lower and upper cooling rolls 33 and 34, and then taken out. Then, the auxiliary jig 11 that fills the space 4 is removed. In this case, the cooling rolls 33, 3 in the subsequent stage
No. 4 is not essential, and after fusion bonding, it may be taken out and allowed to cool naturally. When removing the auxiliary jig 11, the auxiliary jig 11 is provided with a required flexibility, and each member 2,
Since it is not fused to 3, it can be easily removed. In this way, the expandable plastic holder 1 having the intended construction shown in FIG. 1 can be obtained.

In other words, in other words, the lower member 2
It is possible to join the flat-plate foamable plastic member corresponding to the above and the flat-plate foamable plastic member corresponding to the upper member 3 lacking a space portion on the inner side of the plane as expected. In addition, if necessary, the flat plate-like foamable plastic members each having a hollow portion on the inner surface of the plane can be similarly joined to each other.

Next, FIG. 3 is a perspective view schematically showing the structure of a foamable plastic holder to which the method of the second embodiment of the present invention is applied, and FIGS. It is each sectional drawing which shows typically the mode of secondary processing after joining in a forming method of a foamable plastics holder in a 2nd example one by one.

The expandable plastic holder 5 of the second embodiment shown in FIG. 4 has a lower member 6 with a slightly smaller space 6a and an intermediate member 7 with a larger space 7a.
And the upper member 8 lacking the rather small space portion 8a, which are joined in three layers.

Also in the structure of the second embodiment, the foamed plastic material sliced according to the thickness of the article to be housed is used, and first, the lower member 6 whose outer periphery is only cut into a predetermined shape and size, An intermediate member 7 having the outer periphery cut into the same shape and dimensions, and a space 7a having a desired shape and dimensions punched out on the inside of the plane, and the outer periphery having the same shape,
An upper member 8 which is only cut to size is provided for each.

Regarding the joining of these members, although not shown in this case, mutual heating and pressure fusion of the lower member 6 and the intermediate member 7 in which the space 7a is embedded by the auxiliary jig 12 are performed. After performing the attachment in the first step as in the previous example, the space 7a obtained in the first step is placed on the intermediate member 7 which is still filled with the auxiliary jig 12 in the second step by the same operation. The member 8 is heated and pressure-bonded, and subsequently,
As shown in FIGS. 5 and 6, the auxiliary jig 12 embedded in the space 7 a of the intermediate member 7 is advanced by proceeding to the secondary processing stage and using the separately prepared cutting dies 41 and 42. The upper and lower members 8, including the portion 12a of
The corresponding space portions 8a, 6a of 6 are cut and removed, and thereafter,
The remaining portion 12b of the auxiliary jig 12 is removed from the space 7a of the intermediate member 7, and thus the foamable plastic holder 5 as intended is obtained.

In each of the methods of the first and second embodiments, the case where the space portion is formed on the inner side of the plane of either or both of the foamable plastic members to be joined to each other will be described. However, as in the third embodiment shown in FIG. 7, when the space is formed on the outside of the plane, that is, as in the third embodiment shown in FIG. With respect to the lower member 9, the upper member 10 joined to the lower member 9 has a flat plate shape with a smaller planar shape equivalent to that of the outer surface of the plane, and is equivalent to the outer member of the upper member 10. It is also possible to embed the portion by the auxiliary jig 13 and perform fusion bonding in exactly the same manner, and even in this case, the same action and effect can be obtained.

[0033]

As described above in detail with reference to each embodiment, according to the method of the present invention, a foamable plastic member formed into a flat plate shape and a flat plate-like shape are formed by using an already foamed molded plastic material. In the method of joining each other with the foamable plastic member at least partially lacking the space portion, or each of the foamable plastic members formed in a flat plate shape and at least partially lacking the space portion, An auxiliary curing material formed so as to fill at least the space by using a material having an elastic deformation rate close to that of the foam-molded plastic material, a melting point higher than that, and a moderate flexibility and having the same effect. By using the ingredients,
By filling the space in the expandable plastic member with an auxiliary jig, the form of both expandable plastic members,
At least approximately the same plane shape with no space, and by extension, transfer each foamable plastic member maintained under the same conditions regardless of the presence or absence of space, and heat the bonding surface layer by the bonding surface heating part. In addition, since the auxiliary jig is removed and joined after pressure fusion with the pressure roll, the auxiliary jig is embedded in the space in this way and maintained under almost the same conditions. By joining the respective expandable plastic members to each other, the fear of causing the mold to collapse in the space is completely eliminated, and as a result, the joining of the predetermined shape and size can be easily performed with high precision. Moreover, it has an excellent feature that the joining operation can be easily automated by a relatively small number of steps.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing the structure of a foamable plastic holder to which the method of the first embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view schematically showing a pressure-welded state in the method for forming the expandable plastic holder in the first embodiment.

FIG. 3 is a cross-sectional view schematically showing a pressure-welded state in the method for forming a foamable plastic holder in the first embodiment.

FIG. 4 is a perspective view schematically showing the structure of a foamable plastic holder to which the method according to the second embodiment of the present invention is applied.

5A to 5C are cross-sectional views each schematically showing in sequence a secondary processing aspect after joining in the method for forming a foamable plastic holder in the second embodiment.

6A and 6B are cross-sectional views each schematically showing in sequence a secondary processing aspect after joining in the method for forming a foamable plastic holder in the second embodiment.

FIG. 7 is a cross-sectional view schematically showing the structure of a foamable plastic holder to which the method of the third embodiment of the present invention has been applied.

FIG. 8 is a cross-sectional view for explaining a fusion bonding mode when a conventional heating and pressing roll is used.

FIG. 9 is a cross-sectional view for explaining a fusion bonding mode when a conventional heating and pressing roll is used.

[Explanation of reference signs] 1,5 Foamable plastic holder 2,6,9 Lower member 3,8,10 Upper member 4,6a, 7a, 8a Space portion 7 Intermediate member 11,12,13 Auxiliary jig 12a Cutting Part 12b Remaining part 21 Bonding surface heating part 22 Rod heater 31 Lower pressure roll 32 Upper pressure roll 33 Lower cooling roll 34 Upper cooling roll 41, 42 Cleave type

Claims (3)

[Claims] 1. A mutual expansion between a foamable plastic member formed in a flat plate shape and a foamable plastic member formed in a flat plate shape and at least partially lacking a space portion, using an already foamed foamed plastic material. Or a method of joining together foamable plastic members formed in a flat plate shape and at least partially lacking a space portion, the elastic deformation rate being close to that of the foamed plastic material,
And having a melting point higher than this, and using a material of the same effect having an appropriate flexibility, prepare an auxiliary jig formed so as to fill at least the space of the foamable plastic member, After filling the space portion of the foamable plastic member with an auxiliary jig, the foamable plastic member is made into a flat plate shape having at least approximately the same plane without the space portion, and then the joint surface heating portion is provided. On the other hand, in a state in which the required intervals are separated, each foamable plastic member is transferred to heat the joining surface layer surface of both to a temperature at which they can be fused, and both of them are pressure-fused by a pressure roll, After the fusion bonding, the auxiliary jig is removed, and the method of joining the expandable plastic members together. 2. One of the foamable plastic members joined to each other has a flat plate shape having a predetermined planar shape, and the other foamable plastic member has a planar shape of the one foamable plastic member. At least approximately the same plane shape is formed, and it has a flat plate shape in which the space portion is cut off inside the plane surface, and the space portion in the other foamable plastic member is filled with the auxiliary jig to form each foaming material. The method for joining foamable plastic members to each other according to claim 1, wherein both forms of the plastic members can be made to have a flat plate shape having at least substantially the same plane shape without a space portion. 3. One of the foamable plastic members joined to each other has a flat plate shape according to a predetermined planar shape, and the other foamable plastic member has a planar shape of the one foamable plastic member. It has a flat plate shape with a smaller planar shape that is equivalent to the cutout of the plane outer side, and the part corresponding to the cutout on the plane outer side of the other foamable plastic member is embedded by the auxiliary jig, 2. The method for joining foamable plastic members to each other according to claim 1, wherein both of the foamable plastic members can be formed in a flat plate shape having at least substantially the same plane shape with no space portion.