JPH01141721A - Method for high frequency welding olefin-based foam - Google Patents

Abstract

PURPOSE:To strengthen the joining between a base and an olefin-based foam by a method wherein high frequency welding is done under the state that specified fibrous material is pinched between the base and the olefin-based foam. CONSTITUTION:A polyester tricot 3 containing fibers, the fineness of which is 3 deniers or less, is joined in advance with adhesive onto the surface of a fiber board base 3. A surfacing material 6, which consists of polypropylene foam and polyvinyl chloride skin 5, is placed onto the tricot 3. After that, the resultant assembly is set to a high frequency welding equipment so as to be pressed with electrodes 10 and 10 in order to be applied by high frequency voltage under the state that the polypropylene foam 4 is squeezed violently by the electrodes. heat, which generates in the skin 5, melts the polypropylene foam 4 under the compressed state, resulting in penetrating the molten polypropylene foam 4 into tricot 3 so as to entwine each other. Consequently, the skin 5, the tricot 3 and the base 1 are strongly joined one another.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for high-frequency welding of olefin foams.

[Prior Art 1] Laminated bodies having a cushion layer are often used for interior panels of automobiles and the like.

This type of conventional laminate consists of a base made of 7-Iverbow V, etc., and a polyvinyl chloride (hereinafter referred to as PVC) covering the surface of the base.
It is abbreviated as. ) and a cushion layer of polyvinyl chloride 7 ohm (hereinafter abbreviated as PVC 7 ohm) sandwiched between the base and the skin.

However, PVC foam has drawbacks such as being heavy, having poor cold resistance, and residual stress remains after molding, and is also disadvantageous in terms of cost. In particular, when used as an interior panel for an automobile, the plasticizer contained in PvC7ohm may migrate and cause Windplus to become cloudy.

Therefore, recently, polyethylene 7 ohm (hereinafter abbreviated as PE7 ohm), which does not have the above drawbacks and disadvantages, has been developed.

) and polypropylene 7 ohm (hereinafter abbreviated as PP 7 ohm) and other olefin foams are being adopted as the 27932 layer.

[Problem to be Solved by the Invention 1] However, when the cushion layer was made of olefin foam, a new problem occurred that did not occur with PVC 7 ohm.

That is, in the conventional laminate using PVC 7 ohm for the cushion layer, a high frequency welding method was adopted when performing the terminal treatment, etc. According to this high frequency welding method,
The laminate is sandwiched between electrodes, the cushion layer is compressed, and a high frequency voltage is applied to generate heat in the skin, melting the PVC 7 ohm, and bonding the base and the skin via the molten PvC 7 ohm.

However, when high-frequency welding is performed on a laminate using olefin foam using the same method as described above, the adhesion of the molten olefin foam is poor, and the base and skin peel off without bonding. caused a problem.

Means for Solving Problem E 1 This invention was made to solve the above problem, and its gist is that an olefin foam is placed between a base and a polyvinyl chloride sheet, and In the high-frequency welding method for an olefin foam, the olefin foam is compressed and a high frequency voltage is applied, the sheet is heated to melt the olefin foam, and the base and the sheet are joined. A fabric containing fibers of 3 denier or less is placed between the base and the olefin foam, a high frequency voltage is applied, and the molten olefin foam is
This high-frequency welding method for a fin-based foam is characterized in that the seven ablisters and the sheet are joined by soaking into the blink, and the base and the sheet are further joined through a fabric joined to the base.

[Function] The fabric is bonded to the base in advance, or is bonded to the base by a bonded body that is melted when a high frequency voltage is applied. On the other hand, the heated and melted olefin foam soaks into and becomes entangled with the 7 ablitter, joining the sheet and fabric. As a result, the sheet and the base are joined via the fabric.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings from FIG. 1 to FIG. 4. This example describes a mode of high-frequency welding that is carried out when a part of the resin skin constituting the surface of the door trim is replaced with 77 bricks (hereinafter referred to as partial decoration) in the manufacturing process of automobile door trims. It is.

FIG. 1 shows the state before high frequency welding, and this will be explained.

A well-dow urethane 7 ohm 2 with a thickness of 31 is partially placed on a base 1 made of fiberboard with a thickness of 2I1 m, and a tricot (fabric) 3 is placed on top of the weld urethane 7-ohm 2. is placed.

The above-mentioned well dow urethane 7 ohm 2 contains PV of approximately 2.5 times the weight of the urethane 7 ohm in the urethane 7 ohm.
C (zygote) is scattered. Note that the density of the well-dow urethane 7 ohm2 is 0.016 g/al'.

Tricot 3 has a front yarn of 75 denier made by twisting 24 3.1 denier polyester fibers, a middle yarn of 75 denier made by twisting 72 1.0 denier polyester fibers, and a 2° It is formed by twisting 36 1 denier polyester fibers together with a back yarn of 75 denier. That is, this tri-foot 3 satisfies the condition that the middle yarn and back yarn are 3 deniers or less. In addition, Trifoot 3
The basis weight is 340g/+n2.

The base 1 and the tri-foot 3 are made of a PP7 ohm (olefin foam) 4 with a foaming ratio of 30 times and a thickness of 3 degrees, and a PVC skin (sheet) with a thickness of 0.51!1 bonded to its surface. ) 5 is attached by vacuum forming, and a chloroprene-based adhesive is applied to the back side of the PP7 ohm 4 in advance. In this case, the substrate 1 and the PP7 ohm 4 are bonded together. Note that the tricot 3 and the PP7 ohm 4 do not need to be bonded together using the brolobrene adhesive described above.

The door trim in the raw material stage with the above configuration is set in a high frequency welding device with an output of 50 kW. That is, these materials are placed between the lower electrode (not shown) and the upper electrode 10.10.

Next, as shown in Fig. 2, each upper electrode 10 is lowered and a pressure of 3 to 6 kg/c+s2 is applied to crush the PP7 ohm 4 and the well dowel urethane 7 ohm 2, and in this state, the lower electrode A high frequency voltage is applied to each upper electrode 10. Note that the anode current value at this time was 1.4 amperes, and the current application time was about 10 seconds. Then, the PVC skin 5 generates heat, and the heat melts the compressed PP7 ohm 4, and at the same time, the PVC contained in the Welgralev 2 fuselage 2 melts.

The molten PVC hardens the compressed Welgralev 2 frame 2 irreversibly, and a portion of it soaks into the tricot 3 and becomes entangled with the tricot 3, thereby firmly joining the tricot 3 to the base 1. On the other hand, the molten PP7 ohm 4 soaks into the tricot 3 and becomes entangled, thereby firmly joining the epidermis 5 to the tricot 3.

Next, while maintaining the upper electrodes i o and i o in a lowered state, the supply of electricity is stopped and left for about 30 seconds to cool and solidify each of the above-mentioned molten resins. As a result, the base 1 and the skin 5 are firmly joined with the tri-foot 3 sandwiched between them.

After this, as shown in FIG. 3, the cutting edge 1 of each upper electrode 10 is
When the skin 5 cut by 0a and the PP7 ohm 4 are removed, a door trim partially decorated with the tricot 3 is completed, as shown in FIG.

The drawings of FIGS. 5 to 8 show other embodiments, and show a welding method for partially decorating with a fabric that does not contain fibers of 3 deniers or less. 5 corresponds to FIG. 1 of the first embodiment, FIG. 6 corresponds to FIG. 2, FIG. 7 corresponds to FIG. 3, and FIG. 8 corresponds to FIG. 4. corresponds to

As shown in FIG. 5, before welding, a 7-ohm well dowel urethane 2 is placed on the base 1.
On top of this well dow urethane 7 ohm 2, the front thread,
Tricot 7 made of polyester fibers thicker than 3 denier is placed on both the middle yarn and the back yarn. Furthermore, on the back side of this tricot 7, 0.1 to 0.3-
A tricot 3 similar to that of the first embodiment is placed on which a PVC film 8 of one thickness is attached. That is, tricot 3 contains fibers of 3 deniers or less. The base 1 and the tricot 3 are made of PP as in the first embodiment.
It is covered with a covering material 6 consisting of a 7 ohm 4 and a PVC skin 5.

The above material is pressed with an upper electrode 10°10 as shown in FIG.
2 is crushed and a high frequency voltage is applied. Then, the skin 5 generates heat, and the heat melts the compressed PP7 ohm 4, and at the same time, the PvC film 8 and the welg urethane 7
PVC contained in t-me 2 is melted.

The PvC in the melted weld urethane 7 ohm 2 hardens the compressed weld urethane 7 ohm 2 irreversibly, and a part of it soaks into the tricot 7 and becomes entangled, thereby firmly joining the tricot 7 to the base 1.

Further, the melted PVC film 8 soaks into the tricot 3 and the tricot 7 and becomes entangled with them, thereby firmly joining the tricot 3 to the tricot 7. Furthermore, the molten PP foam 4 soaks into and entangles the tricot 3 and firmly joins the skin 5 to the tricot 3.

After this, while maintaining the compressed state by each upper electrode 10,
The energization is stopped and the resin is left to cool and solidify each molten resin. As a result, the base 1 and the skin 5 are firmly joined with the tricot 3 and the tricot 7 sandwiched between them.

Furthermore, as shown in FIG.
After removing the skin 5, PP7 frame 4, tricot 3 and PVC film 8 that have been cut at 0a, the door trim decorated with the Q part by tricot 7 is completed as shown in Fig. 8. .

The drawings of FIGS. 9 to 11 show still another embodiment. This embodiment is not used for partial decoration like the first and second embodiments,
This is an embodiment in which an uneven pattern is formed on the covering material 6.

FIG. 9 shows the state before welding, in which a polyester tricot 3 containing fibers of 3 deniers or less is bonded in advance to the surface of a base 1 made of fiberboard with an adhesive or the like, and the tricot A covering material 6 consisting of a PP7 ohm 4 and a PVC skin 5 is placed on top of the material 3.

This is set in a high frequency welding device, and as shown in FIG. 10, the upper electrode 10.10 is pressed to crush the PP7 ohm 4 and a high frequency voltage is applied.

-Then, the epidermis 5 generates heat Lf and is in a compressed state P due to the heat.
I'7 sum 4 melted 11, melted PP7 oh, mu 4
seeps into the tricot 3 and becomes entangled. By cooling the molten resin in this state, 1) the skin 5 is joined to the 77 to 3 (21.
The epidermis 13 and the base 1 are joined via the.

So, even after arranging the upper electrodes i o and i o,
As shown in FIG. 11, a beautiful uneven pattern remains.

In addition, this Example C is a welding R! = T' Although the tricot 3 is bonded to the base 1, it is possible to bond it during welding as in the first embodiment.

In that case, the well 91 is placed between the tricot 3 and the base 1.
All you have to do is arrange some fluffy talent.

In addition, in this embodiment, the entire surface of the base 1 is coated with tricot 3.
Although it is covered with , it is not necessarily necessary. It is sufficient that the tricot 3 is disposed at least in the welded portion.

FIG. 12 shows an example in which the terminal section is processed by the same method as in the third embodiment.

Also, the thickness is 0. When high-frequency welding was performed in the same manner as in the above-mentioned examples using a surface material made of hm PVC and 7-ohm polyethylene with a foaming ratio of 30 times and a thickness of 2 mm, welding was possible in the same manner as described above. Met.

The welding conditions for olefin foam and PVC foam are compared as follows. Conditions other than those described here are the same.

This invention is not limited to the above-mentioned embodiments, and various embodiments are possible.

For example, 7T blinks are not limited to knitted fabrics like tri-foot, but may also be fabrics, non-woven fabrics, or the like.

Further, the material is not limited to polyester, and may be nylon, a blend of nylon and polyester containing 30 to 50% nylon, or natural fibers such as cotton.

Furthermore, the base is not limited to fiberboard, but may also be a wooden HM board or the like.

Furthermore, the range of application of the high frequency welding method of the present invention is extremely wide, and it goes without saying that it can be used in the manufacturing process of products other than automobile interior panels.

[Effect of the invention 1] As explained above, according to the present invention, the fabric can be made by melting the olefin foam interposed between the PVC skin and the base, impregnating it into the fabric and entangling it. The base and the epidermis can be joined through.

[Brief explanation of the drawing]

The drawings from FIG. 1 to FIG. 4 show sectional views for each step in one embodiment of this method invention, and the drawings from FIG. 5 to FIG. 8 show sectional views for each step in the second embodiment. FIG. The drawings from FIG. 9 to FIG. 11 are sectional views of each step in the third embodiment. FIG. 12 is a sectional view showing an application example of the third embodiment. 1... Base, 3...) T brick ()/Ricot), 4... Olefin foam (PP7-i-me)
, 5... Sheet (epidermis).

Claims (3)

[Claims] (1) An olefin foam is placed between the base and a polyvinyl chloride sheet, the olefin foam is compressed, a high frequency voltage is applied, and the sheet is heated to melt the olefin foam. , in a high-frequency welding method for an olefin-based foam for joining the base and a sheet, a fabric containing fibers of 3 deniers or less is placed between the base and the olefin-based foam, and a high-frequency voltage is applied; A high frequency olefin foam, characterized in that the fabric and the sheet are joined by impregnating the fabric with a molten olefin foam, and the base and the sheet are further joined through the fabric bonded to the base. Welding method. (2) The method for high-frequency welding of olefin-based foam according to claim 1, characterized in that the fabric is bonded to a base in advance before applying the high-frequency voltage. (3) Before applying the high frequency voltage, place a bonded body made of thermoplastic resin between the fabric and the base, and when the high frequency voltage is applied, the bonded body melts and soaks into the fabric. 2. The high-frequency welding method for olefin foam according to claim 1, wherein the fabric is bonded to the base.