JPH0446728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a foam sheet having a textured pattern.

[Prior Art] A conventional method for producing a foam sheet with a textured pattern involves extruding a foamed material into a sheet, adjusting the sheet thickness to a certain level using a calendar roll, and processing the textured pattern on the side of the roll. A method of transferring the pattern onto the surface of the sheet (calendar roll method)
There is. In another method, as shown in FIG. 1, skin material 3 is poured from a skin material supply device 1 onto a belt 2 on which a grain pattern has been applied in advance, and the sheet thickness is adjusted to a constant thickness using a doctor knife 4. Then, a skin layer is formed using a heater 5, and then a foamed material 7 is poured onto the skin layer from a foamed material supply device 6, and the sheet thickness is adjusted to a certain level using a doctor knife 8, and then plasticized using heaters 9 and 10. There is a method of manufacturing a foam sheet by foaming and cooling.

However, with the above conventional methods, (1) the thickness of the foam sheet tends to be uneven, and (2) it is difficult to adjust the grain depth according to the purpose, so the foam sheet is formed by vacuum forming etc. (3) When affixing to an adherend, the grain pattern in the area stretched by vacuum forming etc. is distorted and the grain pattern becomes uneven; (3)
(4) It is difficult to change the color or texture of the material; (5) Especially the latter. The conventional method has drawbacks such as a long production line and a large space requirement.

[Object of the Invention] The present invention is intended to overcome the above-mentioned drawbacks, by making the thickness of a foam sheet uniform, and preventing distortion of the grain pattern when the foam sheet is attached to an adherend by vacuum forming or the like. It also enables deep squeezing of products.
It is an object of the present invention to provide a method for manufacturing a foamed sheet, which has features such as improving the yield of the sheet and reducing the production line for the foamed sheet.

[Structure of the Invention] The method for manufacturing a foamed sheet of the present invention includes a mold in which a cavity is formed from an upper mold and a lower mold, and either one of the upper mold and the lower mold is formed with a mold surface having a textured pattern. A first step is to place a non-foamable vinyl chloride resin raw material to a substantially constant thickness on the textured surface of the mold and heat it to at least partially plasticize the resin raw material. a second step of placing expandable vinyl chloride resin in the remaining part of the cavity and clamping the mold; a third step of heating the mold and plasticizing the non-expandable and expandable vinyl chloride resin raw materials. a fourth step of taking out from the mold a plasticized vinyl chloride resin sheet having a skin layer with a grain pattern on one side and a foam layer integrally molded on the other side of the skin layer; It is characterized by

The first step in the method for manufacturing this foamed sheet is to form a cavity from an upper mold and a lower mold, and use a mold in which one side of either the upper mold or the lower mold is formed with a mold surface having a textured pattern. This is a step of disposing a non-foamable vinyl chloride resin raw material to a substantially constant thickness on the textured surface of the mold.

The "cavity" is two-dimensionally wide between the upper mold and the lower mold. Its thickness is approximately constant, and its planar shape matches the shape of the adherend. The thickness of the cavity varies depending on the purpose and use, and can be approximately uniform, and after pasting the foam sheet produced by this method, the thickness of the stretched part is equal to the thickness of the unstretched part. The thickness of the cavity corresponding to the stretched portion can also be increased so as to be approximately uniform. In this method, at least one of the upper and lower molds of the cavity can be made deep, but in order to ensure more uniformity, it is preferable to make both sides a little deeper. Note that the depth may be changed stepwise or continuously. Therefore, the mold for forming the cavity is usually a mold that matches the shape of the adherend. For example, the mold for producing a foamed sheet for an adherend having the shape shown in FIG. The mold 12 can be shaped to match the shape 11. Note that the mold 12 has a cavity 111 that matches the foam sheet to be manufactured. In addition, the mold is
The mold can be made to match the thickness and shape of the cavity selected according to the purpose and use mentioned above, but the thickness is usually 7 mm in consideration of moldability.
It is set as below. The material of the mold is not particularly limited, and any material may be used as long as it can withstand the temperature and pressure during heating and foaming.

The "grain pattern" may be formed on either the upper or lower surface of the mold, but is usually formed on the lower surface. The depth and density of the "grain pattern" vary depending on the purpose and application, but especially when attaching the foam sheet produced by this method to an adherend, the grain pattern in the stretched portion may be poor. For example, as shown in FIG.
It is possible to set the grain depth to be deeper and the grain density to be larger than that of the original. Further, these grain depths and grain densities can be changed stepwise or continuously.

On the textured surface of the mold described above, a non-expandable vinyl chloride resin (hereinafter referred to as PVC) material is placed at a substantially constant thickness, which varies depending on the purpose and use. The method of installation is not particularly limited. The "non-expandable PVC raw material" may be any non-expandable PVC, and its shape is not particularly limited, but paste-like PVC sol, PVC slush powder, etc. are preferable.

In the first step, the non-expandable PVC raw material is placed and heated to at least partially plasticize the PVC raw material. The heating temperature in this case is usually about 100 to 140°C in mold temperature.

As shown in FIG. 5, the mold includes a lower mold having a grain pattern 15 on the bottom surface, and the PVC raw material in the first step is placed on the bottom surface of the lower mold and is heated to a certain thickness using a doctor knife. This can be done by setting the

The second step is to foam the rest of the cavity.
This is the process of placing PVC. The “foamed PVC” is
Any material that foams in the mold when heated is fine, but
Typically, the resin includes azodicarbonamide, 4,
Paste PVC mixed with a chemical blowing agent such as 4'oxybisbenzenesulfonyl hydrazide or dinitrosopentamethylenetetramine, or mechanically foamed paste PVC is used. The PVC raw material is usually inserted into a cavity. In this insertion method, the upper and lower molds can be attached and then injected, or the lower mold can be injected and then the upper mold can be attached.

The third step is a step of heating the mold and plasticizing the non-expandable and expandable PVC raw materials.
The heating temperature is usually about 160 to 260°C.

In the fourth step, after cooling and hardening the plasticized material as described above, the plasticized skin layer having a grain pattern on one side and the other surface of the skin layer are integrally molded using the mold. This is the process of taking out the PVC sheet with the foam layer.

[Effects of the Invention] In the method for producing a foamed sheet of the present invention, the foamed sheet has a two-dimensionally wide cavity that matches the shape of the adherend, and either one of the upper and lower molds has a textured pattern. Use a mold that has a mold surface with Therefore, according to the present foam sheet manufacturing method, the thickness of the foam sheet manufactured is uniform;
Moreover, since it is possible to manufacture a foam sheet that matches the shape of the adherend, the yield of the foam sheet when pasting the foam sheet to the adherend is good, and the shape of the foam sheet that follows the adherend can be manufactured. Can produce foam sheets.

In addition, according to the method for manufacturing the foamed sheet, when the foamed sheet is attached to an adherend by vacuum forming or the like,
It is easy to manufacture a foam sheet in which the part of the foam sheet that is stretched has a deeper grain depth than other parts. Therefore, according to the present method, it is possible to prevent the grain pattern from collapsing, and to produce an adhered foam sheet product (refers to the foam sheet after being pasted on the adherend) with a substantially uniform grain depth. Can be done. In particular, when a foamed sheet in which both the grain depth and grain density are continuously changed by this method is produced, the uniformity of the grain pattern of the adhered foam sheet product is even more excellent.

Since the manufacturing method of this foam sheet utilizes molding, it is easy to adjust the thickness of the sheet to be thicker in areas where the expansion is large when attaching the foam sheet to an adherend. , it is possible to make the sheet thickness of the adhered foam sheet product uniform.

According to the method for producing a foamed sheet, a foamed sheet consisting of a plasticized skin layer having a grain pattern on one side and a foamed layer integrally molded on the other side of the skin layer can be produced using a mold. . Therefore, according to the present method for producing a foamed sheet, a foamed sheet with a good appearance and a soft feeling can be produced.

The present method for producing a foamed sheet is characterized in that the skin layer and the foamed layer are integrally formed in a mold. Therefore, according to this method, unlike the conventional method, a long belt is not used, so that the production line can be reduced and the space required can be reduced. In addition, in this foam sheet manufacturing method, the mold can be easily replaced, so it is easy to change the color and texture of the foam sheet, which is extremely convenient, especially for manufacturing a wide variety of foam sheets. .

This foam sheet has a non-foaming property in the manufacturing method.
The step of heating the PVC stock after it has been placed to at least partially plasticize the PVC stock can be included. According to this method, it is possible to produce a foamed sheet in which a uniform skin layer is formed and a stable grain pattern is formed.

In this foam sheet production method, the mold includes a lower mold with a textured pattern on the bottom surface, and the mold is non-foamable.
The PVC raw material can be arranged by placing the PVC raw material on the bottom surface of the lower mold and adjusting it to a constant thickness using a doctor knife. Therefore, according to the present method, a foamed sheet having a uniform skin layer can be produced.

[Example] The present invention will be explained below using examples.

Example FIG. 3 shows a plan view of a mold adapted to the shape of the adherend shown in FIG. 2. As shown in FIG. 5, a predetermined grain pattern is provided on the mold surface of the lower mold, which is one component of the mold. The grain depth of the grain pattern formed on the mold surface corresponds to the foam sheet portion 13 shown in FIG. 4 that stretches when the foam sheet produced in this example is attached to an adherend. The depth of the embossment is deep at some locations, and the depth of the embossment is shallow at other locations corresponding to non-stretchable foam sheet portions 14. The mold also has a cavity with a height of about 1.5 mm (approximately uniform height) between the upper mold and the lower mold.

In the cavity of the lower mold as shown in Fig. 5,
As shown in FIG. 6, non-foaming paste PVC 16, which is a skin material, is applied to a thickness of about 0.5 mm. After that, the temperature of the mold is raised to about 120℃ and the paste is
Plasticize PVC.

Thereafter, as shown in FIG. 7, the skin layer 2
1, a foamable paste PVC 22 into which air has been mixed by mechanical foaming is injected, an upper mold 23 is mounted on the lower mold 24, the upper and lower molds 23 and 24 are tightened, and a non-foaming paste is injected with a heater 25. and foamable paste PVC is heated to 160~260℃ to plasticize it,
Foamed. The mold is then cooled to form a plasticized skin layer with a grain pattern on one side and a foam layer integrally molded on the other side of the skin layer.
Take out the PVC sheet.

The PVC sheet produced in the above manner has a planar shape that matches the adherend, as shown in Figure 4.
The thickness of the PVC sheet is approximately uniform, approximately 1.5 mm (the skin layer is approximately 0.5 mm thick, and the foam layer is approximately 1.0 mm thick). Also, regarding the grain depth of the PVC sheet,
The part 13 that stretches when pasted on an adherend is the other part 1
Deeper than 4.

The foamed sheet produced by this method has a uniform sheet thickness and is composed of the skin layer and the foamed layer, so it has a good appearance and a soft feel. Further, according to the present method, the grain depth is stepwise,
In addition, it is possible to manufacture a foam sheet with a shape that matches the adherend, so when attaching the foam sheet to an adherend,
It is possible to obtain a deeply grained product with almost no deterioration of the grain pattern, and the yield is also improved. In addition, according to this method, there is no need to use a long belt, so the space of the manufacturing equipment can be reduced, and since it is easy to replace the mold, it is extremely easy to change the color and texture of the foam sheet. It is.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional foam sheet manufacturing process using a paste material. Fig. 2 is a perspective view of the adherend used in the example, Fig. 3 is a plan view of the mold used in the example, and Fig. 4 is a plan view of the foam sheet manufactured in the example. 5 is a sectional view of the lower die used in the example. Figure 6 is a cross-sectional view of the lower mold shown in Figure 5 with skin material injected, and Figure 7 is a foamed material injected onto the skin layer shown in Figure 6 and the upper mold attached. FIG. 1...Skin material supply device, 2...Belt, 3...
...Skin material, 4,8...Doctor knife, 5,
9, 10, 25... Heater, 6... Foamed material supply device, 7... Foamed material, 11... Planar shape of adherend, 12... Molding mold, 111... Planar shape of cavity, 13... Foam sheet portion that stretches when attached to an adherend, 14... Foam sheet portion that does not stretch when attached to an adherend, 15... Grain pattern, 16...
Non-foaming paste PVC, 21...Skin layer, 2
2... Foaming paste PVC, 23... Upper mold, 2
4...lower mold, 25...heater.

Claims (1)

[Scope of Claims] 1. A mold is used in which a cavity is formed from an upper mold and a lower mold, and either one of the upper mold and the lower mold is formed with a mold surface having a grain pattern; The first step is to place a non-foamable vinyl chloride resin raw material to a substantially constant thickness on the mold surface having a textured pattern, and then heat it to at least partially plasticize the resin raw material; a second step of arranging the foamable vinyl chloride resin raw material and clamping the mold; a third step of heating the mold and plasticizing the non-foamable and foamable vinyl chloride resin raw materials; from the mold; A fourth step of removing a plasticized vinyl chloride resin sheet having a skin layer having a grain pattern on one side and a foam layer integrally formed on the other side of the skin layer. Production method. 2 The mold includes a lower mold with a grain pattern on the bottom,
The method for producing a foamed sheet according to claim 1, wherein the resin raw material in the first step is arranged by using a doctor knife to obtain a constant thickness. 3. The method of manufacturing a foam sheet according to claim 1, wherein the second step is performed by inserting a resin raw material containing air bubbles into a cavity.