JPH01192857A - Production of felt mat - Google Patents

Abstract

PURPOSE:To form a desired skin layer without losing of cushioning properties, by hot-pressing a mat under specific conditions. CONSTITUTION:Opened fibers and a binder (powder or fiber of thermoplastic resin) are mixed and laminated to a mat-like state, then the binder is molten by heating and then the mat-like material is hot pressed under the following conditions: 200<=t(T-TmP<alpha=i2000 [t is pressing time (sec); P is pressing pressure (kg/cm<2>); T is pressing temperature ( deg.C); Tm is melting point of binder ( deg.C); alphais 0.2-2.0]. A good cushioning material having excellent shape retention is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a felt mat using defibrated fibers.

(Prior art and its problems) Conventionally, waste fibers made from disintegrated fabric scraps, etc., have been used to create a binding material made of thermosetting resin such as phenolic resin powder, or thermoplastic resin such as polyethylene powder or polypropylene fiber. A method is known in which a felt mat is produced by blending the above-mentioned waste fibers with the above-mentioned waste fibers and heat-forming the resultant.

However, in the conventional felt mat manufacturing method as described above, since the resulting mat is a homogeneous cushioning material as a whole, it is necessary to add shape retention to the cushioning material or apply appropriate printing etc. A problem arises in that the relatively hard skin layer has to be provided by a further separate process.

Therefore, the technical problem of the present invention is to provide a method for forming the skin layer simultaneously with the production of the cushion material.

(Means for Solving the Problems) The method for producing a felt mat of the present invention uses thermoplastic resin powder or fibers as defibrated i# fibers and a binding material, comprising: (a) the defibrated fibers; (b) heating the mat to melt the binder; (viii) further formulating the following formula, 200≦t (T −TI+,)P≦2000.・・・
・・・・・・・・・(1) In the formula, t, press time (seconds) P: nibless pressure (in g/cm2) T, press temperature (1) T: melting point of binder (1) and hot pressing the mat under conditions such that α is in the range of 02 to 2.0.

(Function) That is, an important feature of the present invention is that in the final step of manufacturing the felt mat, the mat is heat-pressed under specific conditions that satisfy the above general formula (1) to form a desired skin on the mat surface. It consists in forming layers.

For example, when the press pressure is set to I Kg/cm2 or more, the value of α that satisfies the above general formula (1) is 20
If heat pressing is performed under conditions that exist only in a range exceeding exists only in a range lower than 0.2,
As a result of excessive heating and pressurization of the mat surface, the mat itself becomes a hard plate-like body and loses its original cushioning properties.

Furthermore, when the press pressure is less than I8g7cm2, the value of α that satisfies the general formula (1) is 2.0.
If heat pressing is carried out under conditions that exist only in a range exceeding As a result, the original cushioning properties of the mat are lost. Furthermore, if heat pressing is performed under conditions where α exists only in a range lower than 0.2, the mat surface will not be heated and pressed effectively, and the desired skin layer will not be formed. .

Thus, in the present invention, the mat is heat-pressed under specific conditions that satisfy the above general formula (1), thereby forming a desired skin layer without impairing the mat's inherent cushioning properties. This makes it possible.

(Preferred Embodiment of the Invention) Raw Materials In the felt mat manufacturing method of the present invention, defibrated fibers and a binder are used as manufacturing raw materials.

As the defibrated fibers, used are scraps of fabrics discharged during the industrial production process of woven fabrics, etc., and defibrated waste fibers obtained by defibrating old clothes.

Further, the binder is used to bond the defibrated fibers together to impart shape retention, and in the present invention, the binder is a polyolefin such as polyethylene or polypropylene,
Powder or fiber of thermoplastic resin such as polyvinyl chloride or polyester is used.

When using fibers as a binding material, from the standpoint of compatibility with the removed fibers, fibers with a length of 10 cm or less, particularly 5 cm or less, are preferable, and considering the finished state of the final mat, the average fiber length is Synthetic pulp made of polyethylene, polypropylene, low melting point polyester, etc. having a diameter of 01 to 10 mm and an average fiber diameter of 1 to 30 μm is suitable.

In particular, polyolefin-based synthetic valves can be made by hand as a product in which fibers are assembled into a plate shape, so they are used after being defibrated using a curler or a crusher.

These dissolved ml fibers and the binder are used in a weight ratio of 9515 to 50150, particularly 90/10 to 70/30.

In addition, the basis weight of these defibrated fibers and the binding material is -generally 20
0 to 10,000 g/m2, especially 500 to 3,0
It is preferable that it is in the range of 00 g/m2.

If the basis weight is less than the above range, the cushioning properties of the mat will tend to decrease as a result of the formation of a skin layer in the process described below, and if the dog is made from a dog that is less than the above range, the mat itself will become thicker. There is a tendency for the effect of the epidermal layer to be impaired if it is too much.

Mixing and matting of defibrated fibers and binding material In the present invention, when a fibrous material is used as the binding material, defibration can be achieved by simultaneously adding the fibrous binding material during the defibration process of woven fabric, etc. The fibers and binder are easily and uniformly mixed to form a mat.

When a powdery binder is used, the defibrated fibers are laminated to form a bulky mat, and then the powdery binder is sprayed to mix the two and form a mat.

Matting is easily carried out, for example, by continuously dropping the mixture of defibrated fibers and binder onto a continuously moving held conhair.

In this case, when a powdery binder is used, as described above, only the defibrated fibers are dropped to form a mat, and then the powdery binder is sprayed onto this.

Melting of the binder In the present invention, the mat is then heated to melt the binder, thereby bonding the defibrated fibers to each other and securing the shape of the mat.

The heating for melting the bonding material is performed by means known per se, such as infrared heater heating, high frequency heating, and a single-type through dryer, but a single-type through dryer is preferred.

The through dryer type is a heating method using a dryer in which hot air blows through the mat.
As shown in the figure. That is, a mat 2 running on a suitable belt 1
Hot air (indicated by arrow A) is blown onto the mat 2, and the hot air that has blown through the mat 2 is circulated by a fan (not shown) or the like and blown onto the mat 2 again.

As heating means for melting the binder, in addition to the through dryer system described above, there are other means such as infrared heater heating and high frequency heating, but these methods are effective in heating the inside of the mat and are economical. From this point of view, a through dryer type is preferably employed.

It is preferable that the temperature of the hot air during heating is set within a range of not less than the melting point of the binding material used and not more than the melting point +100°C.

Heat Press Treatment In the present invention, a mat whose shape has been secured as described above is heat pressed to form a relatively hard skin layer on its surface without impairing the cushioning properties of the mat itself.

This heat press is carried out using the following formula, where t nibble time (seconds) P press pressure (Kg/cm') T press temperature (℃) To melting point of binder (1) Particularly, the following formula, where t, T , Tm and P represent the meanings described above. The experiment is carried out under conditions such that the value of α exists in the range of 0.2 to 2.0, particularly 05 to 1.5.

This heat press is carried out using means such as heated rolls, heald presses, badge presses, etc., but when this heat press is carried out in multiple stages, such as when multiple heated rolls are used, the integrated value It is necessary to satisfy the above general formula.

(Effects of the Invention) According to the present invention, a good skin layer can be formed without using special materials, without employing troublesome means such as a lamination process, and without impairing the cushioning properties of the mat itself. A felt mat is produced.

Further, conditions for shortening the processing time of hot pressing for forming the skin layer can be easily set as appropriate depending on the material and the like.

Furthermore, by performing hot pressing using a heated roll or a belt press, it has the excellent advantage that integrated production in a line is possible.

The felt mat produced according to the present invention has excellent cushioning properties and has a good skin layer formed on its surface, so it has excellent shape retention and can be used as a good cushioning material for beds and cushions. Used as core material for etc.

The invention is illustrated by the following example.

(Example) In each of the following Examples and Comparative Examples, the following were used as defibrated fibers and binding materials.゛Defibrated waste fiber: 85 parts by weight of defibrated scraps mainly made of cotton.

Binding material, 15 parts by weight Average fiber length ]δmm, melting point 132'C Example 1 A mixture of the two components described above was dropped onto a wire mesh that was suctioned from below to produce a web of 1600 g/m2. did.

This web was fed into a hot air circulation dryer as shown in FIG. 1 and heated at a temperature of 160° C. for 10 minutes to completely melt the binder.

Next, pressurization and heating were performed using a hot platen press at a temperature of 180° C. and a pressure of 5 gf/cm 2 for 7 seconds.

The felt mat obtained by this method had a mat thickness of 15 mm and an apparent density of 0.107 g/cm3, and a good skin layer was formed on the surface, and the inside had a low density and good cushioning properties. .

Examples 2 to 4 and Comparative Examples 1 to 3 Webs were produced in the same manner as in Example 1, and felt mats were produced by varying only the hot pressing conditions.

The hot press conditions and the finished state of the matte are shown in Table 1 together with the results of Example 1.

In addition, F(α) −t (T−Tm)P″ and F (0
,2).

F (0,5), F (1,5) and F (2,0)
The values are also shown in Table 1.

Claims (5)

[Claims] (1) Using defibrated fibers and thermoplastic resin powder or fibers as a binding material, mixing and laminating the defibrated fibers and the binding material to form a mat,
Next, the mat is heated to melt the binding material, and further the following formula, 200≦t(T-T_m)P^α≦2000......(1
) In the formula, t: Pressing time (seconds) P: Pressing pressure (Kg/cm^2) T: Pressing temperature (℃) T_m: Melting point of binder (℃) α is 0.2 to 2 to satisfy the following. .0.0. (2) α is 0.5 to 1 such that the above formula (1) is satisfied.
．． 5. The manufacturing method according to claim 1, wherein hot pressing is carried out under conditions such as those existing in the range of claim 5. (3) The heat pressing of the mat in the state where the binder is melted is performed using the following formula: 500≦t(T-T_m)P^α≦1500 (2
) where t, P, T, and T_m have the meanings described above. Manufacturing method described. (4) α is 0.5 to 1 such that the above formula (2) is satisfied.
．． 5. The manufacturing method according to claim 3, wherein hot pressing is carried out under conditions such as those existing in the range of claim 5. (5) The manufacturing method according to any one of claims 1 to 4, wherein defibrated waste fibers are used as the defibrated fibers.