JPS5947733B2 - Polyester fiber manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a special manufacturing method for synthetic fibers, and in particular, it has multiple quick dyeing properties such as dark, medium and light colors of polyester fibers, and extremely non-uniformity in the length direction of the fibers. This invention relates to the production of polyester fibers that have thick and thin portions and have a special feel (handling) and appearance (appearance) that are different from conventional ones.

Conventionally, it has been known that when undrawn yarn is drawn at a natural draw ratio or lower, thick fiber portions and thin fiber portions occur in each filament.Using this incompletely drawn yarn,
Attempts have been made to express differences in shade dyeing, differences in shrinkage or elongation in the length direction of threads, etc.

However, the undrawn yarn that easily exhibits the above characteristics is a low-oriented spun yarn with an elongation of 200% or more, and since it is subjected to incomplete stretching or heat treatment, its toughness is extremely reduced.

On the other hand, if highly oriented spun yarn with an elongation of 200% or less is used in order to improve toughness, differences in dyeing density and shrinkage are less likely to occur.

Furthermore, there are many problems such as unstable quality due to changes in undrawn yarn over time, and the use of incompletely drawn yarn, which makes processing difficult, resulting in uneven grain texture and changes in physical properties. It is difficult to obtain stable fabrics.

In order to obtain such incompletely drawn yarns or processed yarns using a conventional single undrawn yarn, a compromise undrawn yarn must be used in order to obtain both toughness and incompletely drawn yarn as described above. However, stretching must be carried out under the critical conditions of incomplete stretching and complete stretching.

Here, a compromise undrawn yarn is one with a moderate degree of orientation (elongation of about 1
75-225%) of undrawn yarn.

Undrawn yarn of this level undergoes changes over time that are most difficult to handle in production, and changes gradually over a period of 2 to 3 weeks immediately after spinning.

This change over time does not mean that the strength and elongation of the undrawn yarn changes significantly, but rather that the natural drawing ratio and natural drawing load, which are the most important factors that determine incomplete drawing and complete drawing, gradually increase.

Moreover, in order to obtain both incomplete stretchability and toughness, it is necessary to stretch at around the above-mentioned natural stretching ratio, so that the result is that the film is directly affected by changes over time.

Therefore, as described in Japanese Patent Publication No. 45-38731, we decided to give priority to toughness, which has an elongation of 20 to 40% after drawing, and to use light-colored core threads with an elongation of 10 to 80% (preferably 15%). ~65%) There is a method of simultaneously drawing the large side yarns so that they are dyed in a deep color, and then twisting and winding them to obtain a marbling pattern, but this method requires the operation of combining and twisting. In both cases, low oriented high elongation yarns are drawn at a high draw ratio, so non-uniformity is small and only a relatively uniform marbling pattern can be obtained.

The present inventors have studied various ways to make the most of the characteristics of non-uniformity, and as a result, the optimum embodiment of the present invention is to include high molecular weight polyoxyalkylene glycol (hereinafter referred to as polyether) in the oil component. ) In the present invention, by drawing a relatively thick, low-oriented, high-elongation yarn with an added amount of fineness at a low draw ratio, a significantly non-uniform structure can be obtained, and a stable non-uniform structure can be obtained. In particular, since the highly oriented low elongation yarn is combined with the high elongation yarn and stretched simultaneously, it is possible to maintain a strength and elongation that are sufficiently durable for practical use.

Furthermore, fibers can be obtained that have multiple spot dyeing properties, multiple shrinkage ability, multiple crimp ability, and multiple adhesion ability in dark, medium, light, or more colors, that is, three or more colors.

If the drawn yarn is used as it is, it may be used as is, but if the elongation at break or the shrinkage rate is large, it is recommended to heat set it after stretching, so that a drawn yarn with a stable shape can be obtained.

The heat setting temperature at that time is desirably 70°C or higher, and some re-stretching may be added.

In addition, when forming a processed yarn after non-uniform stretching, false twisting may be performed following the aforementioned stretching, or false twisting, so-called in-draw, may be performed simultaneously with the re-stretching. becomes side yarns, and in either case, drawn yarns and processed yarns with significant non-uniformity are obtained, and in terms of appearance, the overall dyed product has a pongee-like or kasuri-like texture and appearance.

The present invention uses low-oriented, highly elongated undrawn yarn with an elongation of 200% or more in order to have significant non-uniformity in the length direction of the fibers, and highly oriented yarn with an elongation of 250% or less to maintain toughness. It is a combination of undrawn yarn with low elongation.

In order to particularly express non-uniformity, it is better to use yarn with higher elongation, but in this case, by applying an oil agent containing high molecular weight polyether, it is possible to prevent not only excessive agglutination but also the occurrence of fuzz. .

Here, the stretching ratio that can exhibit the non-uniformity of the high elongation yarn is 1.05 times to 60 times the maximum stretching ratio (A) of the high elongation yarn.
% or less (preferably 55 to 30%), the unstretched part is left thick, and even the stretched part may appear different from the core yarn with low elongation, so multiple dyeing spots and Causes shrinkage spots.

Here, the maximum stretching ratio is calculated using the following formula as an empirical guideline: %formula% shall be used.

In addition, this 2A is the maximum draw ratio, that is, the draw ratio immediately before the upper thread actually breaks when one thread is drawn under conditions where it is easy to draw, and this value is the so-called cutting elongation of the thread. This setting was made because it has been empirically known that the value is about 5% larger than the value normally expressed as .

In the present invention, in order to maintain toughness even when such a high elongation yarn is drawn at a low ratio, highly oriented low elongation undrawn yarn having a breaking elongation lower than that of the high elongation yarn by 50% or more is used as a yarn. However, simultaneous stretching is performed.

In the present invention, non-uniformity can be expressed more clearly by using undrawn yarn with a lower orientation and higher elongation, but since high-temperature false twisting is subsequently performed, this is considered to be the lowest limit of the false twist heat set temperature. Even when the temperature is lowered to around 160°C, the processed yarn obtained is highly agglomerated, and despite the presence of highly oriented and low elongation core yarn, the strength and elongation are reduced, and the fabric obtained becomes hard, resulting in poor softness and pliability. This makes it poorly suited for use in clothing.

Therefore, as a preferred embodiment of the present invention, various methods were investigated to fully utilize the non-uniformity of the low oriented high elongation yarn and to suppress sticking as much as possible. When spinning this high elongation undrawn yarn, the oil It has been found that this can be achieved by applying an oil agent containing the following components to the undrawn yarn in an amount of 0.01% or more based on the fiber weight.

That is, it is a polyoxyalkylene glycol with a molecular weight of 4,000 or more, generally propylene oxide (P
A random or block copolymer of O) and ethylene oxide (EO) is suitable, but polyethylene glycol or polypropylene glycol can also be effective.

Regarding the heat setting temperature during false twisting, if it is too low, the characteristics and physical properties (especially heat shrinkage) of the processed yarn obtained by false twisting will change due to post-processing such as dyeing after false twisting.

Therefore, it is necessary to set the heat set temperature to 160°C or higher.

Low-oriented, high-elongation yarns tend to stick significantly even at such low temperatures, but this can be substantially avoided by pre-treatment with an oil agent as described above.

That is, adding high molecular weight polyether to the oil component,
By adding 0.01% or more of a polyether component to the unstretched film, it is possible to suppress thermal adhesion that is equivalent to 20° C. or higher compared to a general oil agent that does not contain polyether.

Here, the effect of this high-volume polyether in suppressing sticking during false twisting (stiffness is caused by strengthening the oil film on the fibers, affecting the heat shrinkability of undrawn yarn, or by thermal decomposition of the polyether itself) Absorption heat is expected, but it is not clear.

Furthermore, in the combination of yarns in the present invention, it is preferable that the yarn denier of the low elongation yarn to be the core yarn is smaller than the yarn denier of the high elongation yarn to be the side yarn;
By doing this, it is easier to create a pongee style or kasuri style as a dyed product.

The present invention will be explained below with reference to Examples and Comparative Examples.

Actual cases and comparative examples Various polyester fibers (processed yarns) were obtained by spinning undrawn polyester yarns by changing various spinning speeds, and simultaneously drawing two types of fibers as shown in Table 1 and then false twisting. Ta.

Claims (1)

[Claims] 1. A plurality of yarns whose elongation at break differs by 50% or more, where the elongation at break of the highly oriented, low elongation yarn is less than 250%, and the elongation at break of the low oriented, high elongation yarn is greater than 200%. Pair the undrawn yarns, 1
．． After stretching at a stretching ratio of 0.05 times to 0.6 OA for high elongation yarn,
A method for producing polyester fiber, characterized by false twisting at 160°C or higher. A=((cutting elongation +100)/100)Xl, 052,
In claim 1, as a low oriented high elongation yarn, polyoxyalkylene glycol having a molecular weight of 4.000 or more is added to an oil component in advance to form an undrawn yarn.
．． 1. A method for producing polyester fiber, characterized in that a polyester fiber having a content of 0.01% by weight or more is used. 3. The method for producing polyester fiber according to claim 1 or 2, characterized in that the drawing is carried out at 0.55A to 0.3OA of high elongation yarn. 4. A method for producing polyester fiber according to any one of claims 1 to 3, characterized in that the yarn denier of the high elongation yarn is larger than the yarn denier of the low elongation yarn.