DE102010061046B3 - Method for the automatic connection of yarn by application of nanosuspensions - Google Patents

Abstract

Automated wet joining process of yarns using nanosuspensions of zinc oxide and / or alumina and / or silica which is capable of increasing the coefficient of friction between the fibers and thus facilitating the bonding process.

Description

Technical sector

The present invention generally relates to the automatic joining of yarns by compressed air jets and liquid.

State of the art

Devices are known for joining non-buttoned textile yarns, commonly called "splicers"; see, for example, the patent applications DE3437026A1 and DE3222260A1 (the Italian patents IT193033 respectively IT1136726 correspond). These are automated pneumatic devices that connect two ends of the yarn by twisting its fibers without knotting them to restore continuity of the yarn with considerable advantages in terms of quality and productivity in the subsequent processing phases, for example in the textile sector. Furthermore, from the DE 31 45 502 A1 discloses a method of joining yarn ends. In this case, a thread is severed by means of knives and reconnected by a suspension of aqueous type.

• – zwei Messer schneiden das überschüssige Garn ab, das den fehlerhaften Teil darstellt, der zu beseitigen ist;
• – die beiden Enden des Garns werden mithilfe von Druckluftwirbeln in zwei Vorbereitungskammern, die nachfolgend als „Vorbereiter” (Vorbereitungsverfahren) bezeichnet werden, getrennt „abgespult”;
• – die auf diese Weise vorbereiteten Garnenden werden verschoben, sodass eine Überlagerung der beiden jeweiligen vorbereiteten Endabschnitte gewährleistet wird, die entsprechend und auf kontrollierte Weise veränderbar ist;
• – die Garnenden werden in eine Verbindungskammer eingeführt, wo sie durch einen Druckluftstrahl trocken (nur mit Druckluft) oder feucht zusammen mit einer Flüssigkeit (beispielsweise Wasser) durch eine Drehung der vorbereiteten Teile (Mischverfahren) verbunden werden;
• – die Verbindungskammer öffnet sich automatisch, und die (textile) Verarbeitung des Garns kann fortgesetzt werden.

The procedure in question, based on the aforementioned patents IT193033 and IT1136726 already known, but not limited to the following phases:

• - two knives cut off the excess yarn representing the defective part to be removed;
• - the two ends of the yarn are "unwound" separately by means of pneumatic vortices in two preparation chambers, hereinafter referred to as the "preparer" (preparation method);
• - the yarn ends prepared in this way are displaced, so that a superposition of the two respective prepared end sections is ensured, which can be changed accordingly and in a controlled manner;
• - The yarn ends are introduced into a connecting chamber, where they are connected by a compressed air jet dry (with compressed air only) or wet together with a liquid (for example, water) by a rotation of the prepared parts (mixing method);
• - The connecting chamber opens automatically, and the (textile) processing of the yarn can be continued.

The process for joining the yarn ends has a duration of one to two seconds, the previous phases not being taken into account in connection with the detection of the defects and the insertion of the yarn ends into the splicer.

In general, the devices which "connect" the two yarn ends can only work with compressed air or with water or with thermal energy in addition to the compressed air. This difference depends on the type of yarn you want to combine.

The object of the present invention, which as a starting point is based solely on the technology of automated dampening, is to improve some features of the connection of the two yarn ends, which is achieved with this wet technique, including the strength of the connection and / or the aesthetic quality of the A connection that must be as similar as possible to the original yarn and / or a reduction in the length and / or thickness of the connection. These better properties of the bond would allow to obtain better quality, more uniform and / or stronger yarns.

The present invention therefore seeks to solve the above-mentioned problems by providing an innovative process which is industrially applicable, in particular, but not exclusively in the textile sector.

Description of some preferred embodiments of the invention

The invention will now be described by way of example but not limitation by way of example. As noted above, the invention is a development of the wet bonding process. A skilled artisan may vary the examples presented without departing from the scope of the invention. Therefore, this part of the description is in no way intended to limit the scope of the invention in any way, but is only to enable an industry-skilled technician to implement them concretely.

• – Der in diesem Zusammenhang verwendete Begriff „Nanosuspension” bezeichnet Suspensionen von Nanopartikeln in Wasser oder kolloidalen wässrigen Lösungen, darunter zum Beispiel jene, die Metallpartikel oder Metalloxidpartikel, insbesondere Aluminiumoxide, Zinkoxide, aber auch Siliziumoxide mit einer Partikelgröße zwischen 4 und 100 nm enthalten.

In particular, the invention provides for the application of nanosuspensions by jetting (jet of nanosuspensions) onto the twine twines to be joined during or immediately after the preparation phase in order to increase the strength of the joint and / or improve its aesthetic quality and / or or reduce the length and / or thickness of the connection. This makes it possible to obtain better quality, more uniform and / or stronger yarns. This jetting process involves spraying the aqueous nanosuspension using a device similar to an inkjet printer capable of producing and depositing microscopic droplets of the above-mentioned nanosuspension.

• The term "nanosuspension" as used herein refers to suspensions of nanoparticles in water or colloidal aqueous solutions, including, for example, those containing metal particles or metal oxide particles, especially aluminum oxides, zinc oxides, but also silicon oxides with a particle size between 4 and 100 nm.

The textile substrates to which these nanosuspensions are applied are cellulosic (both natural such as cotton, linen, etc., as well as artificial, such as viscose, tencel, etc.), protein-based (wool), or synthetic. According to the invention, the most suitable nanosuspensions are selected each time in terms of chemical composition, concentration and functionality for the various substrates mentioned above.

However, this selection can be made by any industry-knowledgeable technician who knows this documentation; therefore, any reference in the description will be omitted.

• – Zusatzstoff Nr. 1: durch dispergierende, verflüssigende und viskositätsstabilisierende Eigenschaften gekennzeichnet und besonders für sehr angereicherte Zusammensetzungen mit Wasser geeignet, der aus einer wässrigen Lösung von Natriumpolyaldehydcarboxylat (Handelsname DEUTERON ND 953) besteht;
• – Zusatzstoff Nr. 2: wirkt in allen Systemen auf Wasserbasis als Bindemittel, Adhäsionsförderer, Katalysator, Dispergiermittel, Entflockungsmittel, Benetzungsmittel, oberflächenaktives Mittel, Viskositätsminderer, Weichmacher, hydrophobisierendes Mittel, korrosionsverhinderndes Mittel und als Aktivator der Flammenverzögerer (Handelsname KEN REACT KR 138S TER50);
• – Zusatzstoff Nr. 3: stark befeuchtend und dispergierend wirkender Stoff (Handelsname OROTAN 731 A).

Commercially available additives may also be added to the aqueous oxide suspensions to prevent phenomena such as clumping, precipitation and settling therein. Some facts about the additives that can be used in the aqueous suspension of oxides are given below:

• Additive no. 1: characterized by dispersing, liquefying and viscosity-stabilizing properties and particularly suitable for very enriched compositions with water consisting of an aqueous solution of sodium polyaldehyde carboxylate (trade name DEUTERON ND 953);
• Additive no. 2: acts in all water-based systems as a binder, adhesion promoter, catalyst, dispersant, deflocculant, wetting agent, surfactant, viscosity reducer, plasticizer, hydrophobizing agent, anticorrosive agent and flame retardant activator (trade name KEN REACT KR 138S TER50) ;
• - Additive No 3: highly moisturizing and dispersing substance (trade name OROTAN 731 A).

The method according to the present invention was tested to prove its effectiveness on a specially developed test bench, in which the effectiveness of the above-mentioned nanomaterials was tested for the connections between the different yarns.

In addition, the method according to the invention was carried out, for example, with an apparatus for automated dampening in which the heads of the "jetting" system of the nanosuspensions were integrated into the preparation chamber (s) or preparer.

Industrial application

The process according to the present invention and the use of the respective nanosuspensions have the effect of increasing the coefficient of friction between the fibers and thus the strength of the joint, to improve their aesthetic quality while also allowing the reduction of the length and thickness of the joint.

In addition, according to the present invention, it is also possible to adapt a specific nanosuspension to a particular yarn (textile substrate) by combining different types of the above-mentioned nanosuspensions and wherein the concentrations of the base nanoparticles, the amount of the solvent (water) and the Amount of any additives are varied.

Therefore, the higher strength of the compound obtained by the method of the invention also allows an increase in the speed of textile processing after winding and the reduction in the number of shutdowns due to yarn breakage. In this way there is an increase in efficiency and productivity in the textile sector and also in other sectors which require this process on a yarn.

Claims (8)

Method for automated dampening connection with compressed air of the ends of a textile yarn, comprising the following phases: - inserting the 2 ends of the thread to be connected; - Cutting off the excess thread, which represents the defect to be eliminated, for example with two knives; - preparation of the thread ends to be connected, which term means the ends after cutting, by unwinding the fibers of the thread end separately with respective air vortices into the two preparers; - Displacement of the two prepared thread ends, so that an overlay of the two end pieces is ensured, wherein the overlay can be changed in a controlled manner by the device, which performs the method; - Introduce the thread ends in a connecting chamber, where they are connected to a jet of compressed air by rotation of the prepared parts, the so-called mixture; - opening the connecting chamber to possibly continue a processing operation using the bonded yarn; characterized in that during the preparation phase or immediately after the same, an aqueous nanosuspension containing, for example, particles of one or more metals or metal oxides, in particular of silicon oxides, is sprayed, the dimensions of the nanoparticles being between about 4 nm and about 100 nm, and then attaches to the two ends of the yarn, wherein the metal oxides which form the nanoparticles are one or more aluminum oxides and / or zinc oxides. A method according to claim 1, characterized in that to prevent the clumping, precipitation or settling of the nanoparticles of the nanosuspensions they are mixed with also commercial additives, including, for example: Deuteron ND 953, Ken React KR 138S TER50 and Orotan 731 A. A method according to any one of the preceding claims, wherein there is provided a prior selection of the nanosuspension and / or the various concentrations of its components for each specific textile substrate of the yarn. A method according to any one of the preceding claims which is particularly applicable to cellulosic, natural-type textile substrates, such as linen and cotton, artificial, such as viscose and tencel, or protein-based, such as wool, or generally to synthetic-type textile substrates. Method according to claim 1, characterized in that the duration of the connection process is typically between one and two seconds. Use of aqueous nanosuspensions of one or more metals or metal oxides and / or silicon oxides for automated wet-bonding of a yarn to increase the coefficient of friction between the fibers prior to their bonding, wherein the metal oxides are one or more aluminum and / or zinc oxides. Use of aqueous nanosuspensions according to claim 6, in which the dimensions of the nanoparticles of the aqueous solution are between about 4 nm and about 100 nm. Use of aqueous nanosuspensions according to claim 6, wherein the nanosuspensions also contain additives to prevent clumping, precipitation and sedimentation.