EP3771759B1 - Paint roller cover comprising a nonwoven material - Google Patents

Description

The invention relates to a paint roller or inking cylinder cover, having a pile fiber non-woven fabric.

The nonwoven material is based on a carded pile with a definable initial fiber position, which is reinforced by stitching to obtain a three-dimensional fiber arrangement.

On the process side, a starting fiber mixture is laid to form a card web and then it is consolidated by means of intermeshing by one-sided fiber pile formation, with the fiber pile layer obtained being predominantly in the form of loops.

In the case of the paint roller or paint cylinder cover according to claim 1, this has a pile fiber non-woven fabric in which some of the pile fibers have a vertical orientation and a loop shape.

It is known to use paint rollers or paint rollers for distributing liquid substances such as paints, varnishes or other media over large areas, for example for painting walls, facades or ceilings or for applying floor coatings. Such paint rollers or inking rollers have a holder with a handle on which a rotatable roller with an absorbent cover, which can also be replaced, is fixed.

A foam or velour, that is to say a fabric with a pile layer, is used in a known manner as such a cover material for paint rollers or rollers.

Such velor can be made on the basis of two panels of fabric connected with additional warp threads. The warp threads are then severed so that the warp threads form a pile layer in which the threads are predominantly arranged vertically.

The material and the pile height can be suitably varied and adapted for use with different colors or varnishes and on different surfaces.

Short pile heights are recommended for smooth application substrates. Covers with pile heights or pile heights of up to 25 mm are used for heavily structured or rough surfaces in order to ensure application down to deep-lying areas.

However, the production of such cover materials is complicated and expensive.

In principle, nonwovens can be provided comparatively inexpensively. However, non-woven fabrics previously proposed as a reference material are not suitable as a qualitatively equivalent velor substitute material.

From the WO 2002/058006 A2 a hydroentangled nonwoven is already known. However, such nonwovens are not very bulky and have only a low absorbency.

The DE 41 06 295 A1 discloses a needle-punched nonwoven which, however, is also not sufficiently bulky and can only be used as an application agent in conjunction with an additional foam.

The US8695151B2 shows a needle-punched nonwoven in which a pile structure can be produced using special needles. The disadvantage there is the poor dimensional stability, which makes an additional reinforcement layer necessary. The achievable pole height of a maximum of 7 mm is too low and restricts that Field of application of such a material clearly. In addition, the integration of the fibers in needle-punched nonwovens is rather poor, so that tearing of the fibers and formation of fluff must be expected when using a paint roller designed in this way.

From the DE 198 39 418 C1 a method for the production of voluminous, multi-layer pile fleece knitted fabrics from individual, identical and different fleece layers is already known, in which stitch layers and pile loop or pile fold layers are formed from fibers or threads with the aid of stitch-forming elements.

In this regard, in a base layer, one or more layers are successively pulled from additionally supplied fiber fleece by means of compound needles into the pile loop or pile fold heads of the pile layer of the base layer supplied in each case. The fibers of the additionally supplied non-woven fabric are formed into a mesh layer and a pile layer. The newly formed layer only penetrates the pile layer of the uppermost layer supplied in the area of the pile loops or pile fold heads. Ultimately, both sides are connected to each other.

Single-layer or multi-layer pile fleece knitted fabrics, pile fiber pleated knitted fabrics, pile thread knitted or woven fabrics can be supplied as the base layer. There are no indications of the use of such non-woven pile fabrics in connection with the problem of high absorbency.

In addition, a pile fabric is known, consisting of a textile support structure with an edging of pile threads anchored in the support structure according to FIG EP 1 163 386 B1 .

The pile threads mainly consist of a multi-filament yarn, which contains fine filaments on the one hand and coarse filaments on the other hand, the titre of which is more than 25 times greater than the titer of the fine filaments. Such a pile fabric is suitable for use as a massage pad or as a massage glove.

From the DD 46202 A1 a paint roller is already known, which consists of a nonwoven fabric. The nonwoven fabric preferably has dense, polar loops that attached to a base. Alternatively, the non-woven fabric consists of a fiber fluorocarbon bonded by synthetic resin impregnation or spraying and wound around the paint roller in a plurality of layers.

The EP 0 069 335 A1 discloses a cover for the carrier body of paint rollers, which consists of pile fabric. Pile tufts or pile fibers consisting of yarn are anchored in a fabric.

From the above, it is the object of the invention to specify a further developed, nonwoven material for a paint roller or paint cylinder cover, whereby a large pile height of the material to be created can be realized and minimal fiber tearing is to be ensured. The material to be created should be able to absorb liquids but also largely release these liquids again without any appreciable mechanical force being applied.

The object of the invention is achieved by the combination of features of the applicable claim 1, directed to a paint roller or paint roller cover.

The nonwoven material according to the invention consists of a carded web with, for example, a longitudinally oriented initial fiber layer. The carded web is strengthened by stitching while maintaining a three-dimensional fiber arrangement.

According to the invention, a fibrous pile layer is formed with a predominantly vertical fiber orientation, with the fibrous pile layer predominantly having a loop shape to avoid fiber tearing.

In one embodiment, a mesh layer can be provided on both sides of the fiber pile layer, with the pile layer surface being additionally meshed in this regard.

The respective mesh layers may have a different density or porosity.

In one embodiment of the invention, a backing made of a thermoplastic or thermally crosslinkable material is provided.

According to the invention, the pole height is in the range from 4 to 25 mm, preferably in the range between 7 and 22 mm.

In one embodiment of the invention, 5 to 30% by mass of binding fibers can be added to the starting fiber mixture.

According to the invention is also the use of the presented absorbent, fleece-based material as a paint roller cover or paint roller cover.

In the process for producing the absorbent, nonwoven-based material, a starting fiber mixture is laid into a carded web.

This is followed by strengthening by means of meshing and one-sided fiber pile formation, with the fiber pile layer obtained being predominantly in the form of loops.

A base web can be added during consolidation to increase the overall strength and dimensional stability of the final product.

In addition, there is the possibility of carrying out an additional, secondary meshing of the fiber pile layer surface, the additional meshing leading to a more open structure of this second mesh layer in comparison to the primary meshing, ie the first mesh layer.

In summary, according to the invention, a pile fiber nonwoven fabric, in which some of the pile fibers have a vertical orientation and a loop shape, is used as a paint roller cover.

The pile fiber nonwoven fabric used, i.e. a nonwoven fabric strengthened by stitch formation, in which some of the fibers have a predominantly vertical orientation and thus form a pile layer, is a new means in relation to the use presented here.

In the production of such nonwovens, fibers of finite length, ie so-called staple fibers, are first used to produce a carded web with a fiber layer that is preferably longitudinally oriented.

Optionally, such a fibrous web can then be laid one on top of the other in several layers by means of cross layers, the fibers here being predominantly oriented transversely to the machine direction.

Several layers of the same or different fiber orientation can also be superimposed.

The starting fiber web produced in this way is fed to a consolidation unit.

In such a consolidation unit, which is known per se, the fibrous web is laid in vertical folds by a compound needle and deflected three-dimensionally, as a result of which the fibrous web is compressed and the basis weight is increased.

The pile is pressed into a hook of the relevant compound needle with a brush-like darning element, with the result that a stitch is formed from the staple fibers when the needle is pulled back.

After this consolidation, the nonwoven fabric has a fibrous pile layer and a mesh layer.

If the pile fiber fleece fabric obtained in this way is then mechanically finished, for example sheared, the surface of the pile layer can be made more uniform.

The mesh structure created from the staple fibers used in pile fiber non-woven fabrics ensures good binding of the fibers, which reduces fiber tearing during use. In addition, the pile layer is predominantly in the form of loops.

In contrast to a pile layer consisting of pure or predominantly individual threads, as is the case with known velorisation, fiber tearing is further reduced according to the invention and the compressive elasticity and compression values and thus the overall stability of the pile layer is increased.

By varying fiber fineness, fiber material and fiber cross-section, the pile fleece structure can be varied from coarse to fine. The mesh gauge, i.e. the number of needles per unit of working width and the stitch length, also have a significant influence on the pile density and thus volume, appearance, strength and elongation of the nonwoven fabric as well as the integration of the fibers. By varying the production parameters, the nonwoven according to the invention can be easily adapted to the different requirements of the areas of application relevant here.

In a further development of the invention, the surface of the pile layer can be additionally meshed in order to further minimize fiber tearing.

For this purpose, the pile fiber fleece fabric described is fed to a further work station with compound needles in such a way that the compound needles penetrate the pile layer, grasp the pile fibers and form them into a second mesh layer.

The result is a three-dimensional fleece fabric with meshed surfaces on both sides and a pile layer on the inside.

Advantageously, the meshing on the two sides with different machine parameters, such as machine gauge or puncture depth, so that a first, denser and firmer side of the mesh and a second, more open side of the mesh are created.

The material has a sufficiently large pile height and absorbency so that, in contrast to previously known nonwovens, an additional layer of textile or foam for padding and/or improving absorbency can be dispensed with.

Fibers of natural origin, for example wool, cotton or viscose, but also synthetic fibers such as polyester or polyamide, and any mixtures of different fibers can be used to produce the pile fiber nonwoven fabric.

The fineness of the fibers should be in the range from 2.5 to 22 dtex, preferably in the range from 3.3 to 15 dtex.

The staple length of the fibers is in the range from 27 to 120 mm, with a staple length of ≧60 mm having turned out to be particularly advantageous in order to achieve good fiber binding and large pile heights.

The fiber mixture preferably contains a proportion of 5 to 30% by mass of binding fibers. These binder fibers have a melting point that is at least 20°C below the melting or decomposition temperature of the other fiber materials. The binding fibers can also be in the form of bi-component fibers, with the components having different melting temperatures and the component with the lower melting temperature acting as a binding agent.

Suitable binder fibers are based, for example, on polylactide, polypropylene or a core-sheath bicomponent fiber with a core of polyethylene terephthalate and a sheath of low-melting copolyester.

If binding fibers of this type are used, after the bonding by means of stitch-bonding, a temperature treatment takes place, in which the nonwoven fabric is heated to a temperature above the melting point of the binding fibers, so that the binding fibers at least partially melt and create an adhesive connection between the remaining fibers. This increases fiber binding and further minimizes fiber tearing, as well as improving the dimensional stability of the product.

In order to further improve the dimensional stability of the cover material and its adhesion to a core material, a backing made of a thermoplastic or thermally crosslinkable material can be applied to the side facing away from the pile layer.

This coating can take place, for example, in the form of an aqueous polymer dispersion based on polyacrylate or ethylene-vinyl acetate copolymer, as a fusible powder or as a hot-melt application.

A film or an adhesive web made of a thermoplastic polymer, such as polyester, polyethylene, polypropylene or polyurethane, is preferably laminated on, which is advantageously carried out at the same time as or also directly after the temperature treatment step already described.

The nonwovens according to the invention typically have a basis weight of 200 to 700 g/m ² , preferably 300 to 550 g/m ² , and a pile height of 4 to 25 mm, preferably 7 to 22 mm.

The invention will be explained below with reference to examples.

A first example is based on a fiber mixture made of polyester, 80% 7dtex, staple length 60 mm; 20% 12 dtex, staple length 76 mm, which is processed into a carded pile with longitudinally oriented fibers.

This fiber batt is fed with a compression ratio of 1:8 to a Malimo bonding unit, type Kunit, machine gauge F18, with one side being meshed to form a pile.

The kunit non-woven fabric produced in this way has a pile height of 9 mm with a weight per unit area of 400 g/m ² .

A second example is based on a fiber blend of 72% polyester, 7 dtex, staple length 60 mm; 18% 12 dtex, staple length 76 mm, 10% core-sheath bicomponent fiber with a copolyester sheath and a melting point of approx. 130°C, 4.4 dtex, staple length 56 mm.

This mixture is processed into a carded pile with, for example, longitudinally oriented fibers. The fiber batt is fed with a compaction of 1:8 to a Malimo type Kunit bonding unit with a mesh gauge of F18, with a first side being meshed to form a pile. The pile side is then meshed with a small puncture depth in a Malimo bonding unit, type Multiknit, machine gauge F18. The result is a multiknit non-woven fabric, which is then subjected to a temperature treatment at 160°C in a flatbed laminating machine. At the same time, a copolyester film with a basis weight of 70 g/m ² and a melting point of 130° C. is fed to the laminating plant and laminated onto the first side of the mesh. The material obtained in this way has a pile height of 7 mm with a multiknit nonwoven fabric weight per unit area of 450 g/m ² .

By way of comparison, a velor fabric known from the prior art made of 100% polyester with a backing made of ethylene-vinyl acetate copolymer has a pile height of 10 mm with a total weight per unit area of 620 g/m ² . A known needle-punched nonwoven made of 100% polyester has a pile height of 3 to 7 mm with a surface weight of 400 g/m ² .

With the materials described here, a comparable pile height can therefore be realized with a lower basis weight than with known materials.

In addition, the use of kunit or multiknit technology surprisingly makes it possible to dispense with an additional base sheet.

Claims (3)

1. A paint roller cover or a paint roll cover, comprising a pole fibre non-woven fabric, in which a part of the pole fibres has a vertical orientation and a loop shape,
   wherein an initial fibre mixture is laid into a carded web, subsequently a strengthening is performed by means of meshing and unilateral fibre pole formation, and the obtained fibre pole layer is preponderantly realized in the form of straps.
2. The paint roller cover or paint roll cover according to claim 1,
   characterized in that
   an additional meshing of the fibre pole layer surface is performed, wherein this additional meshing leads to a second mesh layer having a more open structure as compared to the first mesh layer.
3. The paint roller cover or paint roll cover according to claim 1 or 2,
   characterized in that
   the strengthening is performed by a densification by means of the Kunit or Multiknit processes.