Hangzhou Linan Junjia Decorative Materials Co.,Ltd
Address: No.79,Tangwuli ,Shangquan Village, Linglong Industry Zone , Linan , Hangzhou , Zhejiang
Contact: Jessie Yang
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention discloses a method of impregnating decorative paper and a decorative paper impregnated according to the method. In addition, the present invention also discloses the manufacture and preparation of the board using the decorative paper.
A method of impregnating decorative paper is known from the specification of WO 00/44984. First, the decorative paper is moistened with an amino resin, and thus the decorative paper is impregnated. The metering roller controls the amount of resin used. A decorating agent that is wetted and still moist is then sprayed with a layer of amino resin dispersed in the particular dispersion whereby the final mass per unit area - relative to the dry mass of the untreated paper - is between 100% and 250% . The spray dispersion contains a wear resistant material such as silicon carbide or corundum.
Impregnated decorative paper is used for the manufacture of sheets, in fact especially for the manufacture of slats.
It is known from the specification of EP 0 90 6994 A1, for example, that a slat is usually a relatively long sheet whose sides can be connected to other slats, that is to say along its longitudinal and transverse edges by means of, for example, Slot to connect. The slats interconnected in this way are particularly useful as floor coverings or wall coverings.
According to the prior art, the slab can be manufactured by the following pressing method. A resin-impregnated film layer called "reaction paper" is made. Place the carrier on the reaction paper. The "decorative paper" is applied to the top surface of the carrier in such a way that the facing with the abrasion-resistant corundum or silicon carbide faces outward and the facing is visible from the outside. In addition, apply a layer of cellulose and amino resin on the side with silicon carbide or corundum. This layer of cellulose is called "skin layer."
The decorative paper is then placed between the carrier and the additional layer as a skin layer. Afterwards, the reaction paper, carrier, decorative paper and additional layers are pressed together at a temperature of about 200 ° C. The resin used begins to flow and polycondense to form a rigid web. After removing the layer system from the press, the resin hardens to form the basic components of the slat. A slab of a desired size with side grooves is manufactured by sawing and grinding of the base member.
The carrier makes the slats mechanically stable. Decorating on the decorating paper determines the appearance of the subsequent wall or floor surface. Corundum or silicon carbide layer to ensure good wear resistance and so on. Reaction paper counteracts the deformation of the carrier plate during pressing. The skin protects the surface of the press from damage that may be highlighted by hard silicon carbide or corundum embedded in the amino resin.
For reasons of cost and quality, the preferred press type is a double belt laminator. Driven by the two rollers, the two metal belts are transported to the belt in the same way. The strips are pressed against each other and heated. The above layer system is introduced between the tapes and pressed by the tapes.
Despite the skin, the metal strip is still damaged by corundum and silicon carbide, and as a result, the metal strip surface must be trimmed. Dressing the belt surface is expensive and, in some cases, interrupting production during trimming the surface. In addition, the cellulose layer is cost-intensive.
It is an object of the present invention to provide improved decorative paper for making low cost panels.
The object of the invention is achieved by a method having the features of the first claim as well as by a decorative paper having the features of its juxtaposed claims. Advantageous embodiments are described in the dependent claims.
According to this method, decorative paper is impregnated, and here one side of the decorative paper is provided with not only wear resistant particles such as silicon carbide or corundum, but also fibers and / or pellets. In contrast to wear-resistant particles, the fibers or pellets are composed of a soft material such as polyester, polyamide or glass. During the pressing of the layer system comprising decorative paper, the fibers and / or pellets protect the press belt from damage. It is not necessary to apply the skin over the layer with wear particles. Thus, the cost of impregnating the decorative paper and applying the surface layer in the prior art is saved by about one-third.
In particular, impregnation of the decorative paper includes the following steps. Soak the decorative paper with resin, especially amino resin, and apply wear-resistant particles to the decorative surface. Subsequently, fibers and / or pellets are applied. Make sure that the fibers and / or pellets form a protective coating on the wear resistant particles in the press.
The method can be designed as follows before applying the fibers or pellets.
First, impregnate decorative paper with amino resin to wet the decorative paper. The metering roller controls the amount of resin used. The wetted, still moist decorative paper is then sprayed with a layer of amino resin dispersed in the particular dispersion whereby the final mass per unit area - relative to the dry mass of the untreated paper - is 100% to 250%. Spray dispersions have proven to be beneficial as described in the specification of WO 00/44984. Subsequently, it is beneficial to ensure a smooth and even distribution of the spray dispersion through the drum.
The dispersion is preferably composed of 100 parts of amino resin, 20 to 95 parts of abrasion resistant material, 0.5 to 2.5 parts of silane bonding medium, 5 to 25 parts of glidant, 0.1 to 0.4 part wetting agent, 0.05 to 0.4 parting agent and Amino resin hardener composition.
Specifically, melamine resin is used as the amino resin; for example, polyglycol ether,? -caprolactam or butanediol may be used as a flow aid, and for example, silicon carbide having an average particle size of 60 to 160 m or a particle size of 60 Alumina of ~ 160 μιη corundum or formed from a molten bath as a wear resistant material. An ideal mixture of silicon carbide and aluminum oxide can also be used.
Next, suitably applied fibers and / or pellets are as follows. A mixture of resin, fibers and / or pellets is prepared, and the mixture is then applied to the decorative paper treated as above. Due to the added protection of the resin, the addition of the mixture further improves the protection of the pressure equipment.
The thickness of the fibers or the diameter of the pellets should preferably be selected in such a way that the corundum or silicon carbide particles are kept away from the corresponding surfaces of the press during the pressing of the corresponding layer system of the sheet. In this way, damage to the hard silicon carbide or corundum particles is avoided.
If both fibers and pellets are used, it is preferred that the average diameter of the pellets is greater than the average diameter of the fibers. The pellets thus provide the ideal protection distance between the wear particles and the press belt, for example. The fibers in particular ensure the fixing of the resin and prevent the formation of cracks.
By using wear-resistant particles, such as hard corundum or silicon carbide particles, the invention protects the corresponding surfaces of the press in an improved and especially low-cost manner. The trimming of the corresponding surfaces of the press, such as the so-called squeeze belts of a double belt laminator, is required for relatively long time intervals in order to reduce the production costs and losses associated with surface finishing. All in all, a lot of cost savings.
Typical fibers have a length of at least 0.5 mm, but are preferably at least a few millimeters, such as 2 mm, 4 mm, or 5 mm. The longer the fiber, the more it protects the surface of the sheet and prevents crack formation. In particular, the upper limit of the fiber length depends on the accompanying increase in viscosity. If the viscosity of the resin-fiber mixture is too high, it can no longer be processed. The diameter of the fibers is, for example, about 10 μm or about 100 μm or more.
The typical diameter of the pellets is about 30-200 [mu] m. This ensures, on the one hand, the ideal distance between corundum or silicon carbide particles and the corresponding surface of the press. On the other hand, pellets are small enough to be invisible to the naked eye.
If fibers and / or pellets of the above dimensions are applied and they are embedded in the resin, the visual impression will not be impaired.
The fibers or pellets are preferably composed of polyester, polyamide or glass as these materials provide the properties that are required during and after manufacture. They provide sufficient stability during the manufacturing process. In the present invention, polyester, polyamide or glass is a sufficiently soft material to prevent damage to the pressure equipment. In the finished board, the above materials have sufficient transparency to avoid damaging the visual impression of the decoration. Advantageously, these materials allow relatively long fibers suitable for processing, which lengths far exceed the length of the cellulosic fibers used according to the invention. The increase in length of a synthetic polymer, such as polyester, polyamide fiber or glass fiber, results in a small increase in viscosity as compared to the increase in fiber length of the cellulose.
Long fibers protect the press from damage more than short fibers. This is especially true if the fibers are present in a fleecy form, details of which are given below.
The fibers and / or pellets may be composed of different materials. For example, polyester fibers, polyamide fibers, and glass fibers may be used at the same time.
Fibers are more preferred than pellets because they help prevent surface crack formation. Therefore, pellets are preferably used as a supplement. It is therefore preferable to add hollow spheres composed of glass as spheres for enhancing the protective effect. It is particularly preferable that the spheres have a diameter of 30 to 200 μm for the above reason.
The decorative paper according to the claims preferably has a solid mass of 30 to 300 g / m2. In particular, the fiber content is 5 to 100 g / m2. In addition, reinforcing beads, in particular micro-glass hollow beads, having a density of at most 80 g / m2 are provided.
In another advantageous embodiment, the fibers are present in a fleecy form. It can be said that the fibers are woven together. The fleece-like fibers have a particularly good reinforcing and protecting effect; the risk of crack formation is further reduced and the risk of damaging the corresponding surface to which it is applied is also reduced. When the resin-fiber mixture is applied, the fleece-like fibers fix the resin particularly well during pressing. At this point, the resin contributes significantly to the additional protection of the pressure equipment.
In the application of wool-like fibers, the addition of pellets enhances the protective effect.
The present invention is explained in more detail with reference to the following examples. The present invention passes 70 g / m2 of quality printed decorative paper through an amino resin bath to apply a resin (solid content) of 70 g / m2. At this point, a commercially available amino resin is used. A uniform layer of 15 g / m2 corundum was applied to the decorative top surface. The still damp board is directed to the fluid bed dryer. The dominant temperature in the dryer was 170 ° C. A metered mixture of a commercially available amino resin and a polyester fiber is applied to the treated wet plate. The applied material has a solids content of 70 g / m2. The proportion of fibers in the mixture is about 30% by mass. The average length of the fibers is 5 mm. The average diameter is 80 μm. Subsequently, the second drying step was performed at 160 ° C until the residual moisture was about 7%. The so-impregnated decorative paper is further subjected to the above treatment to form a sheet, and in particular to form a laid slat.