SE461228B - PROCEDURES FOR THE PREPARATION OF DRY FORMATED FIBER MATERIAL - Google Patents

Description

An object of the present invention is to provide a process of the type mentioned in the introduction: in which the disadvantages which have occurred in previously known and above-described production processes of webs of dry-formed fibrous material / now have been eliminated. The features essentially characteristic of the process according to the invention are set out in the following claims.

Thanks to the present invention, an economical and rational solution to the problems described above is achieved by dividing the production into at least two, separate steps: where the first step involves processing a base material without dye or chemical additives in addition to the standard components needed in order to make a coherent manageable material web and subsequent steps, processing of this base material means an order-ending quality: whereby a very good flexibility and at the same time a low production cost is achieved.

This achieves several advantages because you only need to run white material: you can pour higher machine speed when less binder solution needs to be wiped off: you can make longer runs in the paper machine and you get a simpler stocking as master rolls only consist of white base material lower total waste. In the subsequent manufacturing operation in step 2, advantages are obtained such as greater flexibility in color selection, easier to add additives: greater possibility of variation of embossing patterns: better economy by being able to run short series. specific The finishing equipment does not need to be stationed in direct connection with the high-production paper machine but can be found in an adjacent factory or at the customer's. In other words, step 2 can be run in simpler, cheaper machines, whereby the expensive »high-producing paper machine can be better utilized. The invention will be described in more detail below with the aid of a preferred embodiment.

In step 1, fibers are formed into a web which is compressed, binder is added and dried to a degree of treatment which is preferably 60-80%, master rolls. These half correspond to 20-90% of the final quality, and which are rolled up to so-called Manufacturer rolls can be produced with high machine utilization as the number of basic qualities is only a few and with a high and even property quality. The rolls can be easily temporarily stored pending further processing in a subsequent step.

The type and amount of binder can be selected differently for the two sides of the web so that subsequent processing can provide specific properties for each side. Preferably, a regenerable type binder is used to enable the reuse of waste material.

In step 2, the web is processed to final delivery quality with specified properties with regard to, for example,.

In step 2, additional binders are applied: in which the others are mixed. Especially with dyeing, the 2-step process gives a result that is difficult to achieve with other: hitherto applied methods. The dye in the binder used is evenly distributed over the entire area and covers the fibers down to such a depth that a color impression satisfactory to the eye is obtained and that this is the same on both sides when required. The binder in step 2 the proprietary ingredients can be applied in various forms such as liquid (solution, dispersion, suspension), paste, skunl and by various methods such as gravure high pressure, screen printing, roll coating or spraying.

Claims (5)

461 228 Process for the production of dry-formed fibrous material: characterized in that the production takes place in at least two steps, a first step consisting in forming a coherent: manageable web of material during compression and application of a reduced amount of binder to a degree of treatment constituting 20-90% of that obtained in a 1-step process and that the subsequent step consists in the material web being finalized by adding the remaining amount of binder and supplemented up to full final quality by adding dyes and additives to obtain of other properties such as wet strength of flame retardant, surface friction etc. Process according to Claim 1f, characterized in that during step 1 fibers are formed into a web which is compressed and fed with a reduced amount of binder, a degree of treatment corresponding to 60-80% of the final quality being obtained. Process according to Claim 1 or 2, characterized in that the preparation takes place in two steps. A method according to any one of the preceding claims, characterized in that the supplied binder in step 1 is of the regenerable type to enable reuse of waste material and that the binder supplied in step 2 is of such a type that it cancels the regenerability of the binder in step l at the same time as it additively gives full bonding strength in the material web. Process according to one of the preceding claims, characterized in that the other property-giving ingredients are included in the binder which is added in step 2: which gives the desired final quality of the web of material. IN"