KR20070023737A - Constricted rotary-stretching roller and the manufacturing of the same - Google Patents

Abstract

The present invention relates to a stretcher roller (1) to straighten the flexible web material (3a) to be conveyed. The stretcher roller 1 of the present invention comprises a roller body provided with an outer surface 5 comprising tapers 8a, 8b located between both ends of the roller body. Surprisingly, the taper exhibits an excellent effect in reducing the formation of wrinkles in the film, for example by engraving applied to the film, in particular in the region of the tapered portions 8a, 8b.

Stretcher Roller, Taper, Outer Surface

Description

Rotating-stretching roller of a narrow shape and a method of manufacturing the same {CONSTRICTED ROTARY-STRETCHING ROLLER AND THE MANUFACTURING OF THE SAME}

The present invention relates to a rotation-stretching roller for stretching a continuous flexible web material.

Rotating-stretching rollers for stretching continuous flexible web materials, which comprise rigid roller members with bearing pins at the ends of the rollers are already known from German Utility Model Publication No. 295 22 011. Known. A casing cover made of elastomeric material is attached to the roller member. The elastomeric cover provides a groove running obliquely with respect to the longitudinal axis of the roller member from the outer surface of the cover. The groove extends in each case from the inside toward the relative end of the roller, towards the outside of both edges of the radial central plane of the roller. The groove extends in a uniform spiral form and causes stretching during operation.

In order to prevent a poor stretching effect in the central area, the inner grooves are offset by 180 ° relative to one another. The outer edges facing the radial center plane of the rollers are rounded or chamfered to prevent damage and imprint on thin and sensitive web materials.

The elastomeric cover wears out in a few years. After abrasion, the remaining cover is removed from the roller member and a new cover is attached. The spiral is then engraved on the new cover. Finally, round the edges of the skin surface.

Forming grooves in the cover contributes to a very large extent to the repair costs of this kind of roller.

Among other features, a rotation-stretching roller comprising two roller member portions having an outer surface extending conical to each other is already known from US Pat. No. 2,594,846. In addition, the rollers provide grooves which are arranged at an angle at which the gradient changes towards the end. This results in high production costs. The conical form is described as one of several possible forms. This form is not considered to provide a particular technical effect. Thus, this possible form, published decades ago, actually plays no role.

It is an object of the present invention to provide a rotation-stretching roller having more advantages.

This object is achieved by a comprehensive device having the features of claim 1 and a manufacturing method according to the dependent claims. Preferred embodiments are described in the dependent claims.

The rotation-stretching roller according to the present invention provides a roller member. A casing surface or a cover of each shell form is disposed above the roller member, the cover or shell being tapered from outside to inward. The skin surface is typically of elastomeric material.

Surprisingly, as a result of the tapered results, it has been found that the web material is less stressed and overall improved rotational stretching is achieved. The pressure exerted on the web material against the rotation-stretching roller increases inward from the outside of the roller. In particular, the edge regions of the web material are gripped and pulled together by a rotational stretching scheme. Large compressive pressure on the web material in the area between the edges is prevented.

The low mechanical stresses in the central area make it possible to stretch even wet paper, thin paper webs which are already known to be very sensitive and easy to tear. Aluminum web materials are also very sensitive.

Under a given corresponding thickness, material and compressive force or respective tensile force, the central region is not subjected to mechanical stress because the central region of the web material is no longer in contact with the rotating roller. This method has been found to be particularly advantageous for stretching web materials that can only be subjected to low mechanical stresses.

According to a further advantageous embodiment the skin surface can be designed in one piece. As a result, there is no end transition where the foil can be damaged when passing through the rollers.

In one advantageous embodiment, the area between the two tapered portions can be designed in a round manner. Such a manufacturing method is preferable in terms of cost. Edges on the shell-like shell surface that can damage the web material are prevented.

In a further embodiment of the invention, the stretching groove is defined by the edge region. The roller can thus be produced in a more cost-effective manner. For example, in the case where the groove is not formed in 50% of the outer skin surface, the contouring cost can be reduced by 25% compared to the existing technology. In many cases it is possible to eliminate 50% of the grooves. This is especially true where the width of the paper web to be processed is constant. In this case, the width of the rotation-stretching roller can be adjusted to the width of the web material, thereby lowering the cost.

Even when processing non-uniform web materials, a 25% reduction is routinely possible.

According to a further preferred embodiment, the taper is formed by grooves extending towards each other in a conical shape. For example, rollers designed in this way are initially produced after lathe machining and polished to a cylindrical shell surface. The lathe process for the conical part processing is relatively simple. Polishing is done to provide a uniform surface without edges.

In a further preferred embodiment, the sheath surface is provided with a helical groove in which a rotational stretching effect is achieved. This prevents the possibility of a buckling fault that can damage the web material as it enters the groove.

According to a further embodiment, the obtuse angle (ie greater than 90 °) transition from the shell-like shell surface to the groove is rounded or chamfered. This prevents traces on the web material. Surprisingly, since the acute transition generally does not leave any indentations, it is known that the acute transition does not require rounding if it can be ensured that no buckling defects occur when entering the groove while using a helical groove. It became.

According to a further preferred embodiment, the envelope surface is surrounded by a tubular sheath at least in the area providing the groove. If the cover is worn, only the cover is replaced. There is no need to replace the entire sheathed cover with the groove. In this way maintenance costs or individual maintenance costs can be significantly reduced.

The manufacturing cost can be further reduced by combining two roller members with corresponding covers forming one roller member according to the invention. The two roller members are supported together by a shaft. Each cover on the roller member is tapered from right to left or from left to right, respectively, for example providing only one spiral groove each.

The two grooves are therefore undercut in different ways.

The invention also relates to a method of making a rotation-stretching roller. In a first step, the cover in the form of a shell is cured on a roller member, typically made of aluminum, steel or carbon fiber reinforced polymer (CFRP). In a second step, the cover is lathed in a tapered fashion from the outside to the inside. Thereafter, the surface of the cover is polished. In a third step, grooves are provided in the cover.

In order to minimize the groove manufacturing cost, the blades used only move parallel to the roller axis. This results in the depth of the groove being reduced from outside to inside. In addition, the engraving angle does not change in this manner. In this way the undercut angle of the grooves in the cover or the diagonal course of each groove does not change.

In a further embodiment of the method according to the invention, the outer surface in the groove area is polished in order to provide a round transition to the groove in the fourth step. In this way, in particular the groove is advantageously arranged only at the outer end of the roller member. Since conventional spin-stretch rollers provide grooves throughout the spin-stretch rollers, this saves subsequent processing compared to the prior art.

In addition, if desired, at least one tubular cover may be mounted on an area with grooves. Preferably, the cover is made of silicon. Such materials have proved to be particularly suitable.

Through this method, it is possible to produce a rotation-stretching roller which provides the above-mentioned properties in a particularly simple and cost-effective manner.

1 shows a side view of an embodiment of a rotation-stretching roller according to the invention.

2 is a detailed cross-sectional view of a further embodiment.

The rotation-stretching roller 1 provides a roll member having an integral skin surface or a cover 5 each shaped like a skin. The rotating member provides bearing pins 6a and 6b at its ends. The bearing pin is used for the rotatable mounting of the rotation-stretching roller.

The paper web 3a is guided above the roller 1 at an angle of 90 °. 1 shows a cross section of the stretched foil 3b. The envelope surface or envelope-shaped cover 5 provides two parts 8a and 8b which extend concentrically towards one another. The cones 8a, 8b provide grooves 2a, 2b extending helically in the edge region. Rotational stretching of the paper webs 3a, 3b is achieved by helical grooves 2a, 2b.

Depending on the increasing diameter of the roller towards each outermost edge of the roller, the gradient of the conical surface 8a, 8b tapered towards the center is as uniform as possible on the foil in the edge region. Allow pressure to be applied. Among them, the radius of the outer shell surface 5 is tapered or constricted respectively.

While being conveyed, the paper webs 3a, 3b are preferably not in contact with the central portion 4, and if they are not in contact with the central portion 4, the foils 3a, 3b have any adverse mechanical effect. You will not receive. By selecting the approximate contact pressure and guiding the paper web, the paper web is only contacted in the vicinity of the grooves 2a, 2b.

Figure 2 shows a cross section of an embodiment of a rotation-stretching roller according to the invention. The outer surface 5 of the roller member 1a is provided with a spiral inclined groove 2a. The obtuse angle transition portion 9 from the surface of the cover 5 in the form of an envelope to the groove 2a is rounded. The obtuse transition prevents traces on the web material.

The cover 5 in the form of an envelope is surrounded by a tubular cover 10 in the region of the grooves 2a, 2b. Thus, the web material to be stretched by the rotation-stretching rollers is in direct contact with the lid 10 without directly contacting each web 11 formed by the skin surface 5 or the grooves 2a, 2b. If the cover 10 is worn, the cover may be replaced accordingly. Thus, unlike the prior art, very expensive skin replacement costs are generally not necessary.

In order to prevent all of the cover 10 from being covered, only the portions 7a and 7b provided with the grooves 2a and 2b are respectively surrounded by the cover 10.

The depth 14 of the groove or each helical groove 2a decreases from the outside towards the inside, which makes it advantageous in terms of cost.

Under some circumstances, the desired effect can also be achieved by enclosing only the respective edge regions 7a and 7b with the lid 10. This enables a production which is particularly advantageous in terms of cost. However, the desired effect and indeed the prevention of mechanical stress in particular in the central region can be achieved by an improved manner in which the shell-shaped cover 5 of the rotation-stretching roller is generally tapered so as to increase from the outside inward. Can be.

It is preferable to round the transition to prevent corners during the transition between the two tapered portions 8a, 8b. It is preferable that the base 14 of each groove 2a, 2b is also round shape.

The area tapered to some extent relative to the edge area is generally preferably extended by at least about 25% of the total length of the cover 5 in the form of an envelope. Preferably, each tapered portion must be continuous and not particularly stepped in order to avoid adverse corner portions on the surface.

The rotation-stretching roller according to the invention is, for example, a maximum diameter of 240 mm and a length of 2400 mm. The tapered diameter from the outside toward the inside and the center is reduced to 236 mm.

Depending on the application required, it may be advantageous that the minimum diameter is closer to one outer diameter than to the other outer diameter of the rotation-stretching roller.

In general, the rotation-stretching rollers are not driven independently. Dedicated drive only for such rotation-stretching rollers is only desirable if very high rotational speeds are required. In this case, means must also be provided to stop the rotation-stretching roller. The web material should be able to be removed more quickly.

Claims (12)

As a rotation-stretching roller, Rotation-stretching roller, characterized in that the diameter of the roller is tapered from the outside to the inside. In the preceding claims, Rotational-stretching roller, characterized in that it comprises an integral skin surface 5 on the roller member 1a. The method according to any of the preceding claims, Rota-stretching roller, characterized in that the taper is formed by portions (8a, 8b) extending in a conical manner. The method according to any of the preceding claims, Rotation-stretching roller, characterized by having helical grooves (2a, 2b). The method according to any of the preceding claims, Rotary-stretching roller, characterized in that there is no groove in the central region (7c) and in particular the central region is at least 25% of the total length of the rotation-stretching roller. The method according to any of the preceding claims, Rotational-stretching roller, characterized in that it comprises a transition portion 9 in the form of a round from the outer surface into the groove 11. The method according to any of the preceding claims, Rotation-stretching roller, characterized in that it comprises at least one cover (15) disposed on the groove (2a, 2b). The method according to any of the preceding claims, Rotation-stretching roller, characterized in that it is formed from two roller cores (1a) disposed on a shared axis. The method according to any of the preceding claims, And means for stopping said rotation-stretching roller. In the method of stretching the web material 3a, 3b by the rotation-stretching roller 1 according to any one of the preceding claims, A method of stretching web material, characterized in that the web material (3a, 3b) is guided above the rotation-stretching roller (1) in such a way that it is brought into contact only in the edge region of the rotation-stretching roller (1). In the rotation-stretching roller manufacturing method according to any one of the preceding claims, In the first step the shell surface 5 is cured on the roller member 1a, In the second step, the skin surface 5 is lathed in such a manner that the diameter is tapered from the outside to the inside, In the third step, grooves 2a and 2b are provided in the outer end region of the roller member using a relative process of paralleling a U-shaped blade to the outer surface of the rotation-stretching roller axis. Rotation-stretching roller manufacturing method. In the rotation-stretching roller manufacturing method according to any one of the preceding claims, The groove is surrounded by a tubular cover (9).

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