DD252795A1 - DEVICE FOR PRODUCING SINGLE-SIDED, MULTILAYER AND LENGTH-FERROUSED PLASTIC HOLLOW BODIES - Google Patents

Abstract

Device for the production of unilaterally open multilayer Kunststoffolienhohlkoerpern, preferably protective gloves of different sizes of thin film for health care and for special Produktionsstaetten z. B. the microelectronic industry manufactures. According to the invention, the device consists of two plates, in which the contour of the finished product is incorporated, the counterparts of the incorporated contour are congruent, except for a cut with a defined width, which leads the durchgaengige heating tape. These inner parts are mounted so that they can be moved out of the plates. During the separation process, the part of the film which constitutes the finished product is moved out of the plane of the remaining film without interrupting the contact of the welding tool with the edges of the finished product. The welding tool can be loaded by a certain system of fixed and Lospunkte recovery-free with a 100% increase in temperature compared to working temperature. This self-cleaning of the welding tool is realized.

Description

For this 2 pages drawings

Field of application of the invention

The invention relates to a device for producing objects made of multilayer film whose characteristic shape represents a partially open hollow body. One possible application is the production of protective gloves of different sizes from thin foil, which are available in large numbers, eg. In healthcare, as well as in some microelectronics manufacturing facilities.

Characteristic of the known state of the art

A variety of methods and devices are known for the problem of processing plastic films into certain finished products. The corresponding devices are tailored in construction and function very specific to a specific processing case.

So z. B. in DE-OS 2734644 describes an apparatus for the production of packaging material made of plastic, in which the cutting and welding of the film to a packaging bag open at least on one side by means of a welding roller, on which a welding wire is arranged.

DE-AS 2127873 describes the production of objects of certain contour from film by attaching cross-seams on one-time folded plastic webs. In DE-OS 2550464 and DE-OS 2811244 methods and devices are described in which the desired shape is achieved by welding the film by means of ultrasound. In the manufacture of articles of all possible shapes by welding and separating out of film webs often occurs the problem of bonding the finished products with the rest of the film.

In DE-OS 3129424 is offered as a solution to this problem, a repeated separation of the finished products by so-called dividers.

It is also known that in complicated, asymmetrical structures often an unfavorable ratio of finished product to residual film occurs. Relatively large amounts of residual film accumulate and must be made technologically manageable.

For this purpose, DE-PS 2921109 a Folienrestwickelvorrichtung is presented.

In order to achieve a better, optimized utilization of the film web in practice, the contours of objects that should have at least one open side as a finished product, also often arranged on the film web that the surrounding are surrounded by residual film. This requires that the desired opening in a later, additional operation, ζ. Β. by cutting, must be made.

If wire, strip or similar material is used as the welding tool, the type of attachment of this band or the holder in the desired contour must be exactly matched with the required welding temperature in order to prevent "buckling" of the contour due to temperature-induced longitudinal expansion of the welding tool material.

Although this relatively narrow temperature range then allows the execution of perfect welds, but not a self-cleaning of plastic film residues of the welding tool by burning, as this much higher temperatures are required.

Therefore, often has to resort to a time-consuming mechanical cleaning of the welding tools.

Object of the invention

The object of the invention is to provide a device with which one, two or more unilaterally open articles bounded by two or more plastic film layers can be manufactured economically and technically favorably compared with the prior art.

The Enprodukt should be accurate and can be made so reproducible that reliability checks

be limited to random samples. The finished product should no longer require reworking. ,

The production process should be interrupted by no time-consuming mechanical cleaning of the device of plastic residues.

Explanation of the essence of the invention

The technical object of the invention was to handle a plastic film using known technical methods of transport, welding and cutting so that hollow body-like articles, the outer contour of which has at least one open side produced in a work cycle material saving, fast and consistently good quality can be.

Above all, the quality requirements include dimensional accuracy and density, smooth and tear-resistant edges of the articles. An essential part of the technical object of the invention is a prevention of re-bonding of the finished products with the remaining film after separation, a realization of self-cleaning of the welding tool of plastic residues and a process-favorable handling of the remainder of the film.

According to the invention the object is achieved by the following structural design. By a system of transport rollers and clamping devices rolled up on a roll multilayer or longitudinally folded plastic film is transported between two plates and locked there.

In the fixed lower plate of the device, the desired contour is incorporated with the later open side of the article at right angles to the film transport direction in the form of a continuous incision defined width. The lying within the contour part of the plate is mounted in two pivot points so that it can be moved both within certain limits parallel to the lower plate down as well as herausschwenkbar out of the plate. The edges of this inner plate are rounded. On the top plate is congruent with the bottom plate of the same, the outline outlining continuous notch of defined width. The part lying inside the contour is also separately adjustable in relation to the rest of the top plate. In the top plate resilient hold-down are arranged at certain points. Above the top plate is another plate, which is connected to the top plate by means of springs. At this plate is fixed with a certain system of fixed points and Lospunkte or guided continuous heating tape attached as a welding and cutting tool. The guide of this heating tape is exactly in the middle of the incisions, which are located on top and bottom plate. The incisions of upper and lower plate and the heating tape are out of the actual contour out again over the entire width of the film to be processed. Below this interface is a mechanically operated blow bar. -

There are tension springs at both ends of the heating cable. The processing of the film to the finished end product with the device according to the invention takes place in a work cycle with the following steps:

Assignment of the lower plate with the film folded along its longitudinal path, so that the resulting open side of the film is on the side of the lower plate on which the openings of the article are to be later.

The film width is less than the width of the lower plate. This ensures that the connection between several contours is outside the film.

Lowering the top plate and its associated overlying plate on the foil-covered bottom plate. In addition to the pressure of the superimposed plates takes place by the resilient hold-down ah certain points along the contour of an exact positional fixation of the film. With the very low film thickness would be without downholder an ideally flat surface of both plates, combined with very high surface quality, required for fixing the position. Apart from technological restrictions, this high surface quality in the further process would lead to unwanted "sticking" of the film to the plates.

Due to the overlying clearances of the top and bottom plate heated to a certain temperature heating tape is passed through the film. The type of tape attachment guarantees a vertical immersion of the tape in the film.

Immediately after the immersion of the heating tape in the film, the inner part of the top plate and the underlying inner part of the lower plate is driven so by a small distance parallel down that the enclosed by the plates part of the film from the plane of the remaining film is brought, but at the same time still in contact with the heating tape. By this procedure and by the smooth clamping and fixing of the film by the hold-down a separation of the finished product is realized by the remaining film to form a smooth, hermetically closing seam. Then the heating tape is extended from the top and bottom plate. Since the two film parts are in different levels, a sticking of the finished product and the remaining film is prevented.

Due to the over the entire width of the film leading part of the heating tape the remaining film lying between the plates is separated from the rest of the film strip and welded the separation point simultaneously with the cutting and welding of the finished products.

Thus, an exact position of the film ends of the remaining film strip is achieved to each other for the next cycle. Since no method of the film ends is provided in different levels in this part of the device, takes place at the Trennbzw. Welding again a mechanical separation by a blow bar, in order to prevent re-sticking of the film ends occurring after separation here also occurring

 Swing out: The inner part of the lower plate with the finished products lying on it is swiveled down by approx. 45C °.

The round edges of the plate cause the Nahtwülste slide over it and the finished products in provided containers, etc. can fall.

In order to guarantee that the finished parts automatically fall out of the device in any case, air nozzles are still mounted in the pivotable part of the lower plate, which allow additional fading of the finished products. Then follows the lifting of the top plate of the lower plate and the clearing of the separated part of the remaining film of the lower plate.

Immediately after the extension of the heating tape from the film, this heating tape is heated to a much higher temperature than the welding temperature. As a result, a burning off of the plastic residues and thus a self-cleaning of the heating tape.

The length expansion occurring is compensated by the system of fixed and Lospunkten and by the two tension springs at the beginning and at the end of the heating tape so that on straight sections no "buckling" of the tape takes place and the expansion thus effective only in the curves of the contour becomes.

embodiment

Reference to the drawings, an embodiment of the invention will be explained in more detail. The following details of the device are shown.

Fig. 1: Apparatus for the production of plastic foil gloves Fig.2: Cooperation of the upper and lower plate Fig.3: Fixation of the heating tape

On a roll 1, a number of the desired layers of the longitudinally folded plastic film 2 is rolled up. The plastic film is transported through a system of transport rollers and clamping devices between two plates and locked there.

In the fixed lower plate 3, the desired contour is incorporated with the later open side of the article at right angles to the film transport direction in the form of a continuous cut 4 with a defined width.

The lying within the contour part of the plate is mounted in two pivot points 6; 7, that it can move both within certain limits parallel to the lower plate down, as well as herausschwenkbar out of the plate. The edges of this inner plate 5 are rounded.

On the top plate 8 is congruent with the bottom plate of the same, the outline outlining continuous incision defined width. The lying within the contour part, the plate 9 is also moved separately from the rest of the top plate.

In the top plate resilient hold-down 10 are arranged at certain points.

Above the top plate is an outer plate 11, which communicates with the top plate by means of springs. Attached to this plate is a continuous heating band 14 fastened or guided with a specific system of fixed points 12 and dots 13, as a welding and separating tool. The guide of this heating tape is exactly in the middle of the incisions, which are located on upper sub-base.

The incisions of upper and lower plate and the heating tape are out of the actual contour out again over the entire width of the film to be processed 15. Under this interface is a mechanically operated blow bar 16th

There are tension springs 17 at both ends of the heating tape. In order to streamline the industrial manufacture of protective plastic gloves, a device according to the present description has been built and tested.

The production of two different gloves of different sizes within one working cycle was planned.

The arrangement of the glove contours next to each other and at right angles to the transport direction of the film, a very good utilization of the total film surface was achieved. The hand openings of the gloves lie on the open side of the film simply folded in the transport direction. This eliminates a subsequent cutting of the hand openings.

The thickness of the PE film used is 0.02 mm. Other characteristic values are:

Welding or. Separation temperature: 300 ⁰ C

Self-cleaning temperature: 550 to 600 ⁰ C

Duration of a work cycle: 10s

The operation of the heater, in particular its control is described in DDWP 276754.

The individual operations were linked so that a fully automatic production became possible.

The protective gloves correspond in terms of shape, edge or seam formation, crack resistance and tightness of the requirements and were used without rework. There was no sticking of finished product and residual film after the separation or welding process. Finished product and waste were removed from the device separated in time and space.

Claims (4)

1. A device for the production of unilaterally open, multi-layered or longitudinally folded plastic hollow bodies, which consist of lower and upper plate, in each of which the contour of the article is incorporated congruently as continuous incisions with a defined width, characterized in that the part lying within the contour of the Lower plate is mounted in two points so that it is movable in certain limits parallel to the lower plate down, as well as herausschwenkbar from the plate that the inside of the contour lying part of the upper plate is also adjustable relative to this that on another plate, which experiences by means of springs with the top plate through the film plane. 2. Apparatus for the production of unilaterally open, multilayer or longitudinally folded Kunststoffoiienhohlkörpern according to claim 1, characterized in that the positional fixing of the film between the worktops along the contour to be separated out is realized by mounted in the top plate resilient hold-down. 3. A device for the production of unilaterally open multilayer plastic hollow plastic bodies according to claim 1, characterized in that the separating and welding tool is designed as a metal band and the attachment is effected by a system of fixed and Lospunkten. 4. An apparatus for the production of unilaterally open, multi-layered and longitudinally folded hollow plastic hollow body according to claim 1 and 3, characterized in that before the position fixing elements of the film a franking in upper and lower plate is incorporated, in which also enters the separation and welding tool,