EP0117994B1 - Heat-sterilizable cover and a method for its production - Google Patents

Abstract

Heat-sterilizable blanket which has good thermal insulation properties, which is particularly suitable for use in hospitals, old people's homes and hostel institutions, and which comprises a regularly interlaced double cloth into which a wadding pick is additionally incorporated in piquelike fashion and floats over wide stretches. The upper and lower warps and upper and lower wefts of this blanket comprise plain-woven high-twist cellulosic fiber yarns, while the wadding pick is made of a low-twist synthetic fiber yarn having a linear density of 100-1,000 tex. The blanket is shrunk to its final dimensions by washing and drying at temperatures of 100 DEG to 135 DEG C., which at the same time bulks up the blanket and increases its pore volume.

Description

The present invention relates to a heat-sterilizable blanket which is characterized by good thermal insulation properties and preferably also by light weight and is intended for use in hospitals, homes, in particular old people's homes, shelters, etc., and a method for producing this blanket.

Blankets that are to be used in hospitals or hostels must on the one hand have at least one surface that can be sterilized and on the other hand have good heat insulation properties in order to be able to cope with a blanket at normal room temperature. Up to now, the ability to sterilize the surface by heat or a cooking process with simultaneous, good thermal insulation ability could only be achieved by applying suitable sterilisable coverings, which increased the weight of the blanket and meant a lot of work when it was changed frequently. This increased weight plays a major role especially in hospitals and old people's homes, since patients who are sensitive to pressure, particularly on the extremities and who cannot tolerate heavier blankets, must also be cared for here. The requirement for light weight and good thermal insulation capacity has so far not been compatible with the requirement for skin friendliness and good absorbency, which can only be met by a surface made of cellulosic fibers.

From AT-B-191812 ceilings, consisting of two woven outer layers and a weft thread in between, have become known, which have good heat insulation properties due to voids between the outer layers. The outer layers are loosely woven, thick yarn made of material that is usually used for blankets, possibly also made of cotton. Dimensional stability is given to the blanket by the interposed weft of a twine, the tensile strength of which is higher than that of the yarn from which the outer layer is formed, which is interwoven with the outer layers at regular intervals under tension. If the tension is released after completion, the filling section contracts and creates the cavities that determine the thermal insulation. The disadvantage of such blankets is that the heat insulation capacity only remains as long as nothing changes in the tension ratio between the filling section and the outer layers, for example during washing processes.

DE-A-28 50 474 is also the construction of a double fabric made of synthetic fibers, the z. B. for ski clothing can be used in which a filler weft between two fabric layers. a. is integrated like a pique at regular intervals and has a latent ripple. This crimp is developed by a wet finish following manufacture and then fills the voids between the layers. Cookware and sterilization of such materials is naturally not intended.

The present invention has for its object to provide a blanket which can be heat sterilized as a whole, and without a separate coating, by washing at the cooking temperature and drying at a correspondingly high temperature, and yet with such a good, also over numerous, washes resistant, thermal insulation ability that it can be used as a single blanket at normal room temperature and does not require another heat-insulating cover. It should also be absorbent and skin-friendly and preferably have a light weight in order to also be suitable for sensitive patients.

This task could be solved by a blanket in which a slightly twisted, uncrimped filler weft made of a synthetic fiber yarn is pique-like integrated in a double fabric with a hard-wearing upper and lower layer made of cellulosic fibers, whereby this blanket bulges, especially after washing and thereby has good thermal insulation properties.

The present invention accordingly relates to a heat-sterilizable blanket with good thermal insulation properties, in particular for use in hospitals, homes or hostels, consisting of a regularly tied double fabric with an interposed filling weft, which is fixed at regular intervals by a pique-like binding of the two layers of the double fabric that the upper and lower layers of the double fabric consist of strong twists woven from plain weave made of high-strength cellulosic fibers and that a slightly twisted, uncrimped synthetic fiber yarn with a thickness of 100 to 1,000 tex serves as an interposed filler that floats over long distances.

With this new type of ceiling construction, both the top layer and the bottom layer consist of a skin-friendly, absorbent material, so that a coating is no longer necessary. A cotton thread is preferably selected for these layers, and for decorative reasons the top layer can also be kept in a color that is true to cooking.

The thermal insulation ability of the blanket according to the invention is imparted by the intermediate filling weft, which can move freely over longer distances within the double fabric due to the selected pique-like weave and therefore after the first boil washing, in which both the cellulosic fibers and that for the filling weft used synthetic fiber yarn shrinks, bulges and gives the blanket the desired thickness while increasing the pore volume. This bulking effect is particularly pronounced when the synthetic fiber yarn, which is not crimped and has no latent crimp, has a thickness of 200 to 500 tex.

All synthetic fibers that can be used for textiles, such as, for example, polyester fibers, polyacrylonitrile fibers or polyvinyl chloride fibers, are suitable as material for the synthetic fiber yarns to be used according to the invention as filler. However, since a further requirement for the blanket according to the invention is light weight, it is advisable to choose synthetic fibers with the lowest possible specific weight. Yarns made of polypropylene have proven particularly useful here, since they are not only very light, but also have a very good building effect. Polypropylene yarns with a thickness of 250 to 333 tex are particularly preferred as fill weft.

As already mentioned, it is essential for achieving the bulking effect that the filling weft remains unfixed between the two layers of the double fabric over longer distances. This "floating of the filling weft is achieved by the choice of the pattern of the pique-like weave, whereby cavities, that is, areas in the ceiling in which the upper and lower layers of the double fabric do not adhere to one another, which have a minimum length of 5 mm in the weft direction, should be created .

These cavities are best obtained when choosing a waffle pique weave, with it being particularly preferred to choose a waffle pique that is stretched in the warp direction from the weft direction. This means that the cavities in the warp direction preferably have a length of over 5 mm, for example about 1.8 to 2.5 cm. However, other bonds are also suitable which produce hollow tissue-like character by filling filler insertion.

An example of a double-woven construction with a pique-like filling fill that has proven particularly useful for the blanket according to the invention can be seen in FIGS. 1 to 4. In these figures, 1 means the top wefts, 2 the bottom wefts, 3 the top warps, 4 the bottom warps and 5 the fill wefts. The dashed and solid lines each show the threads in longitudinal section, the circles indicate the threads in cross-section, with the numbers in the circles indicating the number of weft and warp threads. Figure 1 shows a chain cut after the binding cartridge at a point where the topstitching 6, which is the pique-like character, can be seen. This section shows the 1st, 2nd, 3rd and 4th weft as well as the 1st to 24th warp. The warp cut shown in FIG. 2 was carried out on the 5th to 8th weft thread and again extends over the 1st to 24th warp thread. With this cut there is no stitching. but to see the 9th and 10th filling weft 5. From this cut one can see the floatation of the filling weft 5. FIG. 3 is a weft cut at the 1st to 4th warp thread, which extends over the 1st to 8th weft thread. Here you can see both the topstitching 7 and the 9th and 10th filling section 5. From the 5th to the 24th warp thread, the weft cut gives the picture which is shown in FIG. 4. The filling weft threads 5 and their free floatation can also be seen here, but no stitching. As can be seen from these figures, the fabric formed from upper weft 1 and upper warp 3 or lower weft 2 and lower warp 4 remain unattached over long distances, which together with the floating filling weft 5, which shrinks when washed at cooking temperature, gives the building effect.

Another object of the present invention is a method for producing the heat-sterilizable blanket according to the invention. according to the upper weft and upper warp as well as lower weft and lower warp, each made of firm twine from cellulosic fibers, which are bound in plain weave, together with the uncrimped synthetic fiber yarn of a thickness of 100 to 1,000tex as filler weft to be processed into a regularly tied double fabric with an additional pique-like integrated weft weft . Since both the cellulosic fibers and the synthetic fibers used for the filling weft shrink during cooking, the subsequent shrinkage must be taken into account when choosing the dimension of the raw blanket. Most of the time you can assume that. that after a maximum of 10 washes at cooking temperature and subsequent drying at 100 to 135 ° C, for example in a tumbler, the final dimension of the blanket has set. At the same time, the building effect also occurs, which is particularly favorable for polypropylene as a material for the filling weft, so that blankets of a thickness of about 3 to 5 mm can be obtained, although in principle they consist of only two layers of cotton. Usually the shrinkage of the blanket is about 9 to 12% in the warp direction by the first cooking treatments, but in the weft direction it is about 13 to 17%. Of course, it depends on various conditions, such as pretreatment of the cellulosic fiber, the nature of the yarns, the size of the pique pattern, etc., and must be predetermined for each specific material combination by a test if the dimensional accuracy of the blanket is important. The advantage here is that to achieve the bulking effect not a separate operation or special equipment is necessary, but that it occurs in the usual, carried out for sterilization laundry and reaches such a state with repeated washing, which does not occur after frequent further washings changed more.

The yarns used can be done by everyone Chen spinning process generated. For the cellulosic fibers, for example, a yarn size of about 85 to 25 tex, preferably about 30 tex, can be used. The yarn for the filling weft can also be produced on conventional spinning machines, such as open-end spinning machines or ring spinning machines, wherein excessive twisting or twisting should be avoided, since the yarn would otherwise crimp, which is undesirable. The woven raw blanket can then be edged in any conventional manner, such as quilting or binding.

The blanket according to the invention offers significant advantages, in particular in companies in which a frequent change is required. Above all, there is complete hygiene, since the entire blanket can be boiled out after every change. It also helps to save work because it can be used without any coating due to its washability and skin-friendly features. If it is carried out with polypropylene as a filling shot, it is very light with good thermal insulation properties, so that it is well tolerated by sensitive and frail people, for example seriously ill or injured patients in hospitals or inmates of old people's homes. The absence of a coating is also a significant advantage in terms of weight. Due to the type of weaving technique, the blanket is also porous and therefore breathable. After all, it is characterized by its particular durability, because no easy-to-remove quilting is necessary and the surfaces can be made from sturdy threads that can easily handle many washes.

Claims (10)

1. Heat-sterilisable blanket having good thermal insulation properties, in particular for use in hospitals, homes of hostelries, consisting of a regularly interlaced double cloth with a wadding pick in between which is held in place by a piquelike binding of the two layers of the double cloth at regular intervals, characterised in that the upper and the lower layers of the double cloth consist of plain-woven high-twist yarns of high-tenacity cellulosic fibres and the intermediate wadding pick which floats over wide stretches is a low-twist uncrimped synthetic fibre yarn with a linear density of 100 to 1 000 tex.

2. Blanket according to claim 1, characterised in that the wadding pick has a linear density of 200 to 500 tex.

3. Blanket according to claims 1 and 2, characterised in that the wadding pick consists of polypropylene yarn.

4. Blanket according to claim 3, characterised in that the wadding pick has a linear density of 250 to 333 tex.

5. Blanket according to claims 1 to 4, characterised in that the upper and lower wefts and the upper and lower warps consist of high-twist cotton yarn.

6. Blanket according to claims 1 to 5, characterised in that the binding produces hollow spaces which are at least 5 mm long in the weft direction.

7. Blanket according to claim 6, characterised in that it is bound in a honeycomb pique weave.

8. Blanket according to claim 7, characterised in that the hollow spaces formed by the honeycomb pique binding have a stretch in the warp direction relative to the weft direction.

9. Process for manufacturing the heat-sterilisable blanket of claims 1 to 8, wherein a double cloth is produced with intermediate wadding pick which is held in place by a piquelike binding of the two layers of the double cloth at regular intervals and shrinkage and bulking thereof by subsequent wet treatment, characterised in that the upper weft and upper warp and also the lower weft and lower warp of the double cloth consist of high-twist yarn of high-tenacity cellulosic fibres which are bound in a plain weave, and the wadding pick used is a low-twist uncrimped yarn of synthetic fibres having a linear density of 100-1 000 tex, in particular a polypropylene yarn, the piquelike binding being effected at intervals, and in that the wadding pick floats over wide stretches, and in the weaving process there is chosen a dimension which allows for the shrinkage of the cellulosic fibre material in the course of the heat sterilisation, whereupon the unfinished blanket thus obtained is subjected to subsequent repeated boil-washing and drying at temperatures of 100 to 136C, which steps are chiefly done in the course of the use of the blanket and have the effect of shrinking the blanket to its final dimension and at the same time of bulking it up owing to the different shrinkages of the two types of fibre.

10. Process according to claim 9, characterised in that the dimension of the unfinished blanket is chosen to be greater than the ultimately desired measurements by about 9 to 12 % in the warp direction and by about 13 to 17 % in the weft direction.

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