HAND PROTECTION FOR HOT WORKPLACES

Abstract: A hand protection for hot workplaces comprises a heat-resistant outermost textile layer (1) and inwardly thereof a thermal insulation layer (3) consisting of fibres. The glove comprises at least the following layers from the outside to the inside: as the outermost textile layer (1) a fabric comprising fire-protected cellulose fibre alone or in a blend; a microporous waterproof film (2) attached with its surface onto the outermost textile layer, the film serving as a layer protecting from hot steams; and on the inside of the film (2), a non-woven web as the thermal insulation layer (3).

Description: Hand protection for hot workplaces The invention relates to a hand protection for hot workplaces of the type presented in the preamble portion of the attached Claim 1. Protective gloves where the outermost textile layer is metallized on its surface in order to protect from splashing hot materials, for example molten materials splashing in various works of metal industry, are known previously. The problem therein is that the wear resistance of the metal layer is not good, and the breathability of the glove is poor. From International Patent Application publication WO 95/08933 is known a protective garment intended mainly for firemen. The publica- tion does not disclose the use of the garment as a hand protection. The outermost layer is adapted to be movable and expandable upon expo¬ sure to a high heat load. Until now there has not been a hand protection, such as a protective glove expressly for medium-hot (not exceeding 250°C) working range where a direct contact with the hot object is often present and, more¬ over, hot steam is present. Examples of such objects are in particular kitchens and bakeries. In addition to the requirement that the hand protection must be able to protect the hand, it must, for the sake of work duties, operate well in grasping and moving various objects. The object of the invention is to eliminate the drawbacks of previous hand protections and to present a hand protection having good proper¬ ties in view of both work operations and protection for the hand. For ac- complishing this object, the hand protection is mainly characterized by what is disclosed in the characterizing portion of the attached Claim 1. The hand protection comprises three layers in mutual cooperation, namely 1. a fabric formed of fire-protective cellulose fibre as a surface layer, 2. a relatively thin microporous waterproof film attached with its surface on the inner side of the former layer for protecting from hot steams, and 3. on the inside of the former layers a non-woven fabric, that is, a thermal insulation layer formed of fibres and forming at the same time the largest portion of the total thickness of the above-mentioned three layers. The following description and the attached dependent Claims 2 — 11 present further some appropriate embodiments concerning the material of the layers, their thickness and the construction of the hand protection itself. The invention will be described more closely in the following with refer- ence to the accompanying drawings, wherein Figs. 1 — 3 show the material of the protection in cross-section, Fig. 4 shows various variants for the protective glove, seen on the thumb side, Fig. 5 is a side view of the protective glove, and Figs. 6 and 7 are longitudinal and transverse cross-sectional views of the protective glove. Figure 1 shows the basic construction of the hand protection intended for hot workplaces within a medium-hot range. The hand protection is a mitten-type protector having a thumb portion for receiving the thumb and a palm portion for receiving jointly the rest of the fingers. On the top, there is a textile layer 1 forming the contact surface with the objects that are grasped and moved and transferred during the work in a hot workplace. This layer is of a fabric that is formed of a fire-protected cellulose fibre. Inside this fabric is attached by lamination a micro- porous waterproof film 2. Inwardly of the combination of the fabric and film there is the thickest layer of all layers of the layered structure, being more fluffy or spongy than the fabric. The layer is a non-woven web or a felt formed of suitable fibres and constituting a thermal insulation layer 3. It can be loose from the above-mentioned two layers. In the in¬ nermost position, that is against the hand, there is still a thin interior lining 4. Figure 2 shows a variant where the thermal insulation layer 3 is formed of two sublayers 3a, 3b, which are felts containing the same fibre or fi¬ bre blend. Figure 3 shows a variant where the sublayers are felts con¬ sisting of different materials. The constructions according to Figs. 2 and 3 are preferably used in the palm portion of the protective glove, where often a higher thermal insulation capacity is needed. In this case the solution according to Fig. 1 can be applied in the rest of the glove. It is, however, possible to use such a protective glove whose material in all regions is made according to Fig. 1 , in other words, it is formed of the same material. In the following, some advantageous material alternatives of different layers will be presented. The textile layer 1 is a densely woven fabhc formed of cellulose fibres and being fire-protected. The fabric can be for example a cotton fabric which after the weaving has been subjected to dyeing and fire protec¬ tion treatment with some suitable fire protection chemical, for example with a nitrogen-containing chemical based on phosphates. It is also possible to use in the weaving a yarn that has already been fire-pro- tected. Compared with synthetic fibres that are inherently heat-resis¬ tant, reasonable price and sufficient heat resistance within the medium- hot range are the advantages of this material. Another altemative for the textile layer can be a fire-protected polyester-cotton fabric, which can be manufactured by weaving together fire-protected cotton yarn and fire-protected polyester yarn. The film 2 laminated on the inside of the textile layer is a microporous breathable waterproof elastic polyurethane film that is available for ex¬ ample under the trade name "PORELLE". The thickness of such film is typically less than 100 μm, most generally 40 — 70 μm. The film is pref¬ erably fire-protected with a suitable chemical so that its LOI value ex¬ ceeds 24. The waterproofness of the film, expressed as the height of water column, is at least 150 cm and preferably at least 300 cm, and the water vapour permeability at 37°C and at 100 % relative humidity is at least 1000 g/m 2 /24 h, preferably at least 2000 g/m 2 /24 h (determination ASTM standard E96). Under "breathable" film is in this context meant a film preventing the passage of liquid water (and wet steam) but allowing water evaporated in gaseous form from the skin and carbon dioxide to pass through. Also other thin films that have cor¬ responding advantageous properties can be applicable, such as poly¬ ethylene-based microporous films, and they are preferably fire-pro¬ tected. The softening point of the polymer material of the film 2 should be over 250°C. Polyurethane films withstand still a temperature of 280°C. The joint basis weight of the exterior textile layer 1 and the film 2 is preferably in the range of 250 — 400 g/m 2 . For the material of the thermal insulation layer 3, a blend made of sta¬ ple fibres containing viscose fibre incorporating polysilicic acid is most preferably used. A viscose fibre of this type is known, and it is supplied for example by Kemira Fibres Oy under trademark "VISIL". Such vis- cose fibre is produced by adding waterglass into the spinning solution, whereafter the waterglass during the spinning of the viscose will be distributed as polysilicic acid uniformly in the fibre. The viscose fibre as such is a good thermal insulator, and in addition to that, the polysilicic acid content improves its resistance to heat. Blended with the viscose fibre, either regular one or that containing polysilicic acid, there is syn¬ thetic heat-resistant fibre, most generally some aramid fibre (aromatic polyamides), e.g. a fibre sold under the trademark "KERMEL". The pur¬ pose of the synthetic fibre is to increase the fire protection by prevent¬ ing flame propagation. In the place of the "KERMEL" fibre, also other aramid fibres or synthetic fibres can be used. A felt of this kind has a particularly low flammability. Another mixture alternative for the thermal insulation felt is a blend of regular viscose fibre and a synthetic fibre that is not of aromatic polyamide and has a heat resistance of at least 250°C, such as a blend of viscose and polyester fibre (PET). These fibres may have been subjected to normal fire protection treatment. These combinations allow to obtain a felt with insulation capacity in the same class as with for ex- ample a felt of the VISIL/KERMEL type, but with a considerably lower price Polyester fibres have inherently good thermal resistance properties, because the melting point of polyester (PET) determined by differential thermal analysis (DTA) is ca 255°C The proportions of the viscose fibre and blend fibre can vary For ex¬ ample viscose fibre containing polysilicic acid can be present in an amount of 50 — 60 wt-% and the heat-resistance synthetic fibre in an amount of 40 — 50 wt-% The fibres are formed into a felt in manners well-known in textile tech¬ nology, for example in a dry method and by mechanically needling the fibres to each other In addition, the separate sublayers can be at¬ tached to each other by needling In this way the thermal insulation layer 3 is simultaneously given a fluffy or spongy structure The total weight of the thermal insulation layer is most preferably in the range of 150— 500 g/m 2 If the thermal insulation layer 3 comprises two sublayers 3a and 3b of different materials, for example in the way according to Fig 3, one of the layers can be a blend of viscose fibre containing polysilicic acid and of synthetic fibre, for example the aforementioned "VISIL/KERMEL", and the other can be a blend of regular viscose fibre and synthetic non- aramid fibre, such as the aforementioned viscose/PET The former blend is suitable for the layer 3a closer to the exterior surface The interior lining 4 can be of any material suitable for the wear com- fort, for example cotton fabric The film 2 is attached onto the outermost textile layer 1 in such a fash¬ ion that it will be fixed theron evenly with its surface Suitable tech¬ niques can be spot-bonding or paste spot method, where a glue pre- sent in a spot-like fashion between the film and the textile layer is spread during calendering to form a relatively uniform layer Sub¬ stances which do not impair the operation of the film 2 can be em¬ ployed as glues, such as known thermoadhesive substances On the inside of the above-mentioned layered structure, the thermal insulation layer 3 can be secured in such a fashion that it is loose from the inner surface of the film 2 and fixed to the top layer only at some of its edges. Furthermore, the interior lining 4 can be loose from the former layers and fixed to them only at its edge portions. Figure 4 shows the hand protection in the form of a protective glove, the palm piece being denoted with hatched area 5. The protective glove can be made according to predetermined handedness (thumb at side) or for both hands (thumb in the middle). Figure 5 shows the glove schematically as a side view, showing also the corresponding area hatched. As mentioned hereinabove, this piece 5 can have a thicker thermal insulation layer 3 than elsewhere. Figures 6 and 7 show the protective glove as longitudinal and trans¬ verse cross-sections. The figure shows how the thermal insulation layer 3 is fixed along the side seams, and elsewhere it can be loose from the rest of the layers, which allows to achieve the best operation in view of breathability and thermal insulation. However, the thermal insu- lation layer can also be attached to the film 2 by light glueing. Fire behaviour, abrasion resistance, and contact heat tests according to protective glove product standards EN 407, EN 388 and EN 702 were performed with a fabric-topped long-sleeve protective glove. Its outer- most layer was of a fire-protected cotton fabric laminated on the inside with ca. 34 g/m 2 weight and ca. 55 μm thick elastic "F.R. PORELLE 55" fire-protected polyurethane film, on the inside of which there was a VISIL/KERMEL felt (55/45 wt-%) of a basis weight of ca. 200 g/m 2 . In the tests it could be affirmed that the glove fulfills the requirements of the product standards. In a summary, the hand protection according to the invention, the so- called baker's mitten, can be said to fulfill the following requirements by virtue of the material selections: - protection against contact heat 250°C, vapour barrier, inflammable material, hygienic requirements, for example washability, wear comfort, no allergenic materials, and good perceivability (colours, dyeability of the top fabric).

Claims: Claims: 1. Hand protection for hot workplaces, comprising a heat-resistant outermost textile layer (1) and inwardly thereof a thermal insulation layer (3) consisting of fibres, characterized in that it is a protective glove of mitten-type comprising a thumb portion and a palm portion, the glove comprising at least the following layers from the outside to the inside: as the outermost textile layer (1) a fabric comprising fire- protected cellulose fibre alone or in a blend, a microporous waterproof film (2) attached with its surface onto the outermost textile layer, the film serving as a layer protecting from hot steams, and on the inside of the film (2), a non-woven web as the ther- mat insulation layer (3). 2. Hand protection according to Claim 1 , characterized in that the non-woven fabric serving as the thermal insulation layer (3) forms the thickest layer of all layers. 3. Hand protection according to Claim 1 or 2, characterized in that the outermost textile layer (1 ) is of fire-protected cotton fabric, possibly blended with a synthetic fibre. 4. Hand protection according to Claim 1 , 2 or 3, characterized in that the microporous waterproof film (2) is fire-protected. 5. Hand protection according to any of Claims 1 — 4, characterized in that the microporous waterproof film (2) is a polyurethane film. 6. Hand protection according to any of the preceding Claims 1 — 5, characterized in that the microporous waterproof film (2) is attached to the outermost textile layer (1 ) by glueing. 7. Hand protection according to any of the preceding Claims 1 — 6, characterized in that the non-woven fabric serving as the thermal in¬ sulation layer (3) comprises a blend of viscose fibre and synthetic fibre. 8 Hand protection according to any of the preceding Claims 1 — 6, characterized in that the non-woven web serving as the thermal insu¬ lation layer (3) comprises a viscose fibre that contains polysilicic acid 9 Hand protection according to Claims 7 and 8, characterized in that the viscose fibre containing polysilicic acid is blended with aramid fibres 10 Hand protection according to any of the preceding Claims 1 — 9, characterized in that the thermal insulation layer (3) is at its edges fixed to the outer layers, leaving the area in the middle loose from them 11 Hand protection according to Claim 1 or 2, characterized in that the thermal insulation layer (3) of the palm portion (5) of the protective glove is thicker than the corresponding layer in the other pieces of the protective glove, being constituted of one integral layer or two or more sublayers (3a, 3b)

Inventors: KOSMALA HARRI, KOSMALA, HARRI
Applicants: KOSMALA HARRI, KOSMALA KY, KOSMALA, HARRI
Application year: 1996
Main classification: A62B17
IPC codes: A41D19, A41D31, A62B17