WO2010007538A1

WO2010007538A1 - A supported elastomeric glove with enhanced gripping surface and a method of transferring of patterns on to a dipped elastomeric glove surface

Info

Publication number: WO2010007538A1
Application number: PCT/IB2009/051284
Authority: WO
Inventors: Walimuni Sunil Elton Fernando; Lakshman Premal Nethsinghe; Rajapakshe Mudiyanselage Tilokraj Premarathna; Kariyawasam Ampegama Gamage Gamini Kularathna
Original assignee: Dipped Products Plc
Priority date: 2008-07-15
Filing date: 2009-03-27
Publication date: 2010-01-21

Abstract

A semi cured supported elastomeric glove with enhanced gripping surfaces achieved by the method of transferring of patterns by means of compression moulding, comprising of a plurality of concave indentations of any pattern and moulded into the gripping surfaces of the glove. Alternatively, the enhanced gripping surface may be formed as suction cups to enhance the gripping effect further.

Description

Field of Invention

The invention relates to grip enhanced elastomeric gloves and a method of transferring patterns on to an elastomeric semi cured glove surface using an engraved moulding plate, and a flat former using compression moulding technique.

Background of the Invention

Surgical, medical and industrial elastomeric gloves generally have a smooth external finish and due to the surface smoothness they do not have good gripping effects, specially when the surfaces are wet. However, in certain applications it is necessary have greater gripping effects.

Following are some ways whereby such gripping effects are embedded onto the outer surfaces of gloves having a partial or full elastomeric outer surface.

1. Transfer of the pattern from the glove fabricating mould onto the glove

2. Chemical modification of the outer surface of the glove

3. Screen printing of patterns onto the surface of the glove

4. Attaching a pre-cured elastomeric sheet to the glove & etc.,

These methods have following inherent limitations.

1. The process may limit number of patterns possible

2. The process may need expensive waste chemical disposal

3. Patterns may be inconsistent throughout the patterned area

4. As the grip is a direct result of the surface texture of a glove manipulation of the effectiveness of the grip may be limited

5. These methods also may result in gloves with low flexibility

There is a need therefore for an easy method that transfers patterns consistently onto an elastomeric glove surface to render the glove more aesthetically pleasing and / or incorporate other desirable patterns such as company logos or brand names and /or give the glove a higher degree of flexibility and / or give the glove a better gripping ability, also to facilitate better wet grip.

WO 2000/019847 describes a method of producing such grip enhanced gloves by way of a mould that have convex patterns on it so that when a glove is manufactured using dipped process, the glove contains concave indentations that give a gripping effect. Practically, these gripping areas are considerable large and they work good on flat surfaces only and this applies only to a nonsuported glove.

WO 2006/053140 describes a method of producing such grip enhanced gloves by using negatively and positively pattered moulds. In this method, gripping elements could be made very small, but due fact two plates - negative and positive - are used, this method cannot be used to transfer patterns to a supported (using liners made of textile , aramides etc.) gloves.

Summary of the Invention

The present invention provides a Supported Elastomeric Glove with Enhanced

Gripping Surface and a method of transfer of patterns on to a glove outer surface using a preformed moulding plate / mould other than the glove fabricating mould itself without the use of a chemical process. The glove may have a fabric lining with an elastomeric coating or be made of an elastomeric material completely. The pattern may take any shape and any such pattern can be transferred onto the glove using the compression moulding method. The pattern shall be used to enhance the aesthetic appearance of the glove or the functionality of the glove in terms of better grip and / or higher flexibility. The pattern may or may not be uniform throughout the surface. The pattern can either cover the outer surface completely or only part / parts of it. The pattern can also have company logos, brand names or other shapes incorporated into it giving variation in pattern within a glove. The glove may be made of any natural or synthetic elastomer or a blend thereof. The fabric liner may be made of any knitting yarn or made by cutting and sewing.

Detailed Description of the Invention

The invention relates to a method of transferring patterns onto an elastomeric glove surface rendering the glove aesthetically pleasing and having enhanced gripping properties to a supported glove made with a natural or synthetic fiber based liner coated with Natural Rubber or Synthetic elastomer or a blend thereof, consisting of a permanent pattern impression made by a non chemical process on the palm and fingers to improve the grip and other properties related to the usage of the glove. The curing process of the glove is interrupted at stage where gel strength of the glove film is such that it could withstand the compression force without cracking up, or disintegrating . The glove is then removed from the dipping former and dressed on to the flat mould. The surface of the glove is then subjected to compression force to leave desired imprint on the elastomeric surface which will become a special grip pattern.

The special grip pattern on the elastomer can have any design but a series of square depressions which will come into contact with the object handled is recommended for better grip by possibly inducing a suction mechanism.

The gripping surface of the novel supported glove with the moulded grip pattern, described above is designed to attach itself to the surface of the object being handled by using a series of square depressions acting in line with the principle of suction cups. The grip pattern could be of any shape, as per the attached drawing ie square, round, diagonal, star, cross etc as long as it helps to push air out of the said depressions during the gripping process and form a localize vacuum.

This is intended to facilitate better handling of smooth surfaces such as sheet metal, glass sheets etc. The depressions on the elastomer acting like suction cups make gripping more efficient where a better grip could be achieved with a relatively less gripping force.

The flexibility of the elastomer film and uniformity of the pattern created by the moulding process makes functioning of suction cup principle possible.

The introduction of the grip pattern by pressing and moulding the elastomer, using a preformed engraved moulding plate makes it possible for the formation of a series of depressions on elastomer which are very uniform in arrangement and dimensions.

This process eliminates the need to have negative and positive plates as mentioned in the prior art. This process makes it much easier to have wide variety of patterns since only one plate need to be cut where a matching negative plate is not required. This process does not alter the dimensions of the glove, Compression moulding process removes entrapped water, which is also advantageous when energy required for curing is considered, The methods described in prior art cannot be used to make a pattern on a supported glove.

Different types of elastomers can be used such as natural, or synthetic rubber, Polyvinile Chloride, Polyurethene, Acrylic resins, Silicone rubber or any blend of the above.

Preferred embodiment

There is provided according to one embodiment of the present invention a glove with a polycotton fabric lining and a natural rubber partial coating with a preformed moulded pattern. While the following description relates to the manufacture of the said glove it will be understood that the present invention may be applied to the manufacture of any other type of fully elastomeric glove or glove with a fabric liner and a partial or full elastomeric coating. A latex based compound for the elastomer film is made using the accelerators, activators, sulphur which are mixed using high speed stirrers, ball mills. etc.

A textile liner is made by special purpose glove knitting machine of gauge 10 (or 13, 15, 18 or using Whole Garment Technology ™ (WG)) with poly cotton 65:35 yarn. This liner can be replaced with a cut and sewn liner if it is desired. The gloves may be made of any blends of material or any other glove knitting / weaving material or leather.

This liner can be treated with anti-penetrative coating.

The liners are dressed on to a mould. The mould referred to here consists of five fingers, palm and section of arm, where the hand is shaped to suite the dipping operation and is made of Aluminum, Ceramic, or with heat resistant polymer resin. Then the dressed liner is dipped in elastomer to obtain a precise coating of elastomer using special purpose dipping machine or a robotic arm.

The elastomer coated liner is then dried and dipped in a special solvent free compound to increase the gel strength of the elastomer coating for the next process to take place.

A pre designed pattern is engraved on to a moulding plate for formation of grip pattern. A moulding plate is cut using a programmable robot programmed on three axis to cut a precise pattern, having specific length, breadth and depth as shown in Fig. 3. The robot is used to get a precise finish. A moulding plate can be cut also using other conventional tools and techniques, or by a chemical engraving process.

Pattern is cut on a metal plate which has sufficient thickness for cutting and strength to prevent deformation during heating and compression.

If a logo is intended for the glove then in fabrication of the moulding plate, the logo is embeded at the base of the moulding plate. The location of logo is carefully selected so that the logo appears at the base of the palm or elsewhere; which does not hinder the function of the elastomer surface in gripping an object. Alternatively chemical engraving of metal plate is also possible. The engraved plate is fixed to preferably a hydraulically operated pressing machine designed to deliver a specific pre determined force / pressure. The moulding plate could be heated by suitable means to achieve a temperature of around 50 - 100⁰C before pressing is done.

The partially dried / cured supported glove is removed and dressed on to a special moulding plate called a flat former. The flat former is made of a metal plate with sufficient thickness, has five fingers, palm, wrist areas, and called a flat former due to its shape. The glove is dressed onto it carefully. The dressed glove is then placed on the lower platen of the hydraulic press machine and compressed under the engraved plate to make an impression on the elastomer. The pressure is controlled so that the elastomer is not damaged. In engraving the pattern on to the metal plate, care has to be taken to not to have edges too sharp which will cut in to the elastomer of the glove and ruin its performance. This is achieved in designing phase of pattern. The glove with the moulded pattern is then removed from the flat former, washed, and cured completely in a curing oven having temperature controls and moisture management technology. In another embodiment a fully cured glove also could be subjected to compression by a heated die to transfer the pattern to the elastomer.

Description of the drawings

It will be understood that this description of the drawing or the enclosed does not limit the scope of the claims and is detailed as one of the many possible examples.

Fig 1 on the drawings page shows a design of the engraved pattern.

Fig 2 on the drawings page shows some of the patterns which could be incorporated to the glove surface. The possible patterns are by no means limited to those illustrated.

Fig 3 on the drawings page shows the moulding plate.

Fig 4 on the drawings page shows the flat former used in compression moulding.

Fig 5 on the drawings page shows the process of moulding a pattern onto the latex dipped supported glove using compression moulding.

Fig 6 on the drawings page shows a plan view of the previously described glove manufactured using the present invention

Claims

1. A method of transfer of patterns on to an elastomeric semi cured glove surface of a dipped glove using a special moulding plate called flat former which is made of a metal plate with sufficient thickness and using another preformed mould called engraved plate where the pre cured glove is dressed on to the said flat former and is placed on the lower platen of the hydraulic press machine or other means of applying pressure on an engraved plate which can either be heated or not and compressed under the engraved plate to make an impression on the elastomer already dipped or coated onto a fabric liner which results in an enhanced grip.

2. A method as set forth in claim 1 wherein foreign objects such as steel balls, studs may be pressed and moulded on to the elastomer surface in the said process of compression moulding.

3. A method as set forth in claim 1 further including the step of compression moulding, washing and curing the glove with the moulded pattern in a curing oven having temperature controls and moisture management capability.

4. A method as set forth in claim 1 wherein said preformed mould is made using a metal plate which has sufficient thickness for cutting, strength to prevent deformation during the heating and compression which is cut using a programmable robot programmed on three axis or by conventional die cutting methods or by chemical engraving process to cut / engrave a precise pattern, having specific length, breadth and depth as shown in Fig. 3 and also a shaped / contoured moulding plate could also be used to transfer the pattern

5. A method as set forth in claim 1 wherein the said dipped glove which is partially dried / cured is dressed on to a flat former placed inside a hydraulic press machine in which the top platen is fitted with the moulding plate with mould heating facility.

6. A method as set forth in claim 1 wherein said moulding plate transfers the surface pattern to the elastomeric surface of the glove by compression moulding or by any other means.

7. A method as set forth in claim 1 wherein said impression includes lines of natural palm with uniform patterns which may be of any kind as showed in FIG 2 and the shape of the said depression / pattern is changed to easily eject dirt and fluid and to improve grip.

8. A method as set forth in claim 1 wherein said dipped supported glove (base glove) is made with a fabric lining and an elastomeric coating, or else the glove could be made solely of elastomer in which case it is called an unsupported glove.

9. A method as set forth in claim 1 wherein said fabric lining is made by special purpose glove knitting machine of gauge 10 (or 13, 15, 18 or using Whole Garment Technology ™ (WG)) with poly cotton 65:35 yarn which can be replaced with a cut and sewn liner if it is desired and may be made of any blends of material or any other glove knitting / weaving material or leather.

10. A method as set forth in claim 1 wherein said elastomeric coating is made of solid rubber which is masticated dissolved in solvent or latex, accelerators, activators, sulphur which are mixed using high speed stirrers, ball mills etc. and the base material for the elastomeric coating may be natural latex, or combination of synthetic latex compound such as Polyvinile chloride, Polyurethene, acrylic resins Silicone rubber or blends of compounds. The said elastomeric compound may be of any color or combination of colours whereby the fabric liner is dipped in the elastomer compound to obtain a precise coating of elastomer using special purpose dipping machine.

11. A method as set forth in claim 1 including the step of treating the fabric liner with anti-penetrative coating before the elastomer dipping takes place.

12. A method as set forth in claim 1 further including a step of drying and dipping the elastomer coated glove in a special solvent free compound, subsequent drying to increase the gel strength of the elastomer coating before the moulding process takes place.

13. A supported elastomeric glove manufactured without the use of a chemical process according to the process as claimed in claim 1 and claim 9.