Hairnets

Abstract

A hairnet 1 having a body portion and a terminal edge portion E, the body portion having a thread density X, the edge portion comprising at least two bands (4, fig.1) of material with thread density o

Description

Hairnets This invention relates to hairnets, specifically, although not exclusively, to hairnets usable in industry, for example the food preparation industry. Food safety and hygiene regulations in the UK, Europe and elsewhere require food businesses, that is businesses involved with, inter alia, food preparation or dispensing, to carry out food-related operations in a hygienic manner. It is a usual requirement that associated food safety hazards are identified and effectively controlled. Hazard Analysis and Critical Control Point (“HACCP”) principles are a widely accepted method of optimising food safety by examining all stages of the food operation to identify critical aspects and implement effective control and monitoring procedures. HACCP is a preventative system and hairnets frequently form part of the control measures in relation to hair containment. Although legislative requirements for food hygiene and extensive use of HACCP principles exist, there is no prescription of the exact requirements for the head and hair. Regularly the matter is addressed through business-specific, food safety guidance documents issued by food producers to their operatives. Often under references to personal hygiene, instructions about head hygiene and the choice of protective wear typically are scant and unqualified. That said, the general approach is to use hairnets and hats to contain hairs, thereby to prevent them from falling from the head and potentially becoming a contaminant. There are current industry movements towards a greater amount of containment, for example using a hat and a hairnet, using two hairnets and / or hairnets of much closer weave than has hitherto been deployed. It is well established procedure that hairnets worn for hygiene purposes should not be re- used and, as best practice, should be replaced on a regular basis. Food production companies will often source a single type of hairnet. Therefore, the move towards using plural types of head / hair protection to minimise hair contamination is unwelcome. It has recently been reported that the average adult sheds between 100 and 150 hairs every day at a constant rate of shedding. This has led to the suggestion that plural hair nets should be worn to ensure optimum containment. In order to achieve such containment of hair it has been suggested to use a first hairnet in contact with the hair and a second hairnet or haircap over the net, the two being of different density and structure. Hairnet design is increasingly moving towards caps with smaller aperture sizes, indeed, some current hairnets have aperture sizes that are so small as to be not visible to the human eye. Such hairnets have or give the appearance of a knitted cap. The aim of such small aperture hairnets is to encourage total flattening of the hair against the scalp and to seek to reduce the number of hairs protruding through the apertures of the hairnet. Whilst we do not agree that hair is shed at a constant rate we also believe that the above- identified solution is sub optimal for many reasons. Firstly, it increases the stock requirement on the user company. Secondly, it drastically increases the cost of hair containment. Thirdly, it leads to serious compliance issues (i.e. it is complicated for the wearer to use) and fourthly it decreases the airflow to the scalp. The last of these reasons is particularly problematic. The greater the reduction in airflow to the head, and particularly the scalp, the more a wearer's head is likely to heat up. An increase in temperature at the scalp will increase the likelihood of sweating and / or irritation. With an increase in sweating and / or irritation the wearer becomes more likely to touch his or her head (e.g. to scratch or rearrange the hairnet). Hairnets are typically made from polymeric yarns (e.g. polyamide, polyester or polypropylene yarns) and, as such, are made from materials which are inherently impervious to water. As will be appreciated, increasing the basis weight of the hair net, for example by using a hairnet of a denser weave or using two hairnets, increases the likelihood of sweating and / or other discomfort. Scratching increases the likelihood that hairs will dislodge from the head. Accordingly, we believe that the current thinking in hairnets (increased containment by doubling up hairnets or providing hainet / haircaps) is likely to exacerbate the issues of hair contamination. It is an object of the current invention to alleviate or mitigate one or more problems associated with the prior art. Accordingly, a first aspect of the invention provides a hairnet comprising knitted yarn, the hairnet comprising an antimicrobial agent. A second aspect of the invention provides a hairnet having a body portion and a terminal edge portion, the body portion providing a majority of the coverage area of the hairnet and having a thread density X, the edge portion comprising at least two bands of material with a thread density of X or greater each adjacent band being separated by a separation band with a thread density of less than X. The body portion and / or terminal edge portion may be formed from a yarn having antimicrobial properties, for example comprising an antimicrobial agent. A third aspect of the invention provides a hairnet having a body portion and a terminal edge portion, the body portion providing a majority of the coverage area of the hairnet and comprising wales, the terminal edge portion having guide points to allow the wearer to align the hairnet with the front and rear of the head, wherein with the hairnet aligned the wales run from the front to the back of the wearer's head. The body portion and / or terminal edge portion may be formed from a yarn having antimicrobial properties, for example comprising an antimicrobial agent. The antimicrobial agent may be primarily an antibacterial agent. The antimicrobial agent may be selected from one or more of a metal or metal salts, (for example silver, copper, zinc, cobalt, titanium, tin, antinomy), silica, quaternary ammonium salts, halogenated organic compounds (for example 2,4,4-hydrophenyl trichloro (Il) ether — sold under the trade name Triclosan (RTM)). The antibacterial agent is preferably active against both Gram positive and Gram negative bacteria. The hairnet or at least one yarn thereof may be coated in an antimicrobial (e.g. antibacterial) agent. Additionally or alternatively, at least one yarn may include the antimicrobial (e.g. antibacterial) agent. Preferably, the antimicrobial (e.g. antibacterial) agent is retained on or within the at least one yarn, for example, so as to inhibit transfer of the antimicrobial (e.g. antibacterial) agent to the hair / scalp of the wearer in use. The yarn may comprise a sheath and core, the antimicrobial (e.g. antibacterial) agent being preferably distributed at or towards the core. The hairnet preferably comprises one or more of a yarn having a specific weight not exceeding 1000kg / m®, preferably not exceeding 950kg / m? a decitex not exceeding 5, and preferably not exceeding 3.5 (i.e. 0.35g / km of yarn), an index of water vapour permeability of at least 0.25 and preferably at least 0.35 (imt), a moisture absorption index of less than 0.2%, preferably less than 0.1% at air humidity 65% and temperature 20°Celsius and moisture transport capability to a level of at least 2, preferably at least 3.75mm / s. Preferably, the hairnet has a wale density of from 2.76 to 4.72 / cm (7 to 12 per inch), and most preferably from 3.14 to 3.94 / cm (8 to 10 per inch). At these wale densities a wearers’ finger-tips are prevented from making contact with the hair and scalp beneath the hairnet as the curvature of the finger-tip sits on the wales themselves. According to the invention, the wales may be knitted of yarn comprising an antimicrobial agent which mitigates risk of bacterial transfer whilst the finger tips are in contact with the wales during unwelcome but inevitable touching of the hairnet by the wearer. Moreover, airflow to the scalp is also satisfactorily promoted at such wale densities. The hairnet may comprise apertures of from 0.5 to 10 mm, more preferably from 1 to 5mm, and most preferably in the range of from 2 to 4 mm. It is advantageous to have larger apertures to encourage airflow to the hair and scalp. We have found that an aperture size of 1 to 5 mm, say 2 to 4mm and most preferably 2 to 3mm, is particularly advantageous because such an aperture size provides a physical antimicrobial (e.g. antibacterial) barrier between hand and hair and / or scalp to reduce the likelihood of direct contact whilst ensuring sufficient airflow. A further aspect of the invention provides a method of knitting, for example forming a hair net, the method comprises providing a knitting machine having four bars and at the periphery of an article to be knitted and knitting using the first and second bars to form a periphery with in succession a first knitted band with a first density a second knitted band with a second density and a third knitted band with a third density, wherein the first and third densities are higher than the second density and either a) using a third bar to lay in elastic into one or both of the first and third knitted band, and / or b) using a fourth bar to increase the density of threads in the first and / or second knitted band in the area of the respective band or bands adjacent or proximate the second knitted band. Therefore, the hairnet of the invention is particularly advantageous insofar as it (i) preferably has a mesh size that facilitates and encourages air flow to the hair and / or scalp (thereby increasing or maintaining user comfort), (ii) it preferably has a mesh size chosen to provide a physical barrier between the hair and a wearer's hand, and (iii) it provides a microbicidal / antibacterial or microbiostatic / bacteriostatic environment to prevent or reduce the likelihood of bacterial transfer via the hand. In order that the invention may be more fully understood, it will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a plan view of a portion of a hairnet according to the invention; and Figure 2 is a side elevation of a wearer wearing the hairnet of Figure 1. A matter which has received little attention within food industry hygiene manuals is the escalated hygiene risk caused by uncomfortable headwear. In particular, occlusive headwear that restricts air flow around the hair directly raises the temperature of the scalp leading to user discomfort. Discomfort brings a heightened risk of fidgeting and scratching by the user, who can self-dislodge hair that would otherwise most likely remain stably attached. Secondly, minor levels of heat build-up promote exponential bacterial growth on the scalp, hair and by consequence the headwear itself. Occasions of touching the hair, scalp and hairnet by the user boosts the risk that the food operative personally becomes a direct source of food contamination. Staphylococcus aureus (“S. aureus”) are Gram-positive bacteria commonly found in the hair and ear areas of the human body. It is estimated that staphylococci are present in 50% or more of healthy people. They have the ability to produce highly heat-stable enterotoxins that cause gastroenteritis in humans. Symptoms of S. aureus enterotoxins include nausea, vomiting, diarrhoea, loss of appetite, severe abdominal cramps and mild fevers. Outbreaks are often linked to food handling. For the most part strains of S. aureus are highly tolerant to salts and sugars. Staphylococcal enterotoxins are single-chain proteins that can move through the human digestive tract without breaking down due to their resistance to proteolytic enzymes such as pepsin and trypsin. They are one of the most resistant non- spore forming human pathogens and represent a common hazard to a wide variety of food types. These include but are not limited to meat and meat products, salads, bakery products, sandwich fillings, dairy products including milk, poultry and egg products. Accordingly, scratching of the head can cause bacteria to be transferred from the head to the hand. This is particularly problematic in food preparation industries and may be exacerbated by focussing on containment as a means of reducing hair contamination, as set out above. Referring now to Figure 1 there is shown a portion of a hairnet 1 which is knitted from a continuous yarn 2 which comprises an antimicrobial agent, for example the yarn may be formed from a polymer which is doped with an antimicrobial agent, for example a polyester, polyamide or polypropylene yarn with an antimicrobial agent provided within the structure of the yarn and / or provided on the exterior surface of the yarn. We prefer the antimicrobial agent to be distributed within the structure of the yarn by capable of exhibiting antimicrobial / antibacterial behaviour. In a preferred embodiment the antibacterial agent is silver (either elemental or as a salt) and the yarn is formed from polypropylene. Whilst any knitting pattern with a suitable inter-wale distance can be used to form a hairnet 1 of the invention, we prefer to use a pattern which generates plural aligned (e.g. parallel) wales 3 with an inter-wale distance X of 2 to 4 mm (i.e. a preferable wale density of 7 to 12 per inch), and most preferably and inter-wale distance X of 2.5 to 3.2 mm (i.e. a preferable wale density of 8 to 10 per inch). As with most hairnets, our hairnet 1 has a main body portion B and a distal edge portion E. The edge portion E of the hairnet 1 comprises one or more terminal bands 4 of a relative closer mesh interspersed with intervening bands of relatively looser mesh 5. As shown there are three terminal bands 4 and two intervening bands 5. The distal terminal band 4d comprises one or more elastic threads 6. The hairnet 1 may be worn on the head as shown in Figure 2. As can be seen the edge portion E is intermittently bound together at points P, which are preferably worn at the front and rear of the wearer's head. Typically the hairnet 1 will be worn over and covering the wearer's ears. As can be seen, the points P conveniently allow a wearer to locate the hairnet 1 in alignment with their head. With the points P located as shown with one below where the forehead is superiorly delineated by the hairline and one at the base of the back of the head below where the hairline meets the neck 6. The wales 3 of the body B (indicated by dotted lines) will run in lines from point P to point P and the terminal bands 4 will lie along the wearer's hairline. We believe that the provision of the terminal bands 4 at and along the wearer's hairline is particularly advantageous because it affords greater hair retention capacity in the area of the hairline which, we believe, is likely to be the candidate site for hair loss. The area where the forehead transitions to the scalp is often reported as a sensitive area. Precisely why this is so does not appear to be consistently agreed. We believe that two distinct skin structures adjacent each other, potential sensitivities to seborrheic dermatitis, stress and drier skin, whether mild or otherwise, combined with more pronounced hair styling all have a part to play in reports of discomfort at the hairline. We consider that the hairline area requires a stronger level of hair holding than is afforded by conventional hairnets in order to mitigate potential aggravation by hairs at the hairline boundary. The terminal bands 4 have the effect of spreading the load on the head over a relatively wide area. Moreover, the intervening bands 5 provide aeration channels at set intervals to enable heat dissipation. The human hairline is not a stable landmark. The, preferably knitted, terminal bands 4 may therefore be of a width that features two or three (or more) distinct sections (separated by aeration channels) in order to promote the opportunity for coverage of the typical hairline. In order to fabricate a hairnet 1 according to the invention, two separate needle bars knit in opposition to each other to produce the body B of the hairnet 1. A further, third bar is used to lay the or each elastic thread 6 at the intended distal edge of the fabric. According to the invention a fourth bar, typically not used in the traditional manufacture of hairnets is utilised. In combination with non-uniform threading of the first and second needle bars (tasked with forming the body of fabric) or by separately and non-uniformly threading of the fourth bar alone, knitting is adapted to create the terminal bands 4 and intervening bands 5. We prefer to fabricate the hairnet 1 of the invention using typical knitting patters for the body B using two needle bars as is known. The edge portion E is formed by using set threading in the first and second machine bar, the bands are achieved using non-uniform needle threading in a combination of thread one, miss one, repeated 5 times, miss one, thread 3, miss 1 repeated twice and thread three, to create the patterning that facilitates the aeration channels; this is supplemented by a third bar laying in elastic and a fourth bar of knitting that achieves more dense knitting adjacent to the aeration channels by use of a needle threading combination of thread one, miss one, repeated seven times, miss two, thread one, miss one, repeated three times, miss two, thread one, miss one, repeated three times. As will be appreciated by the skilled person other patterns may be possible to achieve the objective. The fabric of the edge portion E is bound together at intervals P. This can be achieved by ultrasonic welding equipment which uses high frequency sound waves to cause rapid vibrations in the material, causing friction that raise temperature and enable bonding. Alternatively, the fabric may be knotted using industry specific equipment to apply either a knot or metal staple, both of which equipment types require a human operator. After welding, knotting or stapling, a cut is then made to form an individual hairnet. As stated above, there is a current thought process that a human being will shed from 100 to 150 hairs per day, at a constant rate of hair shedding. However, our research indicates that around 90% of human hairs are in a secure growth phase at any given time with the remaining 10% in a resting (telogen) phase. Only during the telogen phase of the life cycle is hair normally lost. At the end of this stage a new hair is formed and if the old hair has not already been shed it may be dislodged by the new hair. Our research indicates that of typical daily hair loss of up to 100 hairs, the majority of hair strands will be removed during the usual processes of washing, drying and brushing, which will typically take place away from any hygiene-critical environment. Within the remaining minor proportion of the 100 hairs susceptible to dislodgement, most are likely to be dislodged if aggravated by physical force. The most likely physical force that a club (old) hair on a human head will encounter in the food production area is hands used to scratch the scalp or adjust the hair due to headwear discomfort. Maintaining normal airflow around the scalp is vital to avoiding discomforts that lead to physical aggravation and ultimately a higher risk of an old, loose hair becoming a potential contaminant. Thus focussing on containment is likely to lead to both increased dislodgement (via increased ‘scratching’ incidents) and increased bacterial spread (via increased hair touching incidents). The hairnet of the invention is also advantageous insofar as in the unlikely event that a hairnet falls onto a product being prepared, the presence of the antibacterial agent will limit the transfer of bacteria onto or into the product. Accordingly, rather than containment, our research contradicts this prevailing thought and provides an alternative (and contradictory) methodology to reduce hair dislodgement and bacterial spread.

Claims

Claims 1. A hairnet having a body portion and a terminal edge portion, the body portion providing a majority of the coverage area of the hairnet and having a thread density X, the edge portion comprising at least two bands of material with a thread density of X or greater each adjacent band being separated by a separation band with a thread density of less than X, the body portion and / or terminal edge portion is preferably formed from a yarn having antimicrobial properties.

2. A hairnet according to Claim 1, wherein the yarn is coated with or contains an antimicrobial agent.

3. A haimmet according to Claim 1 or 2, wherein the antimicrobial agent is an antibacterial agent.

4. A hairnet according to any of Claims 1, 2 or 3, wherein the antimicrobial agent is selected from one or more of a metal or metal salts, (for example silver, copper, zinc, cobalt, titanium, tin, antinomy), silica, quaternary ammonium salts, halogenated organic compounds (for example 2,4,4-hydrophenyl trichloro (ll) ether).

5. A hairnet according to any preceding Claim, wherein the yarn has one or more of a specific weight not exceeding 1000kg / m?®, preferably not exceeding 950kg / m?, a decitex not exceeding 5, and preferably not exceeding 3.5 (i.e. 0.35g / km of yarn), an index of water vapour permeability of at least 0.25 and preferably at least 0.35 (imt), a moisture absorption index of less than 0.2%, preferably less than 0.1% at air humidity 65% and temperature 20°Celsius and moisture transport capability to a level of at least 2, preferably at least 3.75mm / s.

6. A hairnet according to any preceding Claim, wherein the body portion has a wale density of from 2.76 to 4.72 / cm (7 to 12 per inch), and most preferably from 3.14 to 3.94 / cm (8 to 10 per inch).

7. A hairnet according to any preceding Claim, wherein the terminal edge portion comprises guide points to allow the wearer to align the hairnet with the front and rear of the head, wherein with the hairnet aligned the wales run from the front to the back of the wearer's head.

8. A hairnet according to any preceding Claim, the hairnet comprising apertures of from 0.5 to 10 mm, more preferably from 1 to 5mm, and most preferably in the range of from2tod4 mm.

9. A method of knitting, for example forming a hair net, the method comprises providing a knitting machine having four bars and at the periphery of an article to be knitted and knitting using the first and second bars to form a periphery with in succession a first knitted band with a first density a second knitted band with a second density and a third knitted band with a third density, wherein the first and third densities are higher than the second density and either a) using a third bar to lay in elastic into one or both of the first and third knitted band, and / or b) using a fourth bar to increase the density of threads in the first and / or second knitted band in the area of the respective band or bands adjacent or proximate the second knitted band.

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