The term dry sterilisation process, DSP, denotes a dry aseptic sterilisation process. It is used for instance in the beverage industry during cold aseptic filling of beverages (juices, waters, UHT-milk, etc) into plastic bottles made from PET or HDPE, and also for some applications in the pharmaceutical industry.
In cold aseptic filling the sterile or near-sterile product is filled into a bottle which has to be sterilised prior to bottling to avoid product contamination. Due to the heat-sensitive nature of the plastic material the sterilisation process must not heat the bottles. Therefore chemical sterilisation processes are used for this purpose. The Dry Sterilisation Process uses an aqueous solution of hydrogen peroxide (H2O2) with a concentration of 30...35% to achieve the germ-killing effect.
Procedures
At first the bottles are placed into a sterilisation chamber. This chamber is designed to be a vacuum chamber and is evacuated by vacuum pumps down to the low vacuum range. A certain amount of aqueous solution of hydrogen peroxide is now delivered to an evaporator and abruptly evaporated. Driven only by the pressure difference between the hydrogen peroxide vapor inside the evaporator and the evacuated sterilisation chamber, the vapor flows through an appropriate piping into the sterilisation chamber. The vapor is strongly expanding when it enters the chamber, undercooled thereby and instantaneously condensing. The forming condensate layer is covering all surfaces inside the sterilisation chamber, all inner and outer bottle surfaces and all surfaces of the chamber itself.
The heat of vaporization, released by the phase change from gaseous to liquid, heats the forming condensate layer in such a way, that most of the hydrogen peroxide molecules are thermally dissociated thereby. The resulting free radicals, particularly the oxygen atoms, are immediately killing all the germs adhered to the surfaces already during the condensation. In contrast to other sterilisation processes the killing of the germs occurs instantaneously without any need for residence time.
The condensate layer is removed from the sterilisation chamber and all bottle surfaces immediately after the condensation. This is performed only by means of appropriate vacuum pumps which reduce the pressure inside the sterilisation chamber below 1 Torr. The condensate is rapidly re-evaporating when the decreasing chamber pressure reaches the condensates vapor pressure and the forming vapor is removed from the chamber by the vacuum pumps. This re-evaporation effects a total drying of the bottles and the surfaces inside of the sterilisation chamber and completely removes all hydrogen peroxide.
Prior to deloading of the bottles from the sterilisation chamber, the chamber is vented to ambient pressure with sterile air to avoid recontamination of the sterile bottles.
The complete process time amounts to 6 seconds. Using the common reference germs for hydrogen peroxide sterilisation processes, endospores of different strains of bacillus subtilis and bacillus stearothermophilus, the Dry Sterilisation Process easily achieves a germ reduction of 106...108 (log6...log8) in count reduction tests and also in end point tests.
The sterilised items leave the sterilisation chamber in a completely dry state. Only the surface temperature of the items is slightly increased by a few degrees (10 °C (50 °F)–15 °C (59 °F)) during the sterilisation process. Therefore, the process is particularly useful for the sterilisation of heat sensitive items like plastic bottles. It is also useful for applications which require a high germ reduction and short process times.
[edit]Examples
NB #1: Unfortunately it is common diction to say "the kill rate is log6" or "the germ reduction is log6", which strictly speaking is not only wrong but nonsensical. By saying this one means that the germ reduction is 6 orders of magnitude or the survival probability of each single germ is 10−6. (This wrong diction originates from a misunderstanding of the mathematical expression log 106 = 6)
NB #2: Strictly speaking it is also wrong to talk about single germs or the like. It's correct to use the item cfu or colony forming unit. The main problem is not inevitably the presence of germs (bacteria, spores, ...) but their ability of fast fissiparous, which gives an exponential increase of the number of the germs with time. If one tries to count "a number of germs" one has to, simply spoken, cultivate them on an agar plate, let them grow for a few days and count the macroscopic colonies which have formed. Each of these colonies is resulting from 1 cfu (= 1 "augmentable germ").
Example #1: One item which has to be sterilized carries a contamination of 107 germs prior to sterilisation. The germ reduction capability of the sterilisation process is 6 orders of magnitude (=106 or "log 6"), which means the survival probability of the germs is 10−6. If such items are sterilised the average number of "surviving germs" or, correctly spoken, cfu's which are found on the items after sterilisation is: 107 / 106 = 10 or 107 * 10−6 = 10.
Example #2 (statistically equivalent to #1): A lot of items which have to be sterilized are carrying a contamination of 10 germs each prior to sterilisation. The germ reduction capability of the sterilisation process is 6 orders of magnitude (=106 or "log 6"), which means the survival probability of the germs is 10−6. If one sterilises a statistically significant number of these items the average number of cfu's which is found on the items after sterilisation is: 10 / 106 = 10−5 or 10 * 10−6 = 10−5. This means that, in average 1 cfu is found per 105 = 100000 items.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
Thursday, January 28, 2010
Wednesday, January 27, 2010
Baby Bottle
A baby bottle is a bottle with a nipple to drink directly from. It is typically used when a mother does not breastfeed, or if someone can not (as conveniently) drink from a cup, for feeding oneself or being fed. In particular it is used to feed an infant with infant formula, expressed breast milk or pediatrix electrolyte solution.
Dimensions and design
A large-sized bottle typically holds 270 ml; the small size 150 ml. It is composed of a bottle itself, a teat, a ring to seal the teat to the bottle, a cap to cover the teat and optionally a disposable liner.
The height-to-width ratio of bottles is high (relative to adult cups) because it is needed to ensure the contents flood the teat when used at normal angles; otherwise the baby will drink air. However, if the bottle is too tall, it easily tips. There are asymmetric bottles that ensure the contents flood the teat if the bottle is held at a certain direction.
Teats (or nipples)
The teat itself is typically slimmer and more flexible than the mother's nipple. Contents of a bottle can flow more quickly than breastfeeding. Specialized teats that attempt to mimic the shape of the breast exist to help babies to switch back and forth between bottle feeding and breast feeding for cases where "teat confusion" occurs. Teats come in a selection of flow rates. Different flow rate teats either have more holes or larger holes. The correct flow rate needs to selected based on the age of the infant. Variable flow rate teats are available for older infants. The hole is asymmetric so that by turning the bottle/teat, different flows can occur. Specialized teats are available for infants with cleft palate (see also Haberman feed).
Vented bottles
"Vented" bottles allow air to enter the bottle while the baby is drinking without the need to break the baby's suction during feeding. Alternatively a bottle liner can be used to enclose the formula instead of directly in the bottle. The liner collapses as the formula is drained.
Vented bottles work by allowing air to enter while preventing the liquid inside from escaping. Avent is the most popular brand in this category. It works by an "anti-vacuum skirt" in the base of the teat, where it forms a seal with the bottle. The skirt acts as a one way valve, allowing air to enter the bottle but not liquids to leave. If the sealing ring is tightened too much, the skirt is compressed too tightly to allow it to open and the bottle will not vent. If the sealing ring is too loose, liquid leaks from the bottle.
There are multiple patents for technologies in this area. Initial designs called for a complex spring and valve system that was impossible to clean and sterilize. Current research is in specialized materials with microscopic pores that allow the entry of air without the escape of liquids. This avoids the caregiver having to get the sealing ring tension just right. It remains to be seen whether these materials can withstand the rigours of daily cleaning and sterilization. Another competitor, Dr. Brown's, offers a system whereby the vented air is conducted through a tube to the bottom of the bottle where the airspace is when the bottle is in use. This avoids the vented air from bubbling through the liquid and unnecessarily aerating the liquid.
Variations and accessories
Bottles may be designed to attach directly to a breast pump for a complete "feeding system" that maximizes the reuse of the components. Such systems include a variety of drinking spouts for when the child is older. This converts the bottle into a sippy cup, a cup with lid and spout for toddlers, which is intermediate between a baby bottle and an open top cup. Bottles that are part of a feeding system may include handles that can be attached. The ring and teat may be replaced by a storage lid.
Accessories for bottles include cleaning brushes and drying racks. Brushes may be specially designed for a specific manufacturer's bottles and teats. Bottle warmers warm previously made and refrigerated formula. Coolers designed to fit a specific manufacturer's bottles are available to keep refrigerated formula cold. Special formula powder containers are available to store pre-measured amounts of formula so that caregivers can pre-fill bottles with sterile water and mix in the powder easily. The containers are typically designed to stack together so that multiple pre-measured amounts of formula powder may be transported as a unit.
Specialty, "designer" bottles are now quite common as novelty gifts for parents or just something interesting for the child. They either have special logos or are of special shapes (e.g., animals). Some even have a hole in the middle. Depending on the shape, these bottles can be quite difficult to clean. Another specialty bottle is made from heat sensitive materials that act as a built-in thermometer. If the contents are too hot, the bottle changes color.
Institutions can purchase ready-to-feed formula in containers that can be used as baby bottles. The lid screws off and is replaced by a disposable teat when the formula is ready to be used. This avoids storing the formula with the teat and possibly clogging the teat holes when formula is splashed within the bottle and dries.
Sterilization
If necessary, bottles can be sterilized by boiling in hot water, in a specialized bottle sterilization appliance (which typically uses steam) or in a specialized sterilization container that is microwaved. Modern bottles are difficult to sterilize in boiling water because they tend to float. Bottles were originally composed of glass which was dangerous when babies learned to feed themselves and held the bottle. Mainly for cost reasons, modern bottles are unbreakable plastic. Since bottles have to be made to withstand the heat of sterilization, the bottle can also withstand the heat of dishwashers and are dishwasher-safe.
There is some concern about BPA leakage on polycarbonate bottles due to extended dishwasher or boiling. While bottles were traditionally sterilized in the past, unless there are infant health concerns, or concerns about water contamination, the current recommendation is that baby bottle sterilization can be replaced by cleaning with hot soapy water.
Regulation
While infant formula is highly regulated, baby bottles are not. Only the materials of the teat and bottle itself are specifically regulated in some countries (e.g. British Standards BS 7368:1990 "Specification for babies' elastomeric feeding bottle teats"). In the USA, the Food and Drug Administration (FDA) also regulates teats and the bottle materials. In 1985 it tightened allowable levels of nitrosamines released from bottle teats. A 1999 Consumer Reports study suggesting that plastic bottles release unsafe amounts of bisphenol A was denounced as sensationalism because of the unreasonable conditions the bottles were subject to. Findings since, however, have renewed the initial concerns.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
Dimensions and design
A large-sized bottle typically holds 270 ml; the small size 150 ml. It is composed of a bottle itself, a teat, a ring to seal the teat to the bottle, a cap to cover the teat and optionally a disposable liner.
The height-to-width ratio of bottles is high (relative to adult cups) because it is needed to ensure the contents flood the teat when used at normal angles; otherwise the baby will drink air. However, if the bottle is too tall, it easily tips. There are asymmetric bottles that ensure the contents flood the teat if the bottle is held at a certain direction.
Teats (or nipples)
The teat itself is typically slimmer and more flexible than the mother's nipple. Contents of a bottle can flow more quickly than breastfeeding. Specialized teats that attempt to mimic the shape of the breast exist to help babies to switch back and forth between bottle feeding and breast feeding for cases where "teat confusion" occurs. Teats come in a selection of flow rates. Different flow rate teats either have more holes or larger holes. The correct flow rate needs to selected based on the age of the infant. Variable flow rate teats are available for older infants. The hole is asymmetric so that by turning the bottle/teat, different flows can occur. Specialized teats are available for infants with cleft palate (see also Haberman feed).
Vented bottles
"Vented" bottles allow air to enter the bottle while the baby is drinking without the need to break the baby's suction during feeding. Alternatively a bottle liner can be used to enclose the formula instead of directly in the bottle. The liner collapses as the formula is drained.
Vented bottles work by allowing air to enter while preventing the liquid inside from escaping. Avent is the most popular brand in this category. It works by an "anti-vacuum skirt" in the base of the teat, where it forms a seal with the bottle. The skirt acts as a one way valve, allowing air to enter the bottle but not liquids to leave. If the sealing ring is tightened too much, the skirt is compressed too tightly to allow it to open and the bottle will not vent. If the sealing ring is too loose, liquid leaks from the bottle.
There are multiple patents for technologies in this area. Initial designs called for a complex spring and valve system that was impossible to clean and sterilize. Current research is in specialized materials with microscopic pores that allow the entry of air without the escape of liquids. This avoids the caregiver having to get the sealing ring tension just right. It remains to be seen whether these materials can withstand the rigours of daily cleaning and sterilization. Another competitor, Dr. Brown's, offers a system whereby the vented air is conducted through a tube to the bottom of the bottle where the airspace is when the bottle is in use. This avoids the vented air from bubbling through the liquid and unnecessarily aerating the liquid.
Variations and accessories
Bottles may be designed to attach directly to a breast pump for a complete "feeding system" that maximizes the reuse of the components. Such systems include a variety of drinking spouts for when the child is older. This converts the bottle into a sippy cup, a cup with lid and spout for toddlers, which is intermediate between a baby bottle and an open top cup. Bottles that are part of a feeding system may include handles that can be attached. The ring and teat may be replaced by a storage lid.
Accessories for bottles include cleaning brushes and drying racks. Brushes may be specially designed for a specific manufacturer's bottles and teats. Bottle warmers warm previously made and refrigerated formula. Coolers designed to fit a specific manufacturer's bottles are available to keep refrigerated formula cold. Special formula powder containers are available to store pre-measured amounts of formula so that caregivers can pre-fill bottles with sterile water and mix in the powder easily. The containers are typically designed to stack together so that multiple pre-measured amounts of formula powder may be transported as a unit.
Specialty, "designer" bottles are now quite common as novelty gifts for parents or just something interesting for the child. They either have special logos or are of special shapes (e.g., animals). Some even have a hole in the middle. Depending on the shape, these bottles can be quite difficult to clean. Another specialty bottle is made from heat sensitive materials that act as a built-in thermometer. If the contents are too hot, the bottle changes color.
Institutions can purchase ready-to-feed formula in containers that can be used as baby bottles. The lid screws off and is replaced by a disposable teat when the formula is ready to be used. This avoids storing the formula with the teat and possibly clogging the teat holes when formula is splashed within the bottle and dries.
Sterilization
If necessary, bottles can be sterilized by boiling in hot water, in a specialized bottle sterilization appliance (which typically uses steam) or in a specialized sterilization container that is microwaved. Modern bottles are difficult to sterilize in boiling water because they tend to float. Bottles were originally composed of glass which was dangerous when babies learned to feed themselves and held the bottle. Mainly for cost reasons, modern bottles are unbreakable plastic. Since bottles have to be made to withstand the heat of sterilization, the bottle can also withstand the heat of dishwashers and are dishwasher-safe.
There is some concern about BPA leakage on polycarbonate bottles due to extended dishwasher or boiling. While bottles were traditionally sterilized in the past, unless there are infant health concerns, or concerns about water contamination, the current recommendation is that baby bottle sterilization can be replaced by cleaning with hot soapy water.
Regulation
While infant formula is highly regulated, baby bottles are not. Only the materials of the teat and bottle itself are specifically regulated in some countries (e.g. British Standards BS 7368:1990 "Specification for babies' elastomeric feeding bottle teats"). In the USA, the Food and Drug Administration (FDA) also regulates teats and the bottle materials. In 1985 it tightened allowable levels of nitrosamines released from bottle teats. A 1999 Consumer Reports study suggesting that plastic bottles release unsafe amounts of bisphenol A was denounced as sensationalism because of the unreasonable conditions the bottles were subject to. Findings since, however, have renewed the initial concerns.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
Sunday, January 24, 2010
How to Clean or De-scale a Bottle Sterilizer
The bottle sterilizer has caught on as a great and efficient method for parents to clean and sterilize their baby's bottles, nipples, pacifiers or other accessories.
But it does require a recommended cleaning every 4 weeks. Here's a few tips to make this easy.
1. Empty sterilizer, remove all racks, and wipe down interior of sterilizer with a clean sponge.
2. Fill 1 cup of white vinegar and pour into sterilizer
3. Turn on sterilizer and let it run its cycle. After the cycle has finished, unplug the sterilizer and allow it to cool down, then pour any remaining liquid down the sink.
4. Rinse the interior of the sterilizer well with cool water and use a clean sponge to remove any build-up that came loose as a result of the de-scaling/cleaning process.
5. Plug the sterilizer back in and add regular amount of water you use for normal sterilization. Run cycle with just water and no bottles to remove any additional build-up. Upon completion, rinse sterilizer one last time and you are good to go.
Tips & Warnings
* It's good to clean or de-scale your sterilizer every month or so. This will help the sterilizer work more effectively.
* Don't be surprised by the strong odor that the vinegar gives.
* It may be necessary to repeat Step 5 if you had an unusually large amount of build-up or haven't cleaned your sterilizer in a long time.
* Make sure to unplug sterilizer between certain steps, as described above.
* Make sure Sterilizer has cooled down after its cycle, before handling.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
But it does require a recommended cleaning every 4 weeks. Here's a few tips to make this easy.
1. Empty sterilizer, remove all racks, and wipe down interior of sterilizer with a clean sponge.
2. Fill 1 cup of white vinegar and pour into sterilizer
3. Turn on sterilizer and let it run its cycle. After the cycle has finished, unplug the sterilizer and allow it to cool down, then pour any remaining liquid down the sink.
4. Rinse the interior of the sterilizer well with cool water and use a clean sponge to remove any build-up that came loose as a result of the de-scaling/cleaning process.
5. Plug the sterilizer back in and add regular amount of water you use for normal sterilization. Run cycle with just water and no bottles to remove any additional build-up. Upon completion, rinse sterilizer one last time and you are good to go.
Tips & Warnings
* It's good to clean or de-scale your sterilizer every month or so. This will help the sterilizer work more effectively.
* Don't be surprised by the strong odor that the vinegar gives.
* It may be necessary to repeat Step 5 if you had an unusually large amount of build-up or haven't cleaned your sterilizer in a long time.
* Make sure to unplug sterilizer between certain steps, as described above.
* Make sure Sterilizer has cooled down after its cycle, before handling.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
Wednesday, January 13, 2010
Keeping Baby Healthy: Sterilizers for Baby Bottles, Nipples, Etc
I think that it is good to have a sterilizer for baby bottles, nipples, etc. to help keep the new baby healthy. Babies have little resistance to germs, so it's a good idea to keep their things nice and clean and
sterile. There are sterilizers on the market, that can help you to keep all those bottles, nipples, etc. nice and clean and free from germs. I think it's a good idea to buy a sterilizer and have peace of mind. There are many products to buy for babies, and think that a sterilizer is among the most important of all. When we are caring for a new baby, I think that cleanliness should be observed at all times. A new little baby needs all the love and care that we can provide. I decided to see what I could find in sterilizers for baby bottles, nipples, etc. to help keep the baby healthy.
I found the Phillips Avent 1Q24 Steam Sterilizer that sells for $62.52. This great steam sterilizer can sterilize in 6 minutes. In mode 1, the contents of the sterilizer can be kept sterile for up to 6 hours. In mode 2, the contents can be kept sterile for up to 24 hours. It will accommodate up to 6-9oz. Advent bottles. It has sound alerts, digital display, and an electronic countdown. It measures 9 x 12.6 x 9". It is very easy to use. All you have to do is pour in water, set the mode, and the sterilizer will do all the rest. I think this sounds like a very nice sterilizer, and I think that many parents would like this one to help keep their baby healthy.
I found the First Years Soothie Microwave Sterilizer that sells for $20.18. This helpful sterilizer will hold up to 4 complete bottles. It has a color change indicator, and a steam release valve on the lid top. There is a removable drying rack, and handles on the sides that can act as pouring spouts. It measures 11 x 6.5 x 10.2", and weighs 1.8 lbs. This sterilizer will fit into most standard size microwave ovens. I think that it is very nice that you can sterilize with your microwave oven. I think many people would like this one, and I think it would help to keep the new baby healthy.
I found the Nursery Sanitizer By Germ Guardian that sells for $69.99. This sterilizer reaches a sanitizing temperature that can kill 99.9% per the germs. It takes just 30 minutes to do this. If you put in toys,
pacifiers, etc. there will be no fading. It won't melt plastic or any rubber products. You can also sanitize breast pump attachments with this helpful sanitzer. I think this is a great sterilizer, too and I think it would hard to choose which to buy. If you are interested in sterilizers for baby bottles, nipples, etc. to help keep baby healthy, I am sure you can find many more on the internet.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
sterile. There are sterilizers on the market, that can help you to keep all those bottles, nipples, etc. nice and clean and free from germs. I think it's a good idea to buy a sterilizer and have peace of mind. There are many products to buy for babies, and think that a sterilizer is among the most important of all. When we are caring for a new baby, I think that cleanliness should be observed at all times. A new little baby needs all the love and care that we can provide. I decided to see what I could find in sterilizers for baby bottles, nipples, etc. to help keep the baby healthy.
I found the Phillips Avent 1Q24 Steam Sterilizer that sells for $62.52. This great steam sterilizer can sterilize in 6 minutes. In mode 1, the contents of the sterilizer can be kept sterile for up to 6 hours. In mode 2, the contents can be kept sterile for up to 24 hours. It will accommodate up to 6-9oz. Advent bottles. It has sound alerts, digital display, and an electronic countdown. It measures 9 x 12.6 x 9". It is very easy to use. All you have to do is pour in water, set the mode, and the sterilizer will do all the rest. I think this sounds like a very nice sterilizer, and I think that many parents would like this one to help keep their baby healthy.
I found the First Years Soothie Microwave Sterilizer that sells for $20.18. This helpful sterilizer will hold up to 4 complete bottles. It has a color change indicator, and a steam release valve on the lid top. There is a removable drying rack, and handles on the sides that can act as pouring spouts. It measures 11 x 6.5 x 10.2", and weighs 1.8 lbs. This sterilizer will fit into most standard size microwave ovens. I think that it is very nice that you can sterilize with your microwave oven. I think many people would like this one, and I think it would help to keep the new baby healthy.
I found the Nursery Sanitizer By Germ Guardian that sells for $69.99. This sterilizer reaches a sanitizing temperature that can kill 99.9% per the germs. It takes just 30 minutes to do this. If you put in toys,
pacifiers, etc. there will be no fading. It won't melt plastic or any rubber products. You can also sanitize breast pump attachments with this helpful sanitzer. I think this is a great sterilizer, too and I think it would hard to choose which to buy. If you are interested in sterilizers for baby bottles, nipples, etc. to help keep baby healthy, I am sure you can find many more on the internet.
Read more article about Baby Bottle Sterilizer. You can find more article in http://babybottlesterilizers.net
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