The Tile Shower Pan Liner Membrane - Tips For Success

The shower pan liner membrane is usually a vinyl sheet that's installed in the mortar base of the shower. All kinds of liners have been tried in the past, including liners of steel, iron, copper, lead and even tar. None of these materials were completely satisfactory. The currently used liner sheets seem to be the best solution yet.

membrane air dryer

Don't even think about building a masonry tile shower without a liner membrane. Why not? Well, you see, a shower floor is not waterproof. Water seeps right into the grout of the floor and then down into the shower base. The only thing that keeps the shower leak-proof is the liner layer. It's made to catch all the water that seeps into the floor and route it to special drain holes built into the floor.

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Here's what you get for the liner...

The actual liner sheet is made of either chlorinated polyethylene (CPE) or polyvinyl chloride (PVC). Either material works. The CPE is more flexible and seems to stay soft better, but it's more expensive and harder to find. Most installers use PVC liners and they seem to work perfectly, even if they are a little harder to fold and bend.

Here's how the liner, PVC or CPE, fits in the floor...

The PVC liner is installed between two mortar layers. The bottom mortar layer is sloped and that's what supports the liner sheet and guarantees that the water moves right to the drain. The liner is run up the wall to produce a water proof layer higher than the water could pool in the shower.

The real key to a leak-proof shower is getting the right shower pan liner membrane and getting it installed properly. Installation is not complicated. There are just a few tricks to make it a sure success.

The Tile Shower Pan Liner Membrane - Tips For Success

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Common Field Failures for Polymer Thick Film Membrane Switches

Membrane switches offer a reliable economical, cosmetically appealing answer for electronic switching applications. They provide a normally open, momentarily closed switch system. Used in a wide variety of applications, they can meet stringent requirements for shock and vibration; water, UV and chemical resistance and longevity. With proper design and choice of materials, membrane switches can provide the performance and durability necessary for the most demanding applications.

membrane keypad

The following discussion covers common failure points that can be mitigated, avoided or eliminated with proper design and materials selection.

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Silver Migration: Silver migration problems will be greatest in applications where moisture, heat and humidity are in prevalent. Silver migration is the ionic movement of silver between two adjacent traces where a voltage potential exists. Over time, silver migration can cause an electric short. Silver migration is commonly enabled by moisture. There are several methods to mitigate silver migration, including adhesive sealing, full perimeter gasketing and other design barriers. The mechanical configuration, bond to the device enclosure and connecting hardware can all contribute to sealing failures.

Dielectric Cross-over's, Jumpers or Bridges: When OEM requirements call for dense circuit layouts to meet the need for a high number of switches in a limited X-Y dimension, most membrane switch manufacturers use printed cross-overs, jumpers or bridges (all referring to a similar method). In its simplest manifestation, a silver trace is printed first, followed by a printed dielectric material, and finished with another printed silver trace over the dielectric. The dielectric insulating layer is the weak point in this construction. Because of the inherent properties of the material and application methods, a common failure is micro shorts that occur between the two overlapping traces as the silver leaches through the porous dielectric. While there are manufacturing and test methods to help mitigate this issue, the best way to avoid this failure is to avoid cross-over or jumpers altogether. Some membrane switch manufacturers can provide a double sided circuit where a layer of polyester provides insulation and completely eliminates the risk.

Graphic Overlay: The graphic overlay gets a surprising amount of stress in areas where switch contacts are made. Improper selection of the overlay materials can result in cracking and delaminating graphic layers. This cracking can occur in just a few hundred actuations. While initially manifesting itself as a "cosmetic issue" it can progress to the point of functionally failing non-tactile switch closure.

Collapsed Switches: A non-tactile membrane switch connection is made when a finger or probe pushes a shorting element against a nested finger circuit layer to momentarily close the circuit. The contact surfaces are often only separated by a few thousandths of an inch. Variations in temperature, air pressure or even multiple actuations can cause air to escape from the contact chambers which create a pressure differential leading to collapsed switches. A proper membrane switch design will mitigate this issue. Sealing, tactile domes and venting are a few methods commonly used to prevent collapsed switches.

Plastic domes can collapse due to extreme operating temperatures (high and low) and should be limited to applications in controlled environments. The actuation force is also influenced by temperature, with high temps producing very low actuation force and operator feedback, and low temperature actuation forces producing high actuation force and a "crunch" sound and feeling to the operator. Design parameters for plastic domes are critical to their performance and durability. There is no recovery for a collapsed plastic dome once its geometry is compromised.

Common causes of collapsed metal domes include, but are not limited to the following. If a metal dome is supported by a plastic injection molded enclosure surface, there can be variances in flatness or even pockets or cups that do not support one or more legs of the metal dome. Another manifestation of an irregular base surface is if the metal dome is placed into the membrane switch assembly with one or more legs supported on top of the adhesive spacer layer. Each of these cases cause premature dome failures. Furthermore, care should be taken to choose a metal dome manufacturer with a history of consistently acceptable production processes and choice of materials.

Cracked traces: It is very common for the dielectric substrate to bend, fold or be twisted as part of the assembly process. Polymer thick film traces printed on the substrate are subject to cracking when repeatedly bent or sharply creased on the outside radius. Proper design with good material selection and trace lay out can eliminate most causes of cracked traces. Manufacturers of double sided polymer circuitry have the best solution by placing circuit tail traces on the back or inside radius of the circuit tail and eliminating cross-overs, bridges, jumpers, etc. which can be fraught with cracked traces from printed stack ups over dielectric and conductive circuit traces.

Poor Tactile Life: Tactile feedback switches, if properly designed and manufactured can last millions of cycles. But improper design, material selection or poor manufacturing methods can create switches that lose their tactile response in a short period of time. Contact pad damage, corrosion, poor ventilation, material incompatibility and poor fabrication methods are some of the common causes for poor tactile life.

Creating a robust membrane switch requires an experienced manufacturer who has expertise in materials, reliability, design and robust manufacturing methods. Each and every new custom design should be thoroughly tested before launching into production. Make sure that the membrane switch manufacturer you select has the experience and technology to handle your requirements.

Common Field Failures for Polymer Thick Film Membrane Switches

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Why Use a Water Purifier and Reverse Osmosis Membrane

Are you aware of the fact that half of the world's hospitalization are due to water related diseases? It is but a heart weakening fact that over 1.4 million deaths of children occur every year due to consumption of unpurified water; in almost every 20 seconds a child dies! One of the dreaded diseases that cause death among children under the age of five globally is diarrhea. Records substantiate the fact that one in five child deaths are due to diarrhea, killing more children than malaria, measles, and AIDS combined. Why take risks or cause danger to your child's and your other family members' health when water purifier solutions are available in the market. If you are still drinking water directly from the tap or any other water source, get a water purification system installed right away. A series of the latest water purifier is available at organized retail outlets and also right at the comfort of your home. Choose a reliable brand and go for it.

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It is a worrisome affair too if you are using a conventional water purification system. This is because such a system cannot effectively remove new age contaminants, micro organisms, and other dissolved particles. It is never too late. Switch your system now.

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Using the right purifier in sync with the water type also matters. It is after getting your water tested that you will know which mechanism you need. If you are recommended to use a reverse osmosis water purification system, there are numerous factors that need to be considered. First is choosing a reliable brand, one that has maintained a rapport for delivering superlative hi-tech systems for years together. Another is taking into account the RO membrane incorporated in the reverse osmosis water purification system. Generally, there are two common types of household RO membranes used - Cellulose Triacetate (CTA) membrane and Thin Film Composite (TFC or TFM) membrane.

The water you receive from your tap may be full of micro organisms, chlorine, and other contaminants. Though both the reverse osmosis membranes effectively purify the water, there is yet a difference between them. This difference is related to chlorine tolerance and filtration ability. The CTA membrane though chlorine tolerant, is more vulnerable to fouling from micro organisms. TFC/TFM membrane is less susceptible to organic fouling and rejects 98% of standard contaminants on an average.

Why Use a Water Purifier and Reverse Osmosis Membrane

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What Is a Membrane Sweep?

I have had personal experience with this, with both of my pregnancies I had a membrane sweep as I went past my due date by a few days for both. The first time I don't think it made much difference because I went into labour 4 days after and they say that if the membrane sweep is going to work you will probably go into labour within 48 hours. Now with my second child it definitely worked, I went into labour the next day.

membrane vacuum pump

I remember going for my ante-natal appointment to check my blood pressure as it had been high and she suggested that I had a membrane sweep. At this time I had no idea what this was and became very anxious about what was going to happen. The object of this article is to spread the word about what a membrane sweep is and what you should expect so that you will not feel so anxious about it when the time comes.

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Now a membrane sweep is actually a form of induction and is usually performed once you have reached 40 weeks of pregnancy although can be performed anytime from 38 weeks. It is performed by your midwife or doctor by placing a finger inside your cervix and making a circular 'sweeping' motion to try and seperate the membranes from the cervix, this will cause hormones to be released which in turn could start labour. This is performed to try and increase the chances of labour happening spontaneously without the need for any other form of induction. Whatever you do you must not try to perform this procedure yourself this must always be performed by a registered healthcare provider.

As the midwife/doctor is performing this procedure they will be able to tell if your cervix is favourable or not favourable, what I mean by that is, if your cervix is favourable it will be soft and already starting to open up a little from all those braxton hicks contractions you have been having. On my second visit I remember the midwife telling me that my cervix was already 1-2cm dilated, at that point I got very anxious as I knew 'it was time'.

This procedure does not hurt but does feel a little strange, after the procedure I felt some very low back ache and I had a little bleeding. Before you start to panic, this is normal and I went into labour the next day. Good luck.

What Is a Membrane Sweep?

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Shower Pan Membrane and the Shower Wall Covering

After the shower pan membrane is in place, then the wall boards go on the walls. That's the right order... the liner membrane and only then the wall boards. The best practice for building shower walls is using cement board. Here's how you do it...

membrane keyboard

The liner membrane is installed right over a sloped mortar layer and then sealed to the base of the tile shower drain. Then the liner is run right up the wall against the studs. That gives you a waterproof liner that's up the walls several inches above the height of the curb. Only after the liner is in place do you install the boars for the wall.

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It is board too, as in cement boards. That's because cement boards won't rot and work well around water. Before the boards go on though, there's another important step.

Against the studs and before the wall boards, install a moisture barrier. That's either 15# roofing felt or 4 mil plastic sheet. That way the moisture that might get behind the cement boars is confined by that layer. Then you install the cement boards.

To build a wall properly, leave gaps between boards and then tape and mud the joints to produce a real sealed wall.

The other place to watch is the bottom of the cement boards. Install the boards so there is at least a 1/2 inch gap between the bottom of the cement board and the liner sheet itself? Why???

That gap is to reduce the chance of water wicking up into the cement board. Wet cement boards won't rot but they will mold. That's no good.

The shower pan membrane is the key to a tile shower that works properly. Getting the wall covering in the shower installed is the next step after the liner membrane is in place. With the materials available, it's easy to build a shower that keeps the water in the right place from the floor all the way up the walls.

There are other details that can make the shower walls last for a long time trouble-free...

Shower Pan Membrane and the Shower Wall Covering

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Definition of Hyaline Membrane Disease Respiratory Distress Syndrome (RDS I)

Also known as idiopathic respiratory distress syndrome (RDS) Type I, hyaline membrane disease is an acute disorder found primarily in preterm infants at birth of shortly after birth, most often in infants under 32 week's gestation who weigh less than 3 lb, 4 oz (1,500 g). Roughly 60% of infants born before 29 week's gestation develop RDS.

membrane potentiometer

Fetal lung development and surfactant production are necessary for normal respiratory function; lung development and surfactant production varies with each infant. The preterm infant is born before sufficient surfactant develops or with a lack of mature surfactant production. Surfactant, a lipoprotein that lines the alveoli, prevents alveolar collapse and decreases the work of respiration by decreasing surface tension. With a deficiency, surface tension increases, causing alveolar collapse and decreased lung compliance, which affects alveolar ventilation, leading to hypoxemia and hypercapnia with respiratory acidosis. The reduction in ventilation leads to a poor ventilation and perfusion ratio of the pulmonary circulation, resulting in hypoxemia. Tissue hypoxia and metabolic acidosis result with associated atelectasis and respiratory failure progression.

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RDS, the leading cause of mortality and morbidity in preterm infants, usually lasts 3 to 5 days. The prognosis is poor if prolonged ventilator support is needed; death is less likely after 3 days of treatment.

This plan focuses on care of the infant at risk for or with RDS and on all the associated respiratory support that may be needed.

Etiology and precipitating factors
• prematurely with immature lungs (ranges less than 32 to 35 weeks' gestation) and absence, alteration, or deficiency of pulmonary surfactants
• cesarean delivery of preterm infant
• decreased oxygen present in the fetus or at birth in term or preterm infants

Physical findings

Maternal history
• disorder such as diabetes mellitus
• condition such as placental bleeding
• type and intrapartal stress

Infant status at birth
• prematurely, gestational age
• apart score noting asphyxia
• cesarean delivery of preterm infant

Cardiovascular
• bradycardia (less than 100 beats/minute) with severe hypoxemia

Integumentary
• pallor caused by peripheral vasoconstriction
• pitting edema in hands and feet within 24 hours
• mottling

Neurologic
• immobility, motionlessness; flaccidity
• decreased body temperature

Cardiovascular
• systolic murmur
• heart rate within normal limits

Pulmonary
• tachypnea (more than 60 breaths/minute' may be 80 to 100)
• expiratory grunting or whining
• nasal flaring
• intercostals, suprasternal, or substernal retractions
• cyanosis (circumoral followed by central) related to percentage of destructed hemoglobin
• Decreased breath sounds, crackles, apneic episodes.

Behavioral findings
• lethargy

Diagnostic studies
• serial chest X-rays - reveal clouded appearance with grainy look, areas of density or of atelectasis, and elevated diaphragm with over distended alveolar ducts
• air bronchograms - reveal ventilation of the airway, not the alveoli

Laboratory data
• lung profiles - to determine lung maturity; done on amniotic fluid (for fetuses predisposed to RDS):
o lecithin/sphingomyelin (L/S) ratio of
2:1 or more indicates pulmonary maturity
- 1:1 before 35 weeks' gestation (L: 6 to 9 mg/dl,
S: 4 to 6 mg/dl)
- 4:1 after 35 weeks' gestation (L: 15 to 21 mg/dl,
S: 4 to 6 mg/dl)
o Phosphatidylglycerol: elevated at 35 weeks' gestation
o Phosphatidylinositol level

• Arterial blood gas (ABG) levels - PaO2 less than 50 mm Hg while on 100% oxygen, PaCO2 less than 60 mm Hg, oxygen saturation 92% to 94%, pH 7.31 to7.45
• Potassium levels - increase as potassium is released from injured alveolar cells

Definition of Hyaline Membrane Disease Respiratory Distress Syndrome (RDS I)

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Sports Injury Pain Relief With Natural Eggshell Membrane

If connective tissue damage is keeping you from participating in the sports you love, Natural Eggshell Membrane (NEM) may be the key to getting you back out on the field. Connective tissue damage is common in sports injuries, strains and sprains. This kind of damage manifests as muscle stiffness, aches and the loss of flexibility. These symptoms are commonly overlooked as a part of the natural aging process or simply as normal effects of being active. But joint pain, muscle aches and loss of flexibility can signal connective tissue damage, which if left untreated can result in keeping you out of the game permanently.

kerdi membrane

Treatment and repair of damaged tissue is a complicated process that hinges on controlling inflammation to allow your body to begin repairing tissue. Inflammation can be treated using over the counter medications, vitamin C and Zinc, and other non-prescription treatment options. If inflammation isn't controlled, then the processes necessary to help repair tissue damage cannot take place. Connective tissue repair is actually a two part process that consists of first addressing inflammation and second, providing the necessary nutrients and tools to your body to begin the repair process.

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It is the repair process that can be most helped by NEM. Natural eggshell membrane can help repair connective tissue damage and relieve joint and muscle pain. NEM is the thin membrane between the eggshell and egg white. NEM contains the proteins that are necessary to help repair connective tissue damage.

If you want to get back in the game, a daily supplement containing NEM may be able to help. Supplements that contain natural eggshell membrane are effective, because they contain a high level of NEM. Natural eggshell membrane not only helps repair tissue damage, but it also works to maintain the synovial fluid necessary to keep your joints and tissue healthy. Synovial fluid is located in your joints and helps keep them lubricated so your movements are smooth and painless.

Sports Injury Pain Relief With Natural Eggshell Membrane

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Role of Placental Membrane

Placenta, an organ exceptional to mammals helps in connecting the developing fetus to the uterine wall.

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Placental membrane:

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Placenta has a thin layer of composite extra-fetal tissue that separates the maternal and fetal circulation systems called as 'Placental membrane' or sometimes as 'placental barrier'.

Role of Placental barrier:

The physiological role of placental membrane is to protect the fetus from various harmful substances and help in its development by allowing transport of useful substances from mother.

Cloaking of fetus from maternal immune system:

The placenta and fetus is recognized as 'foreign allograft' by the maternal immune system because of which immune responses are produced to kill and remove them from the body. So immune tolerance in pregnancy also termed as 'Gestational immune tolerance', is required for fetus to continue its development inside mother and to prevent spontaneous termination of pregnancy i.e., abortion or miscarriage which is most common in first few weeks of conception.

The placental barrier thus functions as immunological barrier mainly by two different mechanisms namely:

1) Secretion of neurokinin-B which contains phosphocholine molecules which acts as suppressant for immune responses from mother.

2) Fetus contains small lymphocytic suppressor cells which by inhibiting interleukin-2 stop maternal cytotoxic cells.

Transport of substances from maternal circulation to fetus:

The placental membrane is a semi permeable membrane which allows the selective transport of molecules from maternal blood to fetus blood.

Water is easily transported to fetus. The amount transferred increases as pregnancy advances.

Gases: oxygen, carbon dioxide transport occurs by simple diffusion. Interruption of this transport is very dangerous to the embryonic or fetal survival.

Nutrients: These are essential for fetal development. Water soluble vitamins are transported more quickly than fat soluble vitamins. Free fatty acids enter in small amounts.

Glucose can easily pass the placental membrane.

Hormones: Unconjugated steroid hormones can freely pass through the membrane compared to protein hormones. Thyroxin and Triiodotyroxine are transported in small amounts.

Antibodies: Trans-placental transfer of some antibodies mostly gamma globulins like IgG class occurs frequently. This confers passive immunity to certain diseases like measles, smallpox etc.

Electrolytes: These are widely transported through placental membrane. Intravenous administration of electrolytes to mother may interfere with water and electrolyte status to fetus.

Usage of drugs should be monitored during pregnancy:

Most of the lipid soluble drugs freely pass the placental membrane. This can sometimes lead to harmful effects.

Anti-epileptic drugs such as carbamazepine, valproate and Phenobarbitals in combination with caffeine significantly increases congenital malformations or endanger the fetal survival itself.

Anti-cancer drugs containing 'thalidomide' are potentially harmful to fetus.

Certain antibodies known as 'teratogens' like tetracycline effect fetal bone growth.

Anti-convulsants produce detrimental effects to fetus like mental retardation.

Sulpha drugs increase the bilirubin concentration and may cause death.

Excess alcohol can also interfere with the fetal growth.

Placental-membrane as 'Placental barrier':

It acts as barrier based on size, configuration and charge.

Macromolecules such as cholesterol, triglycerides and phospholipids cannot pass through placental membrane.

Some metabolites, toxins though present in the maternal circulation don't get through the membrane in amounts to affect fetus.

Heparin and bacteria cannot pass the placental barrier.

Alpha and Beta globulins are not easily transported across placental membrane.

So placental membrane plays a pivotal role in healthy fetal development.

Role of Placental Membrane

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Installing a Shower Pan Membrane Liner for a Custom Ceramic Tile Shower

Installing a custom ceramic tile shower in your home is something a do it yourself homeowner can do with a little upfront knowledge. The most important aspect of a successful custom ceramic tile shower installation is properly installing a shower pan membrane liner. The shower pan membrane liner is used to ensure a leak-proof shower.

membrane air dryer

Shower pan membrane liners are used to funnel any water that seeps through the floor or wall grout to the shower drain below. The shower pan membrane liner is made up of a flexible type of plastic material that sits below a bed of mortar, and the tile, in the shower floor area.

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Prior to installing the shower pan membrane liner, the floor of the shower needs to be pre-sloped to ensure that the water will flow towards the shower drain assembly. The pre-slope is accomplished by applying a layer of mortar to the floor of the shower unit area. The layer of mortar is troweled in such as way as to create a gentle slope from the shower wall edges to the center of the shower where the drain resides.

Once the pre-slope mortar has cured, the flexible shower pan membrane liner can then be installed. There are a couple of types of shower pan membrane liners on the market, with each having their own benefits. With either type of membrane, the homeowner needs to form and fold the material into the base of the shower area and secure it to the sides of the shower wall frame with staples and/or nails. In addition, an opening in the membrane should be cut out to allow the adjustable shower drain assembly to slip through.

With the shower pan membrane installed, the cementitious ceramic tile backerboard can then be secured to the framed shower walls. The backerboard is a rigid material that is ideal for attaching tile in wet areas such as a shower stall.

After installing the ceramic tile backerboard, a final coat of mortar needs to be applied on top of the membrane to protect it and to provide a solid base for laying the ceramic floor tile.

With the final coat of mortar cured, the ceramic tile can then be installed in the shower.

Once the tile and grout have been installed, the shower drain assembly should be adjusted so that the drain height sits flush with the finished ceramic tile floor.

For more information on installing a shower pan membrane liner, see the Shower Pan Membrane Liner Installation EBook from HomeAdditionPlus.com. The Shower Pan Membrane Liner EBook will quickly teach you the step-by-step process for installing the shower pan membrane liner correctly. It includes instructions on framing the shower stall, pouring the pre-slope and shower base mortar, and installing the shower pan membrane liner.

Installing a Shower Pan Membrane Liner for a Custom Ceramic Tile Shower

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Damp-Proof Membrane Solutions - The Options

Should I Use A Damp-Proof Membrane On My Damp Walls?

membrane switch

The choice of damp proofing materials is extensive and can be confusing to those who are dealing with damp issues. Damp-proof membranes offer a good solution as they can be installed on virtually any wall surface. Many membranes on the market are meshed, which means that plaster can be applied directly to it. The membrane then acts as an impermeable barrier between the old wall surface and the new plastered surface. This allows the damp wall to dry behind without affecting the new wall surface to the front. By acting as a barrier, these membranes have the added advantage of holding salt and other contaminants away from the damp wall. Damp-proof membranes are made in a stud formation and work by allowing any moisture and moisture vapour to evaporate.

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If in doubt about which membrane to use, it is always advisable to consult a trained damp specialist about your specific project as they can advise on the best solution.

Do I Need A Damp-Proof Course?

Not necessarily. Damp-proof course failure is a leading cause of damp problems in properties. Indeed many older properties there was no damp proof course installed so once you have established this then you will know whether you need to install a physical damp proof course, a chemical injection or a dimpled sheet membrane as a choice. Do-it-yourself damp proofing websites show you all these products above but which one do you chose in which circumstance? Some products just do not work in certain builds. For instance I have witnessed properties with cavity wall insulation damp and builders installing a cream into the cavity wondering why they are using so much material! The simplest damp proof membrane application for damp proofing walls is in my opinion a dimpled membrane. Why? Well these membrane products negate the need for a damp injection, picks up defects in applications of other do-it-yourself damp attempts (black jack, waterproofing paint) even poor quality damp proofing jobs. The 'does what it says on the tin' motto i.e. paint it on and it stops damp does not always work and many people have come to me with a solution after their paint on repellent has pushed dampness to other areas in the property or condensation damp issues have been created. In my experience it can be easily avoided with the right materials and the right ventilation.

What About Below Ground?

Below ground use of damp proof membranes can be tricky. Be careful here as you may not be dealing only with damp. Tanking membranes need careful choice and careful installation and really should be installed by a professional. Damp injection, rising damp and penetrating damp above the ground is less risky, at least we are not dealing with the potential of water here.

Damp-Proof Membrane Solutions - The Options

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Basement Waterproofing Membranes - The Difference Between an Insulated Membrane and Insulating One

I have just come away from a meeting with a major supplier of basement waterproofing membranes.  Like most suppliers in the industry they have always supplied the plastic dimpled membrane for cavity drainage, and condensation has always been a potential hazard with such membranes.  The industry has wrestled with this problem for decades, ever since this generic type of waterproofing became prevalent.

waterproof membrane

In the 1970's and '80's it was industry standard practice to recommend that the air space between the membrane and the plasterboard lining be ventilated top and bottom so as to prevent condensation.  During the '90s and early part of the 21st century this advice was generally changed to 'don't ventilate the cavity' as it can actually increase condensation on the membrane by bringing a constant stream of humid air into contact with the cold surface of the membrane itself.  So the advice changed but the problem did not go away.

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Whilst the development of good quality and affordable dehumidifiers which are now readily available in most electrical stores has helped, the potential for condensation on a cold plastic surface is still a real risk.  This risk is made worse by insulating in front of the membrane.  'Why?' you may ask, 'surely if i insulate something I will keep it warmer?'  I t was hearing that very same quote today that inspired me to write this article especially as it came from a major supplier of plastic membranes.

I am not a physicist, I don't even know whether it is the first or second law of Thermodynamics and it doesn't really matter which, but i know that energy cannot be created or destroyed - that much is accepted wisdom.  So... If you are going to make something WARMER by putting in an insulation barrier, then you must also be making something else COLDER by the same amount.  insulation does not generate heat.  It does not make anything warm.  It just stops the transfer of heat from one place to another, or at least slows it down.  So if the room is warm and the ground outside is cold and the membrane is on the outside wall and you then put insulation in-between the warm room and the cold wall you make the wall and anything else on it (the membrane) COLDER and at the same time you keep the room WARMER.  And if, by doing this you make a vapour barrier colder then you increase it's risk of condensation.

Now the difference between insulating a membrane as described above and an 'insulated' membrane is that in an insulated membrane the insulation is an integral part of the membrane, not a separate element in front of it, in fact the insulation is actually BEHIND the vapour barrier, i.e. in-between the cold wall and the vapour barrier itself so that the vapour barrier is actually kept warmer rather than colder.  It is as simple as that.  Insulating in front of a membrane and thinking that you are keeping it warmer, is an easy mistake to make I guess but with a little careful thought also an easy one to avoid.

Read more on thermally insulated membranes and waterproofing basements

Basement Waterproofing Membranes - The Difference Between an Insulated Membrane and Insulating One

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Water Filtration via Membrane Technology

Purification or Filtration by Membrane technology is primarily used in commercial and industrial applications

membrane vacuum pump

There are 4 membrane processes that operate by applying water pressure to a membrane; ie. Reverse Osmosis :

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Microfiltration

(MF) is a process where water is forced under pressure through a porous membrane. Membranes with a pore size of 0.45 Microns are normally used.This size is relatively large compared with the other membrane filtration processes. This process has not been generally applicable to drinking water treatment because it either does not remove substances that require removal from potable water, or the problem substances can be removed more economically using other processes.

The primary use of MF is by industries to remove very fine particles from process water, as in electronic manufacturing. Additionly MF is often used as a pretreatment for other membrane processes. In particular, RO membranes are susceptible to clogging or filter binding unless the water being processed is already quite clean.

Ultrafiltration

(UF) is a process that uses a membrane with a pore size generally below .1 microns. The smaller pore size is designed to remove colloids and substances that have larger molecules, which are called high-molecular-weight materials. UF membranes can be designed to pass material that weigh less than or equal to a certain molecular weight. This weight is called the molecular weight cutoff (MWC) of the membrane. Although UF does not generally work well for removal of salt or dissolved solids, it can be used effectively for removal or most organic chemicals.Again often used in combination with Reverse Osmosis as a very effective pretreatment.

Nanofiltration

(NF) is a process using membranes that will reject even smaller molecules than UF. The process has been used primarily for water softening and reduction of total dissolved solids (TDS). NF operates with less pressure that reverse osmosis and is still able to remove a significant proportion of inorganic and organic molecules.

Reverse Osmosis

(RO) is a membrane process that has the highest rejection capability of all the membrane processes. These RO membranes have very low MWC pore size that can reject ions at very high rates, including chloride and sodium. Water from this process is very pure due to the high reject rates. R.O is used mainly in the water industry for desalinization of seawater because the costs are equitable with other processes for this service

The RO also works effectively on most organic chemicals, and radionuclides and microorganisms. Industrial water uses such as semiconductor manufacturing is also an important RO process. Unlike domestic R.O units industrial strength membranes are able to dump less than 30% of the flush water to waste. This reject water is very concentrated, difficult to eradicate and in the case of desalination it is often pumped deep offshore into drill holes.

Domestic R.O units are particularly inexpensive and do a fantastic job of purifying drinking water for the home. They do, however, require relatively clean pretreated water in order to protect the membranes.

Water Filtration via Membrane Technology

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Silver Migration in Membrane Switches

Silver is a metal commonly used in many electronics and microelectronic applications including hybrid electronics, microelectronic components and membrane switches. Silver is a very attractive metal to use because it has good conductivity, durability and relatively low costs. It is much less susceptible to oxidation than bare copper and in fact silver oxide is actually more conductive than the silver itself. It has been used in polymer thick film membrane switches for over 30 years. Silver based conductive compositions are usually screen printed to form the conductive traces in membrane switches.

membrane air dryer

One of the problems associated with silver is a phenomenon known as dendrite growth or silver migration. Silver migration is the ionic movement of metal, usually between two conductive traces where an electric potential exists. Given enough movement, the migration will cause a short between two traces and render the electronic device useless. Because silver has a free ion it tends to be more active than other metals, thus more susceptible to the dendrite growth.

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Silver migration will occur if there is moisture present between two traces with a potential. The rate of migration depends on the amount of moisture, the temperature and the voltage. Silver migration can be created in a test lab by applying a droplet of water between traces with a voltage potential. The migration will happen within seconds.

Membrane switches that are exposed to high humidity or moisture conditions are more likely to experience silver migration. I am personally aware of a major silver migration field failure issue that occurred in a microwave oven. This was back in the early 1980's and the application was stove top microwave oven. Boiling water on the stove created the moisture conditions. Additionally the configuration of the assembly made this particularly susceptible to moisture collection. The "pig tail" was crimped to the main body of the membrane switch, which actually formed natural collection points for moisture. A simple design change actually eliminated the crimps and the field failure dropped to near zero.

The following are some common techniques used to reduce or eliminate silver migration.

There are several new polymer thick film pastes available that contain palladium, which has been demonstrated to significantly reduce (but not eliminate) the tendency of silver to migrate. Cost and performance may be a trade off with these pastes. Protecting the traces with a carbon coating or dielectric can be effective if the proper material is adequately applied. Some materials tend to be porous and are susceptible to small "air gaps" that allow moisture to penetrate. Increasing the conductor spacing between traces that have a voltage potential will decrease the likelihood of silver migration. Keeping moisture from penetrating the membrane switch can be effective in preventing migration. There are several methods and materials available that can effectively seal a membrane switch from its environment.

Silver migration is a potential problem that needs to be addressed in the design and manufacturing process.

Silver Migration in Membrane Switches

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Hair - Vision - Skin And Mucous Membrane Requires For Vitamin A

Vitamin A is responsible for moisten your eyes, skin and mucous membranes; it also helps to adjust your eyes to light changes. Vitamin A is also called retinol. Most primarily source of vitamin A is animal foods. But there are some plant-based foods which supplies beta-carotene which is then turned into a Vitamin A. It also has antioxidant effect that protects your body from tissue and cellular harms.

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Vitamin A, a fat-soluble vitamin, plays essential roles in vision, growth, and development; the development and maintenance of healthy skin, hair, and mucous membranes; immune functions; and reproduction.

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Vitamin A is a necessary human nutrient. It may be found in any of these forms:
Retinol, the animal form of vitamin A, is a yellow fat-soluble, antioxidant vitamin with importance in vision and bone growth, it belongs to the family of chemical compounds known as retinoid.
Other retinoids, a class of chemical compounds that are related chemically to vitamin A, they are used in medicine. Carotenoids or other substances that enable the body to synthesize retinoids. Carotenoids are organic pigments that are naturally occurring in plants and some other photosynthetic organisms like algae, some types of fungus and some bacteria.

Benefits of vitamin A
Rebuilds health of tissues such as retina
Helps skin and mucous membranes to stay healthy and dry
Improves growth of teeth
Promotes development for skeletal and soft tissue

Food sources:
Liver, fish oil, eggs, milk fortified with vitamin A; red, yellow and orange fruits and vegetables, many dark-green, leafy vegetables.

However, you might find it difficult to take all necessary vitamins with food in daily usage. Nutrition supplements helps to fulfill your body needs (which might be higher when taking up hard exercises) and balance your nutrition and diets.

Benefits of taking nutrition supplements:

Supplements contain a dosage of necessary amount of vitamin per day. It is comfortable to use because they are already concentrated and body doesn't need much effort to absorb the foods and take necessary minerals or vitamins. Furthermore most supplements contain more than one kind of vitamin so you'll be also provided with some more ingredients necessary for your health.

Usualy when eating food which is poor in nutrition you can compensate it by the nutrition supplements.

Hair - Vision - Skin And Mucous Membrane Requires For Vitamin A

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Membrane Bioreactors & the Sequencing Batch Reactor, Improve Secondary WWT in the Food Industry

Wastewater treatment (WWT) uses many different processes to achieve the ultimate goal of discharging wastewater that meets all applicable regulations. In the Food and Beverage industry the composition of wastewater streams can be very complex, and highly variable, making the treatment of wastewater quite challenging, especially in the Secondary WWT phase. The demands made on the food and beverage industry are numerous and range from health and financial issues to environmental concerns.

membrane potentiometer

Two additional factors are adding to this challenge. First, environmental discharge regulations continue to tighten, making it difficult for some facilities to consistently operate without NPDES violations. Second, climate change, drought conditions and the trend towards water conservation are forcing some WWT facilities to recycle a portion of their water for in-plant use. The end-use of this recycled water may dictate an even higher quality standard than what is required for discharge.

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Wastewater treatment can be divided into five processes: pre-treatment, primary, secondary, and tertiary treatment then finally disinfection.

Secondary WWT is arguably the most important of the processes used in the treatment of waste in the Food & Beverage industry, due to the high and varying levels of soluble and suspended organic matter in the wastewater. Unfortunately, it is also arguably the most complex of the WWT processes, and can therefore create many challenges from an operations perspective.

The Activated Sludge Process

The first major development in Secondary WWT was the introduction of the activated sludge process in England in 1913. The activated sludge process combines sewage, a concentrated mass of microbes, and high levels of dissolved oxygen to promote the consumption of organic content.

The activated sludge process is still very widely used, and has evolved into many different variations, depending upon specific waste treatment requirements.

The activated sludge process can be quite daunting to operate properly. Loss of control by WWT plant operators, can result in loss of the activated sludge, decimation of the microorganism population, and ultimately in non-compliance.

It takes experience and expertise to operate an activated sludge facility in the event of upset conditions. Another issue with most traditional activated sludge processes is the large footprint and the associated high initial capital costs.

As a result of these issues with the activated sludge process, newer technologies have been developed over the past few years. The Membrane Bioreactor (MBR) and the Sequencing Batch Reactor (SBR) processes are two such technologies.

The use of MBR and SBR has become widespread in the Food and Beverage industry, due to the typical wastewater composition, a general tightening of discharge regulations, and water shortages. MBR and SBR treated wastewater is much better suited for reuse or recycle than activated sludge treated effluent.

The MBR process combines activated sludge treatment with a membrane for liquid-solid separation. While MBR can achieve almost complete separation of suspended solids and dramatic reduction in contaminants, it is prone to membrane fouling. Fortunately, the recent advent of PTFE membranes and improved system designs have minimized the need for membrane maintenance to prevent fouling.

A SBR process typically consists of at least two identically equipped reactors with a common inlet, valved to direct flow to one reactor or the other. As the name implies, the reactors work as batch operations and by nature are easier to operate than continuous flow systems since every batch can be treated and controlled separately. In addition, SBR systems often have a smaller footprint and capital cost and are easier to operate than other types of systems. On the downside, SBR may be limited to smaller wastewater flows.

Membrane Bioreactors & the Sequencing Batch Reactor, Improve Secondary WWT in the Food Industry

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Choosing a Good Quality Membrane Home Water Filter

Our body is estimated to be about 60 to 70 percent water. Our organs like muscles, lungs, and brain and blood all contain a lot of water. Our body needs water to transport oxygen and nutrients to our brain and our cells. Water also helps to maintain body temperature also removes waste from our liver.

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Drinking sufficient amount of water is important, also not forgetting the water quality from our home tap is essential too! In our home, it may be wise to install a good quality water filter to maintain a high quality standard of drinking water.

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First it is important to choose a good quality membrane elements in the water filter system. An effective membrane filter will delivers water that are virtually free from any harmful biological matter. Performance is characterized by hardness reduction, color removal, and organic pollutants reduction. Energy conversion and salt rejection performance are also very important considerations.

A good water filter must remove chemicals including trihalomethanes, pesticides and herbicides, lead, mercury, chlorine (taste and odor), cryptosporidium and giardia cysts, bad taste and odor, and fine sediment. A good quality filter system will even the tea, coffee, juices, etc. that you make! A good water filter system will comes with a carbon block filter that can reduce chlorine taste and odour as well as sediment, rust, particulates and other containments. The carbon block filter cartridge is replaceable and typically can last up to 150,000 gallons of water usage.

A home water filter unit should be compact, space-saving design fits conveniently underneath the sink. Some unit comes with electronic monitoring system to remind you to replace the filter elements.

In some developed countries like Singapore which recycle used sanitary water using advance RO and Nano filtration technique as a form of water recovery. Nano filtration uses a series of thin-film membrane elements engineered for use with fouling-prone brackish water applications. Normally nano filters is designed to utilize an three-layer membrane, of which a proprietary middle layer creates extreme smoothness. Good quality membrane are superior than standard polyamide spiral wound membrane elements for desalination of difficult feed water sources. High quality membranes enables lower fouling, reduced overall energy usage, increased membrane service life and an extension of operating time between required cleanings, which in turn reduce expenditures on required chemicals.

These type of industrial membranes provides high rejection of divalent and multivalent anions while monovalent ion rejection is dependent upon feed concentration and composition.

These types of membranes consist of family of thin film ultrafiltration membrane elements which are characterized by a molecular weight cutoff of 8000 on polyethylene glyol and a smooth fouling resistant membrane surface. These ultrafiltration elements are used for RO pretreatment, color, TOC reduction and colloidal iron and silica removal.

Choosing a good quality membrane elements for municipal drinking water plants need to consider that it should provide a low pressure and cost effective nanofiltration alternative in addition to standard RO treatment. The result product should be virtually free from any harmful biological matter. Performance is characterized by hardness reduction, color removal, and orghanic pollutants reduction. Energy conversion and salt rejection performance is also very important considerations.

Health is important, do not neglect our drinking water quality.

Choosing a Good Quality Membrane Home Water Filter

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How Do I Seal a Leaking Pond Membrane?

If your pond membrane is leaking there are three main ways to fix it: the blanket method, the mixed blanket method, and the Sprinkle Method. Once you decide on a method you will need to test your soil to determine what the application rate of your sealant needs to be.

membrane vacuum pump

Testing the Pond's Soil

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Testing your soil is something that you must do to find out what kind of soil you have at the bottom of your pond. Take a can and perforate the bottom of it and then fill the bottom with about two inches of gravel. Cover the gravel with six inches of soil from the bottom of your pond and then tap it. Elevate the can so that the bottom is open and then fill the can with water.

The sealant you choose should have directions on how much should be used per square foot of soil on the bottom of your pond. Typically these application rates differ depending on what kind of soil you've used.

The Blanket Method

This is the most effective method for sealing your leaking pond membrane, but you will need to take more care when applying it. After you prepare the surface that needs to be sealed, remove between four and six inches of the soil at the bottom of the pond. Fill any deep crevices or holes with your sealant-the mixture should be one part sealant to five parts of soil, then smooth everything over with a drag or a roller. After that, cover the area with your sealant-make sure that the sealant layer is even and that there aren't any thin or bare spots. When the sealant is as even as you can get it to be, replace the soil you removed, but take care to not disturb your layer of sealant.

The Mixed Blanket Method

Prepare the area that you need to seal just like you did with the blanket method. If the soil is dry then you will need to add enough water to moisten it lightly and then disc or plow the bottom of the pond between four and twelve inches deep and then drag or roll the surface until the surface is smooth. When everything is smooth, apply your sealant in the correct amount. Mix the sealant with the to four to twelve inches of soil by hand raking, tilling or dicing until it has mixed uniformly, and then compact the bottom of the pond by tamping or rolling.

The Sprinkle Method

You should only use the sprinkle method when you can't drain the pond or if there is an isolated leak in which spotted treatment might be an alternative. This is the least effective method because the accurate and uniform application of the sealant is hard and because the bottom of the pond might not be clear of debris. Simply sprinkle the appropriate amount of sealant onto the water's surface and allow it to fall down into place and plug the leaks. The particles will be drawn to the leaks naturally and will repair the leaks without much effort on your part.

How Do I Seal a Leaking Pond Membrane?

MEMBRANE

Damp Proof Membrane - How to Choose the Correct Membrane For Your Problem?

The damp proof membrane market is increasing in choice everyday. Which product do you choose to get the required result "No more Damp"? Well first you need at assess whether you are just dealing with damp or if indeed you are dealing with the prospect of water entering the property. The rule of thumb here is have a look outside of the property to assess if you have high ground levels. This is really earth which is banked up directly against your wall which would allow water to move through it and enter the property. If you do indeed have this then it is best practise to dig it away from the wall thus getting rid of the risk of water. Some properties have only slightly high ground levels. You may just need to make a call on this but be aware that it may be a risk if the levels are not lowered.

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Now that your ground levels are lower than your internal floors, let's look at other sources of moisture ingress which may be affecting the property prior to choosing your damp proof membrane. Here's a list of external sources that need to be examined.

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• Leaking Gutters

Are your gutters overflowing and allowing water a direct route down your walls, causing staining? If so then clean them out! The moisture that has run down the walls may manifest in salting or staining internally. This is ok, you can deal with that with a damp proof membrane.

• Damaged Roof Tiles or Lead Flashings

This moisture source at high level is similar to the leaking gutter and may manifest internally at high level. You can deal with this with the correct damp proof membrane.

• Abutting Walls and Retaining Walls

Moisture can move laterally into structures through abutting walls so this needs to be examined and isolated with a damp proof membrane if possible.

• Blocked Drains

Look also for blocked drains and obvious sources of poor drainage in and around the property which could cause dampness to travel internally. This is very important when choosing the appropriate damp proof membrane option.

With external sources noted we can now look at the best damp proof membrane for your job.

All properties built within the last 50 years, at least in the UK, should have a physical barrier inserted into the brick/block work at 150mm above external ground levels. These are commonly described as a damp proof course (dpc). This form of damp proof membrane inserted into the mortar course is a highly effective barrier to deal with dampness from the ground moving up through capillary action to manifest internally within your property. So first it is very important to establish whether you have one.

It may not be a physical barrier since there are also chemical damp proof membranes which are used on properties which weren't built with a physical dpc or have been retrofitted to the structure if the original was defective. Evidence of this can be seen in small holes that have been drilled into the mortar course and later filled in, 150mm above ground level. This may have been done to deal with damp. These types of damp proof membranes are now utilising better technology from that used twenty years previously. Take note these type of products will still need skilled application and will require re-rendering up to 1m internally with a salt retardant additive. The rendering process will take time and will be introducing wet trades so you will be unable to redecorate quickly - maybe up to 6 weeks afterward. It is important to note that if your property does not have a uniform mortar course than the application of a chemical damp proof membrane will be extremely difficult. Be wary if someone offers you this damp proof membrane option.

Paint applied damp proof membranes are also an option. This is not simply a matter of slapping a bit of black bitumen paint on the wall and hoping for the best. There are plenty of "miracle" cure, paint-on options. Surprisingly enough these can actually cause more problems than were there in the beginning. Preparation is the absolute key when applying this type of product and will be the difference in it working, not working or making it worse. So be very clear to get this right and understand the amount of time required to get the prep right. The most common problem with this type of application is the product. If it does deal with damp, it could form a barrier and either move damp to where you haven't treated or push damp higher up the wall. These products also will not be very sympathetic to listed buildings and you may not be able to ever get them off!

Look at cavity membrane systems as well as a damp proof membrane solution. These products are dimpled sheets which can be applied mechanically with special fixings internally or externally (stopping penetrating damp through poor pointing) and applying either a direct plaster to the mesh on the membrane or dot and dab plasterboard on to the product. The latter is very popular now as once the damp proof membrane is applied to the wall you will not be waiting for drying out times and you can fix the membrane over stable existing plasterwork. There are choices with these types of damp proof membranes from 3mm to 8mm in depth and are made of hdpp or hdpe. The choices there are varied so you can marry these up with exiting plasterwork or if you like you can run them up the walls. These can also add thermal qualities to your wall. The air gap created behind allows for the walls to breath or dry out and forms a physical barrier so internal finishes are not contaminated with damp.

If you are in any doubt about which damp proof membrane is right for your project consult an established and reputable supplier or installation specialist. Always ask for case studies and testimonials to confirm quality. It never hurts!

Damp Proof Membrane - How to Choose the Correct Membrane For Your Problem?

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Biofuel Production - Is Membrane Technology the Answer?

Biofuel production with the help of membrane filtration technology is not entirely new technology as some think it is. In fact we are talking here about tried and proved industrial method that has been utilized in many industrial facilities, and after many positive experiences has been now implemented in biofuels production.

membrane air dryer

Many energy experts expect that with the help of membrane filtration technology "second-generation" cellulosic ethanol production could be significantly improved, especially in terms of fuel recovery as well as getting as much as possible secondary products from the used feedstock. To put things as simply as possible this new technology should mostly help improve the efficiency of biofuel production by offering lower overall energy costs.

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The things you need to know about the membranes used in this process is that they are highly engineered, and they are designed to allow the passage of materials only up to a certain size and shape. As said above the process of membrane filtration has been used extensively in several different industry facilities for many years. The best examples to mention here would be sugar, food, wine, and similar other enzyme manufacturing sectors.

But let us get back to biofuel production. Membrane filtration technology is becoming very important in production of biodiesel, where membranes are used to facilitate water reuse, this is especially helpful in areas where water is scarce..

Energy experts expect that within this decade we will see lot more biofuel facilities that will use this process for biofuel production. This should also increase the popularity of biodiesel and other biofuels on global level.

Biofuel Production - Is Membrane Technology the Answer?

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The Future of Touch Screens & Membrane Switches

A customer of mine has seen the future of user interface, and he loves it! People are shocked when they hear that the price of a touch screen has dropped below in some cases.

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In case you don't know, a touch screen is a control panel that offers users pin point input accuracy and pen recognition. With an LCD behind it the control panel becomes customizable, vivid, and very user friendly in a simple to use format. Most people think a touch screen requires an LCD, but for a manufacturer like RSP, Inc. (www.rspinc.com) we can print legends directly on the glass essentially making it into a flat membrane switch. The standard control panel (user interface) technology is a membrane switch with printed legends. A membrane switch is a piece of printed plastic with 1 or 2 circuit layers buried inside. It can be mounted to a flat or flexible surface. Membrane switches have been around for over 25 years now. Millions of membrane switches can be found on microwaves, coffee makers, remote controls, and many other household items. While membrane switches have become a low price commodity, slowly but surely the cost of touch screens have continued to drop. Are touch screen the next commodity?

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The popularity of the iPhone has made everyone very familiar with touch technology. Consumer products are now featuring them. Everyone has seen a touch screen kiosk in the mall and at the ATM machine but have you seen one on a television? The future of touch screens is big, bright, and bendable! Yes. Touch screens, long criticized for their thickness and rigidity, can now bend, twist, and even lightly fold. Why shouldn't your laptop have a touch interface? Next year they will if the products being shown at consumer electronic shows reach the marketplace.

Another historical draw back to touch screens has been that they lack tactile response. A membrane switch typically has a tactile metal dome inside that gives the user feedback and a 'snap' feel. In the past 2 years, touch screens have been designed with user feedback so that the user does not miss out on the 'snap'.

The Future of Touch Screens & Membrane Switches

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