Posts by Rachel Kohn
How Ultrasonic Baths Safely Clean Radiator and Air Conditioner Coils and Fins
Periodic automotive radiator flushing helps clean coils but does not remove mineral deposits. Air conditioner heat exchanger and condenser coils cannot easily be flushed. Power washing risks damaging delicate fins essential to heat dissipation. The answer for automotive repair technicians and HVAC professionals is ultrasonic cleaning. This post describes how ultrasonic baths safely remove contaminants from radiator and air conditioner coils and fins – together termed heat exchangers.
It presents:
- A definition of heat exchangers as used in this post
- Industry experience in ultrasonic cleaning heat exchanger components
- How ultrasonic energy cleans radiator and air conditioner coils and fins
- Suggestions on selecting ultrasonic cleaners and cleaning formulas
What is a Heat Exchanger?
The term heat exchanger describes a system involving heat transfer. It covers a lot of ground. Examples include
- Industrial heat exchangers in chemical, petroleum and food processing operations
- Radiators in automotive and marine engines to avoid overheating
- Condensers
Moisture Balance Ideal for QC in Molding Plastics
Operators of extrusion molding, injection molding, thermoforming and related equipment must pay particular attention to resin moisture content because too much or too little moisture will impact the quality of molded products. Correct moisture content depends on the resins being used and is specified by plastic resin manufacturers.
Resin manufacturers may ship product at the correct moisture content but equipment operators should take steps to ensure ambient conditions at the plant do not raise or lower the content prior to processing. Two important steps in quality control are proper resin storage and using commercial drying ovens. Periodic checks with a benchtop moisture analyzer programmed for plastic resins provide assurances that moisture content is on target, or otherwise call for pre-processing adjustments.
The Benchtop DSC 71P Lab Moisture Analyzer for Quality Control
Operating on the LOD (loss of weight on drying) process it handles samples to 71 grams and delivers … Read the rest
Selection Tips for Moisture Analyzers
If you are shopping for a moisture analyzer and feel stymied by the number of choices, these moisture analyzer selection tips should help.
Moisture balance selection criteria are based on factors including:
- Resolution or the smallest difference that can be read on the display. This is also termed readability or readout.
- Repeatability – the ability of a moisture balance to display the same result when the same sample is tested repeatedly. Expressed as a standard deviation.
- Features important to performing moisture analysis. These are based on the characteristics of product being analyzed such as those require special heating profiles.
- Specialized capabilities such as testing products with extremely low moisture content specs, providing graphic displays of changing moisture content, and building libraries of frequently performed tests.
Four Candidate Moisture Analyzers
Tovatech offers several models of moisture analyzers from which researchers or QC personnel can select the most cost-effective solution to their … Read the rest
How to Ultrasonically Clean Epoxy Dispensing Nozzles
Epoxy resin adhesives used in manufacturing liquid crystal display (LCD) screens and similar applications are applied to surfaces with automated dispensing machines through precisely machined nozzles.
As an example a nozzle can be 2.5 cm long with a 0.2 to 0.5 mm diameter tip at the point of dispensing. It is affixed into an approximately 80 x 60 x 50 mm module that receives epoxy by pneumatic pressure.
During the process the epoxy temperature is high enough to keep it liquefied. At the end of a cycle it quickly solidifies in the module and nozzle and must be removed.
Cleaning is performed daily after equipment shut-down. Manually scrubbing these assemblies is unsatisfactory for two reasons:
- it is not thorough, resulting in substandard epoxy application and
- it can damage the precise nozzle configuration.
How Ultrasonic Cavitation Delivers Fast, Safe, Epoxy Dispenser Cleaning
In contrast to mechanical scrubbing an ultrasonic cleaner is … Read the rest
How Counting Scales Count
Counting scales are great time savers that also improve the accuracy of counts when the objective is to ship or receive X numbers of widgets. They are also great for inventory management because they allow you to quickly determine how many widgets are in stock and when it is time to order more.
How do Piece Counting Scales Count?
Keep in mind that a piece counting scale can be programmed to determine the count of a number of products that are kept in the scale’s internal memory but each product must be the same. You must separate bolts from nuts, (and lock washers while we’re at it) not combine them unless you are counting assembled nuts, bolts and lock washers. And all bolt, nut and lock washer assemblies being counted must be the same. A counting scale with an internal memory of 100 items can store data for up to … Read the rest
Analytical Balance Best Practices
It doesn’t take much to throw an analytical balance off. What are the analytical balance best practices to keep your balance without error. The opportunities for errors to occur increase dramatically as the resolution or readout of analytical balances increases. That’s why labs and other users of an analytical balance should establish and post a “best practices” list and remind researchers to employ them at all times.
Once again we refer to the operations manual supplied with analytical balances such as the Kern series offered by Tovatech. These multi-page manuals, however, are not always “user friendly” although most instructions regarding to-do-or-not-to-do are published in the setup pages. Here we provide a brief analytical balance best practices bulletin to serve as a reminder. They are in no particular order of importance because all are important.
That said, a key point to remember is that sensitive balances are sensitive to many extraneous … Read the rest
Manual or Auto-Defrost Cold Storage Units for Lab
Lab refrigerators and lab freezers come in various sizes and temperature capabilities, many of which are designed for specific storage functions. What you store in these units has a large part in determining the type of unit you purchase. This post will cover decision-making factors such as storage temperature capability and whether manual or auto-defrost equipment should be specified when you choose manual or auto-defrost cold storage units for the lab.
We’ll separately take a look at scientific refrigerators and scientific freezers, then provide suggestions on how to manage defrosting operations.
Always keep in mind that temperature monitoring and alarming is a subject onto itself in laboratory refrigerators and freezers. The defrosting operation by definition signals a change in storage temperature within these units, whether a scientific freezer or scientific refrigerator. We’ll touch on this briefly at the end of our post.
In addition, two important points to include in … Read the rest
Choosing a Moisture Analyzer for Sludge Dewatering Operations
Moisture content is a critical criterion to determine the acceptability of treated sewage sludge (called biosolids or sludge cake) as an acceptable product for use as a fuel and a nutrient-rich organic material. Moisture analyzers play a vital role in quality control procedures at sludge dewatering plants.
After the brief intro our post explains two options for moisture analysis at these plants.
A Brief Intro to Sludge Dewatering at Sewage Treatment Plants
Improved wastewater treatment processes separate sewage sludge, called cake, as a usable biomass from water that must meet regulated levels of purity before being discharged into water courses.
For the cake to be useable its moisture content must be known to within 0.5 – 1%. This knowledge helps operators to control the drying process that turns biomass into a fuel. Industrial-scale dryers are used in this operation. As you might imagine, the lower the moisture content the more … Read the rest
Maximize Performance of your Ultrasonic Bath
If you have invested in an ultrasonic bath you have an appreciation of how these units contribute to fast, safe and efficient removal of contaminants from virtually any product that can be safely wetted in a biodegradable ultrasonic bath. In this post we provide recommendations on maximizing the performance of your ultrasonic bath, thereby contributing to the efficiency of your ultrasonic cleaning operations.
Points covered include:
- Selecting the correct cleaning bath chemistry
- Cleaning time and cleaning temperature
- Tips on extending the effective life of ultrasonic baths
Ultrasonic Cleaning Bath Chemistry
There is a wide variety of formulations available to support ultrasonic cleaning operations. Some manufacturers term these ultrasonic cleaning solutions, others use an overall category called soaps. One can’t argue with that because using soaps conjures up images of cleaning, whether in the car wash, clothes washer or shower.
Regardless of nomenclature, these formulations are designed to perform specific cleaning … Read the rest
Moisture Analyzer for Plastic Resins
When you select a moisture analyzer for low-moisture plastic resins you will need a model that that not only can quickly but also accurately gauge the moisture content of these resins. And as with many quality control requirements that involve moisture content, you’ll want a moisture balance that can meet standards set by trade associations and professional organizations.
In this post you’ll get a briefing on the following:
- why low moisture content is important in plastic resins
- a technical standard that applies to determining moisture in plastics
- how benchtop moisture analyzers work
- a standards-compliant moisture analyzer
for plastic resins
Why Low Moisture Content is Important
Owners of injection molding companies and operators of injection molding machines are aware that incorrect moisture content in plastic resins can result in an inferior finished product.
Product shipped from resin suppliers may have the specified moisture content but ambient conditions … Read the rest
