Archives for May 2018

Welding Chillers and Heat Management During Welding

NSC Admin · May 30, 2018 ·

Welding is a common procedure used to join two or more pieces of metal for use in a wide range of applications. The process can be done at outdoor locations (e.g. farms, highways, construction sites) or in an indoor setting, typically shops and factories.

[read: An Introduction to Welding]

Worker Welding

Welding requires the following components: metals to be joined, a heat source, and a filler metal. The most common types of welding found in industrial environments are: Gas Tungsten Arc Welding (GTAW), Stick Welding, Gas Metal Arc Welding (GMAW), and Flux Core Arc Welding.

It may go without saying, but high-quality welding requires careful heating/temperature management. Temperature management before, during and after welding defines the preciseness and quality of the weld.

Here are a few reasons why we’re careful about temperature control when it comes to welding:

It can prevent some costly and time-consuming reworks

When working on common materials like cast irons, copper (and its alloys) aluminum, and steels, proper heat dispersion and management prevents stress and weakened metals. Quick changes in temperature can mean extra work if not wasted materials. Take it from us: any time saved by cutting corners on heat control will only come back to haunt you. It’s better to take your time with temperature to maintain the integrity of your materials and product.

It reduces the risk of Hydrogen Induced Cracking (HIC)

Hydrogen Induced cracking, is “caused by the blistering of a metal due to a high concentration of hydrogen.” Carefully approaching the heating and cooling of welded materials allows hydrogen to be properly drawn out. This effectively reduces or eliminates the risk of HIC and, consequently, expensive and time-consuming reworks (see above).

It relieves residual stress

Collapsed Bridge — (The Silver Bridge in Ohio, 1967, believed to have collapsed due to residual stress from uneven cooling)

In welding, the quick thermal expansion and reduction created along a very limited spot could become a major source of residual stress. This is stress that remains within an object/material after the external source of stress has been removed. While residual stress may be desirable in some engineering applications, uncontrolled residual stress should be avoided at all costs. This uncontrolled, undesirable stress leads to weak welds and premature structural failure.

Residual stress frequently occurs when a welded metal’s temperatures are raised and quickly lowered with little or no control or when cooling occurs unevenly. Slowly and carefully removing heat from welded materials prevents the welded spot from becoming too fragile and ductile.

At North Slope Chillers, we’re all about taking the stress out of welding temperature control (pun intended). Our products provide controlled, even, process cooling that will help maintain the strength and integrity of your welded products. Additionally, we offer custom solutions– whatever your cooling needs are, we can help!

Give us a call at (866) 826-2993 if you’re interested in incorporating a chiller into your welding process.

Cooling During Injection Molding

NSC Admin · May 29, 2018 ·

Injection molding is a manufacturing process wherein raw materials, most commonly thermoplastic resins in pellet form, are consecutively melted, remolded and cooled. This manufacturing method is typically used in mass-production processes were the same part is being produced thousands or even millions of times in succession. The components made through this process can be found on almost every product that you encounter– from automotive products and electronics to housewares and food packaging.

Weighing plastic particles to be prepped for injection mold

Cooling during Injection Molding

In the injection molding industry, process cooling covers an average 95% of the cycle time. After the end of the first stage of injection, the rest of the molding sequence is cooling. Processors, however, often disregard this critical phase of molding, which can result in a large loss of profit.

While heating and mold cooling are both extremely important during injection molding, cooling is much more critical. It is more difficult to ensure that cooling happens at an even, uniform rate and results in a high-quality product. When cooling is taken seriously and proper cooling tools are in place, manufacturers can reap some impressive benefits.

Benefits of Focusing on Cooling

Save Time and Money

When you have the right tools to heat and cool more quickly, the production process and cycle time can be completed in just a matter of days and requires fewer raw materials. This has the potential to save some serious money, especially on high volume production projects.

[READ: Why Conformal Cooling Makes $ense]

Product Uniformity

Having conformal mold cooling channels allow the coolant to access all part locations evenly. This can reduce the presence of any thermal stress defects such as warpage, sink marks, weld lines, etc.

Colorful plastic blocks

Chemical Consistency

Cooling is vital because the thermoplastic resin doesn’t like to be molten for a long time. If this happens, changes in its chemical make-up will degrade and the plastic might become unusable. Utilizing a high-quality cooling solution will help ensure product integrity.

Scrap Rate Reduction

Efficient cooling reduces scrap rates. Temperature variation is minimized via conventional cooling channels. This helps ensure consistent, reliable, high-quality product.

North Slope Chillers’ injection molding chillers and Fluxwrap fluid channel blankets help you keep your process cooling temperatures under control.

We provide inexpensive and dependable cooling options specifically modeled with our customers’ needs and demands.

Cooling in Printing

NSC Admin · May 11, 2018 ·

Cooling in Printing

Throughout the printing process heat is generated as a result of friction between component parts and then transferred to ink and paper. There is also an elevated ambient temperature within the press room. This increased heat can deteriorate the quality of the ink and the overall quality of the printing operation. Printing chillers and process cooling can preserve and improve print jobs and extend the life of printing equipment.

Moisture is Important

Many outside the printing industry take for granted the fine details and attention required to create the printed materials we read and enjoy every day. For example, did you know that there is moisture in paper?
Yes, paper is hygroscopic. This means that paper either absorbs or releases moisture to maintain balance with the moisture in the air. Moisture content is important for inkjet, laser, digital and offset printing, and if unbalanced, it can affect toner adhesion, paper jams, fuser roller temperature, interaction between ink and paper, and ultimately the overall quality of the print job.
Cooling in Printing

Effects of Heat

Because moisture is an important factor in printing, operations are acutely aware of heat. Heat, a natural byproduct of printing, is created by friction and speed in the printing process, causes moisture in paper or the surrounding air to evaporate, lowering the moisture content. Heat also affects the viscosity of the ink. Ink viscosity increases at lower temperatures, which will slow ink flow and print density. It can also cause mottled print and excessive linting. When temperatures rise, ink lowers in viscosity and over emulsification can occur. Heat can also lead to ink dripping, smearing, misting, or spitting.

Printing Industry Cooling Options

Fans

Some printing operations use fans and air conditioning systems to address heat issues within their facility. Some large scale printers and are equipped with internal fans to help regulate process cooling in printing. Due to the unstable chemicals and compounds used, fans are often required to remove and exhaust harmful fumes and odors. Some fans are engineered to work within exhaust systems.

Vent/Exhaust Systems

Another option for removing heat is a vent system. This works much like a dryer vent in the laundry room. Heat created in the printing process is forced outside through a vent. Ventilation kits are available for some printers and duplicators. These are exhaust ventilation systems that remove air directly from the machine to an exterior location.

Industrial Chillers

Chillers apply the most direct form of cooling in the printing process. In the printing industry, industrial chillers remove heat generated by the friction of printing rollers and cool down the paper after it comes out of the ink drying ovens.

As printing machines improve and increase in speed, temperatures of all printing processes become higher. Roller temperature during the press’ start-up phase and in full operation is an important factor to control to protect ink quality. Chillers are specially designed to regulate temperatures, decreasing print time and improving efficiency.

A chiller cools process fluids, typically water or a water/glycol mix. These process fluids remove heat from rollers and other component parts, paper, and ink. The fluid absorbs the heat from the printing process and is then recirculated through the chiller to cool again and again. Using a chiller in the printing process is a cost effective and reliable method or reducing high temperatures, saving time, and preserving machinery and materials.

DOWNLOAD THE CHILLER SELECTION GUIDE

Welding Chillers and Heat Management During Welding

It can prevent some costly and time-consuming reworks