Gentle vacuum drying for non-flammable and flammable solvents

Vacuum drying chambers are used in many areas of science and industry in order to dry heat-sensitive materials quickly and effectively.

Conventional drying processes can damage heat-sensitive materials such as food, medication, chemicals or electronic components, or change their product properties. Carrying out the drying process in a vacuum drying chamber reduces this risk to a minimum. Vacuum drying is one of the most effective and gentle drying methods available. The aim of this method is to gently dry a high-grade product that contains water or a solvent without endangering the materials. Drying in a vacuum drying chamber is particularly recommended for compounds containing flammable solvents. Due to the oxygen in the air in particular, these compounds often develop an explosive atmosphere during the drying process. This is prevented when dried in a vacuum drying chamber. Vacuum drying also minimizes the risk of scaling or oxidation residue.

In the vacuum-drying process, the material to be dried is subjected to a reduced pressure environment, which reduces the boiling point and aids evaporation of the water or capillary transport. The targeted supply of heat and pressure control optimizes the drying process. Another positive effect is the low energy costs, as the vacuum makes it possible to dry materials at very low temperatures.

Huge range of applications

Typical applications for vacuum drying chambers include drying heat-sensitive products, semiconductors, and electronic components such as connectors, switches, and relays after cleaning. The chambers are also used to condition materials such as plastics and resins, as well as for certain aerospace tests, for fast and gentle drying of powder or granulate, or for drying materials with low heat conductivity. Further applications include drying tissue samples in the fields of cancer research and pathology, drying easily decomposable materials such as pigments, proteins, or vitamins, or drying seed materials such as cornmeal in order to eliminate moisture.

 

For more on Vacuum drying ovens: CLICK HERE

The role of ESD lab coats in ESD Protected Areas (EPAs)

People tend to believe that if a person is wearing a wrist strap, an ESD lab coat (also known as smocks) is redundant. This is due to the belief that any charge on the person or their clothes would find its way to ground via the wrist strap. This is a very common misconception and this blog post will explain in more detail why you should be considering the use of ESD lab coats in your ESD Protected Area (EPA).

Purpose of ESD lab coats

While the ESD Standard does not require ESD lab coats, they are a very practical. Some even believe, ESD lab coats represent the single most important step to demonstrate commitment to an ESD control programme. Clothing, particularly when made from synthetic fibres, are significant charge generators. Worse for ESD control, the fabric is an insulator so the result can be very hostile: an isolated charged insulator which cannot be grounded.

An insulator will not let charges flow and will therefore hold the charge until either neutralised over time (naturally over hours or days) or with an air ioniser (artificially under a few seconds).

In the meantime, your sleeves, waist, etc. may have several thousand volts (a very significant electric field to expose nearby conductors) that may induce charges on nearby isolated conductors. This is the main reason people wear ESD lab coats: so they can shield the insulative clothing and minimise the electric fields generated from their clothing.

Examples of lab coats - for more details click here

The ESD risk provided by everyday clothing cannot be easily assessed. The current general view of experts is that the main source of ESD risk may occur where ESDS [ESD sensitive items] can reach high induced voltage due to external fields from the clothing, and subsequently experience a field induced CDM [Charged Device Model] type discharge. So ESD control garments may be of particular benefit where larger ESDS having low CDM withstand voltage are handled, and operators habitually wear everyday clothing that could generate electrostatic high fields.” [CLC TR 61340-5-2 2008 User guide Garments clause 4.7.7.1 Introductory remarks]

ESD lab coat properties

Most lab coats are constructed of a dissipative material which incorporates texturised polyester and carbon nylon fibres. The conductive nylon fibres are woven in a chain-link design throughout the material, providing continuous and consistent charge dissipation.

ESD lab coats are an ESD protective product that should possess the following ESD control characteristics:

  • Antistatic low-charging so they decrease the generation of electrostatic charges;
  • Dissipative so when grounded they will remove charges to ground;
  • Shielding creating a “Faraday Cage” effect so they will restrict charges generated on the user’s clothing to the inside of the ESD lab coat and
  • Groundable so the user can easily and reliably connect them to ground.

Installation and grounding of ESD lab coats

Below are directions for correct installation and grounding of ESD lab coats:

  • Place the lab coat on and fasten all of the snaps on the front of the lab coat, making sure that clothing is not exposed outside of the lab coat.
  • Throughout use, it is essential that the conductive cuff is in intimate contact with the wrist skin. The conductive cuff should never be allowed to be pulled up and over the shirt sleeve.
  • Ground the ESD lab coat. A common way to ground an ESD lab coat is with a coiled cord either attached to a snap on the waist area of the lab coat or via a wrist strap snapped to the inside cuff of an ESD lab coat. If none of these methods are appropriate, the lab coat should be grounded via the person’s wrist removing charges via ESD footwear to ESD protected flooring.

Wearing your ESD lab coat correctly

"Garments on which high levels of static electricity can be generated are one of the causes of ESD damage. It is important that such charged garments do not come into contact with ESDS. The covering garments need to be grounded, either through direct contact with the wearer's skin, or by alternative means such as being electrically connected to a wrist strap. It is important that the ESD protective garment sleeves cover the end of the inner garment sleeves." [EN 61340-5-2 paragraph 5.2.5.]

Grounding a lab coat using the snap at the waist

ESD lab coats are a conductor and therefore should be grounded. If not grounded, the ESD garment can be a potentially hostile isolated charged conductor. If an operator is wearing a lab coat but is not electrically connecting the lab coat to either their body's skin or ground, then charges on the lab coat may have nowhere to go or discharge to.

Testing of ESD lab coats

Panel-to-panel conductivity is vital to ensure portions of the lab coat are not left as isolated charged conductors. A Resistance Test Kit can quickly measure resistance of the fabric and ensure panel-to-panel conductivity by placing 2.5kg electrodes on different fabric panels.

Surface ESD Tester

Surface ESD Tester

To ensure that the fabric is low tribocharging, a Static Field Meter can be used to measure charges generated by causing contact and separation with other materials. In addition, the Static Field Meter can demonstrate shielding by measuring a charged object and then covering the charged item with the ESD lab coat. Being shielded the measured charge should be significantly reduced.

Cleaning of ESD lab coats

The correct method to clean a lab coat is to wash the garment in cool or warm water, tumble dry with low heat or hang dry. Do not bleach your ESD lab coats! Please insure you only use non-ionic softeners and detergents when laundering.

Please also note that lab coats should not be altered in any way. The lab coats effectiveness is in fully covering the human body and street clothes – particularly at the wrists and front of the body. Altering the lab coat in any way will nullify its effectiveness.

The typical useful and effective life of a lab coat under normal wearing and recommended washing conditions is a minimum of 75 washings.

Questions for you: Do you use lab coats? If so, what's the reason you started using them?

JBC introduces the NEW SF Automatic Solder Feeder

Feed solder wire automatically from any position.

JBC, a leading manufacturer of soldering and rework equipment, has introduced the SF Automatic Solder Feeder, its latest technological innovation in hand soldering. The SF speeds up the soldering process and increase production efficiency.

This new solder feeder allows you to feed solder wire automatically from any position. You can easily configure parameters such as speed and length of the dispensed wireand monitor the consumption thanks to the integrated counters.

 

JBC SF Automatic Solder Feeder

JBC SF Automatic Solder Feeder

3 working modes

You can choose from continuous, discontinuous and programs mode. You can define up to 35 dynamic programs. In each one you can configure up to 3 steps with different length wire and dispensing speed. Execute them sequentially and cyclically with the concatenation option.

With V-Cut

The solder feeder features a small blade that perforates the solder wire down to the flux core while feeding it. This perforation process allows better flux flow and outgassing avoiding solder and flux splashing during the soldering process (also available without V-cut).

Ergonomic design

The ergonomic SF280-A Solder Feed Handle allows you to feed solder wire easily from any position. It is compatible with solder diameters of Ø 0.8 mm, 1mm & 1.5 mm. This means you can change the guide tube to suit your working needs.