Web Coating Blog

Measurement of Paint Coating Thickness on Different Materials

Measurement of Paint Coating Thickness on Different Materials
Javier Marín Zafrilla
PCE Group Ibérica S.L.

Ultrasonic Principle
An ultrasonic technique is used when measuring the thickness of paint. The probe of the instrument contains an ultrasonic transducer that sends a pulse through the coating. The pulse reflects back from the substrate to the transducer and is converted into a high frequency electrical signal that is analyzed to determine coating thickness.
A example is the PCE-CT 28 coating thickness meter / gauge for cars is for measuring the thickness of paint and plastic on ferrous or non-ferrous materials without damaging the coating's surface. The coating thickness meter / gauge stands out due to its high range of measurement. This coating thickness meter / gauge should be one of the tools used by technicians in areas of paint or lacquering such as in production, automotive body repair or quality control.
The coating thickness meter / gauge is particularly useful in detecting damage to vehicles produced by an accident, for preventing possible damage or as a toll in auto body repair. Also, in the industrial sector, this device is essential for quality control in shipping and receiving and during production. It is ergonomincal with an integrated sensor and it shows results of measurements quickly and accurately. It was designed for non-magnetic coatings such as plastic, chrome, zinc, copper, etc. and insulation such as rubber, plastic, glass and paper over steel, iron, aluminium, brass and stainless steel. Thanks to its wide measurement range, the coating thickness detector is ideal for the naval and metal industries.

Paint thickness over exterior automotive materials is best measured with hand-held, electronic instruments.

Could you kindly suggest appropriate steps to prevent edge buildup in Mayer Rod Coating?

Mayer Rod Coating Edge Build-up

There are several reasons for the coating to build-up at the edges of the web:

• The gap between mayer rod(s) and web may not be uniform across the web.

• The web is not laying flat because of tension variations and web planarity. This could create wider gap at the edges leading to higher coating thickness.
• The coating solution surface tension may be too high and it is pulling the coating away from the free surface at the end of the web leading to build-up. surface tension. This should approve edge coating.

• If the web ispaper we would talk about a baggy edge. Is it possible the fabric has less strength ( for lack of a better term ) such that it is a little stretched at the edges thereby reducing web tension at the edges. This could allow a thicker coating at the edges.

I am also forwarding your memo to a Mayer Rod vendor who might be able to help.

How can we remove curling in coating PP/LDPE film on PP substrate?

Response to Blog Query on Curl

There are several actions that can be taken to reduce curl:

• Increase the relative humidity in the drying zone when the coating is in the falling rate zone. This will reduce shrinkage stress from the drying coating, which is causing the curl.

• Increase the relative humidity in space between the end of the dryer and the rewind.

• Plasticize the coating to reduce drying stresses.

• Use a coating on the backside of the substrate. This will counter act the stresses casing curl from the active side of the substrate.

• Consider thicker and higher modulus substrate.

• An increase in web tension can “pull out” some of the curl. However, depending on the physical properties of the substrate, the tension might distort the substrate,

Response to Question on Gravure Coating

Request :
explain to me in detail about gravure roller. what is meant by mesh size of gravureroller? how does it affects on coating gsm?

Response:

AIMCAL is sponsoring a series of Webinars on the Coating Process. A recent webinar was “Is Gravure Coating Right for You?”. It will answer all the questions that you have.

It is available for viewing on the AIMCAL website www.AIMCAL.org . At the home page click on Converting Portal and it will guide you to article

Response to apppropriate wiping angle of doctor blade

Comment: 
 Appropriate wiping angle of doctor blade, which will result in good result.

Response

The general recommendations for the contact angle for a conventional doctor blade is generally 55:65º, with 60º being most manufacturers' specified contact angle. The manufacturer of the blade you are using should give recommendations to use as a starting point.

However; there are several factors in addition to the contact angle that can affect performance. They are blade thickness straightness. tolerances, lip shape, deflection, wear, damage to the blade and surface roughness of the roll that us being doctored.

When defects occur, the doctor blade conditions should be optimized to eliminate defects.