ASTM D3285 Cobb Test

Testing Standard:

ASTM D3285 Test Method for Water Absorptiveness of Non-Bibulous Paper and Paperboard (Cobb Test)

Overview:

ASTM D3285 is used to evaluate the materials rate of water absorption. This test method applies to most non-bibulous materials, such as paper and paperboard. Purple Diamond Testing offers ASTM D3285 Testing as part of our packaging compliance and validation services. 

According to https://www.document-center.com/standards/show/ASTM-D3285, “1.1 This test method covers the determination of the quantity of water absorbed in a specified time by non-bibulous paper and paperboard with a minimum thickness of 0.1 mm. This test method is generally applicable to sized paper and paperboard, but is not recommended as a sizing test for writing papers. The test method is based upon studies by Cobb and Loew, Cobb, and other investigators (1, 2, 3, 4).

The ability to resist the penetration of water in packaging is really important, especially if the packaged goods are moving internationally in distribution. In particular, the Cobb Test determines the quantity of water that will be absorbed by the surface of the paper or board in a given time frame. Due to various paper and board characteristics, the test of water absorption is a function is relative to the sizing and porosity of the paper and board being tested. This test is often involved in obtaining certain certifications such as those that involve hazardous materials packaging. The standard method is useful when testing a different variety of hygroscopic surfaces that are originally designed to resist water absorption.

Rationale for ASTM D3285:

Test Method for Water Absorbency of Non-Bibulous Paper and Paperboard (Cobb Test). The amount of moisture in paper materials affects the overall physical strength, porosity, and end useability. This test method can be ideal when comparing different materials or verifying a material is within a specified range of acceptance. A predetermined volume of water is applied to the material and the time it takes to be absorbed is recorded. 

According to Scribd.com, “The Water Absorption Apparatus, to permit one side of the specimen to be wetted uniformly at the moment the soaking period begins, and to allow controlled rapid removal of the water from the specimen at the end of the test period. The cross bar has a hole at one end and a slot at the other to facilitate assembly and use. On the base plate is a rubber mat, larger than the outside dimensions of the ring, on which the specimen is clamped.

The metal parts should preferably be of brass or other corrosion-resistant material. Several versions of the water absorption apparatus are now available. Although the basic procedure for performing the test is not changed, the clamping mechanism is. This may affect the time required to remove the specimen from the apparatus.”

Key Points for ASTM D3285:

Related Standards:

As always, Purple Diamond offers you the ability to either schedule an initial consultation, complimentary, OR you can book a facility tour and come on in and visit. Definitely feel free to stop in to the lab if you are close to the Lehigh Valley. The packaging and whole Purple Diamond team is here to assist you anyway that we can. The initial consultation can be either a phone call or a zoom call, whatever is more convenient for you. Reach out via the Contact Us page by either filling out the contact us form OR booking some time on the calendar below the contact form. Either way we will get back to you! Thank you so much for reading down this far and thank you for considering Purple Diamond as your dedicated testing, engineering, and design facility for all of your packaging needs.

Accreditations

Achieving ISO 17025 Accreditation is the pinnacle in third-party laboratory testing accreditation. It confirms that the facility has management, quality, and technical systems in place to ensure accurate and reliable analyses.
ISTA is revered as the certification standard for package testing for distribution. ISTA’s Testing Protocol remains a series of testing methodologies and standards well recognized within the packaging community.
A select few companies are authorized by PHMSA as an approved third-party packaging testing laboratory in accordance with Hazardous Materials Regulations, critical to ensuring safe transport of dangerous goods.

Affiliations

With over 12,000 standards globally, ASTM International’s fully transparent standards development enhances performance and confidence in consumer choices.
The Technical Association of Pulp and Paper Industry’s peer-reviewed standards improve production through operational methods and industry recognized best practices.

 

 The APASS program was designed by Amazon to help support vendors, sellers, and manufacturers in obtaining certification of their products as Frustration Free Packaging (FFP), Ships in Own Container (SIOC), or Prep-Free Packaging (PFP).

Your Concept, Our Expertise

Enter your contact information below to get in contact today

To View Our Accreditation, Please Fill Out This Form

ANAB ISO 17025 Accreditation Certificate

ANAB Accreditation Gated Form

  • This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

  • This field is for validation purposes and should be left unchanged.

To View Our Accreditation, Please Fill Out This Form

ISTA Accreditation Certificate

ISTA Accreditation Gated Form

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

This field is for validation purposes and should be left unchanged.

To View Our Accreditation, Please Fill Out This Form

UN/DOT Accreditation Certificate

DOT Accreditation Gated Form

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

This field is for validation purposes and should be left unchanged.