Client Login

forgot password

Author Archive

Permethrin Testing at Vartest

Vartest is one of the few labs that are able to deal with both the textile technology and organic chemistry aspects of permethrin testing.

 

Permethrin is the most widely used insect repellent against mosquitoes, ticks, cockroaches, and other pest insects. It is typically applied as a finish to both textile piece goods and finished apparel.

 

Permethrin molecule, displayed from 2 angles

 

Using gas chromatography/mass spectrometry (GC/MS) based industry standard methods and military specifications, Vartest is able to report the amount of permethrin present on a garment both as a percentage on weight of fabric (OWF) and as a mass per unit area (grams per square meter or ounces per square yard).

 

Vartest is also able to assess the amount of permethrin present on a garment after refurbishment, using both diagnostic and industrial wash formulas as well as dry cleaning.

 

For more information, contact us at info@vartest.com.

DR. PREETI ARYA AND HER FIT CLASS VISIT VARTEST

Vartest hosted Dr. Preeti Arya and her Fashion Institute of Technology (FIT) Textile Development and Marketing class.  Students watched a PowerPoint focusing on the difference between Product Performance Specifications and Test Methods.

The students toured the lab seeing ASTM, AATCC, ISO, GB, ACT, BIFMA and Federal Standard 191 test methods for testing fiber, yarn, fabric (both coated and uncoated), used in apparel, aerospace, medical, military, couture, upholstery and active sportswear end uses.  Specialty testing markets like HVSA (High Visibility Safety Apparel) were reviewed in detail.

Vartest is glad to have built a relationship with the textile and apparel quality assurance and compliance executives of the future and continues to work with both FIT and its students.

Bed Sheet Thread Count Testing

Thread counts are an important characteristic of top of the bed fabrics, both for consumers and technologists.

As commonly used in the United States the thread count, or “T number,” of a top of the bed (bed sheet) fabric is the sum of the ends (lengthwise yarns) per inch plus the picks (widthwise yarns) per inch contained in the fabric.

The most common woven fabric construction for top of the bed fabrics is the plain weave.  Light and scanning electron images of a lightweight 100% plain weave cotton sheeting fabric are shown below:

 

Light Microscopy of 100% Cotton Sheeting Fabric

 

Scanning Electron Microscopy of 100% Cotton Sheeting Fabric

 

Graphically, this is represented as:

 

Plain Weave

 

Another common woven structure for top of the bed products is the satin weave:

 

Satin Weave

 

Fabrics made of 100% cotton can always have their thread counts determined unambiguously using current definitions, as can intimate blends of cotton and polyester staple (polyester fibers cut up to a length similar to cotton). Top of the bed fabrics containing continuous filament yarns can be trickier to deal with, partially due to unclear definitions of how to count continuous filament yarns in top of the bed products, and partially because of the nature of continuous filament yarns.

The following shows the back of a top of the bed woven satin made with 100% cotton yarns. This fabric uses “10 pick insertion.”  10 individual picks are inserted into the shed (the temporary separation between the upper and lower warp yarns through which the filling is woven) of the loom before the harnesses of the loom alternate and a new shed is formed.

Several years ago ASTM updated the standard terminology for how plied yarns used in bed sheets are counted:

“ASTM D7023 06 (Reapproved 2012) Standard Terminology Relating to Home Furnishings:

thread count, n—in woven textiles as used in sheets and bedding, the sum of the number of warp yarns (ends) and filling yarns (picks) per unit distance as counted while the fabric is held under zero tension and is free of folds and wrinkles, individual warp and filling yarns are counted as single units regardless of whether comprised of single or plied components.

DISCUSSION—The thread count of sheets and bedding articles is frequently displayed on the outside packaging of such items, or utilized in advertising literature. The specific construction of the warp and filling yarns used to construct the fabric in such items may also be displayed. Examples:

“300 Thread count, 2 ply yarn.” A representation of “600 thread count” for this same product would be likely to mislead consumers about the quality of the product purchased.

“Finely woven 380 2 ply fabric.” The representation of “finely woven 760 threads per square inch” is considered to be misleading to the consumer.

The following shows the back of a top of the bed satin fabric made with a 100% polyester filament filling and 100% cotton warp.”

With filament filling yarns the presence of distinct separable yarns comprising a multiple pick insertion fabric can be hard to determine.

To find out more about bed sheets, Take A Video Tour Of An Indian Top Of The Bed Factory or contact us directly.

Vartest is an ISO 17025 Accredited Laboratory in Manhattan providing fast turnaround and technical drill down testing for all aspects of fiber, yarn, fabric and end product testing.

Vartest Approved Under Underwriters Laboratories (UL) Data Acceptance Program

HOME_2

Vartest Laboratories conducts testing of high-visibility safety apparel (HVSA), including garments, retroreflective tapes, and background materials for a range of global standards.  This includes ANSI/ISEA 107, CSA Z96, ISO 20471, ASNZS 1906.4, and NFPA 1971.

As of August 2016, Vartest is certified to participate in Underwriters Laboratories’ (UL) Third Party Test Data Program (TPTDP). Under this program, test data from Vartest will be accepted by UL in support of UL Mark certification.  Vartest’s scope of testing under this program applies to UL’s Personal Protective Equipment (PPE) Standard, Including ISEA 107, CSA-Z96, and NFPA 1971. These standards cover compliance of high-visibility garments, background materials, and retroreflective tapes.

UL’s typical certification process requires samples to be tested and approved through one of their own laboratories. This means that manufacturers and vendors seeking a UL Mark for one of their products must test and approve samples for compliance, and then have them tested a second time by UL themselves. When working with a TPTDP participant, however, only one round of testing is necessary, as the participant’s data is accepted by UL. Per UL’s website, this alternative process provides “increased control over the timing and schedule for their product testing and certification program,” because testing, and approval can all be performed at one location. This can significantly reduce the time and expenses incurred during testing.

Vartest prides itself on being an independent third party lab focused on quick and accurate test results. Our ISO/IEC 17025 accreditation through A2LA makes us fully qualified to test under ANSI/ISEA 107-2015.