Different countries, industries, and manufacturers often use different terms for the same material or specification. For example, the reinforcement layer may be referred to as Base Fabric, Polyester Mesh, Polyester Scrim, or Woven Fabric, depending on the supplier. Similarly, terms such as PHR, hardness, and softness may vary due to differences in formulations, testing methods, and industry practices.
To make these terms easier to understand, we've compiled this guide to explain the most commonly used technical terminology in the PVC film and PVC tarpaulin industry.
What Is PHR?
PHR (Parts per Hundred Resin) is commonly used to indicate the amount of plasticizer added to PVC resin. In general, a higher PHR value means more plasticizer and a softer finished product.
PHR < 10: Rigid PVC
PHR 10~30: Semi-rigid PVC
PHR > 50: Flexible PVC (In general, higher PHR results in greater flexibility.)
Please note: Our PVC films are specifically designed for flexible applications and are available in a PHR range of 22 to 66. The exact PHR is customized according to the required softness and the intended application.
Warp knitted fabric VS woven fabric
Warp knitted fabric and woven fabric are the two most commonly used reinforcement fabrics in PVC tarpaulin. However, many buyers are unfamiliar with the differences between them, and some suppliers may use different terms such as base fabric, polyester scrim, or reinforcement fabric, which can easily lead to confusion. In fact, these two fabric types differ in their manufacturing structure, physical properties, and suitable applications. In practice, we recommend the most appropriate reinforcement fabric based on the customer's sample, technical specifications, and end-use requirements, rather than simply choosing one type over the other.
Warp knitted fabric is made by forming loops with multiple yarns running in the warp direction. Unlike woven fabric, the yarns are knitted rather than interlaced.
Woven fabric is produced by interlacing warp yarns (lengthwise) and weft yarns (crosswise) at right angles, creating a stable and durable structure.
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Feature
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Warp Knitted Fabric
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Woven Fabric
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Structure
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Flexible and elastic
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Stable and firm
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Stretch
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Higher
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Low
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Dimensional Stability
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Good
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Excellent
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Tensile Strength
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Generally lower
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Generally higher
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Tear Resistance
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Good
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Excellent
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Surface
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Softer
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Firm
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What Does 840D Mean?
840D refer to the yarn density (Denier) of the polyester base fabric inside the PVC tarpaulin.
Many buyers often ask: What does the "D" in 500D actually mean?
Denier (D) is a unit of measurement used to indicate the thickness (linear density) of fibers or yarns. It is defined as the weight in grams of 9,000 meters of yarn. For example, 1000D means that 9,000 meters of the yarn weighs 1,000 grams. In general, the higher the denier, the thicker and heavier the yarn.
Common denier specifications: 400D, 500D, 700D, 840D, 1000D, and 1300D.
The higher the Denier (D), the thicker and stronger the polyester yarn, which generally provides better tensile and tear strength.
![Common PVC Terms Every Buyer Should Know 2]()
What Does 18×17 Mean?
Many buyers notice specifications such as 18 × 17, 9 × 9, or 30 × 30, but are unsure what these numbers actually represent.
18 × 17 refers to the fabric construction or weave density, which indicates the number of yarns woven into one square inch of the base fabric.
Specifically:
18 = 18 warp yarns (lengthwise yarns) per inch
17 = 17 weft yarns (crosswise yarns) per inch
In other words, within a 1-inch × 1-inch (25.4 mm × 25.4 mm) area of the fabric, there are 18 warp yarns and 17 weft yarns interwoven together.
PVC laminated tarpaulin is produced by laminating PVC films onto a polyester base fabric using heat and pressure (or adhesive, depending on the process). The PVC film and the fabric are bonded together to form the finished material.
PVC coated tarpaulin is a waterproof fabric that is coated with the PVC solution. The main aim of coating is to enhance the durability and enhance its resistibility against atmospheric wear and tears. The material features a smooth surface which is well-suited for various applications including printing and branding.
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Key Differences
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Laminated PVC Tarpaulin
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Coated PVC Tarpaulin
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Manufacturing Process
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PVC films are laminated onto the polyester base fabric using heat and pressure
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Liquid PVC paste is directly coated onto the polyester fabric and fused during heating, creating a stronger bond between the PVC and the fabric
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Bonding Method
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The PVC film is bonded to the surface of the base fabric
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The PVC coating adheres directly to the base fabric, resulting in better adhesion
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Adhesion Strength
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Good
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Excellent
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Mechanical Strength
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Good tensile and tear strength for general applications
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Higher tensile and tear strength, suitable for heavy-duty applications
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Weather Resistance
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Good resistance to rain and sunlight for normal outdoor use
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Better resistance to UV exposure, aging, and harsh outdoor environments
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Durability
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Suitable for short-to medium-term outdoor use
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Designed for long-term outdoor applications with enhanced durability
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Flexibility
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Soft and flexible, suitable for general fabrication
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Maintains good flexibility while offering improved structural strength
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Weight
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Usually lighter under the same specification
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Usually slightly heavier due to the coating process
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Cost
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More economical and cost-effective
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Higher production cost because of the more complex coating process
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Typical Applications
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Truck covers, tents, agricultural covers, promotional products, general outdoor protection
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Industrial curtains, tensile structures, heavy-duty truck tarps, long-term outdoor covers, premium inflatable products
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Super Clear PVC Film & Normal Clear PVC Film
Our transparent PVC film is available in Super Clear and Normal Clear grades. While both offer excellent transparency, they differ in optical performance and visual appearance, making them suitable for different applications.
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Feature
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Super Clear PVC Film
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Normal Clear PVC Film
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Transparency
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Exceptional crystal-clear transparency
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Good overall transparency
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Surface Appearance
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High gloss with minimal haze
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Slight haze may be visible
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Light Transmission
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Higher light transmission for maximum clarity
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Standard light transmission
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Visual Effect
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Provides a clearer view with minimal distortion
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Suitable for general visibility and everyday applications
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To avoid misunderstandings and ensure the correct material is selected, we highly recommend providing a sample or detailed technical specifications whenever possible. This allows us to accurately identify the product and recommend the most suitable solution for your application.
