Terry Towel Calculations – 1
Calculating the Weight of Ground Warp in a Terry Towel
A terry towel is different from an ordinary woven fabric because it has a looped surface. These loops are responsible for the towel’s softness, bulk, absorbency and characteristic hand feel. Unlike a simple plain woven cloth, a terry towel normally uses two warp systems and one weft system. These are the ground warp, pile warp and weft.
The ground warp forms the foundation of the towel. It gives strength and stability to the fabric. The pile warp forms the loops on the surface. The weft binds the warp systems together and helps create the final towel structure. In this article, we shall calculate only the weight of the ground warp used in one towel. The pile warp and weft calculations can be taken separately.
Table of Contents
- Understanding the Terry Towel Structure
- Given Data
- Understanding Tex
- Why Ground Warp Is Calculated in Two Parts
- Formula for Ground Warp in Grey Fabric
- Calculation of Ground Warp in Grey Fabric
- Why Warp Crimp Is Important
- Formula for Ground Warp in Fringe
- Calculation of Ground Warp in Fringe
- Total Ground Warp Weight
- Why the Ground Warp Weight May Look Small
- Practical Notes for Textile Calculations
- Key Learning
- Related Reading
- Sources
- General Disclaimer
1. Understanding the Terry Towel Structure
In a terry towel, the pile loops are not accidental. They are deliberately formed by controlling the movement and tension of the pile warp during weaving. The pile warp is usually kept under lower tension than the ground warp, so that it can be pulled forward and formed into loops. The ground warp remains more tightly controlled and works as the structural base of the towel.
This is why terry towel weight calculation is not done exactly like a simple flat fabric calculation. We have to treat each yarn system according to its function in the fabric. The ground warp, pile warp and weft do not consume yarn in the same way. Their yarn counts, lengths, crimp values and structural roles may be different.
2. Given Data
Let us assume the following construction details for the towel. These values are used to explain the method of calculation. In practical mill work, the values should be taken from actual fabric construction, loom settings, yarn count records and production data.
| Parameter | Value |
|---|---|
| Length of grey towel | 106 cm |
| Number of ground warp ends | 694 |
| Ground warp count | \(25 \text{ tex} \times 2\) |
| Warp crimp | 8% |
| Warp crimp factor | 1.08 |
| Fringe length | 2 cm |
The ground warp count is given as \(25 \text{ tex} \times 2\). This means that the yarn is a two-ply yarn. Each ply is 25 tex, so the effective yarn count for calculation is:
\[ 25 \times 2 = 50 \text{ tex} \]
3. Understanding Tex
Tex is a direct yarn count system. It tells us how many grams are present in 1000 metres of yarn. In direct count systems, a higher tex value means a heavier or coarser yarn, while a lower tex value means a finer yarn.
\[ \text{Tex} = \frac{\text{Weight in grams}}{1000 \text{ metres}} \]
So, if a yarn is 50 tex, it means that 1000 metres of that yarn weighs 50 grams. This makes tex very useful for calculating yarn weight when the length of yarn is known.
Practical point: Whenever tex is used, the length must ultimately be converted into metres. Since towel dimensions are often written in centimetres, the centimetre-to-metre conversion must be handled carefully.
4. Why Ground Warp Is Calculated in Two Parts
The ground warp is present in two places. It is present in the main grey fabric body of the towel, and it is also present in the fringe portion. These two portions are treated separately because the yarn behaviour is different in both areas.
In the grey fabric body, the ground warp interlaces with the weft. Because of this interlacement, the yarn does not remain perfectly straight. It follows a slightly wavy path. This extra length is called warp crimp or warp take-up.
In the fringe portion, the yarn is generally considered to be straight and loose. Therefore, warp crimp is usually not added to the fringe calculation in a basic estimate.
\[ \text{Total ground warp weight} = \text{Ground warp in grey fabric} + \text{Ground warp in fringe} \]
5. Formula for Ground Warp in Grey Fabric
The formula for calculating the ground warp weight in the grey fabric body is:
\[ \text{Ground warp weight in grey fabric} = \frac{ \text{Grey length} \times \text{Warp crimp factor} \times \text{Number of ground ends} \times \text{Yarn tex} }{ 100 \times 1000 } \]
The denominator \(100 \times 1000\) is used for unit conversion. The fabric length is given in centimetres, while tex is based on metres. Since \(100 \text{ cm} = 1 \text{ metre}\), and tex is based on \(1000 \text{ metres}\), the conversion factor becomes:
\[ 100 \times 1000 = 100000 \]
6. Calculation of Ground Warp in Grey Fabric
Substituting the values:
\[ \text{Ground warp weight} = \frac{ 106 \times 1.08 \times 694 \times 25 \times 2 }{ 100 \times 1000 } \]
Since \(25 \times 2 = 50\), we can write:
\[ \text{Ground warp weight} = \frac{ 106 \times 1.08 \times 694 \times 50 }{ 100000 } \]
\[ = 39.72 \text{ grams approximately} \]
Therefore:
\[ \boxed{\text{Weight of ground warp in grey fabric} = 39.72 \text{ g}} \]
7. Why Warp Crimp Is Important
Warp crimp is the extra yarn length required because of interlacement. In a woven fabric, warp yarns pass over and under the weft yarns. This makes their actual path longer than the straight fabric length. Therefore, if we calculate warp consumption only from the straight fabric length, we may underestimate the yarn actually required.
If the fabric length is 100 cm and the warp crimp is 8%, the actual yarn length consumed is:
\[ 100 \times 1.08 = 108 \text{ cm} \]
So an 8% crimp means that for every 100 cm of fabric length, 108 cm of warp yarn is required. In this example, a crimp factor of 1.08 has been used:
\[ 1 + \frac{8}{100} = 1.08 \]
In actual production, warp crimp may vary depending on yarn tension, weave structure, reed setting, picks per cm, finishing shrinkage and loom conditions. Therefore, crimp should ideally be taken from mill records or measured from actual fabric samples.
8. Formula for Ground Warp in Fringe
The fringe length is calculated separately. The formula is:
\[ \text{Ground warp weight in fringe} = \frac{ \text{Fringe length} \times \text{Number of ground ends} \times \text{Yarn tex} }{ 100 \times 1000 } \]
In this basic calculation, crimp is not added to the fringe because the fringe yarn is not interlaced like the main fabric body. However, for a detailed production costing, fringe trimming, knotting, twisting and wastage may also have to be considered.
9. Calculation of Ground Warp in Fringe
Substituting the values:
\[ \text{Ground warp weight in fringe} = \frac{ 2 \times 694 \times 25 \times 2 }{ 100 \times 1000 } \]
Since \(25 \times 2 = 50\):
\[ \text{Ground warp weight in fringe} = \frac{ 2 \times 694 \times 50 }{ 100000 } \]
\[ = 0.69 \text{ grams approximately} \]
Therefore:
\[ \boxed{\text{Weight of ground warp in fringe} = 0.69 \text{ g}} \]
10. Total Ground Warp Weight
Now we add both parts:
\[ \text{Total ground warp weight} = \text{Ground warp in grey fabric} + \text{Ground warp in fringe} \]
\[ = 39.72 + 0.69 \]
\[ = 40.41 \text{ grams approximately} \]
Therefore:
\[ \boxed{\text{Total ground warp weight} = 40.41 \text{ g}} \]
11. Why the Ground Warp Weight May Look Small
At first glance, the ground warp weight may appear small. However, this is understandable in terry towel construction. A terry towel is not a flat fabric where the ground warp, weft and total fabric weight are closely balanced. In a terry towel, the pile warp contributes a major share of the final weight because the pile warp forms the loops.
The ground warp is mainly a foundation system. Its purpose is to hold the fabric together and provide dimensional stability. It is not expected to contribute the largest portion of the towel weight. The pile warp, because of its loop formation and pile ratio, normally consumes much more yarn than the ground warp.
12. Practical Notes for Textile Calculations
This calculation is a basic yarn consumption estimate. It is useful for understanding how ground warp weight is calculated, but actual mill calculations may require additional allowances. In production, theoretical yarn consumption and practical yarn requirement are not always the same.
| Factor | Why it matters |
|---|---|
| Actual warp crimp | Changes the real yarn length consumed in the fabric body. |
| Loom waste | Extra yarn is required during weaving, tying, starting and ending. |
| Beam gaiting waste | Warp preparation and loom setting may consume additional yarn. |
| Fringe trimming | The final towel may lose some yarn during trimming or finishing. |
| Sizing material | Sizing may increase grey fabric weight before desizing or washing. |
| Moisture regain | Measured yarn and fabric weight may vary with atmospheric moisture. |
| Yarn count variation | Actual yarn may differ slightly from the nominal tex value. |
| Finishing shrinkage | Final dimensions and GSM may change after washing and finishing. |
Therefore, for production costing, this theoretical value should be adjusted using mill experience and actual fabric measurements. The formula gives the logic, but the mill data gives the practical correction.
13. Key Learning
The ground warp weight of a terry towel depends on four main things: the length of the towel, the number of ground warp ends, the yarn count in tex and the warp crimp or take-up. The basic logic is simple:
\[ \text{Yarn weight} = \frac{ \text{Yarn length} \times \text{Number of yarns} \times \text{Tex} }{ 100 \times 1000 } \]
The most important point is to handle the units carefully. Since tex is based on grams per 1000 metres and towel length is often given in centimetres, the conversion factor must be applied properly. A calculation may look simple, but a small unit error can produce a very large difference in yarn consumption and costing.
For a textile student, merchandiser or production planner, this calculation gives a useful foundation for understanding towel costing and yarn consumption. The ground warp is only one part of the towel. To calculate the complete towel weight, one must also calculate the pile warp and weft weights separately.
\[ \text{Total towel weight} = \text{Ground warp weight} + \text{Pile warp weight} + \text{Weft weight} \]
In the next part, we can calculate the pile warp weight, which is usually the most important contributor to the weight, feel, absorbency and bulk of a terry towel.
Sources
- Hutex. Terry Towel: Terry Weaving. Available at: https://hutex.co.kr/wp-content/uploads/2023/06/Terry_Towel.pdf
- ScienceDirect Topics. Pile Warp - An Overview. Available at: https://www.sciencedirect.com/topics/engineering/pile-warp
- Textile School. Terry Towels: Fabrics That Can Absorb Large Amounts of Water. Available at: https://www.textileschool.com/3211/terry-towels-fabrics-that-can-absorb-large-amounts-of-water/
- Resil Chemicals. Technical Tuesday: Terry Towel. Available at: https://resiltextiles.com/wp-content/uploads/simple-file-list/Technical-Tuesday/2014/TT-Terry-Towel.pdf
- ResearchGate. An Investigation into the Parameters of Terry Fabrics Regarding the Production. Available at: https://www.researchgate.net/publication/293131432_An_investigation_into_the_parameters_of_terry_fabrics_regarding_the_production
General Disclaimer
This article is intended for educational understanding of terry towel yarn consumption calculations. The numerical values used here are illustrative and should not be treated as universal production standards. Actual mill calculations may vary depending on yarn count variation, loom settings, pile ratio, warp and weft crimp, sizing, wastage, finishing shrinkage, moisture regain and the specific construction of the towel.
For commercial costing, production planning or quality control, the calculation should be verified with actual fabric samples, mill records and approved technical specifications.
Goyal, P. Terry Towel Calculations-1. My Textile Notes. Available at: http://mytextilenotes.blogspot.com/2009/07/terry-towel-calculations-1.html
If you have a question related to this topic, you are welcome to ask it in the My Textile Notes Discussion Forum.
Students, merchandisers, designers, researchers and textile professionals are welcome to participate.
it is very nice. But, Please reconfirm the calculation with 16/s Yarn in weft+pile & 20/2 in Warp with 1" salvage on both ends.
ReplyDeleteThanks for the query. If we take 16s yarn for pile and weft, and 20/2 yarn for ground warp, then 16s is approximately 36.91 tex and 20/2 is approximately 59.05 tex. Using the same construction values, the ground warp weight comes to about 47.73 g, the pile warp weight to about 114.10 g, and the weft weight to about 49.67 g if 1 inch selvedge is added on both sides. Therefore, the total towel weight is approximately 211.50 g. If the reed width already includes the selvedge, the total will be about 207.52 g.
DeleteHow we calculate pile ratio
ReplyDeletePile ratio is based mainly on pile height, pile warp tension, ground warp tension, terry beat-up setting, picks per cm, yarn count, required GSM, softness and absorbency. Higher pile height and softer, bulkier towels need more pile yarn, so the pile ratio increases. Lower pile height and lighter towels need less pile yarn, so the pile ratio decreases. In other words, pile ratio is decided by the required towel construction and performance, not by yarn count alone.
DeleteHow to calculate calculated gsm of terry towel
ReplyDeleteCalculated GSM = (Calculated towel weight in grams × 10000) ÷ (Length in cm × Width in cm)
DeleteHere, towel weight = 211.50 g, length = 106 cm, and width including selvedge = 63.48 cm.
GSM = (211.50 × 10000) ÷ (106 × 63.48) = 314.22
Therefore, the calculated GSM is approximately 314 GSM.
How to calculate pile hight terry towel
ReplyDeletePile height in a terry towel means the approximate height of the loop standing above the ground fabric. It is related to pile ratio, picks per cm and the way the loop is formed during terry weaving.
ReplyDeleteIn simple terms, pile ratio tells us how much pile yarn is consumed compared with the towel length. The extra yarn, beyond the straight fabric length, goes into forming the loop.
Approximate pile yarn consumed per unit fabric length = Pile ratio factor
Extra yarn available for loop formation = Pile ratio factor − 1
Since one loop has two legs, the approximate pile height can be estimated as:
Pile height ≈ Extra pile yarn length per loop ÷ 2
A simplified practical formula is:
Pile height in cm ≈ (Pile ratio factor − 1) ÷ (2 × picks per cm)
For example, if pile ratio is 52:10, then pile ratio factor = 52 ÷ 10 = 5.2. If picks per cm are 20:
Pile height ≈ (5.2 − 1) ÷ (2 × 20)
Pile height ≈ 4.2 ÷ 40
Pile height ≈ 0.105 cm
So the approximate pile height is 0.105 cm, or about 1.05 mm.
This is only an approximate theoretical value. Actual pile height depends on pile warp tension, ground warp tension, beat-up setting, yarn bulk, loop shape, finishing, washing and shrinkage. Therefore, in production, pile height should ideally be measured physically on the finished towel.