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What is Pressley Strength Tester?

What is Pressley Strength Tester?

Pressley strength tester

Pressley strength tester is used to determine the bundle of fiber strength of textile raw materials which is finally expressed in pressley valve for example tensile strength in lbs/square inch. SIt includes clamps ( distance from 0″ to 1/8″ can be choosen ). Use of Pressley requires a torsion balance up to 5 mg and 0,01 mg accuracy ( code 259D). An instrument of  Pressley strength tester determine the resistance of cotton fibers.

 Specification of Pressley strength tester

  • Product Category:Yarn
  • Machine Category: Yarn QC
  • Product Name: Pressley strength tester
  • Product Model:According to Manufacturer
  • Product Class: New
  • Origin: Made in China
  • Brand/ Manufacturer: Name of Manufacturer
  • Agent in Bangladesh: No/Yes
  • Power:380v
  • Temperature:Normal
  • Certification:SGS/Others
  • Production Capacity:NA

Quality Standard for Ring frame Cop-Combed Cotton

Sl.No Yarn characteristic Required value for 30s Other  counts
01 Average yarn count 30 ( 29.6 – 30.4) nominal count plus or minus 1.3%
02 Count C.V% less than  1.5 Less than 1.5%
03 Twist Multiplier 3.5 – 3.6 3.5 – 3.6
04 TPI  C.V% less than 2.5 less than 2.5%
05 U% 9.2 – 9.8 5 – 10 % Uster Stat. value
06 -50% thin place / 1000m less than 4 5 – 10 % Uster Stat. value
07 -30% thin place / 1000m less than 650 5 – 10 % Uster Stat. value
08 +50% thick place / 1000m less than 30 5 – 10 % Uster Stat. value
09 +200 Neps / 1000m less than 50 5 – 10 % Uster Stat. value
10 Total Imperfection / 1000 m less than 85 5 – 10 % Uster Stat. value
11 RKM ( tenacity) gm/tex more than 16.5 more than 16.5
12 RKM C.V% less than 7.5 % 5 – 10 % Uster Stat. value
13 Elongation % more than 5.5 more than 5.5
14 Hairiness H 4.0 – 4.5 < 50% value of Uster Statistics
15 Hairiness Standard Deviation less than 1.5 25% Uster stat value
16 Objectionable classimat faults(short & long) less than 1 per 100 km less than 1/100km
17 Total classimat faults less than 150 5 – 10 % Uster Stat. value
18 H1- thin faults less than 5 per 100 km 5 – 10 % Uster Stat. value

How to Buy Cotton?

Cotton buying is the most important function that contributes to optimum profit of a Spinning Mill.

  • Quality Evaluation : Cotton quality evaluation is usually based more on experience than on scientific characteristics testing.
  • Timing of purchase: Purchase timing depends on comprehensive knowledge about various factors which affect prices.
  • Choosing supplier : Reliable supplier choosing for reliability of delivery schedules & ability to supply within prescribed parameters define cotton quality.
  • Price bargaining : Bargaining for the lowest price depends on buyer’s reputation for prompt payment & accepting delivery without dispute irrespective of price fluctuations.
  • Logistic organising : Organising logistics for goods transportation & payment for value of goods enhance benefits arising out of transaction.
  • Profit making : Profit making depends on producing high quality yarn to fetch high prices. Influence of raw material quality is very important in producing quality yarn. But, quality of yam is a compound effect of quality of raw material, skills of work-force, performance of machines, process know-how of technicians & management expertise.

A good spinner is one who produces reasonably priced yarn of acceptable quality from reasonably priced fibre. Buying a high quality, high priced cotton does not necessarily result in high quality yarn or high profits.

Guidelines for Cotton Contracts:

Buyer & seller should clearly reach correct understanding on following issues:

  1. Country of Origin, Area of Growth, Variety, Crop year
  2. Quality – Based on sample or
    1. Description of grade as per ASTM standard or sample,
    2. For grade only & specifying range of staple length,
    3. Range of Micronaire, range of Pressley value, uniformity,
    4. Percentage of short fibre, percentage of non-lint content,
    5. Tolerable level of stickiness,
  3. Percentage of Sampling at destination
  4. Procedure for settling disputes on quality or fulfilment of contract obligations.
  5. Responsibility regarding contamination or stickiness.
  6. Price in terms of currency, Weight & place of delivery.
  7. Shipment periods
  8. Certified shipment weights or landing Weights
  9. Tolerances for Weights & Specifications
  10. Port of Shipment & port of destination, partial shipments allowed or not, transhipment allowed or not, shipments in containers or Break-bulk carriers
  11. Specifications regarding age of vessels used for shipment, freight payment in advance or on delivery
  12. Responsibility regarding Import & Export duties
  13. Terms of Insurance cover
  14. Accurate details of Seller, Buyer & Broker
  15. Terms of Letter of. Credit regarding bank negotiation, reimbursement & special conditions, if any

 Choose Correct Supplier or Agent:

Apart from ensuring correct terms of Contract, Buyer should ensure that purchase is made from Reliable Supplier or through a Reliable Agent. Some suppliers evade supplies under some pretext if market goes up. Otherwise, they supply inferior quality either way buyer suffers. By establishing long term relationship with reliable Suppliers, Buyers have satisfaction of getting correct quality, timely deliveries & fair prices. So, it is good to establish long term relationship with a few agents who represent reputed Trading Companies in various Cotton Exporting Countries. They usually give reliable market information on quality, prices & market trends so that buyer can take intelligent decision. As cotton is not a manufactured commodity, it is good to buy from dependable suppliers, who ensure correct quality supply with a variation within acceptable limits at correct price & also deliver on due date.

Choosing Quality:

In a market with varying supply-demand situation buyers should decide which counts of Yarn to be spun & samples to be collected suitable for spinning yarn counts programmed for production. Many spinners plan to do under-spinning. For Example, cotton suitable for 44s is used for spinning 40s & some do over-spinning. They buy cotton suitable for 40s & spin 44s Ne. But, is advisable to spin optimum count to ensure quality & also keep raw material cost as minimum as possible. Some spinners also buy more than two varieties & blend them for optimum spinning which requires a good knowledge to evaluate cotton quality & co-relate with yarn properties of required specifications. So, cotton buyer should develop expertise in assessing cotton quality. Machine tests are done only to confirm manual evaluation.

Taking Right Option:

It is not advisable just to look at price quoted by supplier. Correct costing should be done to work out actual cost when cotton arrives for being processed. Lower price does not always mean highest profit for buying. Profitability may be affected by factors below:

  • If trash content is higher, that produce more waste resulting in reducing Yarn out- turn & hence profitability.
  • If uniformity is less, end-breakages become higher reducing productivity & profitability.
  • If grade is poorer or immature fibres content is higher, yarn appearance is affected which fetches less price in market.
  • Longer transit period for cotton transport reduces profitability due to funds blocking for a longer period & increased Bank Interest.
  • Rate of Sales Tax varies from State to State which should be taken in to account.
  • Hence, thorough costing should be worked out before deciding on quoted price only.

Profit margin in spinning cotton should be calculated before deciding. Options available depending on market conditions should be studied carefully & factors below to be considered for taking options:

  • Count for which demand is good in market
  • Prices for various counts for which demand exists.
  • Cost of manufacturing various counts.
  • Adequacy of machinery for selected count.
  • Various varieties of cotton available for spinning selected count.
  • Profit margin for each count using different varieties.
  • Price quoted by different Agents for same variety of selected cotton.
  • Reliability of supplier for quality & timely delivery.

 Cost Consideration:

Apart from price quoted by seller, other incidental costs must be taken into consideration before buying:

  • Duration for goods to reach Buyer’s mill from seller’s Warehouse as longer time incurs higher interest charges.
  • Cost of Transportation & Taxes.

Resolution of differences

If any discrepancy arises in quality, weight & delivery periods, sellers should be willing to resolve differences amicably & quickly. In case matter is referred to Arbitrator, award of Arbitrator must be immediately enforced.

Bench Marks for Easy Reference

It is better if quality bench marks are established for different varieties so that buying decisions are easy for buyers. Following standards are found to be appropriate for Strict Middling Grade Cotton of staple 1.3/32″.

  1. Staple-length : ( 2.5% Spun Length) – Minimum 1.08″ or 27.4mm
  2. Micronaire : Minimum 3.8 & Maximum 4.6. Variation within bulk sample should not be more than 0.1.
  3. Colour : Rd not less than 75 not more than 10
  4. Neps Content : Less than 150/gm
  5. Strength : More than 30gm/tex
  6. Length Uniformity Ratio : Not less than 85%
  7. Elongation : More than 8%
  8. Short Fibre Content : Less than 5%
  9. Seed Count Fragments : Less than 15/gm

 

About Engr. Kh. Mashiur Rahman

He is Garment Automation Technologist and Editor in Chief of Autogarment. He is certified Echotech Garment CAD Professional-China, Aptech-India, NCC-UK and B.Sc. in CIS- London Metropolitan University, M.Sc. in ICT-UITS. He is working as a Successful Digital Marketer and Search Engine Specialist in RMG sector during 2005 to till now. Contact him- apparelsoftware@gmail.com

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One comment

  1. “single yarn strength tester”. It is very useful item for everyone.

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