Advanced Fibre Information System (AFIS)

Introduction:

Advanced Fibre Information System is based on the single fibre testing. There are two modules, one for testing the number of neps and the size of neps, while the other one is used for testing the length and the diameter. Both modules can be applied separately or together.

Among all physical properties of the cotton, fiber length varies the most within any one sample. There are two sources of variability;

1) Variability that comes from mixing cottons of various lengths

2) Variability that is biological in nature and exists within a sample of the same origin.

The same variety grown under different conditions, with lower or higher fertilizer doses, irrigation, or pest control, can produce various lengths. This is why fibre length is tested as an average of many fibres. Fibres also break during handling and processing thus, emphasizing the need for measurement of magnitude of the length variation. There are many different measurements of fibre length, including staple length, model length, mean length (aver-age length), 2.5% span length, effective length, upper quartile length, upper-half mean length, length uniformity index, length uniformity ratio, span length, short fibre contents and floating fibre length.

The AFIS test provides several length parameters deduced from individual fibre measurements. The main measurements include: the mean length, the length upper percentiles, the length CV%, and the Short Fibre Content (defined as the percentage of fibres less than 12.7 mm in length). Fibre length information is provided as a number or as weight-based data (by number/by weight). The length distribution by weight is determined by the weight-frequency of fibres in the different length categories, that is the proportion of the total weight of fibres in a given length category. The length distribution by number is given by the proportion of the total number of fibres in different length categories. The length parameters by weight and by number are computed from the two distributions accordingly. Once the AFIS machine determines the length distribution, the machine computes the length distribution by weight assuming that all fibres have the same fineness. Samples do not require any preparation and a result is obtained in 2-3 minutes. The results generally show a good correlation with other methods.

With the introduction of AFIS, it is possible to determine the average properties for a sample, and also the variation from the fibre to fibre. The information content in the AFIS is more. The spinning mill is dependent on the AFIS testing method, to achieve the optimum conditions with the available raw material and processing machinery. The AFIS-N module is dealt here and it is basically used for counting the number of neps and the size of neps. The testing time per sample is 3 minutes in AFIS-.N module.

This system is quick, purpose oriented and reproducible counting of neps in raw material and at all process stages of short staple spinning mill. It is thus possible, based on forecasts supervisory measures and early warning information to practically eliminate subsequent complaints with respect to finished product. The lab personnel are freed from the time consuming, delicate and unpopular, proceeding of nep counting. Personnel turnover and job rotation no more affects the results of the nep counting. The personnel responsible for quality can now at least deal with the unpopular neps in a more purpose-oriented manner than ever before.

AFIS -Working principle:

A fibre sample of approximately 500 mg is inserted between the feed roller and the feed plate of the AFIS-N instrument Opening rollers open the fibre assembly and separate off the fibres, neps, trash and dust. The trash particles and dust are suctioned off to extraction. On their way through the transportation and acceleration channels, the fibres and neps pass through the optical sensor, which determines the number and size of the neps.

The corresponding impulses are converted into electrical signals, which are then transmitted to a microcomputer for evaluation purposes. According to these analyses, a distinction is made between the single fibres and the neps. The statistical data are calculated and printed out through a printer. The measuring process can be controlled through a PC-keyboard and a screen.

Uster AFIS PRO- application report

Various HVI models available in market in present date are:

· USTER® AFIS PRO 2

Optional Modules:

• Length and Maturity (L&M) Module to measure cotton fiber length and maturity, integrating results into the USTERÒ AFIS PRO 2.

• Trash (T) Module to measure the dust and trash content in cotton, integrating results into the USTERÒ AFIS PRO 2.

• USTERÒ AFIS AUTOJET (AJ) Module to measure up to 30 samples automatically, reducing idle operating time.

• UPS – Uninterrupted Power Supply device to support the computer and monitor

Read more »

Posted in: Fibres,Sporttech

Ultrasonic Technology in Nonwoven and Textile Industry

Flexible technology for a flexible market:

Today’s textile and nonwoven market is so complex that fields of application, production techniques and technologies for further processing as well as the variety of new products are difficult to grasp, even for specialists.The variety of new composite materials of fleece, paper, films and fabric as well as the numerous possibilities in terms of combinations have one requirement in common: a safe and reliable process.

Ultrasonics is also the method of choice for these materials, for example for parting fabrics so that there is no thickening of the material along the cut edges.

No consumables such as glue, staples or sewing thread are needed. The fabric remains intact, because no external thermal energy is directed into the fleece. Position, shape and displacement of the welding points can even support the desired properties of the composite.

Textiles is thus a field where ultrasonic technology can prove its uniqueness.

The Functioning Principle of Ultrasonic Welding:

Low frequency mains voltage is transformed into high frequency electrical energy. A converter connected in line converts these electrical oscillations into mechanical vibrations. This is done using a piezoelectric transducer having an efficiency above 95 %.

The mechanical vibrations are transferred to a transformer element coupied to the converter, the so-called booster. This booster optimises the amplitude for the horn.

The horn is individually manufactured for each application and transfers the ultrasonic energy to the material to be processed. To build up a mechanical clamping force, a so-called anvil is required enabling the energy to effect melting on account of physical processes (internal and external absorption).

The Optimum Process for any Application:

Cycle-controlled process:

The actuator applies a defined pressure onto the anvil and hence onto the part to be welded between the two components. Usually, the ultrasonic irnpulse applied  simultaneously is time-controlled. Using the weld depth or the amount of energy applied as criteria for deactivation is also possible.

Main fields of application for cyclecontrolled welding:

• Overlapping welding of belts and tapes
• Linear welding of fabric and nonwoven
• Welding textile materials with thermoplastic contents
• Joining the end of a material strip to the start of a roll to prevent costintensive drawing in of material into the production equipment.

Seal and cut edges can also be manufactured to excellent quality. This only requires a special design of horn and anvil which is important for the following particular applications:

• Cut belt strips to length and/or punching
• Parting of edge binding for blankets
• Manufacturing buttonholes and eyes applying a certain structure to the rim in order to leave the impression of a sewn edge
• Parting colour ribbons in bureau machine industry

Continuous Process:

Two or more overlapping material strips are fed between horn and anvil which, if required, is rotating. Again, different systern combinations are possible:

Fixed Horn/Rotating Anvil:

This is the most commonly applied combination. Material strips (e. 9. fleece for use in agriculture) are joined at very high speeds using special profile wheels. Using profile wheels, sandwich structures can be generated. Combinations of different materials such as paper, films and textiles are particularly interesting applications. This combination can also be used for cutting processes. This usually involves cutting without sealing or with only slight edge sealling. The extension of the service life as well as the reduction of the cutting force and hence an increased cutting speed are strong arguments for the application of ultrasonic technology. Non-thermoplastic materials can also be cut. In this case ultrasonic energy supports breaking of the materials. Maximum precision is of course a prerequisite in such applications.

Rotating Horn/Rotating Anvil:

In this combination horn and anvil serve both to weld and to transport the welded product. In most cases both horn and anvil are driven synchronously. As in this system only a limited amplitude can be generated. This method is usually used for thin materials having a low mass per unit area.

Fixed HornlFixed Anvil:

This combination is usually used for cutting/ parting applications with simultancous sealing. However, it can also be used for continuous welding of paper, films, or textiles.

Read more »

Posted in: Sporttech,Technical textile