Interlining

  Interlining

 

Interlining is a layer of fabric inserted between the two layers of a garment. It is considered as an accessory which stays in between two layers of fabric in a garment to support, reinforce and control areas of garments and to retain actual shape. They may provide improved hand feeling and improve performance for garments.

 

Cause of using interlining:

 

1. Interlining is used in the garments to support, reinforce and control areas of garments and to retain actual shape of the garment component.

2. To make the particular component beautiful, strong and attractive.

3. To get better hand feel and better performance.

 

 

Types of Interlining:

There are two types of Interlining;

a. Sewn Interlining or non fusible Interlining

b. Fusible Interlining

 

 

a. Sewn Interlining or non fusible Interlining: When interlining is attached with the outer fabric by sewing is called sewn interlining. In sewn interlining, a piece of fabric is treated with starch and let that dry before sewn with the main fabric.

 

Advantages of sewn interlining:

 

1. Flame retardant garments can be made in this process.

2. Simple and easy technique.

3. No need of using special machine.

 

Disadvantages of sewn interlining:

 

1. Quality is poor and appearance is not same to all the garments as it made by sewing.

2. Not suitable for large scale production.

3. Not readily available in the market.

4. It requires comparatively more time.

5. It is a highly labor intensive process.

 

b. Fusible Interlining: The interlining that attached with the garment component by fusing resin applying heat and pressure for certain time is called fusible interlining. Thermoplastic resin gives the desired bond in the fusible interlining.

 

Heat, pressure and fusing time is correlated with each other. 

For fusing, maximum recommended temperature is 165-170˚C, time (5-20) seconds and required pressure is depends on the fusing technique.

 

Advantages of Fusible Interlining:

1. Comparatively better appearance, shape retention and better performance.

2. Easy to produce same quality product.

3. Fusible interlining is readily available in the market.

4. Comparatively cheap.

5. As fusing time is less, labor cost is low and production is high.

6. Overall performance is better than non-fusible

7. As technique is easy, no need of skilled operator to operate the machine.

Disadvantage of Fusible Interlining:

 

▪ High temperature and pressure is required. So, special care is needed.

▪ Initial investment is relatively higher.

 

 

Required properties of Fusible Interlining

 

1. The fusing temperature must not be too high that may damage the outer fabric or its color.   Usual maximum temperature is 175˚C, but recommended temperature is 150˚C.

 

2. The fusing temperature must not be too low that may lead weak bonding between base fabric and outer fabric. The lower limit of temperature is generally 110˚C. Weak bond may be broken by washing or during use.

 

3. The resin should provide a bond which can suitably resist washing or dry cleaning.

 

4. The thermoplastic nature of resin should be such that adjustment of temperature is sufficient to permit resin to penetrate the outer fabric to give a bond without flowing excessively to give strike through or strike back.

 

5. The resin should contribute to achieve the desired hand feel.

 

6. It should not be hazardous for health during processing or use.

 

7. Its color should be white in common cases and it should be transparent.

 

8. It should have low dye retention properties.

 

Types of Fusible Interlining:

 

On the basis of resin coating and its properties, fusible interlining can be classified as follows:

1. Polyethylene coated Interlining

2. Polyamide coated Interlining

3. PVC coated Interlining

4. Polyester coated Interlining

5. Polypropylene coated Interlining

6. PVA coated Interlining

 

1.      Polyethylene coated Interlining

 

● Here polyethylene is used as resin coating

● It is used in collar, cuff and waist band.

●The fabric is attached with this type of interlining is water washable.

 

2.      Polyamide coated Interlining

 

● Here polyamide is used as resin coating

● Polyamide is widely used for dry cleanable garments.

● It may be water washable but washing temperature should not exceed 60˚C.

 

3. PVC coated Interlining

 

● Here polyvinyl chloride (PVC) is used as resin coating.

● It is both dry cleanable and water washable. Polyamide is widely used for dry cleanable garments.

● This resin is generally applied on the base fabric as a plasticized paste.

 

 

4. Polyester coated Interlining

 

● Here polyester is used as resin coating.

● It is both dry cleanable and water washable.

● This type of resin can be applied in all kinds of fabric.

● It is called ideal interlining.

●It is an expensive interlining

 

5. Polypropylene coated Interlining

 

● Here polypropylene is used as resin coating.

● Fabric attached with this type of resin is only washable.

● Comparatively high fusing temperature is required.

 

6. PVA coated Interlining

 

● Here polyvinyl acetate (PVA) is used as resin.

● It is not dry cleanable and has limited wash ability.

● It requires low temperature and pressure.

● This type of resin is normally in the form of continuous coating for fusing leather.

● Very limited use in textile industry.

 

 

 

Conditions of Fusing:

 

The process of fusing must fulfill the following conditions:

                                                                                                                        

1. Luster: The laminate produced by the fusing should pose the desired luster in the finished garments.

 

2. Strength: The strength of the bond of the laminate should be sufficient so that fabric of that is attached with interlining would not be separated. It is essential that that durability of the interlining should be equal or greater to the life time of the garments. Strength may be poor due to under fuse or the problem of determining the right fusing technique.

 

3. Correct Fusing: Fusing must take place without causing strike through or strike back. During fusing, the fused resin can come to the front of outer fabric is called strike through. If the melted resins come towards below of the interlining fabric by penetrating is called strike back. Both strike through and strike back is unwanted and harmful for both garment and fusing machine.

                

4. Compression by temperature: Fusing range is 150˚C to 175˚C.  Outer fabric may shrink in that temperature.  During fusing, care must be taken to avoid any kind of shrinkage. Otherwise produced component may be short than the desired size.

 

 

5. Color of the fabric: During fusing, the color of the fused parts must not be changed. If the color of the fused parts be changed, within garments shade variation may found.   

 

6. Similarity in external shape: Pile fabric may bend in fusing due to high temperature. If that happens, fused and unfused fabrics can be seen different in external shape. Care must be taken to get similarity in the external appearance.

 

7. Special Characteristics: The fusing process must not damage of special properties of fabric that has been developed by finishing. Shower proof or wind proof properties of any fabric should remain unchanged after attaching interlining.   

 

 

 

Quality Control in fusing:

a.      Temperature: Fusing fabric manufactures usually advice the suitable temperature for perfect fusing.  Fusing temperature depends on the types of fusing. Too low or too much temperature gives poor bonding and strike through/strike back respectively. Certain temperature is set for the certain interlining. Temperature may be tested by two ways, portable pyrometre and thermopaper.

b.      Pressure: The pressure should be uniform and sufficient during fusing to get uniform bonding strength. 

c.       Fusing time: The equipment must give enough time to allow the temperature and pressure to induce melting of the resin and penetration of the outer fabric in order to produce a satisfactory bond. Fusing time may set prior fusing. Stop watch may also be used to determine the fusing time.

d.      Pilling strenght: Melted resin of the base fabric attached with the outer fabric.  The bonding strength between the outer fabric and interlining is checked and compared with the standard one. A sample of 5x15 cm is taken from fused interling and measured its bonding strength by tensile testing machine.

e.       Dry cleaning or washing: Changing in appearance or changing in bond strenght by washing or by dry cleaning must be checked.

 

Methods of fusing:

1. Hand Iron

2. Flat bed fusing machine

3. Continuous fusing Machine

4. High frequency fusing machine

 

 

 

1. Hand Iron

 

In this method, fusing of interlining is done by hand iron to small components like cuff, collar etc. In this method, temperature, pressure and pressing time can not be controlled perfectly.

 Flat bed fusing press:

Features:

v  This type of machine contains two components. these as (a) Head and (b) Buck.

v  The head is spring loaded and movable and buck remains fixed.

v  Buck is covered with soft mat which is prepared with fabric, blanket or silicon rubber.

v  Both surface of buck and head is covered with PTFE.

v  Head is heated with current or steam.

v  Sometimes heating arrangement is joined with buck.

 

Sketch

Working principle:

Ø At first the part of the garment to be fused and spread over flately on the buck and the resin coated interlining is placed on it correctly.

Ø The head is gradually lowered on the buck by switch and the required pressure is applied and heating is done uniformly on the surface of the buck.

Ø Head is separated from the buck after applying heat and pressure till predermined time.

Ø Then the suction chamber sucks air from the buck.

Ø After sucking the air, the interlining becomes cold and fuses in the fabrics permanently.

Advantages:

      Temperature, pressure and fusing time is adjustable.

      Easier process and most commonly used.

      Low cost.

      Tends to reduce fabric shrinkage.

  Disadvantage:

      Not suitable for large scale production.

      Needs checking of fusing condition after certain period.

Continuous fusing press machine:

Features:

v  The machine consists of a fusing chamber with continuous belt or feed sheet.

v  The heating chamber is controlled by a switch.

v  Two pressure rollers are in the fusing chamber and roller pressure are produced by spring or pneumatic power and have condition to increase or decrease of required heat.

Sketch

Working principle:

v  In this machine, interlining is placed between two layers of the fabric and passed to the fusing chamber.

v  In fusing chamber, the required heat and pressures are applied.

v  Direct heating or indirect heating are applied for heating the interlining.

v  After heating, required pressure are applied by two pressure rollers.

v  The fusing time is cotrolled by controlling the speed of feed sheet.

v  Then the fabric is taken out from the fusing chamber.

Advantages:

v  Mostly used in country.

v  Higher production.

v  Good quality fusing.

v  Very suitable for pile fabric using.

v  No possibility of fabric shrinkage.

Disadvantages:

v  High cost.

v  Large space required.

v  Different bond strength of fused parts.