Laminate, Bonded and coated fabrics

Definition: A material composed of two or more layers at least one of which is textile fabric, bonded closely together by means of an added adhesive or by the adhesive properties of one or more of the component layers.

A special type of fabric produced by attaching more than one layer of fabrics together. Off course, laminated fabrics can also be produced by applying a coating to the fabric, where a fabric is coated with a continuous layer of polymer.   

A bonded material is made from two fabrics that have been adhered together. The backing fabric is usually acetate or nylon tricot, and the face fabric may be almost any conceivable type of cloth. Both of the face and backing fabrics are individually unsuitable for apparel for their lightweight and cost (when weight is increased). After bonding two fabrics, much better fabric having all the good properties including substantial gain weight can be produced this can be used for specific purposes. Thus bonded fabrics are very important in textile and apparel market as they provide better appearance, surface, touch stability and durability at much lower cost than identical single fabric.

A laminated or more specifically foam laminated usually consists of three layers adhered together; a face fabric, a middle foam layer (usually polyurethane foam), and a backing fabric (usually acetate or nylon tricot). Laminated fabrics are sometimes produced without any backing, these fabrics are called unbaked or foam backed laminated fabric. The foam laminates can be produced up to ½ inch thickness of foam layers however, in most cases they are produced in the range of  ¹/₈ to ³/₁₆ inch.

Foam laminated fabrics are mainly produced for clothing insulation, interlining. Sometimes the outer fabric is directly laminated, which is economical because it eliminated sewing of the fabric and interlining, however the fabrics becomes stiffer and the garment retains all of its durability. This is why this type of lamination is used in case coat which does not take any unsightly appearance.

Difference between bonded and laminated fabric

Laminated	Bonded fabric
1. Fabric is attached with a continuous sheet	1. Two fabrics are joined together
2. Good wrinkle resistance	2. Poor wrinkle resistance
3.  Tailoring property not so good	3. Good tailoring property
4. Good insulation property with light weight	4. Insulation property is not so good
5. Stability is less than bonded fabric	5. Good stability
6. Not so hygienic for wearing	6. Hygienic & good for wearing
7. Comparatively heavier than bonded fabric s	7. Relatively light weight.

Method of lamination

1.      Sewing or stitching

2.      Bonding with an adhesive

3.      Welding with high frequency electric current

4.      Slightly melting one layer

5.      Laminated with foam

Techniques of lamination

(a)    Roller (heated)

(b)   Spray

(c)    Film

(d)   Flame

(e)    Hot pressing

(f)    Curing of the adhesive

Different types of bonding agent

1. Liquid bonding agent

2.      powdered ( may be thermoplastic e.g PVC, PVA, PE or it can be melted by infra red radiation then calendering)

3.      cold setting of water based rubber

4.      High temperature resin

Foam material or different backing material used

1.      Polyurethane (mostly used)

2.      Polyester

3.      polyether

4.      poly urea

Coating materials

(i)                 Polyvinyl Chloride (PVC)

(ii)               Polyvinylidene Chloride (PVDC)

(iii)             Polytetrafluoroethylene (PTFE)

(iv)             Natural Rubber

(v)               Styrene Butadine Rubber

(vi)             Nitrile rubber

(vii)           Butyl Rubber

(viii)         Polychloroprene (neoprene)

(ix)             Chlorosulphonated polyethylene(Hypalon)

(x)               Silicone Rubber

(xi)             Polyurethanes

                 

Coating techniques

-          Lick roll

-          Knife coating

-          Gravure coating (engraving)

-          Rotary screen coating

-          Hot melt coating

-          Transfer coating 

Properties: Properties of bonded, laminated and coated fabric for clothing or garments/Factors to be considered to evaluate the performance of laminated fabrics.

1.      Durability of the bond

2.      Shrinking behavior-should be non shrinkable

3.      Good crease resistant property

4.      Permissible disappearance of foam (after a certain period foam will degrade but time should be approved)

5.      Good thermal insulation where necessary.

6.      Should not be dissolved in organic solvents

7.      Should not hamper the elasticity of the component fabric

8.      Should not grow bacteria

9.      Should be odorless, there is any, it should be harmless

10. Should not burn or melt easily

11. Should not be toxic

12. Should be comfortable.

Care of laminated, bonded and coated fabrics:

Chemical cleaning: Perchloroethylene or white spirit, petrol,

Washing temp: 20-25⁰C. For water resistant and water proof products and coated materials careful wash with soap may be useful.

Reason for good thermal insulation

1.      No of trapped air is more

2.      Greater thickness due to adhesive

3.      Thermal insulation is higher due to polyurethane foam

Characteristics of bonding materials

1.      Duarability

2.      Sensitivity to heat

Reasons for superiority of polyurethane over polyether or polyester

1.      Weak solubility in conventional otganic solvents

2.      Resistant to elevated temp.

3.      High adhesiveness to practically all materials

4.      Good thermal insulation due to air trap in the foam

5.      They may be given any degree of elasticity

6.      It is very light

7.      Resistant to creasing

8.      High dimensional stability

9.      Good elastic recovery

10.  Sand absorbency

11.  Does not support of growth of bacteria

12.  Odourless & non-odour reatining

13.  Does not melt, burnt, shrink  or stretch

14.  It is not toxic & non allergic

Characteristics of various types of lamination

Sewing

Adv.

1.      Easy process

2.      More air permeability

Disadv.

1.      Poor appearance

2.      Less insulation due to stitch

Adhesive bonding

Adv.

1.      Good wrinkle recovery

  

Disadv:

1.   Less air permeability

2.      Problem with water soluble adhesive

3.      Layers may be separated due to rough handling

4.      If, the composite fabrics shrink differently after bonding, then puckering will be found in the ultimate fabric.

Welding

Adv: Good bonding property

Disadvantage: Costly process

Melting

Adv: Easy process

Disadv:

1.      Less thermal insulation due to air pocket

2.      Decrease D.P due to heat

3.      Strength may also decrease

4.      Stiffness may decrease

End Use

Woven:

• As artificial leather in Suit cases, Brief cases and various types career bags.
• Mainly in apparel production, shoes, convertible tops for cars and awnings.
• For winter/Autumn/Spring jacket/ heavy and light jacket,
• Waist coat, ladies suit.
• Widely used in interlining velveteen.
• Winter coat (foam lamination), furnishing fabric:
• Carpet, rug,
• Insulating materials.
• Table cloths

Knitted:

• Ladies & youth coat, Men’s heavy & light jacket, ladies suit, waiste coat, gowns, children cloth, Woolen type.