Conventional liners are made with filament yarns (spun / continuous multifilament or monofilament yarns) having circular cross section. In a plain-woven liner with these yarns, protrusions and indentations / pattern marks occur on the fabric surface. The fabric surface is also somewhat rough. When this is used to wind along with un-vulcanized rubber articles, the rubber tends to penetrate the indentations. This tendency not only reduces the its release property from liner but also its tackiness. The fabric surface needs to be modified to improve un-vulcanized rubber characteristics.
to mitigate this problem of fabric surface indentations
There are many ways to improve the fabric surface characteristics, such as
- Dip Coating with low-viscosity polymer solution e.gacrylic,
- Use of special yarns in warp or weft,
- Surface modification such as coating with high viscosity Polymer or weaving with bi-component yarns and fusing yarns to fill the indentations.
- Dip coating with low-viscosity polymer solution:- MECORDS offer a wide choice of water based acrylic polymer coated (AC) Polyester and Polypropylene liners such as:
- PPML - Polypropylene Multi x Multi
- PPOL – Polypropylene Multi x Mono
- PYOL – Polyester Multi x Mono
- PPSL – Polypropylene Spun x Spun
- Use of Special yarns in Warp or weft:- By this the contact points of liner fabric surface with un-vulcanized rubber is greatly reduced.These are "Easy Release Liners".
- Use of Special yarn
Polypropylene fibrillated yarn (tapeyarn broken into continuous short or narrow fibers or fibrils) is used in this product. The fibrils are thin fibers or threads having one of their ends attached to the tape yarn, either on the edges of the yarn or in the margins of the slit openings. When twisted, these yarn / fibrils form protrusions which comes in contact with the un-vulcanized rubber. - The contact points are less as compared to continuous filament twisted yarn
- In cross direction, a monofilament yarn is used which offers transverse rigidity to liner fabric.
- These liners undergo further finishing process which make the release of un-vulcanized rubber easy without loss of tackiness.
- PPOL,FIBMO are our liners in this category
- Use of Polypropylene (PP) Tape yarns
- The tape yarn improves the smoothness of fabric surface which greatly enhances the release property.
- The yarn cross-section, being flat reduces the indentation / pattern marks on the rubber surface which also helps in the release property.
- The denier combination, results in minimum contact points between liner fabric and un-vulcanized rubber component.
- Use of tape yarns makes the liner fabric flexible, hence low width lines do not wrinkle easily.
- PPTT are our liners in this category
- Fabric Surface Modified liners or "Super Release Liners"
- Coated Fabrics
To fill the indentations on fabric surface, the liners are coated with water based polyurethane polymer. - With PU coating, the indentations and texture marks on the fabric surface are greatly reduced which greatly improves the release property and tack.
- Our PUC liners are from this category
- Liners made with bi-component yarns
Bi-component multi-filament polyester yarn which has sheath and core part for each filament is used in different directions. In the finished form of the liner, only the sheath part of each filament melts, and it becomes solid remaining fiber shape (like mono-filament). - Use of bi-component yarns improves the smoothness of fabric surface which greatly enhances the release property
- Since the sheath melts and flattens, the indentations and texture marks are greatly reduced in the fabric which further improves the release property.
- Use of bi-component yarns improves the rigidity of liner fabric once the sheath is melted in the finishing process.
- Longer life
- No wrinkles formation
- Good Dimensional Stability
- Resistant to abrasion
- Lightweight,
- No fraying
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