Mono-Layer Sheet
Single layer sheet is the simplest and most economical to produce. Choices of materials and colors are virtually unlimited, but properties are limited to what the single material provides. Packaging thermoformed from monolayer sheet is only suitable for low or no barrier applications.

The most commonly extruded sheet polymers are HIPS, PP and PET. PVC is better calendered.

The trend for extruding sheets from biopolymers, like PLA, is increasing rapidly as new materials are developed.

Multi-Layer Sheet
Any combination of desired properties can be achieved by combining layers of different polymers in a single sheet structure via coextrusion. Multi-layer sheet encompasses everything from simple 2 extruder, dual layer structures to very complex structures using 5 or more extruders, producing 9 or more layers.

Basic coextruded sheet is often desired to obtain special effects or properties. Using just 2 extruders, this can make such products as 2 layer sheet with a thin high gloss layer on high impact polystyrene, multiple color sheet, or a 3 layer sheet with a scrap layer buried in the center.

Depending on the application, multi-layer sheet can be symmetrical or asymmetrical.

Barrier Sheet
High barrier sheet used for long shelf life food containers is a special type of coextrusion, where as many as nine layers of five different materials are coextruded to achieve low moisture and oxygen transmission. This is mostly done with single layer dies preceded by multiple extruders which are combined by feed blocks.

Coextrusion with two extruders is easy but it becomes increasingly difficult with more layers and more extruders. Highly complex lines should be reserved for specific applications and are very inefficient for multiple applications. This type of sheet is used in aseptic, hot fill and retort packaging applications.

Depending on the application, multi-layer sheet can be symmetrical or asymmetrical.

Lenticular Sheet
Lenticular sheet is produced by running sheet very precisely through specially engraved embossing rolls, cutting the sheet to length, and printing it in register. The lenticular pattern adds 3-D imagery and motion to the printed images. Lenticular sheet is used for point of sale signage, specialized product packaging, merchandise tags, Logo products, DVD covers, phone cards, postcards and more.

Photovoltaic Sheet (PV)
As the name implies, photovoltaic ("photo" meaning light, and "voltaic" refers to producing electricity) refers to systems that generate electricity from sunlight. Welex is a leading supplier of extrusion systems used in the production of EVA Photovoltaic (PV) encapsulant film.

Corrugated Sheet
Corrugated extruded sheet is not only strong and lightweight, but also moisture, chemical and abrasive resistant. These properties make it popular in construction of commercial signage, plastic containers, and reusable packaging. Common materials include polypropylene and polyethylene.

Additives can be added to the resin to achieve many additional properties, such as ultra violet protection, custom colors, flame retardant, corrosion inhibitors, static-dissipative, etc.

Geomembrane
Geomembrane refers to a flexible impermeable sheet product that is used in a variety of geotechnical and environmental applications. Geomembrane is commonly used at landfills to contain hazardous and municipal waste, and as pond or canal liners. Depending on the application and subsequent properties required, it can be made of a variety of materials. Polymers include LDPE, HDPE, PVC, and PP. EPDM rubber is also a common material. Proper seaming of adjacent sheets is critical.

Variations include composite structures, such as one that sandwiches a fibrous mat between membranes to facilitate drainage.

Geogrids
Geogrids are produced by extruding sheet (commonly HPDE or PP), and puncturing or stamping it before orienting it. Depending on whether it is uniaxially or biaxially oriented, the orientation process imparts tensile strength to the product in one or more directions. The end product is strong, chemical and UV resistant, permeable, and relatively lightweight. Common uses include structural reinforcement of land, solid waste retention, and snow and construction fencing.

Optical Sheet
Optical sheet can be made in a variety of resins. Extra care is needed to operate equipment properly and to maintain dustless, extremely clean environment.

Industrial Sheet
Industrial sheet generally comprises flat and thick sheet that is subsequently thermoformed into items like refrigerator interiors, automotive and truck components, pallets, boat components, and portable sanitation facilities. Industrial sheet is produced in widths up to 15 ft (5 meters) and is made from materials such as ABS, HDPE and also some HIPS. UV resistance in the case of ABS is often improved by coextruding a thin layer of acrylic polymer on the outer layer. Baby pools are made from HDPE, as are twin shell formed snow boards.

Knobby Sheet
Industrial sheet generally comprises flat and thick sheet that is subsequently thermoformed into items like refrigerator interiors, automotive and truck components, pallets, boat components, and portable sanitation facilities.

Industrial sheet is produced in widths up to 15 ft (5 meters) and is made from materials such as ABS, HDPE and also some HIPS. UV resistance in the case of ABS is often improved by coextruding a thin layer of acrylic polymer on the outer layer. Baby pools are made from HDPE, as are twin shell formed snow boards.

Polyside Side-By-Side Sheet
Industrial sheet generally comprises flat and thick sheet that is subsequently thermoformed into items like refrigerator interiors, automotive and truck components, pallets, boat components, and portable sanitation facilities.

Industrial sheet is produced in widths up to 15 ft (5 meters) and is made from materials such as ABS, HDPE and also some HIPS. UV resistance in the case of ABS is often improved by coextruding a thin layer of acrylic polymer on the outer layer. Baby pools are made from HDPE, as are twin shell formed snow boards.