Antioxidant, UV Stabilizer, Pigment, OBAs for Polyolefin
Polyolefins are quantitatively the largest group of plastics. Depending on the starting materials (monomers) and the density (processing temperature), polyolefins may be classified according to the following principal groups:
- LDPE = Low-Density Polyethylene
- LLDPE = Linear Low-Density Polyethylene
- HDPE = High-Density Polyethylene
- PP = Polypropylene.
Antioxidant, UV Absorber And Light Stabilizer For Polyolefin
Hindered phenolic antioxidant 1010 is most frequently used in polyolefins’ processing. phosphite antioxidant 168 or thioester antioxidant DLTDP sometimes used with 1010 to achieve a synergetic effect. Benzophenone UV absorber 531, light stabilizer 622, 770 or HALS blends is used individually or together to protect polyolefins from photodegradation caused by light. The typical use of antioxidant and UV stabilizer additives for polyolefins as the table below.
| Material | Application | Antioxidants | UV Stabilizer | Remark |
| PP thick section | 260-280℃ Outdoor table & chair | 1010+DSTDP | 622+326 | DSTDP=3*1010 |
| PP thin section Fiber & strip | 240-300℃ | PP fiber:1425
| Fiber: 770 without heat 622 with heat Strip:791 | Low volatile； Heat stability； Extraction resistance； Gas yellowing |
| HDPE | 180-240℃ blowing, injection, extrusion | 1010+168 | 791 ,944 | Compatibility |
| LDPE | Film, packing, cover, mulch, greenhouse cover | 1010 | 622+531 | ＜0.1% |
| LLDPE | Film, blowing, injection | 1010+168 | 944 / 622+531 | / |
| PEX | Wire & cable | TMB 6 | / | / |
| PB | Pipe | 1010+ DLTDP | Extraction resistance |
Optical Brightener For Polyolefin
| Application | OBAs Adding Form | Typical OBAs | Issue to mind |
| Polyolefin | Dry powder mix | FP 127 | Compatibility PP＞hdpe＞ldpe Immigration resistance |
Organic Pigment For Polyolefin (please click on title)
Things to know when selecting pigments for polyolefin
1. Distortion & Shrinkage
A number of organic pigments cause distortion in certain types of polyolefins, especially in HDPE. These pigments also enhance the shrinkage of polyolefins, particularly in the direction of the flow.
2. Dispersibility
The dispersibility of an organic pigment which is to be incorporated in a polyolefin is of particular importance. This is especially true for the coloration of extrusion films and for HDPE or PP ribbon made from stretched blown film or from sheeted extrusion film, as well as for the coating or melt spin dyeing. Powder form pigment dispersion is not adequate in these applications. Poor dispersion causes filler specks, holes in films, and other faults. Pigment preparations, usually in combination with polyolefins as a carrier, are frequently used to color polyolefins.
Pigment powders continue to be used in thick-walled articles, such as extruded sheets, or hollow objects, or in injection-molded products; although color concentrates are beginning to be more important even in these areas.
Pigment / polyolefin paste preparations containing between 20 and 70% pigment are also used. They are manufactured by means of three-roll mills, agitated ball mills, or dissolves or similar equipment. Such preparations are employed primarily to produce bottles, injection-molded articles, or extrusion sheets. These preparations have the advantage of being applicable in volumetric doses and may be premixed in slow mixers or gravitation mixers to uniformly adhere to the plastic granulate.