HDPE, LDPE, PP, PET and polycarbonate - properties, food-grade rules and regrind policy, matched to every container you produce.
Two plants can run identical machines and produce containers of completely different quality - because the machines do not decide quality, the material does. The resin you feed determines clarity, strength, chemical resistance, food safety and cost per unit. Choose it as deliberately as you chose the machine.
This guide profiles the five plastics that matter in container production, the food-grade and regrind rules that protect your brand, and the matching table that answers "which material for which container." It pairs with our mould design guide - the metal and the plastic are one decision made twice - and our raw materials division supplies every grade mentioned.
The MaterialsChemical resistance, impact strength, rigid but tough. Bottles, jerrycans, 5-20L drums and jars. Food-grade grades available. The default for anything opaque and durable.
Softer and more flexible than HDPE. Squeeze bottles, dispensing containers, liners. Rarely structural - its softness is the feature.
Higher temperature tolerance than HDPE, excellent hinge behaviour, great for caps, closures and hot-fill-adjacent uses. Stiffer finish, slightly brittle in cold.
Crystal clear, strong at low weight, the beverage standard. Always preform-based on stretch blow machines. Heat-set variants for hot-fill.
Polycarbonate: clarity plus extreme impact resistance, rated for 80-100+ wash cycles. The 20L returnable water jar standard. Needs careful drying before processing.
PET, preform-based. Hot-fill juice: heat-set PET or glass - per the juice guide.
HDPE, UN-rated compounds where certification applies - per the jerrycan guide.
Polycarbonate for the true returnable standard; HDPE for value or non-returnable - per the jar guide.
PP almost universally - torque tolerance and hinge behaviour. Injection moulded per the injection range.
HDPE bottles and jerrycans; PET for retail oil bottles where clarity sells. Both food-grade for edible oil - per the oil guide.
Food-grade is not a colour or a feel - it is certification: migration testing and compliance with your national food-contact regulation. Buy virgin resin with supplier documentation for every product-contact layer, and file the certificates with batch records. Our raw materials division supplies certified grades with papers.
Trim and scrap reground and reused is good economics - capped at 20-25 percent of the blend for non-food containers. It must be clean, dry and correctly graded, per the troubleshooting guide - dirty regrind is the top cause of black specks and brittleness.
Where regulations allow recycled content, co-extrusion or multi-layer design sandwiches regrind between virgin inner and outer walls - savings without product contact. A mould and machine conversation, not just a material one.
PC and PET are hygroscopic - moisture in the pellet becomes bubbles and silver streaks in the product. Dry to spec, verify with a moisture meter, and never mix wet material into a batch.
Material and mould are one decision: shrinkage, cooling and stiffness all shape the design. Per our mould guide - decide both together.
The fastest way to fail a food-safety inspection and lose a brand. Recycled content goes in the core layer, never against the product.
Hot-fill-adjacent uses and high-torque capping warp HDPE closures. Match the material to the temperature, not the price list.
Cheap resin without certificates is cheap until the first audit, claim or recall. Documentation travels with the drum - insist on it.
PET - chosen for crystal clarity, food safety and strength at low weight. Water and beverage bottles are stretch-blown from PET preforms; the material is defined by the preform you buy, not the machine.
HDPE - the workhorse: chemical resistance, impact strength and food-grade grades available. UN-rated drums use certified HDPE compounds per container design.
Not in the food-contact layer. Where regulations allow recycled material, it goes in multi-layer containers as a sandwiched core between virgin inner and outer walls - never touching the product.
PP handles higher temperatures than HDPE, tolerates torque during capping, and its living-hinge property suits flip-top caps. It also seals well against PET and HDPE finishes.
Food-grade resins carry certification from the supplier - compliance with your national food-contact regulations and migration testing. Buy virgin resin with documentation for product-contact layers, and keep the certificates with your batch records.
Send the container and the product inside it - we specify the material, supply it certified, and match the machine and mould. Within 24 hours.