Recycling blades should generally be replaced as soon as cutting performance drops, but winter conditions make this happen much sooner than in warmer months. Cold temperatures make plastics, rubber, and mixed waste far tougher to process, which increases strain on granulators, shredders, pelletisers, and guillotines. Because of this, most facilities should inspect blades weekly and expect to replace or regrind them up to 20-30% more frequently during winter.

Here are the key signs and timeframes to follow:

1. Replace Blades When You See Reduced Cutting Efficiency

If your machine begins struggling to draw material through, or if cuts appear ragged, this is an early sign the knives are dull. Winter makes material stiffer, so even a slightly blunted edge causes immediate performance loss.

2. Replace Immediately If You Notice Chipping or Small Cracks

Cold, brittle material puts more shock load on the blades. Any visible cracking or chipping means the blade is at risk of failure and should be replaced without delay.

3. Increase Replacement Frequency by 20–30% in Winter

Most recycling facilities find they need to swap or regrind blade sets more often between December and February. Keeping a spare set ready is essential to avoid downtime.

4. Regrind Blades as Soon as the Cutting Angle Degrades

If your blade is still structurally sound, a professional regrind can restore performance at a fraction of the cost of replacing the blade. During winter, more frequent regrinds keep machinery running smoothly.

Saturn Machine Knives offers expert blade sharpening for machine blades, restoring your blades to full sharpness and keeping them working for longer.

5. Replace Blades If Machines Start Drawing More Power

Higher amperage, unusual vibrations, or increased wear on bearings often indicate blades are too dull to process cold, dense material efficiently.

6. Replace Blades if You Process Large Volumes of Cold, Stored Material

Waste that’s been sitting outdoors becomes denser and harder to cut. Facilities handling this type of feedstock regularly should plan for more frequent blade changes.

Best Practice Recommendation

Inspect blades weekly during peak winter conditions and replace or regrind as soon as performance begins to drop. Running winter-worn blades for too long risks machine damage, higher energy costs, poorer granulation quality, and unexpected downtime.

Investing in high quality blades from the get-go can save you costly issues down the road and help reduce downtime. Our blades are manufactured from high quality steel in the heart of the Steel City, Sheffield, so you can be assured of their quality, durability and reliability. Get in touch today to find out how we can help your business through winter.